The development of multifunctional and efficient electromagnetic wave absorbing materials is a challenging research hotspot.Here,the magnetized Ni flower/MXene hybrids are successfully assembled on the surface of mela...The development of multifunctional and efficient electromagnetic wave absorbing materials is a challenging research hotspot.Here,the magnetized Ni flower/MXene hybrids are successfully assembled on the surface of melamine foam(MF)through electrostatic self-assembly and dip-coating adsorption process,realizing the integration of microwave absorption,infrared stealth,and flame retardant.Remarkably,the Ni/MXene-MF achieves a minimum reflection loss(RLmin)of−62.7 dB with a corresponding effective absorption bandwidth(EAB)of 6.24 GHz at 2 mm and an EAB of 6.88 GHz at 1.8 mm.Strong electromagnetic wave absorption is attributed to the three-dimensional magnetic/conductive networks,which provided excellent impedance matching,dielectric loss,magnetic loss,interface polarization,and multiple attenuations.In addition,the Ni/MXene-MF endows low density,excellent heat insulation,infrared stealth,and flame-retardant functions.This work provided a new development strategy for the design of multifunctional and efficient electromagnetic wave absorbing materials.展开更多
Hard carbon has been regarded as the most promising anode material for sodiumion batteries(SIBs)due to its low cost,high reversible capacity,and low working potential.However,the uncertain sodium storage mechanism hin...Hard carbon has been regarded as the most promising anode material for sodiumion batteries(SIBs)due to its low cost,high reversible capacity,and low working potential.However,the uncertain sodium storage mechanism hinders the rational design and synthesis of high-performance hard carbon anode materials for practical SIBs.During the past decades,tremendous efforts have been put to stimulate the development of hard carbon materials.In this review,we discuss the recent progress of the study on the sodium storage mechanism of hard carbon anodes,and the effective strategies to improve their sodium storage performance have been summarized.It is anticipated that hard carbon anodes with high electrochemical properties will be inspired and fabricated for large-scale energy storage applications.展开更多
Hepatocellular carcinoma(HCC)is the fourth leading cause of cancer-associated death worldwide.Angiogenesis,the process of formation of new blood vessels,is required for cancer cells to obtain nutrients and oxygen.HCC ...Hepatocellular carcinoma(HCC)is the fourth leading cause of cancer-associated death worldwide.Angiogenesis,the process of formation of new blood vessels,is required for cancer cells to obtain nutrients and oxygen.HCC is a typical hypervascular solid tumor with an aberrant vascular network and angiogenesis that contribute to its growth,progression,invasion,and metastasis.Current anti-angiogenic therapies target mainly tyrosine kinases,vascular endothelial growth factor receptor(VEGFR),and plateletderived growth factor receptor(PDGFR),and are considered effective strategies for HCC,particularly advanced HCC.However,because the survival benefits conferred by these anti-angiogenic therapies are modest,new anti-angiogenic targets must be identified.Several recent studies have determined the underlying molecular mechanisms,including pro-angiogenic factors secreted by HCC cells,the tumor microenvironment,and cancer stem cells.In this review,we summarize the roles of pro-angiogenic factors;the involvement of endothelial cells,hepatic stellate cells,tumor-associated macrophages,and tumor-associated neutrophils present in the tumor microenvironment;and the regulatory influence of cancer stem cells on angiogenesis in HCC.Furthermore,we discuss some of the clinically approved anti-angiogenic therapies and potential novel therapeutic targets for angiogenesis in HCC.A better understanding of the mechanisms underlying angiogenesis may lead to the development of more optimized anti-angiogenic treatment modalities for HCC.展开更多
The objective of this clinical study was to assess the safety and feasibility of the collagen scaffold, Neuro Regen scaffold, one year after scar tissue resection and implantation. Scar tissue is a physical and chemic...The objective of this clinical study was to assess the safety and feasibility of the collagen scaffold, Neuro Regen scaffold, one year after scar tissue resection and implantation. Scar tissue is a physical and chemical barrier that prevents neural regeneration. However, identification of scar tissue is still a major challenge. In this study, the nerve electrophysiology method was used to distinguish scar tissue from normal neural tissue, and then different lengths of scars ranging from 0.5–4.5 cm were surgically resected in five complete chronic spinal cord injury(SCI) patients. The NeuroR egen scaffold along with autologous bone marrow mononuclear cells(BMMCs), which have been proven to promote neural regeneration and SCI recovery in animal models, were transplanted into the gap in the spinal cord following scar tissue resection. No obvious adverse effects related to scar resection or Neuro Regen scaffold transplantation were observed immediately after surgery or at the 12-month follow-up. In addition, patients showed partially autonomic nervous function improvement, and the recovery of somatosensory evoked potentials(SSEP) from the lower limbs was also detected. The results indicate that scar resection and Neuro Regen scaffold transplantation could be a promising clinical approach to treating SCI.展开更多
Atmospheric oxygen （02） is the most crucial element on earth for the aerobic organisms that depend on it to release energy from carbon-based macromolecules. This is the first study to systematically analyze the glob...Atmospheric oxygen （02） is the most crucial element on earth for the aerobic organisms that depend on it to release energy from carbon-based macromolecules. This is the first study to systematically analyze the global O2 budget and its changes over the past 100 years. It is found that anthropogenic fossil fuel combustion is the largest contributor to the current O2 deficit, which consumed 2.0 Gt/a in 1900 and has increased to 38.2 Gt/a by 2015. Under the Representative Concentration Pathways （RCPs） RCP8,5 scenario, approximately 100Gt （gigatonnes） of O2 would be removed from the atmosphere per year until 2100, and the O2 concentration will decrease from its current level of 20.946% to 20.825%. Human activities have caused irreversible decline of atmospheric O2. It is time to take actions to promote O2 production and reduce O2 consumption.展开更多
With the rapid development of wearable intelligent devices,low-cost wearable strain sensors with high sensitivity and low detection limit are urgently demanded.Meanwhile,sensing stability of sensor in wet or corrosive...With the rapid development of wearable intelligent devices,low-cost wearable strain sensors with high sensitivity and low detection limit are urgently demanded.Meanwhile,sensing stability of sensor in wet or corrosive environments should also be considered in practical applications.Here,superhydrophobic microcracked conductive paper-based strain sensor was fabricated by coating conductive Ti_(3)C_(2)T_(x) MXene on printing paper via dip-coating process and followed by depositing superhydrophobic candle soot layer on its surface.Owing to the ultrasensitive microcrack structure in the conductive coating layer induced by the mismatch of elastic modulus and thermal expansion coefficient between conductive coating layer and paper substrate during the drying process,the prepared paper-based strain sensor exhibited a high sensitivity(gauge factor,GF=17.4)in the strain range of 0–0.6%,ultralow detection limit(0.1%strain)and good fatigue resistance over 1000 cycles towards bending deformation.Interestingly,it was also applicable for torsion deformation detection,showing excellent torsion angle dependent,repeatable and stable sensing performances.Meanwhile,it displayed brilliant waterproof,self-cleaning and corrosion-resistant properties due to the existence of micro/nano-structured and the low surface energy candle soot layer.As a result,the prepared paper-based strain sensor can effectively monitor a series of large-scale and small-scale human motions even under water environment,showing the great promising in practical harsh outdoor environments.Importantly,it also demonstrated good applicability for spatial strain distribution detection of skin upon body movement when assembled into electronic-skin(E-skin).This study will provide great guidance for the design of next generation wearable strain sensor.展开更多
The Bohai Bay Basin(BBB)is the most petroliferous Cenozoic basin in the east of China.It consists of seven depressions.Each depression has been subjected to different stress states and then has experienced varying fau...The Bohai Bay Basin(BBB)is the most petroliferous Cenozoic basin in the east of China.It consists of seven depressions.Each depression has been subjected to different stress states and then has experienced varying faulting processes since the Neogene,especially during the Neotectonism(from the Pliocene to the present).On the basis of the investigation of fault patterns,fault densities and fault activity rates(FARs)for each depression,this paper demonstrates the discrepancy of faulting development and evolution across the BBB.The dynamic mechanism for the differences in faulting is also discussed by the analysis of the regional stress state.The Bozhong Depression is just situated in the transtensional zone induced by the two active strike-slip faults,namely Yingkou-Weifang and Beijing-Penglai.In this depression,the major faults which cut through the Paleogene or the Cenozoic have had higher than 10 m/Ma FARs since the Neogene,and the highest FARs have reached or exceeded 25 m/Ma during the Neotectonism.As a result,most of the petroleum has migrated along these major faults and accumulated within the Neogene.In contrast,in the other depressions of the BBB away from the Bozhong Depression,the FARs of the major faults were decreased to lower than 10 m/Ma since the Neogene,and tended to be zero during the Neotectonism.Therefore,the major faults could not serve as vertical conduits for petroleum migration,and the petroleum was entrapped in the Paleogene.Consequently,the faulting since the Neogene,especially during the Neotectonism,controlled the petroleum richness in vertical strata.展开更多
Wearable strain sensors based on flexible conductive polymer composites(FCPCs)have attracted great attention due to their applications in the fields of human–machine interaction,disease diagnostics,human motion detec...Wearable strain sensors based on flexible conductive polymer composites(FCPCs)have attracted great attention due to their applications in the fields of human–machine interaction,disease diagnostics,human motion detection,and soft robotic skin.In recent decades,FCPC‐based strain sensors with high stretchability and sensitivity,short response time,and excellent stability have been developed,which are expected to be more versatile and intelligent.Smart strain sensors are required to provide wearable comfort,such as breathability,selfcooling ability,and so forth.To adapt to the harsh environment,wearable strain sensors should also be highly adaptive to protect the skin and the sensor itself.In addition,portable power supply system,multisite sensing capability,and multifunctionality are crucial for the next generation of FCPC‐based strain sensor.展开更多
With the rapid development of smart wearable devices, flexible and biodegradable sensors are in urgent needs. In this study, ‘‘green" electrically conductive Ag nanowire (Ag NW)/cellulose nanofiber (CNF) hybrid...With the rapid development of smart wearable devices, flexible and biodegradable sensors are in urgent needs. In this study, ‘‘green" electrically conductive Ag nanowire (Ag NW)/cellulose nanofiber (CNF) hybrid nanopaper was fabricated to prepare flexible sensors using the facial solution blending and vacuum filtration technique. The amphiphilic property of cellulose is beneficial for the homogeneous dispersion of Ag NW to construct effective electrically conductive networks. Two different types of strain sensors were designed to study their applications in strain sensing. One was the tensile strain sensor where the hybrid nanopaper was sandwiched between two thermoplastic polyurethane (TPU) films through hot compression, and special micro-crack structure was constructed through the pre-strain process to enhance the sensitivity. Interestingly, typical pre-strain dependent strain sensing behavior was observed due to different crack densities constructed under different pre-strains. As a result, it exhibited an ultralow detection limit as low as 0.2%, good reproducibility under different strains and excellent stability and durability during 500 cycles (1% strain, 0.5 mm/min). The other was the bending strain sensor where the hybrid nanopaper was adhered onto TPU film, showing stable and recoverable linearly sensing behavior towards two different bending modes (tension and compression). Importantly, the bending sensor displayed great potential for human motion and physiological signal detection. Furthermore, the hybrid nanopaper also exhibited stable and reproducible negative temperature sensing behavior when it was served as a temperature sensor. This study provides a guideline for fabricating flexible and biodegradable sensors.展开更多
With the development of electronic commerce,there is a special phenomenon in rural areas of China that a lot of farmers in these areas depend on opening shops on Taobao online for a living. The products are made from ...With the development of electronic commerce,there is a special phenomenon in rural areas of China that a lot of farmers in these areas depend on opening shops on Taobao online for a living. The products are made from the village workshop,and farmers become fullyfledged network businessmen. Electronic business platform mode of " Taobao Village" is the result of integrated development of primary,secondary and tertiary industries. In this study,we take two kinds of typical Taobao villages( Dongfeng Village and Yanxia Village) as sample areas,and conduct comparative analysis of this new rural business model based on field survey data,case studies and theoretical research. We also probe into the problems in the development of Taobao villages,and set forth the recommendations for the new rural business model.展开更多
Atmospheric Oxygen(O2)is one of the dominating features that allow the earth to be a habitable planet with advanced civilization and diverse biology.However,since the late 1980 s,observational data have indicated a st...Atmospheric Oxygen(O2)is one of the dominating features that allow the earth to be a habitable planet with advanced civilization and diverse biology.However,since the late 1980 s,observational data have indicated a steady decline in O2 content on the scale of parts-per-million level.The current scientific consensus is that the decline is caused by the fossil-fuel combustion;however,few works have been done to quantitatively evaluate the response of O2 cycle under the anthropogenic impact,at both the global and regional scales.This paper manages to quantify the land O2 flux and makes the initial step to quantificationally describe the anthropogenic impacts on the global O2 budget.Our estimation reveals that the global O2 consumption has experienced an increase from 33.69±1.11 to47.63±0.80 Gt(gigaton,109 t)O2yr^-1 between 2000 and 2018,while the land production of O2(totaling 11.34±13.48 Gt O2yr^-1 averaged over the same period)increased only slightly.In 2018,the combustion of fossil-fuel and industrial activities(38.45±0.61 Gt O2yr^-1)contributed the most to consumption,followed by wildfires(4.97±0.48 Gt O2yr^-1)as well as livestock and human respiration processes(2.48±0.16 and 1.73±0.13 Gt O2yr^-1,respectively).Burning of fossil-fuel that causes large O2 fluxes occurs in East Asia,India,North America,and Europe,while wildfires that cause large fluxes in comparable magnitude are mainly distributed in central Africa.展开更多
As an important contributor to the habitability of our planet, the oxygen cycle is interconnected with the emergence and evolution of complex life and is also the basis to establish Earth system science. Investigating...As an important contributor to the habitability of our planet, the oxygen cycle is interconnected with the emergence and evolution of complex life and is also the basis to establish Earth system science. Investigating the global oxygen cycle provides valuable information on the evolution of the Earth system, the habitability of our planet in the geologic past, and the future of human life. Numerous investigations have expanded our knowledge of the oxygen cycle in the fields of geology,geochemistry, geobiology, and atmospheric science. However, these studies were conducted separately, which has led to onesided understandings of this critical scientific issue and an incomplete synthesis of the interactions between the different spheres of the Earth system. This review presents a five-sphere coupled model of the Earth system and clarifies the core position of the oxygen cycle in Earth system science. Based on previous research, this review comprehensively summarizes the evolution of the oxygen cycle in geological time, with a special focus on the Great Oxidation Event(GOE) and the mass extinctions, as well as the possible connections between the oxygen content and biological evolution. The possible links between the oxygen cycle and biodiversity in geologic history have profound implications for exploring the habitability of Earth in history and guiding the future of humanity. Since the Anthropocene, anthropogenic activities have gradually steered the Earth system away from its established trajectory and had a powerful impact on the oxygen cycle. The human-induced disturbance of the global oxygen cycle, if not controlled, could greatly reduce the habitability of our planet.展开更多
An \%S\%_dependent GFR method and a generalized conjugate gradient method are designed. Two estimated values of upper bounds for the ratio of β k to β FR k are given. The two convergence theorems are proved. The glo...An \%S\%_dependent GFR method and a generalized conjugate gradient method are designed. Two estimated values of upper bounds for the ratio of β k to β FR k are given. The two convergence theorems are proved. The global convergent properties of \%s\%_dependent GFR method are obtained adopting several choice strategies of steplength and some results in recent literature are extended.展开更多
Insights into the mechanism of hydrate nucleation are of great significance for the development of hydrate-based technologies,hydrate relevant flow assurance,and the exploration of in situ natural gas hydrates.Compare...Insights into the mechanism of hydrate nucleation are of great significance for the development of hydrate-based technologies,hydrate relevant flow assurance,and the exploration of in situ natural gas hydrates.Compared with the thermodynamics of hydrate formation,understanding the nucleation mechanism is challenging and has drawn substantial attention in recent decades.In this paper,we attempt to give a comprehensive review of the recent progress of studies of clathrate hydrate nucleation.First,the existing hypotheses on the hydrate nucleation mechanism are introduced and discussed.Then,we summarize recent experimental studies on induction time,a key parameter evaluating the velocity of the nucleation process.Subsequently,the memory effect is particularly discussed,followed by the suggestion of several promising research perspectives.展开更多
Purpose: This study aimed to evaluate the value of precise localization of nodules using pre-video-assisted thoracic surgery(VATS) Xper–CT in combination with real-time fluoroscopy-guided coil in the resection of pul...Purpose: This study aimed to evaluate the value of precise localization of nodules using pre-video-assisted thoracic surgery(VATS) Xper–CT in combination with real-time fluoroscopy-guided coil in the resection of pulmonary nodules using VATS. Materials and Methods: Precise localization of nodules using Xper-CT in combination with real-time fluoroscopy-guided coil and wedge resection using VATS were conducted on 15 patients with 17 small pulmonary nodules(diameter 0.5–1.5 cm) from April 2015 to January 2016. The value of localization was evaluated in terms of procedure time, type of coils, associated complications of localization, and VATS success rate. Results: The success rate of coil localization was found to be 100% in the primary stage(as shown by the CT scan), and the average procedure time was 30–45 min(35.6 ± 3.05 min). No deaths or major complications occurred. Minor complications included five incidents of pneumothorax(the morbidity was 29.4%, 5/17; no patient required chest tube drainage). The dislocation of coil was found in one patient. The results of pathological examination of 17 small pulmonary nodules revealed 11 primary lung cancers, 1 mesenchymal tumor, 3 nonspecific chronic inflammations, 1 hamartoma, and 1 tuberculosis. Two patients with primary lung cancer underwent lobectomy with mediastinal lymph node dissection. Conclusion: The preoperative precise localization of small pulmonary nodules using Xper-CT-guided coil is an effective and safe technique. It helps in the resection of nodules using VATS. It increases the rate of lung wedge resection with few complications and allows for proper diagnosis with a low thoracotomy conversion rate.展开更多
Polylactic acid(PLA) is one of the most suitable candidates for environmental pollution treatment because of its biodegradability which will not cause secondary pollution to the environment after application.However,t...Polylactic acid(PLA) is one of the most suitable candidates for environmental pollution treatment because of its biodegradability which will not cause secondary pollution to the environment after application.However,there is still a lack of a green and facile way to prepare PLA oil-water separation materials.In this work,a water-assisted thermally induced phase separation method for the preparation of superhydrophobic PLA oil-water separation material with honeycomb-like structures is reported.The PLA material shows great ability in application and could adsorb 27.3 times oil to its own weight.In addition,it could also be applicated as a filter with excellent efficiency(50.9 m^3 m^(-2) h^(-1)).展开更多
For most strip-like plastic injection molded parts, whose cross section size is much smaller than their length, the traditional Hele-Shaw model and three-dimensional model do not work well in the prediction of the war...For most strip-like plastic injection molded parts, whose cross section size is much smaller than their length, the traditional Hele-Shaw model and three-dimensional model do not work well in the prediction of the warpage be- cause of their special shape. A new solution was suggested in this work. The strip-like plastic part was regarded as a little-curved beam macrnscopically, and was divided into a few one-dimensional elements. On the section of each elemental node location, two-dimensional thermal finite element analysis was made to obtain the non- uniform thermal stress caused by the time difference of the solidification of the plastic melt in the mold. The stress relaxation, or equivalently, strain creep was dealt with by using a special computing model. On the bases of in-mold elastic stress, the final bending moment to the beam was obtained and the warpage was predict- ed in good a^reement with practical cases.展开更多
Silicon is a low price and high capacity ancxje material for lithium-ion batteries.The yolk-shell structure can effectively accommodate Si expansion to improve stability.However,the limited rate performance of Si anod...Silicon is a low price and high capacity ancxje material for lithium-ion batteries.The yolk-shell structure can effectively accommodate Si expansion to improve stability.However,the limited rate performance of Si anodes can't meet people's growing demand for high power density.Herein,the phosphorus-doped yolk-shell Si@C materials(P-doped Si@C)were prepared through carbon coating on P-doped Si/SiO_(x)matrix to obtain high power and stable devices.Therefore,the as-prepared P-doped Si@C electrodes delivered a rapid increase in Coulombic efficiency from 74.4%to 99.6%after only 6 cycles,high capacity retention of-95%over 800 cycles at 4 A·g^(-1),and great rate capability(510 mAh·g^(-1)at 35 A·g^(-1)).As a result,P-doped Si@C anodes paired with commercial activated carbon and LiFePO_(4)cathode to assemble lithium-ion capacitor(high power density of〜61,080 W·kg^(-1)at 20 A·g^(-1))and lithium-ion full cell(good rate performance with 68.3 mAh·g^(-1)at 5 C),respectively.This work can provide an effective way tofurther improve power density and stability for energy storage devices.展开更多
Natural gas hydrate(NGH)is a highly efficient and clean energy,with huge reserves and widespread distribution in permafrost and marine areas.Researches all over the world are committed to developing an effective explo...Natural gas hydrate(NGH)is a highly efficient and clean energy,with huge reserves and widespread distribution in permafrost and marine areas.Researches all over the world are committed to developing an effective exploring technology for NGH reservoirs.In this paper,four conventional in-situ hydrate production methods,such as depressurization,thermal stimulation,inhibitor injection and CO2 replacement,are briefly introduced.Due to the limitations of each method,there has been no significantly breakthrough in hydrate exploring technology.Inspired by the development of unconventional oil and gas fields,researchers have put forward some new hydrate production methods.We summarize the enhanced hydrate exploiting methods,such as CO2/N2–CH4 replacement,CO2/H2–CH4 replacement,hydraulic fracturing treatment,and solid exploration;and potential hydrate mining techniques,such as self-generating heat fluid injection,geothermal stimulation,the well pattern optimization of hydrate exploring.The importance of reservoir stimulation technology for hydrate exploitation is emphasized,and it is believed that hydrate reservoir modification technology is a key to open hydrate resources exploitation,and the major challenges in the process of hydrate exploitation are pointed out.The combination of multiple hydrate exploring technologies and their complementary advantages will be the development trend in the future so as to promote the process of hydrate industrialization.展开更多
Mesoporous CeMnOx composite oxides catalysts were prepared by surfactant-assisted co-precipitation method and used for the catalytic oxidation of toluene.The effect of different cerium precursors[Ce(NO3)3 and(NH4)2 Ce...Mesoporous CeMnOx composite oxides catalysts were prepared by surfactant-assisted co-precipitation method and used for the catalytic oxidation of toluene.The effect of different cerium precursors[Ce(NO3)3 and(NH4)2 Ce(NO3)6] on catalyst structure,surface properties and toluene combustion activities of mesoporous CeMnOx catalysts were investigated.The Ce(Ⅲ)MnOx catalyst prepared from Ce(NO3)3 precursor shows higher catalytic activity,with a 90% conversion temperature of 240℃,which is better than the Ce(Ⅳ)MnOx catalyst derived from[(NH4)2 Ce(NO3)6] precursor.On the basis of characterizations,it reveals that abundant surface content of Mn4+,better redox behavior and larger concentration of surface active oxygen species are responsible for the excellent catalytic performance.展开更多
基金The authors thank National Natural Science Foundation of China(51803190)National Key R&D Program of China(2019YFA0706802)financial support.
文摘The development of multifunctional and efficient electromagnetic wave absorbing materials is a challenging research hotspot.Here,the magnetized Ni flower/MXene hybrids are successfully assembled on the surface of melamine foam(MF)through electrostatic self-assembly and dip-coating adsorption process,realizing the integration of microwave absorption,infrared stealth,and flame retardant.Remarkably,the Ni/MXene-MF achieves a minimum reflection loss(RLmin)of−62.7 dB with a corresponding effective absorption bandwidth(EAB)of 6.24 GHz at 2 mm and an EAB of 6.88 GHz at 1.8 mm.Strong electromagnetic wave absorption is attributed to the three-dimensional magnetic/conductive networks,which provided excellent impedance matching,dielectric loss,magnetic loss,interface polarization,and multiple attenuations.In addition,the Ni/MXene-MF endows low density,excellent heat insulation,infrared stealth,and flame-retardant functions.This work provided a new development strategy for the design of multifunctional and efficient electromagnetic wave absorbing materials.
基金Key Research Program of Hubei Province,Grant/Award Number:2020BAA030National Nature Science Foundation of China,Grant/Award Number:U20A20249 and 21972108。
文摘Hard carbon has been regarded as the most promising anode material for sodiumion batteries(SIBs)due to its low cost,high reversible capacity,and low working potential.However,the uncertain sodium storage mechanism hinders the rational design and synthesis of high-performance hard carbon anode materials for practical SIBs.During the past decades,tremendous efforts have been put to stimulate the development of hard carbon materials.In this review,we discuss the recent progress of the study on the sodium storage mechanism of hard carbon anodes,and the effective strategies to improve their sodium storage performance have been summarized.It is anticipated that hard carbon anodes with high electrochemical properties will be inspired and fabricated for large-scale energy storage applications.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFA0803700)the National Natural Science Foundation of China(Grant Nos.91639108,81770272,and 81970425)+1 种基金the Beijing Natural Science Foundation(Grant No.7212044)the Beijing Hospital Authority Youth Program(Grant No.QML20190306)。
文摘Hepatocellular carcinoma(HCC)is the fourth leading cause of cancer-associated death worldwide.Angiogenesis,the process of formation of new blood vessels,is required for cancer cells to obtain nutrients and oxygen.HCC is a typical hypervascular solid tumor with an aberrant vascular network and angiogenesis that contribute to its growth,progression,invasion,and metastasis.Current anti-angiogenic therapies target mainly tyrosine kinases,vascular endothelial growth factor receptor(VEGFR),and plateletderived growth factor receptor(PDGFR),and are considered effective strategies for HCC,particularly advanced HCC.However,because the survival benefits conferred by these anti-angiogenic therapies are modest,new anti-angiogenic targets must be identified.Several recent studies have determined the underlying molecular mechanisms,including pro-angiogenic factors secreted by HCC cells,the tumor microenvironment,and cancer stem cells.In this review,we summarize the roles of pro-angiogenic factors;the involvement of endothelial cells,hepatic stellate cells,tumor-associated macrophages,and tumor-associated neutrophils present in the tumor microenvironment;and the regulatory influence of cancer stem cells on angiogenesis in HCC.Furthermore,we discuss some of the clinically approved anti-angiogenic therapies and potential novel therapeutic targets for angiogenesis in HCC.A better understanding of the mechanisms underlying angiogenesis may lead to the development of more optimized anti-angiogenic treatment modalities for HCC.
基金supported by grants from the "Stem Cell and Regenerative Medicine Strategic Priority Research Program of the Chinese Academy of Sciences" (Grant No. XDA01030000)the Key Research Program of the Chinese Academy of Sciences (Grant No. ZDRW-ZS-2016-2)
文摘The objective of this clinical study was to assess the safety and feasibility of the collagen scaffold, Neuro Regen scaffold, one year after scar tissue resection and implantation. Scar tissue is a physical and chemical barrier that prevents neural regeneration. However, identification of scar tissue is still a major challenge. In this study, the nerve electrophysiology method was used to distinguish scar tissue from normal neural tissue, and then different lengths of scars ranging from 0.5–4.5 cm were surgically resected in five complete chronic spinal cord injury(SCI) patients. The NeuroR egen scaffold along with autologous bone marrow mononuclear cells(BMMCs), which have been proven to promote neural regeneration and SCI recovery in animal models, were transplanted into the gap in the spinal cord following scar tissue resection. No obvious adverse effects related to scar resection or Neuro Regen scaffold transplantation were observed immediately after surgery or at the 12-month follow-up. In addition, patients showed partially autonomic nervous function improvement, and the recovery of somatosensory evoked potentials(SSEP) from the lower limbs was also detected. The results indicate that scar resection and Neuro Regen scaffold transplantation could be a promising clinical approach to treating SCI.
基金supported by the National Natural Science Foundation of China (41521004)the China University Research Talents Recruitment Program (111 project, B13045)
文摘Atmospheric oxygen （02） is the most crucial element on earth for the aerobic organisms that depend on it to release energy from carbon-based macromolecules. This is the first study to systematically analyze the global O2 budget and its changes over the past 100 years. It is found that anthropogenic fossil fuel combustion is the largest contributor to the current O2 deficit, which consumed 2.0 Gt/a in 1900 and has increased to 38.2 Gt/a by 2015. Under the Representative Concentration Pathways （RCPs） RCP8,5 scenario, approximately 100Gt （gigatonnes） of O2 would be removed from the atmosphere per year until 2100, and the O2 concentration will decrease from its current level of 20.946% to 20.825%. Human activities have caused irreversible decline of atmospheric O2. It is time to take actions to promote O2 production and reduce O2 consumption.
基金supported by the National Natural Science Foundation of China(51803191,12072325)the National Key R&D Program of China(2019YFA0706802)+2 种基金the 111 project(D18023)Key Scientific and Technological Project of Henan Province(202102210038)Major projects of Ningbo。
文摘With the rapid development of wearable intelligent devices,low-cost wearable strain sensors with high sensitivity and low detection limit are urgently demanded.Meanwhile,sensing stability of sensor in wet or corrosive environments should also be considered in practical applications.Here,superhydrophobic microcracked conductive paper-based strain sensor was fabricated by coating conductive Ti_(3)C_(2)T_(x) MXene on printing paper via dip-coating process and followed by depositing superhydrophobic candle soot layer on its surface.Owing to the ultrasensitive microcrack structure in the conductive coating layer induced by the mismatch of elastic modulus and thermal expansion coefficient between conductive coating layer and paper substrate during the drying process,the prepared paper-based strain sensor exhibited a high sensitivity(gauge factor,GF=17.4)in the strain range of 0–0.6%,ultralow detection limit(0.1%strain)and good fatigue resistance over 1000 cycles towards bending deformation.Interestingly,it was also applicable for torsion deformation detection,showing excellent torsion angle dependent,repeatable and stable sensing performances.Meanwhile,it displayed brilliant waterproof,self-cleaning and corrosion-resistant properties due to the existence of micro/nano-structured and the low surface energy candle soot layer.As a result,the prepared paper-based strain sensor can effectively monitor a series of large-scale and small-scale human motions even under water environment,showing the great promising in practical harsh outdoor environments.Importantly,it also demonstrated good applicability for spatial strain distribution detection of skin upon body movement when assembled into electronic-skin(E-skin).This study will provide great guidance for the design of next generation wearable strain sensor.
基金supported by National Natural Science Foundation of China (Grant Nos. 90914006, 41271265)National Science & Technology Specific Project (Grant No. 2011ZX05023-006-07)
文摘The Bohai Bay Basin(BBB)is the most petroliferous Cenozoic basin in the east of China.It consists of seven depressions.Each depression has been subjected to different stress states and then has experienced varying faulting processes since the Neogene,especially during the Neotectonism(from the Pliocene to the present).On the basis of the investigation of fault patterns,fault densities and fault activity rates(FARs)for each depression,this paper demonstrates the discrepancy of faulting development and evolution across the BBB.The dynamic mechanism for the differences in faulting is also discussed by the analysis of the regional stress state.The Bozhong Depression is just situated in the transtensional zone induced by the two active strike-slip faults,namely Yingkou-Weifang and Beijing-Penglai.In this depression,the major faults which cut through the Paleogene or the Cenozoic have had higher than 10 m/Ma FARs since the Neogene,and the highest FARs have reached or exceeded 25 m/Ma during the Neotectonism.As a result,most of the petroleum has migrated along these major faults and accumulated within the Neogene.In contrast,in the other depressions of the BBB away from the Bozhong Depression,the FARs of the major faults were decreased to lower than 10 m/Ma since the Neogene,and tended to be zero during the Neotectonism.Therefore,the major faults could not serve as vertical conduits for petroleum migration,and the petroleum was entrapped in the Paleogene.Consequently,the faulting since the Neogene,especially during the Neotectonism,controlled the petroleum richness in vertical strata.
基金Henan Province University Innovation Talents Support Program,Grant/Award Number:20HASTIT001National Natural Science Foundation of China,Grant/Award Numbers:51773183,U1604253,U1804133Innovation Team of Colleges and Universities in Henan Province,Grant/Award Number:20IRTSTHN002。
文摘Wearable strain sensors based on flexible conductive polymer composites(FCPCs)have attracted great attention due to their applications in the fields of human–machine interaction,disease diagnostics,human motion detection,and soft robotic skin.In recent decades,FCPC‐based strain sensors with high stretchability and sensitivity,short response time,and excellent stability have been developed,which are expected to be more versatile and intelligent.Smart strain sensors are required to provide wearable comfort,such as breathability,selfcooling ability,and so forth.To adapt to the harsh environment,wearable strain sensors should also be highly adaptive to protect the skin and the sensor itself.In addition,portable power supply system,multisite sensing capability,and multifunctionality are crucial for the next generation of FCPC‐based strain sensor.
基金supported by the National Natural Science Foundation of China(51803191)the China Postdoctoral Science Foundation(2018M642782)the 111 project(D18023)
文摘With the rapid development of smart wearable devices, flexible and biodegradable sensors are in urgent needs. In this study, ‘‘green" electrically conductive Ag nanowire (Ag NW)/cellulose nanofiber (CNF) hybrid nanopaper was fabricated to prepare flexible sensors using the facial solution blending and vacuum filtration technique. The amphiphilic property of cellulose is beneficial for the homogeneous dispersion of Ag NW to construct effective electrically conductive networks. Two different types of strain sensors were designed to study their applications in strain sensing. One was the tensile strain sensor where the hybrid nanopaper was sandwiched between two thermoplastic polyurethane (TPU) films through hot compression, and special micro-crack structure was constructed through the pre-strain process to enhance the sensitivity. Interestingly, typical pre-strain dependent strain sensing behavior was observed due to different crack densities constructed under different pre-strains. As a result, it exhibited an ultralow detection limit as low as 0.2%, good reproducibility under different strains and excellent stability and durability during 500 cycles (1% strain, 0.5 mm/min). The other was the bending strain sensor where the hybrid nanopaper was adhered onto TPU film, showing stable and recoverable linearly sensing behavior towards two different bending modes (tension and compression). Importantly, the bending sensor displayed great potential for human motion and physiological signal detection. Furthermore, the hybrid nanopaper also exhibited stable and reproducible negative temperature sensing behavior when it was served as a temperature sensor. This study provides a guideline for fabricating flexible and biodegradable sensors.
基金Supported by Student Research Training(SRT)Program of Jiangsu Province,China(201410307007Y)
文摘With the development of electronic commerce,there is a special phenomenon in rural areas of China that a lot of farmers in these areas depend on opening shops on Taobao online for a living. The products are made from the village workshop,and farmers become fullyfledged network businessmen. Electronic business platform mode of " Taobao Village" is the result of integrated development of primary,secondary and tertiary industries. In this study,we take two kinds of typical Taobao villages( Dongfeng Village and Yanxia Village) as sample areas,and conduct comparative analysis of this new rural business model based on field survey data,case studies and theoretical research. We also probe into the problems in the development of Taobao villages,and set forth the recommendations for the new rural business model.
基金Supported by the National Natural Science Foundation of China (41521004)China 111 Project (B13045)
文摘Atmospheric Oxygen(O2)is one of the dominating features that allow the earth to be a habitable planet with advanced civilization and diverse biology.However,since the late 1980 s,observational data have indicated a steady decline in O2 content on the scale of parts-per-million level.The current scientific consensus is that the decline is caused by the fossil-fuel combustion;however,few works have been done to quantitatively evaluate the response of O2 cycle under the anthropogenic impact,at both the global and regional scales.This paper manages to quantify the land O2 flux and makes the initial step to quantificationally describe the anthropogenic impacts on the global O2 budget.Our estimation reveals that the global O2 consumption has experienced an increase from 33.69±1.11 to47.63±0.80 Gt(gigaton,109 t)O2yr^-1 between 2000 and 2018,while the land production of O2(totaling 11.34±13.48 Gt O2yr^-1 averaged over the same period)increased only slightly.In 2018,the combustion of fossil-fuel and industrial activities(38.45±0.61 Gt O2yr^-1)contributed the most to consumption,followed by wildfires(4.97±0.48 Gt O2yr^-1)as well as livestock and human respiration processes(2.48±0.16 and 1.73±0.13 Gt O2yr^-1,respectively).Burning of fossil-fuel that causes large O2 fluxes occurs in East Asia,India,North America,and Europe,while wildfires that cause large fluxes in comparable magnitude are mainly distributed in central Africa.
基金supported by the National Natural Science Foundation of China (Grant No. 41888101, 41521004 & 41991231)the China University Research Talents Recruitment Program (111 Projects, Grant No. B13045)。
文摘As an important contributor to the habitability of our planet, the oxygen cycle is interconnected with the emergence and evolution of complex life and is also the basis to establish Earth system science. Investigating the global oxygen cycle provides valuable information on the evolution of the Earth system, the habitability of our planet in the geologic past, and the future of human life. Numerous investigations have expanded our knowledge of the oxygen cycle in the fields of geology,geochemistry, geobiology, and atmospheric science. However, these studies were conducted separately, which has led to onesided understandings of this critical scientific issue and an incomplete synthesis of the interactions between the different spheres of the Earth system. This review presents a five-sphere coupled model of the Earth system and clarifies the core position of the oxygen cycle in Earth system science. Based on previous research, this review comprehensively summarizes the evolution of the oxygen cycle in geological time, with a special focus on the Great Oxidation Event(GOE) and the mass extinctions, as well as the possible connections between the oxygen content and biological evolution. The possible links between the oxygen cycle and biodiversity in geologic history have profound implications for exploring the habitability of Earth in history and guiding the future of humanity. Since the Anthropocene, anthropogenic activities have gradually steered the Earth system away from its established trajectory and had a powerful impact on the oxygen cycle. The human-induced disturbance of the global oxygen cycle, if not controlled, could greatly reduce the habitability of our planet.
文摘An \%S\%_dependent GFR method and a generalized conjugate gradient method are designed. Two estimated values of upper bounds for the ratio of β k to β FR k are given. The two convergence theorems are proved. The global convergent properties of \%s\%_dependent GFR method are obtained adopting several choice strategies of steplength and some results in recent literature are extended.
基金Supported by the National Key Research and Development Program of China(2016YFC0304003,2017YFC0307302)the National Natural Science Foundation of China(21636009,51576209,21522609)the Innovative Talents Support Program for Postgraduates(BX201700288)
文摘Insights into the mechanism of hydrate nucleation are of great significance for the development of hydrate-based technologies,hydrate relevant flow assurance,and the exploration of in situ natural gas hydrates.Compared with the thermodynamics of hydrate formation,understanding the nucleation mechanism is challenging and has drawn substantial attention in recent decades.In this paper,we attempt to give a comprehensive review of the recent progress of studies of clathrate hydrate nucleation.First,the existing hypotheses on the hydrate nucleation mechanism are introduced and discussed.Then,we summarize recent experimental studies on induction time,a key parameter evaluating the velocity of the nucleation process.Subsequently,the memory effect is particularly discussed,followed by the suggestion of several promising research perspectives.
文摘Purpose: This study aimed to evaluate the value of precise localization of nodules using pre-video-assisted thoracic surgery(VATS) Xper–CT in combination with real-time fluoroscopy-guided coil in the resection of pulmonary nodules using VATS. Materials and Methods: Precise localization of nodules using Xper-CT in combination with real-time fluoroscopy-guided coil and wedge resection using VATS were conducted on 15 patients with 17 small pulmonary nodules(diameter 0.5–1.5 cm) from April 2015 to January 2016. The value of localization was evaluated in terms of procedure time, type of coils, associated complications of localization, and VATS success rate. Results: The success rate of coil localization was found to be 100% in the primary stage(as shown by the CT scan), and the average procedure time was 30–45 min(35.6 ± 3.05 min). No deaths or major complications occurred. Minor complications included five incidents of pneumothorax(the morbidity was 29.4%, 5/17; no patient required chest tube drainage). The dislocation of coil was found in one patient. The results of pathological examination of 17 small pulmonary nodules revealed 11 primary lung cancers, 1 mesenchymal tumor, 3 nonspecific chronic inflammations, 1 hamartoma, and 1 tuberculosis. Two patients with primary lung cancer underwent lobectomy with mediastinal lymph node dissection. Conclusion: The preoperative precise localization of small pulmonary nodules using Xper-CT-guided coil is an effective and safe technique. It helps in the resection of nodules using VATS. It increases the rate of lung wedge resection with few complications and allows for proper diagnosis with a low thoracotomy conversion rate.
基金National Natural Science Foundation of China(Nos.51803190,11432003,11572290)National Key Research and Development Program of China(No.2016YFB0101602)+2 种基金China Postdoctoral Science Foundation(Nos.2018M642779,2019M652573,2019T120643)International Postdoctoral Exchange Fellowship Program,University Key Research Project of Henan Province(No.18A430031)Guangdong Province Pearl River Scholar Funded Scheme(2016)for financial support。
文摘Polylactic acid(PLA) is one of the most suitable candidates for environmental pollution treatment because of its biodegradability which will not cause secondary pollution to the environment after application.However,there is still a lack of a green and facile way to prepare PLA oil-water separation materials.In this work,a water-assisted thermally induced phase separation method for the preparation of superhydrophobic PLA oil-water separation material with honeycomb-like structures is reported.The PLA material shows great ability in application and could adsorb 27.3 times oil to its own weight.In addition,it could also be applicated as a filter with excellent efficiency(50.9 m^3 m^(-2) h^(-1)).
基金Supported by the Key Program of National Natural Science Foundation of China(11432003)the Key Research Project for Henan Universities(15A430009)
文摘For most strip-like plastic injection molded parts, whose cross section size is much smaller than their length, the traditional Hele-Shaw model and three-dimensional model do not work well in the prediction of the warpage be- cause of their special shape. A new solution was suggested in this work. The strip-like plastic part was regarded as a little-curved beam macrnscopically, and was divided into a few one-dimensional elements. On the section of each elemental node location, two-dimensional thermal finite element analysis was made to obtain the non- uniform thermal stress caused by the time difference of the solidification of the plastic melt in the mold. The stress relaxation, or equivalently, strain creep was dealt with by using a special computing model. On the bases of in-mold elastic stress, the final bending moment to the beam was obtained and the warpage was predict- ed in good a^reement with practical cases.
基金Science and Technology Commission of Shanghai Municipality(Nos.20520710400,18230743400,18QA1402400)the National Natural Science Foundation of China(No.21771124)+1 种基金Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(No.SL2020MS020)SJTU-Warwick Joint Seed Fund(2019/20).
文摘Silicon is a low price and high capacity ancxje material for lithium-ion batteries.The yolk-shell structure can effectively accommodate Si expansion to improve stability.However,the limited rate performance of Si anodes can't meet people's growing demand for high power density.Herein,the phosphorus-doped yolk-shell Si@C materials(P-doped Si@C)were prepared through carbon coating on P-doped Si/SiO_(x)matrix to obtain high power and stable devices.Therefore,the as-prepared P-doped Si@C electrodes delivered a rapid increase in Coulombic efficiency from 74.4%to 99.6%after only 6 cycles,high capacity retention of-95%over 800 cycles at 4 A·g^(-1),and great rate capability(510 mAh·g^(-1)at 35 A·g^(-1)).As a result,P-doped Si@C anodes paired with commercial activated carbon and LiFePO_(4)cathode to assemble lithium-ion capacitor(high power density of〜61,080 W·kg^(-1)at 20 A·g^(-1))and lithium-ion full cell(good rate performance with 68.3 mAh·g^(-1)at 5 C),respectively.This work can provide an effective way tofurther improve power density and stability for energy storage devices.
基金Supported by the National Key Research and Development Program of China(2017YFC0307302,2016YFC0304003)the National Natural Science Foundation of China(21636009,51576209,51676207,21522609)
文摘Natural gas hydrate(NGH)is a highly efficient and clean energy,with huge reserves and widespread distribution in permafrost and marine areas.Researches all over the world are committed to developing an effective exploring technology for NGH reservoirs.In this paper,four conventional in-situ hydrate production methods,such as depressurization,thermal stimulation,inhibitor injection and CO2 replacement,are briefly introduced.Due to the limitations of each method,there has been no significantly breakthrough in hydrate exploring technology.Inspired by the development of unconventional oil and gas fields,researchers have put forward some new hydrate production methods.We summarize the enhanced hydrate exploiting methods,such as CO2/N2–CH4 replacement,CO2/H2–CH4 replacement,hydraulic fracturing treatment,and solid exploration;and potential hydrate mining techniques,such as self-generating heat fluid injection,geothermal stimulation,the well pattern optimization of hydrate exploring.The importance of reservoir stimulation technology for hydrate exploitation is emphasized,and it is believed that hydrate reservoir modification technology is a key to open hydrate resources exploitation,and the major challenges in the process of hydrate exploitation are pointed out.The combination of multiple hydrate exploring technologies and their complementary advantages will be the development trend in the future so as to promote the process of hydrate industrialization.
基金Project supported by the National Natural Science Foundation of China(21503184)the Natural Science Foundation of Jiangsu ProvinceGeneral Program(BK20171273)+1 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(18KJA610004)the Opening Project of the Jiangsu Key Laboratory for Environment Functional Materials(SJHG1806)
文摘Mesoporous CeMnOx composite oxides catalysts were prepared by surfactant-assisted co-precipitation method and used for the catalytic oxidation of toluene.The effect of different cerium precursors[Ce(NO3)3 and(NH4)2 Ce(NO3)6] on catalyst structure,surface properties and toluene combustion activities of mesoporous CeMnOx catalysts were investigated.The Ce(Ⅲ)MnOx catalyst prepared from Ce(NO3)3 precursor shows higher catalytic activity,with a 90% conversion temperature of 240℃,which is better than the Ce(Ⅳ)MnOx catalyst derived from[(NH4)2 Ce(NO3)6] precursor.On the basis of characterizations,it reveals that abundant surface content of Mn4+,better redox behavior and larger concentration of surface active oxygen species are responsible for the excellent catalytic performance.
