This study investigated the regional differences of China′s urban land expansion from the late 1980s to the year of 2008, based on the spatio-temporal analysis of CLCD (China′s land cover/land use database) datasets...This study investigated the regional differences of China′s urban land expansion from the late 1980s to the year of 2008, based on the spatio-temporal analysis of CLCD (China′s land cover/land use database) datasets which were mainly produced from remote sensing imagery data. A newly defined urbanization level index (UI), based on urban land area, is proposed to describe Chinese urban expansion process at 1 kilometer, provincial, regional, and na-tional scales, together with the absolute urban expansion index (UEa) and the relative urbanization expansion index (UEr). The results indicate that the percentages of total land area occupied by urban in the late 1980s, 1995, 2000, 2005, and 2008 were approximately 0.25%, 0.32%, 0.33%, 0.43% and 0.52% of China′s total land area, respectively. Between the late 1980s and 2008, the total urban expansion in the mainland of China was 2.645 × 104 km2, resulting in an annual urban expansion area of about 1322.7 km2/yr, with the UEr of 111.9%. This study also finds that there has been an obvious spatial gradient of urbanization ratio running from the east coast to the west inland, and the urbanization gaps among different regions have persisted over the past two decades. The study also reveals obvious temporal varia-tions of the urbanization rates. There was very little urban growth during the period of 1995-2000 due to the governmental policy factors.展开更多
The Yangtze River is one of the largest and longest rivers in Asia.The river originates in the Tibet-Qinghai Plateau(headwater reach),passes through the mountainous provinces of Sichuan,Yunnan and Chongqing(upper reac...The Yangtze River is one of the largest and longest rivers in Asia.The river originates in the Tibet-Qinghai Plateau(headwater reach),passes through the mountainous provinces of Sichuan,Yunnan and Chongqing(upper reach),flows into the Central Plain(middle reach)and Lower Plain(lower reach),and finally empties into the East China Sea in Shanghai(estuary).The Yangtze River Economic Belt(YREB;Fig.1)has a surface area of 2.1展开更多
This paper presents a systematic investigation of the microstructure and magnetocaloric properties of melt-extracted Sm_(20)Gd_(20)Dy_(20)Co_(20)Al_(20)high-entropy microwires.The fabricated wires exhibited an amorpho...This paper presents a systematic investigation of the microstructure and magnetocaloric properties of melt-extracted Sm_(20)Gd_(20)Dy_(20)Co_(20)Al_(20)high-entropy microwires.The fabricated wires exhibited an amorphous structure,and the temperature interval of the undercooled liquid AT was 45 K.The microwires underwent a second-order magnetic transition from a ferromagnetic to a paramagnetic state near the Curie temperature(T_(C)=52 K),The maximum magnetic entropy change(-ΔS_M^(max)),the relative cooling power and the refrigeration capacity reached 6.34 J·kg^(-1)·K^(-1).422.09 J·kg^(-1)and 332.94 J·kg^(-1),respectively,under a magnetic field change of 5 T.In addition,the temperature-averaged entropy changes with two temperature lifts(3 and 10 K)were 6.32 and 6.27 J·kg^(-1)·K^(-1),respectively.The good magnetocalorie performance highlights the significant potential for the Sm_(20)Gd_(20)Dy_(20)Co_(20)Al_(20)microwires to be used as magnetic refrigerant materials in low-temperature region applications.This work will serve as a valuable reference for future investigations on low-temperature high-entropy magnetocaloric materials.展开更多
Anneal hardening has been one of the approaches to improve mechanical properties of solid solution alloys with the face-centered cubic(FCC) structure,whereby a considerable strengthening can be attained by annealing o...Anneal hardening has been one of the approaches to improve mechanical properties of solid solution alloys with the face-centered cubic(FCC) structure,whereby a considerable strengthening can be attained by annealing of cold-worked alloys below the recrystallization temperature(T_(rx)).Microscopically,this hardening effect has been ascribed to several mechanisms,i.e.solute segregation to defects(dislocation and stacking fault) and short-range chemical ordering,etc.However,none of these mechanisms can well explain the anneal hardening recently observed in phase-pure and coarse-grained FCC-structured high-entropy alloys(HEAs).Here we report the observations,using high-resolution electron channeling contrast imaging and transmission electron microscopy,of profuse and stable dislocation substructures in a cold-rolled CoCrFeMnNi HEA subject to an annealing below T_(rx).The dislocation substructures are observed to be thermally stable up to T_(rx),which could arise from the chemical complexity of the high-entropy system where certain elemental diffusion retardation occurs.The microstructure feature is markedly different from that of conventional dilute solid solution alloys,in which dislocation substructures gradually vanish by recovery during annealing,leading to a strength drop.Furthermore,dilute addition of 2 at.% Al leads to a reduction in both microhardness and yield strength of the cold-rolled and subsequently annealed(≤500℃) HEA.This Al induced softening effect,could be associated with the anisotropic formation of dislocation substructure,resulting from enhanced dislocation planar slip due to glide plane softening effect.These findings suggest that the strength of HEAs can be tailored through the anneal hardening effect from dislocation substructure strengthening.展开更多
High entropy alloys(HEAs)based on transition metals display rich magnetic characteristics,however attempts on their application in energy efficient technologies remain scarce.Here,we explore the magnetocaloric applica...High entropy alloys(HEAs)based on transition metals display rich magnetic characteristics,however attempts on their application in energy efficient technologies remain scarce.Here,we explore the magnetocaloric application for a series of Mn_(x)Cr_(0.3)Fe_(0.5)Co_(0.2)Ni_(0.5)Al_(0.3)(0.8<x<1.1)HEAs by integrated theoretical and experimental methods.Both theory and experiment indicate the designed HEAs have the Curie temperature close to room temperature and is tunable with Mn concentration.A non-monotonic evolution is observed for both the entropy change and the relative cooling power with changing Mn concentration.The underlying atomic mechanism is found to primarily emerge from the complex impact of Mn on magnetism.Advanced magnetocaloric properties can be achieved by tuning Mn concentration in combination with controlling structural phase stability for the designed HEAs.展开更多
Background:Liver transplantation(LT)is one of the most effective surgical treatment for patients with end-stage liver disease.Steatosis is a contributor for inferior graft quality.But its impact and safety on transpla...Background:Liver transplantation(LT)is one of the most effective surgical treatment for patients with end-stage liver disease.Steatosis is a contributor for inferior graft quality.But its impact and safety on transplantation was less assessed in Chinese patients.Methods:Graft steatosis and related information involved in recipients,donors and surgical procedures were retrospectively collected from 239 patients.Results:Donor macrosteatosis(MaS)caused about 2.14 and 2.80 folds of increment on patient and graft mortality.Dose-response analysis revealed prominent risk of grafts on overall patient/organ mortality when MaS content exceeded 10%(P<0.05).Noteworthy,deaths were only observed in MaS group when concurrent with extremely higher post-transplant alanine aminotransferase(ALT,64%).However,microsteatosis(MiS)grafts didn’t affect outcomes after LT.In a cohort of Chinese patients,MaS had comprehensive effects on post-transplant outcomes with relatively lower safety threshold at 10%.Mortality gap caused by MaS grafts was observed in patients with severer ischemia reperfusion injury.Conclusions:Our study revealled the graft MaS affected the post-transplant outcomes in lower risk cutoff in Chinese patients.Further study is worthy to validate these results and investigate inner mechanism under the phenomenon.展开更多
In this paper, the thermodynamics and kinetics of nature rutile carbochlorination in a fluidized-bed were investigated. The thermodynamic calculations of TiO2-C- C12 system show that when C is excess in the solid phas...In this paper, the thermodynamics and kinetics of nature rutile carbochlorination in a fluidized-bed were investigated. The thermodynamic calculations of TiO2-C- C12 system show that when C is excess in the solid phase, titanium tetrachloride and carbon monoxide can exist sta- bly. At high temperature, the reaction with CO as the product is the dominant reaction. The appropriate reaction conditions are as follows： reaction temperature of 950 ℃, reaction time of 40 min, carbon ratio of 30 wt% of rutile, natural rutile particle size of -96 μm, petroleum coke size of -150 μm, and chlorine flow of 0.036 m3.h-1. Under the above conditions, the reaction conversion rate of TiO2 can reach about 95 %. This paper proposed a reaction rate model, and got a rutile chlorination rate formula, which is generally consistent with the experimental data. For the TiO2-C-C12 system, the reaction rate is dependent on the initial radius of rutile particle, density, and the partial pressures of C12. From 900 to 1,000 ℃, the apparent activation energy is 10.569 kJ.mo1-1, and the mass diffu- sion is found to be the main reaction-controlling step. The expression for the chlorine reaction rate in the C-C12 sys- tem is obtained, and it depends on the degree of reaction, the partial pressure of C12, and the size of rutile particle.展开更多
Molybdenum(Mo)has been recognized as an essential alloying element of the MP35N(Co_(35.4)Cr_(22.9)Ni_(35.5)Mo_(6.2),at.%)superalloy for enhancing strength and corrosion resistance.However,a full understanding of the a...Molybdenum(Mo)has been recognized as an essential alloying element of the MP35N(Co_(35.4)Cr_(22.9)Ni_(35.5)Mo_(6.2),at.%)superalloy for enhancing strength and corrosion resistance.However,a full understanding of the addition of Mo on microstructure and mechanical properties of the Mo-free parent alloy is lacking.In this work,we consider five(Co_(37.7)Cr_(24.4)Ni_(37.9))_(100-x)Mo_(x)(x=0,0.7,2.0,3.2,and 6.2)alloys,and reveal that yield/tensile strength and ductility are continuously increased for these alloys with increasing Mo content while a single-phase face-centered cubic structure remains unchanged.It is found that strong solid solution strengthening(SSS)is a main domain to the improved yield strength,whereas grain boundaries are found to soften by the Mo addition.The first-principles calculations demonstrate that a severe local lattice distortion contributes to the enhanced SSS,and the grain boundary softening effect is mostly associated with the decreased shear modulus.Both first-principles calculations and scanning transmission electron microscopy observations reveal that the stacking fault energy(SFE)reduces by the Mo addition.The calculated SFE value decreases from 0.4 mJ/m^(2) to-11.8 mJ/m^(2) at 0 K as Mo content increases from 0 at.%to 6.2 at.%,and experimentally measured values of SFE at room temperature for both samples are about 18 mJ/m^(2) and 9 mJ/m^(2),respectively.The reduction of SFE promoted the generation of stacking faults and deformation twins,which sustain a high strain hardening rate,thus postponing necking instability and enhancing tensile strength and elongation.展开更多
Background Alzheimer’s disease(AD)is associated with metabolic abnormalities linked to critical elements of neurodegeneration.We recently administered combined metabolic activators(CMA)to the AD rat model and observe...Background Alzheimer’s disease(AD)is associated with metabolic abnormalities linked to critical elements of neurodegeneration.We recently administered combined metabolic activators(CMA)to the AD rat model and observed that CMA improves the AD-associated histological parameters in the animals.CMA promotes mitochondrial fatty acid uptake from the cytosol,facilitates fatty acid oxidation in the mitochondria,and alleviates oxidative stress.Methods Here,we designed a randomised,double-blinded,placebo-controlled phase-II clinical trial and studied the effect of CMA administration on the global metabolism of AD patients.One-dose CMA included 12.35 g L-serine(61.75%),1 g nicotinamide riboside(5%),2.55 g N-acetyl-L-cysteine(12.75%),and 3.73 g L-carnitine tartrate(18.65%).AD patients received one dose of CMA or placebo daily during the first 28 days and twice daily between day 28 and day 84.The primary endpoint was the difference in the cognitive function and daily living activity scores between the placebo and the treatment arms.The secondary aim of this study was to evaluate the safety and tolerability of CMA.A comprehensive plasma metabolome and proteome analysis was also performed to evaluate the efficacy of the CMA in AD patients.Results We showed a significant decrease of AD Assessment Scale-cognitive subscale(ADAS-Cog)score on day 84 vs day 0(P=0.00001,29%improvement)in the CMA group.Moreover,there was a significant decline(P=0.0073)in ADAS-Cog scores(improvement of cognitive functions)in the CMA compared to the placebo group in patients with higher ADAS-Cog scores.Improved cognitive functions in AD patients were supported by the relevant alterations in the hippocampal volumes and cortical thickness based on imaging analysis.Moreover,the plasma levels of proteins and metabolites associated with NAD+and glutathione metabolism were significantly improved after CMA treatment.Conclusion Our results indicate that treatment of AD patients with CMA can lead to enhanced cognitive functions and improved clinical parameters展开更多
The great challenges faced by modern power systems require a fresh look at the conventional operation paradigm. The significant challenges faced by modern power systems require an innovative method for the conventiona...The great challenges faced by modern power systems require a fresh look at the conventional operation paradigm. The significant challenges faced by modern power systems require an innovative method for the conventional operation paradigm. We claim that the decarbonization of the power grid and extensive electrification of numerous sectors of human activity can only be fostered by a self-adaptable and smart power grid that manifests similar qualities to those of the Internet. The Internet is constructed on a layered architecture that facilitates technology innovations and its intelligence is distributed throughout a hierarchy of networks. In this paper, the fundamental differences between the network data flows and power flows are examined, and the basic requirements for an innovative operation paradigm are highlighted. The current power grid is operated in a highly inflexible, centralized manner to meet increased security goals. A new highly flexible, distributed architecture can be realized by distributing the operation responsibility in smaller areas or even in grid components that can make autonomous decisions. The characteristics of such a power grid are presented, and the key features and advances for the on-going transition to a sustainable power system are identified. Finally, a case study on distributed voltage control is presented and discussed.展开更多
Biomedicalβ-phase Ti-Nb-Ta-Zr alloys usually exhibit low elastic modulus with inadequate strength.In the present work,a series of newly developed dual-phase Ti-xNb-yTa-2Zr(wt.%)alloys with high performance were inves...Biomedicalβ-phase Ti-Nb-Ta-Zr alloys usually exhibit low elastic modulus with inadequate strength.In the present work,a series of newly developed dual-phase Ti-xNb-yTa-2Zr(wt.%)alloys with high performance were investigated in which the stability ofβ-phase was reduced under the guidelines of ab initio calculations and d-electronic theory.The effects of Nb and Ta contents on the microstructure,compressive and tensile properties were investigated.Results demonstrate that the designed Ti-xNb-yTa-2Zr alloys exhibit typical characteristics ofα+βdual-phase microstructure.The microstructure of the alloys is more sensitive to Nb rather than Ta.The as-cast alloys exhibit needle-likeα′martensite at a lower Nb content of 3 wt.%and lamellarα′martensite at an Nb content of 5 wt.%.Among the alloys,the Ti-3Nb-13Ta-2Zr alloy shows the highest compressive strength(2270±10 MPa)and compressive strain(74.3%±0.4%).This superior performance is due to the combination ofα+βdual-phase microstructure and stressinducedα"martensite.Besides,lattice distortion caused by Ta element also contributes to the compressive properties.Nb and Ta contents of the alloys strongly affect Young's modulus and tensile properties after rolling.The as-rolled Ti-3Nb-13Ta-2Zr alloy exhibits much lower modulus due to lower Nb content as well as moreα"martensite andβphase with a good combination of low modulus and high strength among all the designed alloys.Atom probe tomography analysis reveals the element partitioning between theαandβphases in which Ta concentration is higher than Nb in theαphase.Also,the concentration of Ta is lower than that of Nb in theβphase,indicating that theβ-stability of Nb is higher than that of Ta.This work proposes modernα+βdual-phase Ti-xNb-yTa-2Zr alloys as a new concept to design novel biomedical Ti alloys with high performance.展开更多
The grey wolf （Canis lupus） is one of the most widely distributed terrestrial mammals, and its distribution and ecology in Europe and North America are largely well described. However, the distribution of grey wolve...The grey wolf （Canis lupus） is one of the most widely distributed terrestrial mammals, and its distribution and ecology in Europe and North America are largely well described. However, the distribution of grey wolves in southern China is still highly controversial. Several well-known western literatures stated that there were no grey wolves in southern China, while the presence of grey wolves across China has been indicated in A Guide to the Mammals of China, published by Princeton University Press. It is essential to solve this discrepancy since dogs may have originated from grey wolves in southern China. Therefore, we systematically investigated Chinese literatures about wild animal surveys and identified more than 100 articles and books that included information of the distribution of grey wolves in China. We also surveyed the collections of three Chinese natural museums and found 26 grey wolf skins specimens collected across China. Moreover, we investigated the fossil records in China and identified 25 archaeological sites with wolf remains including south China. In conclusion, with the comprehensive summary of Chinese literatures, museum specimens and fossil records, we demonstrate that grey wolves do distribute across all parts of the Chinese mainland, including the most southern parts.展开更多
Carbohydrates constitute the most abundant organic matter in nature, serving as structural components and energy sources, and mediating a wide range of cellular activities. The emergence of nanomaterials with distinct...Carbohydrates constitute the most abundant organic matter in nature, serving as structural components and energy sources, and mediating a wide range of cellular activities. The emergence of nanomaterials with distinct optical, magnetic, and electronic properties has witnessed a rapid adoption of these materials for biomedical research and applications. Nanomaterials of various shapes and sizes having large specific surface areas can be used as multivalent scaffolds to present carbohydrate ligands. The resulting glyconanomaterials effectively amplify the glycan-mediated interactions, making it possible to use these materials for sensing, imaging, diagnosis, and therapy. In this review, we summarize the synthetic strategies for the preparation of various glyconanomaterials. Examples are given where these glyconanomaterials have been used in sensing and differentiation of proteins and cells, as well as in imaging glycan-medicated cellular responses.展开更多
Hole-transporting material(HTM)plays a paramount role in enhancing the photovltaic performance of perovskite solar cells(PSCs).Currently,the vast majority of these HTMs employed in PSCs are organic small molecules and...Hole-transporting material(HTM)plays a paramount role in enhancing the photovltaic performance of perovskite solar cells(PSCs).Currently,the vast majority of these HTMs employed in PSCs are organic small molecules and polymers,yet the use of organic metal complexes in PSCs applications remains less explored.To date,most of reported HTMs require additional chemical additives(e.g.Li-TFSI,t-TBP)towards high performance,however,the introduction of additives decrease the PSCs device stability.Herein,an organic metal complex(Ni-TPA)is first developed as a dopant-free HTM applied in PSCs for its facile synthesis and efficient hole extract/transfer ability.Consequently,the dopant-free Ni-TPAbased device achieves a champion efficiency of 17.89%,which is superior to that of pristine Spiro-OMeTAD(14.25%).Furthermore,we introduce a double HTM layer with a graded energy bandgap containing a Ni-TPA layer and a CuSCN layer into PSCs,the non-encapsulated PSCs based on the Ni-TPA/CuSCN layers affords impressive efficiency up to 20.39%and maintains 96%of the initial PCE after 1000 h at a relative humidity around 40%.The results have demonstrated that metal organic complexes represent a great promise for designing new dopant-free HTMs towards highly stable PSCs.展开更多
As a problem in data science the inverse Ising(or Potts)problem is to infer the parameters of a Gibbs-Boltzmann distributions of an Ising(or Potts)model from samples drawn from that distribution.The algorithmic and co...As a problem in data science the inverse Ising(or Potts)problem is to infer the parameters of a Gibbs-Boltzmann distributions of an Ising(or Potts)model from samples drawn from that distribution.The algorithmic and computational interest stems from the fact that this inference task cannot be carried out efficiently by the maximum likelihood criterion,since the normalizing constant of the distribution(the partition function)cannot be calculated exactly and efficiently.The practical interest on the other hand flows from several outstanding applications,of which the most well known has been predicting spatial contacts in protein structures from tables of homologous protein sequences.Most applications to date have been to data that has been produced by a dynamical process which,as far as it is known,cannot be expected to satisfy detailed balance.There is therefore no a priori reason to expect the distribution to be of the Gibbs-Boltzmann type,and no a priori reason to expect that inverse Ising(or Potts)techniques should yield useful information.In this review we discuss two types of problems where progress nevertheless can be made.We find that depending on model parameters there are phases where,in fact,the distribution is close to Gibbs-Boltzmann distribution,a non-equilibrium nature of the under-lying dynamics notwithstanding.We also discuss the relation between inferred Ising model parameters and parameters of the underlying dynamics.展开更多
Omics data address key issues in liver transplantation(LT)as the most effective therapeutic means for end-stage liver disease.The purpose of this study was to review the current application and future direction for om...Omics data address key issues in liver transplantation(LT)as the most effective therapeutic means for end-stage liver disease.The purpose of this study was to review the current application and future direction for omics in LT.We reviewed the use of multiomics to elucidate the pathogenesis leading to LT and prognostication.Future directions with respect to the use of omics in LT are also described based on perspectives of surgeons with experience in omics.Significant molecules were identified and summarized based on omics,with a focus on post-transplant liver fibrosis,early allograft dysfunction,tumor recurrence,and graft failure.We emphasized the importance omics for clinicians who perform LTs and prioritized the directions that should be established.We also outlined the ideal workflow for omics in LT.In step with advances in technology,the quality of omics data can be guaranteed using an improved algorithm at a lower price.Concerns should be addressed on the translational value of omics for better therapeutic effects in patients undergoing LT.展开更多
Laboratory measurements of airborne particles from sliding contacts are often performed using a tri- bometer located in a ventilation chamber. Although knowledge of particle transport behavior inside the chamber is re...Laboratory measurements of airborne particles from sliding contacts are often performed using a tri- bometer located in a ventilation chamber. Although knowledge of particle transport behavior inside the chamber is required because it can influence the analysis of measurements, this knowledge is lacking. A numerical model was built based on the same geometry as a pin-on-disc measurement system to explain particle transport behavior inside the chamber and to determine the deviation between real amounts of generated and measured particles at the outlet. The effect of controlled flow conditions on the airflow pattern and particle transport inside the chamber was studied for different experimental conditions. Cal- culations show that a complex airflow pattern is formed by the spinning disc, and that it differs for each rotational speed. Simulation results reveal that particle transport in the chamber is governed mainly by the airflow pattern. The deposition velocity in the chamber was estimated and the possibility that part of the generated particles would remain in the chamber was studied. This led to an approximate estima- tion of particle loss rate. A comparison between experimental and simulated results with respect to the particle mass flow rate close to the outlet yields a reference factor of 0.7, which provides an indication of the difference between measured and real values.展开更多
The effect of irreversibly adsorbed Bi on commercial Pt/C catalyst toward glucose electro-oxidation re- action （GOR） in different electrolytes （acidic, neutral, alkaline） is studied. Bi is successfully deposited o...The effect of irreversibly adsorbed Bi on commercial Pt/C catalyst toward glucose electro-oxidation re- action （GOR） in different electrolytes （acidic, neutral, alkaline） is studied. Bi is successfully deposited on Pt/C from Bi3＋ containing acidic solution from 0 to 90% coverage degree. The stability of the Bi layer in acid and alkaline corresponded to previous studies and started to dissolve at 0.7 V and 0.8 V versus re- versible hydrogen electrode （RIIE）, respectively. However, in neutral phosphate buffer the layer showed remarkable stability to at least 1.2V versus RHE. Bi modification at low （20%） and high （80%） coverage showed the highest increase in the activity of Pt/C toward GOR by a factor up to 7 due to the increased poisoning resistance of the modified catalyst. The effect of poisoning was especially reduced at high Bi coverage （80%）, which shows that adsorbate blocked by Bi through the third-body effect is effective. Finally, with or without Bi modification GOR on PtIC was most active in alkaline conditions.展开更多
A combined model to predict austenite grains growth of titanium micro-alloyed as-cast steel during reheating process was established.The model invoIves the behaviors of austenite grains growth in continuous heating pr...A combined model to predict austenite grains growth of titanium micro-alloyed as-cast steel during reheating process was established.The model invoIves the behaviors of austenite grains growth in continuous heating process and isothermal soaking process,and the variation of boundary pinning efficiency caused by the dissolution and coarsening kinetics of sec on d-phase particles was also con sidered into the model.Furthermore,the experimental verificatio ns were performed to examine the prediction power of the model.The results revealed that the mean austenite grains size increased with the increase in reheating temperature and soaking time,and the coarsening temperature of austenite grains growth was 1423 K under the current titanium content.In addition,the reliability of the predicted results in continuous heating process was validated by continuous heating experimenls.Moreover,an optimal regression expression of austenite grains growth in isothermal soaking process was obtained based on the experimental results.The compared results indicated that the combined model in conjunction with precipitates dissolution and coarsening kinetics had good reliability and accuracy to predict the austenite grains growth of titanium micro-alloyed casting steel during reheating process.展开更多
Problems associated with carbon support corrosion under operating fuel cell conditions require the identification of alternative supports for platinum-based nanosized electrocatalysts.Platinum supported on manganese v...Problems associated with carbon support corrosion under operating fuel cell conditions require the identification of alternative supports for platinum-based nanosized electrocatalysts.Platinum supported on manganese vanadate(Pt/MnV_(2)O_(6))was prepared by microwave irradiation method and characterized using X-ray diffraction,Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,scanning electron microscopy with energy dispersive spectroscopy,and transmission electron microscopy.The borohydride oxidation reaction(BOR)on Pt/MnV_(2)O_(6) was studied in highly alkaline media using voltammetry,chronoamperometry,and electrochemical impedance spectroscopy.BOR electrocatalytic activity of Pt/MnV_(2)O_(6) was also compared with that of commercial Pt/C(46 wt%Pt)electrocatalyst.The apparent activation energy of BOR at Pt/MnV_(2)O_(6) was estimated to be 32 k J mol^(-1) and the order of reaction to be 0.51,indicating that borohydride hydrolysis proceeds in parallel with its oxidation.Long-term stability of Pt/MnV_(2)O_(6) under BOR typical conditions was observed.A laboratory-scale direct borohydride fuel cell assembled with a Pt/MnV_(2)O_(6) anode reached a specific power of 274 W g^(-1).Experimental results on Pt/MnV_(2)O_(6) were complemented by DFT calculations,which indicated good adherence of Pt to MnV_(2)O_(6),beneficial for electrocatalyst stability.展开更多
基金Under the auspices of National Basic Research Program of China (No. 2010CB950900)National Natural Science Foundation of China (No. 40971223)Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-EW-306)
文摘This study investigated the regional differences of China′s urban land expansion from the late 1980s to the year of 2008, based on the spatio-temporal analysis of CLCD (China′s land cover/land use database) datasets which were mainly produced from remote sensing imagery data. A newly defined urbanization level index (UI), based on urban land area, is proposed to describe Chinese urban expansion process at 1 kilometer, provincial, regional, and na-tional scales, together with the absolute urban expansion index (UEa) and the relative urbanization expansion index (UEr). The results indicate that the percentages of total land area occupied by urban in the late 1980s, 1995, 2000, 2005, and 2008 were approximately 0.25%, 0.32%, 0.33%, 0.43% and 0.52% of China′s total land area, respectively. Between the late 1980s and 2008, the total urban expansion in the mainland of China was 2.645 × 104 km2, resulting in an annual urban expansion area of about 1322.7 km2/yr, with the UEr of 111.9%. This study also finds that there has been an obvious spatial gradient of urbanization ratio running from the east coast to the west inland, and the urbanization gaps among different regions have persisted over the past two decades. The study also reveals obvious temporal varia-tions of the urbanization rates. There was very little urban growth during the period of 1995-2000 due to the governmental policy factors.
基金partially funded by Chinese Academy of Sciences (Y62302,Y45Z04,Y55Z06,and Y62Z17)World Wide Fund for Nature (Y56002 and Y63Z08)
文摘The Yangtze River is one of the largest and longest rivers in Asia.The river originates in the Tibet-Qinghai Plateau(headwater reach),passes through the mountainous provinces of Sichuan,Yunnan and Chongqing(upper reach),flows into the Central Plain(middle reach)and Lower Plain(lower reach),and finally empties into the East China Sea in Shanghai(estuary).The Yangtze River Economic Belt(YREB;Fig.1)has a surface area of 2.1
基金financially supported by the National Natural Science Foundation of China(No.51827801)the support by the Overseas Visiting Study Program of Harbin Institute of Technology。
文摘This paper presents a systematic investigation of the microstructure and magnetocaloric properties of melt-extracted Sm_(20)Gd_(20)Dy_(20)Co_(20)Al_(20)high-entropy microwires.The fabricated wires exhibited an amorphous structure,and the temperature interval of the undercooled liquid AT was 45 K.The microwires underwent a second-order magnetic transition from a ferromagnetic to a paramagnetic state near the Curie temperature(T_(C)=52 K),The maximum magnetic entropy change(-ΔS_M^(max)),the relative cooling power and the refrigeration capacity reached 6.34 J·kg^(-1)·K^(-1).422.09 J·kg^(-1)and 332.94 J·kg^(-1),respectively,under a magnetic field change of 5 T.In addition,the temperature-averaged entropy changes with two temperature lifts(3 and 10 K)were 6.32 and 6.27 J·kg^(-1)·K^(-1),respectively.The good magnetocalorie performance highlights the significant potential for the Sm_(20)Gd_(20)Dy_(20)Co_(20)Al_(20)microwires to be used as magnetic refrigerant materials in low-temperature region applications.This work will serve as a valuable reference for future investigations on low-temperature high-entropy magnetocaloric materials.
基金financially supported by the National Natural Science Foundation of China (No. 52001120)the Fundamental Research Funds for the Central Universities (No. 531118010450)+10 种基金the Hundred Talent Program of Hunan Provincethe State Key Laboratory of Powder Metallurgy,Central South University,Changshathe State Key Laboratory of Advanced Metals and Materials(No. 2021-Z09)University of Science&Technology Beijing,Chinasupported by the National Natural Science Foundation of China (No. 51801060)supported by the Swedish Research Councilsupported by the National Science Foundation under Contract (No. DMR-1408722)sponsored by the Whiting School of EngineeringJohns Hopkins Universityfunded by the National Key Research and Development Program of China (No. 2016YFB0300801)the National NaturalScience Foundation of China (Nos. 51831004, 11427806, 51671082,51471067)。
文摘Anneal hardening has been one of the approaches to improve mechanical properties of solid solution alloys with the face-centered cubic(FCC) structure,whereby a considerable strengthening can be attained by annealing of cold-worked alloys below the recrystallization temperature(T_(rx)).Microscopically,this hardening effect has been ascribed to several mechanisms,i.e.solute segregation to defects(dislocation and stacking fault) and short-range chemical ordering,etc.However,none of these mechanisms can well explain the anneal hardening recently observed in phase-pure and coarse-grained FCC-structured high-entropy alloys(HEAs).Here we report the observations,using high-resolution electron channeling contrast imaging and transmission electron microscopy,of profuse and stable dislocation substructures in a cold-rolled CoCrFeMnNi HEA subject to an annealing below T_(rx).The dislocation substructures are observed to be thermally stable up to T_(rx),which could arise from the chemical complexity of the high-entropy system where certain elemental diffusion retardation occurs.The microstructure feature is markedly different from that of conventional dilute solid solution alloys,in which dislocation substructures gradually vanish by recovery during annealing,leading to a strength drop.Furthermore,dilute addition of 2 at.% Al leads to a reduction in both microhardness and yield strength of the cold-rolled and subsequently annealed(≤500℃) HEA.This Al induced softening effect,could be associated with the anisotropic formation of dislocation substructure,resulting from enhanced dislocation planar slip due to glide plane softening effect.These findings suggest that the strength of HEAs can be tailored through the anneal hardening effect from dislocation substructure strengthening.
基金supported by the Swedish Research Council(2015-5335 and 2017-06474)the Swedish Foundation for Strategic Research (S14-0038 and SM16-0036)+3 种基金the Swedish Foundation for International Cooperation in Research and Higher Education(CH2015-6292)the Swedish Energy Agency,the Hungarian Scientific Research Fund (OTKA 128229)the Carl Tryggers Foundationsupport from the Swedish Energy Agency (Energimyndigheten),ST and UPP and e SSENCE
文摘High entropy alloys(HEAs)based on transition metals display rich magnetic characteristics,however attempts on their application in energy efficient technologies remain scarce.Here,we explore the magnetocaloric application for a series of Mn_(x)Cr_(0.3)Fe_(0.5)Co_(0.2)Ni_(0.5)Al_(0.3)(0.8<x<1.1)HEAs by integrated theoretical and experimental methods.Both theory and experiment indicate the designed HEAs have the Curie temperature close to room temperature and is tunable with Mn concentration.A non-monotonic evolution is observed for both the entropy change and the relative cooling power with changing Mn concentration.The underlying atomic mechanism is found to primarily emerge from the complex impact of Mn on magnetism.Advanced magnetocaloric properties can be achieved by tuning Mn concentration in combination with controlling structural phase stability for the designed HEAs.
基金This study is supported by Innovative Research Groups of National Natural Science Foundation of China(81721091)Major program of National Natural Science Foundation of China(91542205)+7 种基金National S&T Major Project(2017ZX10203205)National Natural Science Foundation of China(81902813)Zhejiang International Science and Technology Cooperation Project(2016C04003)Zhejiang Provincial Natural Science Foundation of China(LY18H030002)Zhejiang Medical Association(2019ZYC-A81)International Youth Exchange Programme by China Association for Science and Technology(2019)Tianqing Liver Diseases Research Fund(TQGB20200114)Open Fund of Key laboratory of High-Incidence-Tumor Prevention&Treatment(Guangxi Medical University),Ministry of Education.
文摘Background:Liver transplantation(LT)is one of the most effective surgical treatment for patients with end-stage liver disease.Steatosis is a contributor for inferior graft quality.But its impact and safety on transplantation was less assessed in Chinese patients.Methods:Graft steatosis and related information involved in recipients,donors and surgical procedures were retrospectively collected from 239 patients.Results:Donor macrosteatosis(MaS)caused about 2.14 and 2.80 folds of increment on patient and graft mortality.Dose-response analysis revealed prominent risk of grafts on overall patient/organ mortality when MaS content exceeded 10%(P<0.05).Noteworthy,deaths were only observed in MaS group when concurrent with extremely higher post-transplant alanine aminotransferase(ALT,64%).However,microsteatosis(MiS)grafts didn’t affect outcomes after LT.In a cohort of Chinese patients,MaS had comprehensive effects on post-transplant outcomes with relatively lower safety threshold at 10%.Mortality gap caused by MaS grafts was observed in patients with severer ischemia reperfusion injury.Conclusions:Our study revealled the graft MaS affected the post-transplant outcomes in lower risk cutoff in Chinese patients.Further study is worthy to validate these results and investigate inner mechanism under the phenomenon.
基金financially supported by the National Natural Science Foundation of China(Nos.51374064,51004033,and 51074044)the National High-Tech Research and Development Program of China(No.2012AA062303)+1 种基金the National Key Technology Support Program during the 12th Five-Year Plan Period(No.2012BAE01B02)the Fundamental Research Funds for the Central Universities(Nos.N130402012 and N130702001)
文摘In this paper, the thermodynamics and kinetics of nature rutile carbochlorination in a fluidized-bed were investigated. The thermodynamic calculations of TiO2-C- C12 system show that when C is excess in the solid phase, titanium tetrachloride and carbon monoxide can exist sta- bly. At high temperature, the reaction with CO as the product is the dominant reaction. The appropriate reaction conditions are as follows： reaction temperature of 950 ℃, reaction time of 40 min, carbon ratio of 30 wt% of rutile, natural rutile particle size of -96 μm, petroleum coke size of -150 μm, and chlorine flow of 0.036 m3.h-1. Under the above conditions, the reaction conversion rate of TiO2 can reach about 95 %. This paper proposed a reaction rate model, and got a rutile chlorination rate formula, which is generally consistent with the experimental data. For the TiO2-C-C12 system, the reaction rate is dependent on the initial radius of rutile particle, density, and the partial pressures of C12. From 900 to 1,000 ℃, the apparent activation energy is 10.569 kJ.mo1-1, and the mass diffu- sion is found to be the main reaction-controlling step. The expression for the chlorine reaction rate in the C-C12 sys- tem is obtained, and it depends on the degree of reaction, the partial pressure of C12, and the size of rutile particle.
基金financially supported by the Young Scientists Fund of the National Natural Science Foundation of China(No.52001120)the Hunan Provincial National Science Fund for Distin-guished Young Scholars(No.2022JJ10015)+2 种基金the State Key Labora-tory of Advanced Metals and Materials(No.2021-Z09)the Univer-sity of Science&Technology Beijing,China.X.Q.Li was supported by the Swedish Research Council(No.2020-03736)funded by the Swedish Research Council through grant agreement(No.2018-05973)。
文摘Molybdenum(Mo)has been recognized as an essential alloying element of the MP35N(Co_(35.4)Cr_(22.9)Ni_(35.5)Mo_(6.2),at.%)superalloy for enhancing strength and corrosion resistance.However,a full understanding of the addition of Mo on microstructure and mechanical properties of the Mo-free parent alloy is lacking.In this work,we consider five(Co_(37.7)Cr_(24.4)Ni_(37.9))_(100-x)Mo_(x)(x=0,0.7,2.0,3.2,and 6.2)alloys,and reveal that yield/tensile strength and ductility are continuously increased for these alloys with increasing Mo content while a single-phase face-centered cubic structure remains unchanged.It is found that strong solid solution strengthening(SSS)is a main domain to the improved yield strength,whereas grain boundaries are found to soften by the Mo addition.The first-principles calculations demonstrate that a severe local lattice distortion contributes to the enhanced SSS,and the grain boundary softening effect is mostly associated with the decreased shear modulus.Both first-principles calculations and scanning transmission electron microscopy observations reveal that the stacking fault energy(SFE)reduces by the Mo addition.The calculated SFE value decreases from 0.4 mJ/m^(2) to-11.8 mJ/m^(2) at 0 K as Mo content increases from 0 at.%to 6.2 at.%,and experimentally measured values of SFE at room temperature for both samples are about 18 mJ/m^(2) and 9 mJ/m^(2),respectively.The reduction of SFE promoted the generation of stacking faults and deformation twins,which sustain a high strain hardening rate,thus postponing necking instability and enhancing tensile strength and elongation.
基金funding provided by Royal Institute of Technology.This work was financially supported by ScandiBio Therapeutics and Knut and Alice Wallenberg Foundation(72110).
文摘Background Alzheimer’s disease(AD)is associated with metabolic abnormalities linked to critical elements of neurodegeneration.We recently administered combined metabolic activators(CMA)to the AD rat model and observed that CMA improves the AD-associated histological parameters in the animals.CMA promotes mitochondrial fatty acid uptake from the cytosol,facilitates fatty acid oxidation in the mitochondria,and alleviates oxidative stress.Methods Here,we designed a randomised,double-blinded,placebo-controlled phase-II clinical trial and studied the effect of CMA administration on the global metabolism of AD patients.One-dose CMA included 12.35 g L-serine(61.75%),1 g nicotinamide riboside(5%),2.55 g N-acetyl-L-cysteine(12.75%),and 3.73 g L-carnitine tartrate(18.65%).AD patients received one dose of CMA or placebo daily during the first 28 days and twice daily between day 28 and day 84.The primary endpoint was the difference in the cognitive function and daily living activity scores between the placebo and the treatment arms.The secondary aim of this study was to evaluate the safety and tolerability of CMA.A comprehensive plasma metabolome and proteome analysis was also performed to evaluate the efficacy of the CMA in AD patients.Results We showed a significant decrease of AD Assessment Scale-cognitive subscale(ADAS-Cog)score on day 84 vs day 0(P=0.00001,29%improvement)in the CMA group.Moreover,there was a significant decline(P=0.0073)in ADAS-Cog scores(improvement of cognitive functions)in the CMA compared to the placebo group in patients with higher ADAS-Cog scores.Improved cognitive functions in AD patients were supported by the relevant alterations in the hippocampal volumes and cortical thickness based on imaging analysis.Moreover,the plasma levels of proteins and metabolites associated with NAD+and glutathione metabolism were significantly improved after CMA treatment.Conclusion Our results indicate that treatment of AD patients with CMA can lead to enhanced cognitive functions and improved clinical parameters
文摘The great challenges faced by modern power systems require a fresh look at the conventional operation paradigm. The significant challenges faced by modern power systems require an innovative method for the conventional operation paradigm. We claim that the decarbonization of the power grid and extensive electrification of numerous sectors of human activity can only be fostered by a self-adaptable and smart power grid that manifests similar qualities to those of the Internet. The Internet is constructed on a layered architecture that facilitates technology innovations and its intelligence is distributed throughout a hierarchy of networks. In this paper, the fundamental differences between the network data flows and power flows are examined, and the basic requirements for an innovative operation paradigm are highlighted. The current power grid is operated in a highly inflexible, centralized manner to meet increased security goals. A new highly flexible, distributed architecture can be realized by distributing the operation responsibility in smaller areas or even in grid components that can make autonomous decisions. The characteristics of such a power grid are presented, and the key features and advances for the on-going transition to a sustainable power system are identified. Finally, a case study on distributed voltage control is presented and discussed.
基金financially supported by the National Natural Science Foundation of China(Nos.52011530181 and 51831011)the Shanghai Science and Technology Commission(No.20S31900100)。
文摘Biomedicalβ-phase Ti-Nb-Ta-Zr alloys usually exhibit low elastic modulus with inadequate strength.In the present work,a series of newly developed dual-phase Ti-xNb-yTa-2Zr(wt.%)alloys with high performance were investigated in which the stability ofβ-phase was reduced under the guidelines of ab initio calculations and d-electronic theory.The effects of Nb and Ta contents on the microstructure,compressive and tensile properties were investigated.Results demonstrate that the designed Ti-xNb-yTa-2Zr alloys exhibit typical characteristics ofα+βdual-phase microstructure.The microstructure of the alloys is more sensitive to Nb rather than Ta.The as-cast alloys exhibit needle-likeα′martensite at a lower Nb content of 3 wt.%and lamellarα′martensite at an Nb content of 5 wt.%.Among the alloys,the Ti-3Nb-13Ta-2Zr alloy shows the highest compressive strength(2270±10 MPa)and compressive strain(74.3%±0.4%).This superior performance is due to the combination ofα+βdual-phase microstructure and stressinducedα"martensite.Besides,lattice distortion caused by Ta element also contributes to the compressive properties.Nb and Ta contents of the alloys strongly affect Young's modulus and tensile properties after rolling.The as-rolled Ti-3Nb-13Ta-2Zr alloy exhibits much lower modulus due to lower Nb content as well as moreα"martensite andβphase with a good combination of low modulus and high strength among all the designed alloys.Atom probe tomography analysis reveals the element partitioning between theαandβphases in which Ta concentration is higher than Nb in theαphase.Also,the concentration of Ta is lower than that of Nb in theβphase,indicating that theβ-stability of Nb is higher than that of Ta.This work proposes modernα+βdual-phase Ti-xNb-yTa-2Zr alloys as a new concept to design novel biomedical Ti alloys with high performance.
基金supported by grants from the National Natural Science Foundation of China(91531303)the 973 program(2013CB835200 and 2013CB835202)+3 种基金the Breakthrough Project of Strategic Priority Program of the Chinese Academy of Sciences(XDB13000000)grants from the Carl Trygger Foundationthe Agria and Swedish Kennel Club research foundationsupported by the Youth Innovation Promotion Association,Chinese Academy of Sciences
文摘The grey wolf （Canis lupus） is one of the most widely distributed terrestrial mammals, and its distribution and ecology in Europe and North America are largely well described. However, the distribution of grey wolves in southern China is still highly controversial. Several well-known western literatures stated that there were no grey wolves in southern China, while the presence of grey wolves across China has been indicated in A Guide to the Mammals of China, published by Princeton University Press. It is essential to solve this discrepancy since dogs may have originated from grey wolves in southern China. Therefore, we systematically investigated Chinese literatures about wild animal surveys and identified more than 100 articles and books that included information of the distribution of grey wolves in China. We also surveyed the collections of three Chinese natural museums and found 26 grey wolf skins specimens collected across China. Moreover, we investigated the fossil records in China and identified 25 archaeological sites with wolf remains including south China. In conclusion, with the comprehensive summary of Chinese literatures, museum specimens and fossil records, we demonstrate that grey wolves do distribute across all parts of the Chinese mainland, including the most southern parts.
基金The authors are grateful for financial supports from the National Institutes of Health （Nos. R01GM080295 and 2R15GM066279）, the National Science Foundation （No. CHE-1112436）, the University of Massachusetts Lowell, and KTH--Royal Institute of Technology, Sweden.
文摘Carbohydrates constitute the most abundant organic matter in nature, serving as structural components and energy sources, and mediating a wide range of cellular activities. The emergence of nanomaterials with distinct optical, magnetic, and electronic properties has witnessed a rapid adoption of these materials for biomedical research and applications. Nanomaterials of various shapes and sizes having large specific surface areas can be used as multivalent scaffolds to present carbohydrate ligands. The resulting glyconanomaterials effectively amplify the glycan-mediated interactions, making it possible to use these materials for sensing, imaging, diagnosis, and therapy. In this review, we summarize the synthetic strategies for the preparation of various glyconanomaterials. Examples are given where these glyconanomaterials have been used in sensing and differentiation of proteins and cells, as well as in imaging glycan-medicated cellular responses.
基金the National Natural Science Foundation of China(22065038)the Key Project of Natural Science Foundation of Yunnan(KC10110419)+4 种基金the High-Level Talents Introduction in Yunnan Province(C619300A010)the Fund for Excellent Young Scholars of Yunnan(K264202006820)the Program for Excellent Young Talents of Yunnan University and Major Science(C176220200)the International Joint Research Center for Advanced Energy Materials of Yunnan Province(202003AE140001)the Technology Project of Precious Metal Materials Genetic Engineering in Yunnan Province(No.2019Z E001-1202002AB080001)for financial support。
文摘Hole-transporting material(HTM)plays a paramount role in enhancing the photovltaic performance of perovskite solar cells(PSCs).Currently,the vast majority of these HTMs employed in PSCs are organic small molecules and polymers,yet the use of organic metal complexes in PSCs applications remains less explored.To date,most of reported HTMs require additional chemical additives(e.g.Li-TFSI,t-TBP)towards high performance,however,the introduction of additives decrease the PSCs device stability.Herein,an organic metal complex(Ni-TPA)is first developed as a dopant-free HTM applied in PSCs for its facile synthesis and efficient hole extract/transfer ability.Consequently,the dopant-free Ni-TPAbased device achieves a champion efficiency of 17.89%,which is superior to that of pristine Spiro-OMeTAD(14.25%).Furthermore,we introduce a double HTM layer with a graded energy bandgap containing a Ni-TPA layer and a CuSCN layer into PSCs,the non-encapsulated PSCs based on the Ni-TPA/CuSCN layers affords impressive efficiency up to 20.39%and maintains 96%of the initial PCE after 1000 h at a relative humidity around 40%.The results have demonstrated that metal organic complexes represent a great promise for designing new dopant-free HTMs towards highly stable PSCs.
基金the National Natural Science Foundation of China(Grant No.11705097)the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20170895)+1 种基金the Jiangsu Government Scholarship for Overseas Studies of 2018 and Scientific Research Foundation of Nanjing University of Posts and Telecommunications,China(Grant No.NY217013)the Foundation for Polish Science through TEAM-NET Project(Grant No.POIR.04.04.00-00-17C1/18-00).
文摘As a problem in data science the inverse Ising(or Potts)problem is to infer the parameters of a Gibbs-Boltzmann distributions of an Ising(or Potts)model from samples drawn from that distribution.The algorithmic and computational interest stems from the fact that this inference task cannot be carried out efficiently by the maximum likelihood criterion,since the normalizing constant of the distribution(the partition function)cannot be calculated exactly and efficiently.The practical interest on the other hand flows from several outstanding applications,of which the most well known has been predicting spatial contacts in protein structures from tables of homologous protein sequences.Most applications to date have been to data that has been produced by a dynamical process which,as far as it is known,cannot be expected to satisfy detailed balance.There is therefore no a priori reason to expect the distribution to be of the Gibbs-Boltzmann type,and no a priori reason to expect that inverse Ising(or Potts)techniques should yield useful information.In this review we discuss two types of problems where progress nevertheless can be made.We find that depending on model parameters there are phases where,in fact,the distribution is close to Gibbs-Boltzmann distribution,a non-equilibrium nature of the under-lying dynamics notwithstanding.We also discuss the relation between inferred Ising model parameters and parameters of the underlying dynamics.
基金supported by Innovative Research Groups of National Natural Science Foundation of China(81721091)Major Program of National Natural Science Foundation of China(91542205)+8 种基金National S&T Major Project(2017ZX 10203205)National Natural Science Foundation of China(81902813)Zhejiang International Science and Technology Cooperation Project(2016C04003)Zhejiang Provincial Natural Science Foundation of China(LY18H030002)Zhejiang Medical Association(grant no.2019ZYC-A81)International Youth Exchange Programme by China Association for Science and Technology(2019),Tianqing Liver Diseases Research Fund(TQGB20200114)Medical Health Science and Technology Project of Zhejiang Provincial Health Commission(2021KY145)Organ Transplantation Overseas Training for Youth Talents from Shulan Excellent Talent Project,CSCO(Chinese Society Of Clinical Oncology)-Bayer Tumor Research Funding(Y-bayer202001/zb-0003)Open Fund of Key laboratory of High-Incidence-Tumor Prevention&Treatment(Guangxi Medical University)belonged to Ministry of Education.
文摘Omics data address key issues in liver transplantation(LT)as the most effective therapeutic means for end-stage liver disease.The purpose of this study was to review the current application and future direction for omics in LT.We reviewed the use of multiomics to elucidate the pathogenesis leading to LT and prognostication.Future directions with respect to the use of omics in LT are also described based on perspectives of surgeons with experience in omics.Significant molecules were identified and summarized based on omics,with a focus on post-transplant liver fibrosis,early allograft dysfunction,tumor recurrence,and graft failure.We emphasized the importance omics for clinicians who perform LTs and prioritized the directions that should be established.We also outlined the ideal workflow for omics in LT.In step with advances in technology,the quality of omics data can be guaranteed using an improved algorithm at a lower price.Concerns should be addressed on the translational value of omics for better therapeutic effects in patients undergoing LT.
文摘Laboratory measurements of airborne particles from sliding contacts are often performed using a tri- bometer located in a ventilation chamber. Although knowledge of particle transport behavior inside the chamber is required because it can influence the analysis of measurements, this knowledge is lacking. A numerical model was built based on the same geometry as a pin-on-disc measurement system to explain particle transport behavior inside the chamber and to determine the deviation between real amounts of generated and measured particles at the outlet. The effect of controlled flow conditions on the airflow pattern and particle transport inside the chamber was studied for different experimental conditions. Cal- culations show that a complex airflow pattern is formed by the spinning disc, and that it differs for each rotational speed. Simulation results reveal that particle transport in the chamber is governed mainly by the airflow pattern. The deposition velocity in the chamber was estimated and the possibility that part of the generated particles would remain in the chamber was studied. This led to an approximate estima- tion of particle loss rate. A comparison between experimental and simulated results with respect to the particle mass flow rate close to the outlet yields a reference factor of 0.7, which provides an indication of the difference between measured and real values.
基金Jane and Aatos Erkko FoundationJenny and Antti Wihuri Foundation for funding
文摘The effect of irreversibly adsorbed Bi on commercial Pt/C catalyst toward glucose electro-oxidation re- action （GOR） in different electrolytes （acidic, neutral, alkaline） is studied. Bi is successfully deposited on Pt/C from Bi3＋ containing acidic solution from 0 to 90% coverage degree. The stability of the Bi layer in acid and alkaline corresponded to previous studies and started to dissolve at 0.7 V and 0.8 V versus re- versible hydrogen electrode （RIIE）, respectively. However, in neutral phosphate buffer the layer showed remarkable stability to at least 1.2V versus RHE. Bi modification at low （20%） and high （80%） coverage showed the highest increase in the activity of Pt/C toward GOR by a factor up to 7 due to the increased poisoning resistance of the modified catalyst. The effect of poisoning was especially reduced at high Bi coverage （80%）, which shows that adsorbate blocked by Bi through the third-body effect is effective. Finally, with or without Bi modification GOR on PtIC was most active in alkaline conditions.
基金National Natural Science Foundation of China(Grant Nos.51504048,51874060,51874059 and 51611130062)The authors would like to acknowledge the members of Laboratory of Metallurgy and Materials,Chongqing University,for the support of this work.
文摘A combined model to predict austenite grains growth of titanium micro-alloyed as-cast steel during reheating process was established.The model invoIves the behaviors of austenite grains growth in continuous heating process and isothermal soaking process,and the variation of boundary pinning efficiency caused by the dissolution and coarsening kinetics of sec on d-phase particles was also con sidered into the model.Furthermore,the experimental verificatio ns were performed to examine the prediction power of the model.The results revealed that the mean austenite grains size increased with the increase in reheating temperature and soaking time,and the coarsening temperature of austenite grains growth was 1423 K under the current titanium content.In addition,the reliability of the predicted results in continuous heating process was validated by continuous heating experimenls.Moreover,an optimal regression expression of austenite grains growth in isothermal soaking process was obtained based on the experimental results.The compared results indicated that the combined model in conjunction with precipitates dissolution and coarsening kinetics had good reliability and accuracy to predict the austenite grains growth of titanium micro-alloyed casting steel during reheating process.
基金the Ministry of Education,Science and Technological Development of Republic of Serbia for support within project no.451–03–68/2020–14/200146Funda??o para a Ciência e a Tecnologia(FCT,Portugal)for contract no.IF/01084/2014/CP1214/CT0003 under IF2014 Programme(D.M.F.Santos)and no.IST-ID/156–2018(B.?ljuki?)+1 种基金sponsored in part by the NATO Science for Peace and Security Programme under grant G5729(I.A.Pa?ti and B.?ljuki?)the support from the Carl Tryggers Foundation for Scientific Research(grant no.18:177)。
文摘Problems associated with carbon support corrosion under operating fuel cell conditions require the identification of alternative supports for platinum-based nanosized electrocatalysts.Platinum supported on manganese vanadate(Pt/MnV_(2)O_(6))was prepared by microwave irradiation method and characterized using X-ray diffraction,Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,scanning electron microscopy with energy dispersive spectroscopy,and transmission electron microscopy.The borohydride oxidation reaction(BOR)on Pt/MnV_(2)O_(6) was studied in highly alkaline media using voltammetry,chronoamperometry,and electrochemical impedance spectroscopy.BOR electrocatalytic activity of Pt/MnV_(2)O_(6) was also compared with that of commercial Pt/C(46 wt%Pt)electrocatalyst.The apparent activation energy of BOR at Pt/MnV_(2)O_(6) was estimated to be 32 k J mol^(-1) and the order of reaction to be 0.51,indicating that borohydride hydrolysis proceeds in parallel with its oxidation.Long-term stability of Pt/MnV_(2)O_(6) under BOR typical conditions was observed.A laboratory-scale direct borohydride fuel cell assembled with a Pt/MnV_(2)O_(6) anode reached a specific power of 274 W g^(-1).Experimental results on Pt/MnV_(2)O_(6) were complemented by DFT calculations,which indicated good adherence of Pt to MnV_(2)O_(6),beneficial for electrocatalyst stability.
