Wireless sensor networks (WSNs) offer an attractive solution to many environmental,security,and process monitoring problems.However,one barrier to their fuller adoption is the need to supply electrical power over exte...Wireless sensor networks (WSNs) offer an attractive solution to many environmental,security,and process monitoring problems.However,one barrier to their fuller adoption is the need to supply electrical power over extended periods of time without the need for dedicated wiring.Energy harvesting provides a potential solution to this problem in many applications.This paper reviews the characteristics and energy requirements of typical sensor network nodes,assesses a range of potential ambient energy sources,and outlines the characteristics of a wide range of energy conversion devices.It then proposes a method to compare these diverse sources and conversion mechanisms in terms of their normalised power density.展开更多
An enormous amount of long non-coding RNAs（lnc RNAs） transcribed from eukaryotic genome are important regulators in different aspects of cellular events. Cytoplasm is the residence and the site of action for many ln...An enormous amount of long non-coding RNAs（lnc RNAs） transcribed from eukaryotic genome are important regulators in different aspects of cellular events. Cytoplasm is the residence and the site of action for many lncRNAs. The cytoplasmic lncRNAs play indispensable roles with multiple molecular mechanisms in animal and human cells. In this review, we mainly talk about functions and the underlying mechanisms of lncRNAs in the cytoplasm. We highlight relatively well-studied examples of cytoplasmic lncRNAs for their roles in modulating mRNA stability,regulating m RNA translation, serving as competing endogenous RNAs, functioning as precursors of microRNAs, and mediating protein modifications. We also elaborate the perspectives of cytoplasmic lncRNA studies.展开更多
Volatile organic compounds(VOCs)released from the waste treatment facilities have become a significant issue because they are not only causing odor nuisance but may also hazard to human health.Non-thermal plasma(NTP)t...Volatile organic compounds(VOCs)released from the waste treatment facilities have become a significant issue because they are not only causing odor nuisance but may also hazard to human health.Non-thermal plasma(NTP)technologies are newly developed methods and became a research trend in recent years regarding the removal of VOCs from the air stream.Due to its unique characteristics,such as rapid response at room temperature,bulk homogenized volume,high reaction efficiency,dielectric barrier discharge(DBD)plasma technology is considered one of the most promising techniques of NTP.This paper reviews recent progress of DBD plasma technology for abatement of VOCs.The principle of plasma generation in DBD and its configurations(electrode,discharge gap,dielectric barrier material,etc.)are discussed in details.Based on previously published literature,attention has been paid on the effect of DBD configuration on the removal of VOCs.Effect of various process parameters such as initial concentration,gas feeding rate,oxygen content and input power on VOCs removal are also considered.Moreover,the role of catalysis and inhibitors in VOCs removal by DBD system are presented.Finally,a modified configuration of the DBD reactor,i.e.double dielectric barrier discharge(DDBD)for the abatement of VOCs is discussed.It was suggested that the DDBD plasma reactor could be used for higher conversion efficiency as well as for avoiding solid residue deposition on the electrode.These depositions can interfere with the performance of the reactor.展开更多
Metal halide perovskites are crystalline materials originally developed out of scientific curiosity. They have shown great potential as active materials in optoelectronic applications. In the last 6 years, their certi...Metal halide perovskites are crystalline materials originally developed out of scientific curiosity. They have shown great potential as active materials in optoelectronic applications. In the last 6 years, their certified photovoltaic efficiencies have reached 22.1%. Compared to bulk halide perovskites, low-dimensional ones exhibited novel physical properties. The photoluminescence quantum yields of perovskite quantum dots are close to 100%. The external quantum efficiencies and current efficiencies of perovskite quantum dot light-emitting diodes have reached 8% and 43 cd A^(-1),respectively, and their nanowire lasers show ultralow-threshold room-temperature lasing with emission tunability and ease of synthesis. Perovskite nanowire photodetectors reached a responsivity of 10 A W^(-1)and a specific normalized detectivity of the order of 10^(12 )Jones. Different from most reported reviews focusing on photovoltaic applications, we summarize the rapid progress in the study of low-dimensional perovskite materials, as well as their promising applications in optoelectronic devices. In particular, we review the wide tunability of fabrication methods and the state-of-the-art research outputs of low-dimensional perovskite optoelectronic devices. Finally, the anticipated challenges and potential for this exciting research are proposed.展开更多
Sweet and sour are the most important taste of blueberries,and they are produced by sugar and acid,respectively.Their contributions to the taste depend not only on the levels of sugar and acid,but also on the types an...Sweet and sour are the most important taste of blueberries,and they are produced by sugar and acid,respectively.Their contributions to the taste depend not only on the levels of sugar and acid,but also on the types and relative proportions of sugar and acid.Therefore,it is very important to evaluate the composition and levels of sugar and acid in blueberries.Regional differences and variety diversity also affect the sugar and acid characteristics of fruits.Therefore,this study selected two main producing regions in northern China(Weihai and Yingkou)to examine the sugar and acid characteristics of 11 common blueberry cultivars.The indexes measured included soluble sugars,organic acids,soluble solid content and titratable acidity.The results showed that glucose and fructose were the major sugars,and citric acid and quinic acid were the major organic acids.Correlation analysis showed that glucose,fructose,and sucrose were positively correlated with total sugar content;the citric acid content was positively correlated with the titratable acidity and total organic acids.Titratable acidity,glucose,fructose,sucrose,total sugar content,citric acid,shikimic acid and total acid content of the blueberries varied significantly between regions(P<0.05).In general,compared with Weihai blueberries,Yingkou blueberries had higher sugar content and lower acid content.The results of this study may provide useful references for the evaluation of sweet and sour flavors and cultivar selection of blueberries.展开更多
Background High temperature stress at peak flowering stage of cotton is a major hindrance for crop potential.This study aimed to increase genetic divergence regarding heat tolerance in newly developed cultivars and hy...Background High temperature stress at peak flowering stage of cotton is a major hindrance for crop potential.This study aimed to increase genetic divergence regarding heat tolerance in newly developed cultivars and hybrids.Fifty cotton genotypes and 40 F1(hybrids)were tested under field conditions following the treatments,viz.,high temperature stress and control at peak flowering stage in August and October under April and June sowing,respectively.Results The mean squares revealed significant differences among genotypes,treatments,genotype×treatment for relative cell injury,chlorophyll contents,canopy temperature,boll retention and seed cotton yield per plant.The genetic diversity among 50 genotypes was analyzed through cluster analysis and heat susceptibility index(HSI).The heat tolerant genotypes including FH-Noor,NIAB-545,FH-466,FH-Lalazar,FH-458,NIAB-878,IR-NIBGE-8,Weal-AGShahkar,and heat sensitive,i.e.,CIM-602,Silky-3,FH-326,SLH-12 and FH-442 were hybridized in line×tester fashion to produce F1 populations.The breeding materials’populations(40 F1)revealed higher specific combining ability variances along with dominance variances,decided the non-additive type gene action for all the traits.The best general combining ability effects for most of the traits were displayed by the lines,i.e.,FH-Lalazar,NIAB-878 along with testers FH-326 and Silky-3.Specific combining ability effects and better-parent heterosis were showed by the crosses,viz.,FH-Lalazar×Silky-3,FH-Lalazar×FH-326,NIAB-878×Silky-3,and NIAB-878×FH-326 for seed cotton yield and yield contributing traits under high temperature stress.Conclusion Heterosis breeding should be carried out in the presence of non-additive type gene action for all the studied traits.The best combiner parents with better-parent heterosis may be used in crossing program to develop high yielding cultivars,and hybrids for high temperature stress tolerance.展开更多
2,6-Dimethylnaphthalene(2,6-DMN) is a commercially important chemical for the production of polyethylenenaphthalate and polybutylene naphthalate. However, its complex synthesis procedure and high production cost signi...2,6-Dimethylnaphthalene(2,6-DMN) is a commercially important chemical for the production of polyethylenenaphthalate and polybutylene naphthalate. However, its complex synthesis procedure and high production cost significantly reduce the use of 2,6-DMN. In this study, the synthesis of 2,6-DMN was investigated with methylation of 2-methylnaphthalene(2-MN) over metal-loaded beta zeolite catalysts including beta zeolite, Cu-impregnated beta zeolite and Zr-impregnated beta zeolite. The experiments were performed in a fixed-bed reactor at atmospheric pressure under a nitrogen atmosphere. The reactor was operated at a temperature range of 400–500 °C and varying weight hourly space velocity between 1 and 3 h^(-1).The results demonstrated that 2,6-DMN can be synthesized by methylation of 2-MN over beta type zeolite catalysts.Besides 2,6-DMN, the product stream also contained other DMN isomers such as 2,7-DMN, 1,3-DMN, 1,2-DMN and 2,3-DMN. The activity and selectivity of beta zeolite catalyst were remarkably enhanced by Zr impregnation, whereas Cu modification of beta zeolite catalyst had an insignificant effect on its selectivity. The highest conversion of 2-MN reached81%, the highest ratio of 2,6-DMN/2,7-DMN reached 2.6 and the highest selectivity of 2,6-DMN was found to be 20% by using Zr-modified beta zeolite catalyst.展开更多
Mechanical shear resistance of wheat grain is a significant concern for the designers and researchers related to the design of threshing,handling and processing machinery of the field crops.The grain mechanical proper...Mechanical shear resistance of wheat grain is a significant concern for the designers and researchers related to the design of threshing,handling and processing machinery of the field crops.The grain mechanical properties directly affect the machine geometry and its operational parameters.The present study was carried out to determine the shear resistance of five wheat varieties(Locally names;TD-02,Sindhu-1105,Benazir,China and SKD-118)influenced by moisture content(16.7%,18.7%and 19.5%)and loading rate(3 mm/s,6 mm/s and 9 mm/s).However,some physio-dimensional properties(length,width,thickness,slenderness ratio,surface area and sphericity)were obtained at different moisture contents.The results showed that the shear resistance reduced by increasing the moisture content and loading rate.The average shear resistance decreased from 10.45 N to 3.74 N for 3-9 mm/s loading rate at moisture content of 16.7%to 19.5%.Thus,the maximum correlation(r=0.905)of shear resistance obtained at 16.7%,whereas minimum correlation(r=0.692)obtained at 19.5%.The shear resistance of wheat grain was highly significant(p<0.05)at 9 mm/s for 19.5%.Shear resistance decreased with an increase in the moisture content in the grain whereas deformation is increasing with the increase of moisture content.However,the maximum bulk density of wheat grain obtained at 19.5%for SKD-118,while the minimum obtained at 16.7%for TD-02.It is recommended that the design and modification of wheat grain processing equipment should be executed on the physio-mechanical properties of grain varieties.展开更多
The effect of cold rolling and post-rolling heat treatment on the microstructural and electrochemical properties of the 316L stainless steel was investigated.Two-pass and four-pass cold-rolled stainless steel specimen...The effect of cold rolling and post-rolling heat treatment on the microstructural and electrochemical properties of the 316L stainless steel was investigated.Two-pass and four-pass cold-rolled stainless steel specimens were heat-treated by annealing at 900℃followed by quenching in water.During the cold rolling,the microstructure of the as-received specimen transformed from austenite to strain-inducedα′-martensite due to significant plastic deformation that also resulted in significant grain elongation(i.e.,~33%and 223%increases in the grain elongation after two and four rolling passes,respectively).The hardness of the heat-treated as-received specimen decreased from HV 190 to 146 due to the recovery and recrystallization of the austenite grain structure.The cyclic polarization scans of the as-rolled and heat-treated specimens were obtained in 0.9wt%NaCl solution.The pitting potential of the four-pass rolled specimen was significantly increased from 322.3 to 930.5 mV after post-rolling heat treatment.The beneficial effect of the heat treatment process was evident from~10-times-lower corrosion current density and two-orders-of-magnitude-lower passive current density of the heat-treated specimens compared with those of the as-rolled specimens.Similarly,appreciably lower corrosion rate(3.302×10^(−4)mm/a)and higher pitting resistance(1115.5 mV)were exhibited by the postrolled heat-treated specimens compared with the as-rolled 316L stainless steel specimens.展开更多
Hypophosphataemia is defined as low level of phosphate in the blood (normal range 0.8 - 1.4 mmol/l), which can be drug-induced such as uniphyline. We present a case of elderly female patient with known chronic obstruc...Hypophosphataemia is defined as low level of phosphate in the blood (normal range 0.8 - 1.4 mmol/l), which can be drug-induced such as uniphyline. We present a case of elderly female patient with known chronic obstructive pulmonary disease, admitted with acute respiratory failure and low serum phosphate level, her clinical signs and serum phosphate level did not improve with conventional therapy and intravenous phosphate replacement, until her recently commenced uniphyline was discontinued. This highlights the importance of awareness amongst the clinicians about this rare but potential side effect of uniphyline. We suggest monitoring phosphate levels in patients admitted with acute respiratory failure especially those on extended bronchodilator therapy.展开更多
Cerebellopontine angle (CPA) lesions account for up to 10% of all intracranial tumors. Most CPA tumors are benign, but can cause nerve damage or compress the surrounding structures if left untreated. The typical prese...Cerebellopontine angle (CPA) lesions account for up to 10% of all intracranial tumors. Most CPA tumors are benign, but can cause nerve damage or compress the surrounding structures if left untreated. The typical presentation is with adult-onset sensorineural hearing loss or non-pulsatile tinnitus. In some patients, this goes unnoticed, and presentation is delayed until the lesion is much larger and presents with symptoms related to mass effect. We present the case study of 63 years old gentleman, who had suspected left CPA lesion on CT head done few years ago for dizziness and left-sided facial numbness. MRI could not be done at that time due to his MRI incompatible pacemaker leading to delay in his management eventually causing loss of patient to the follow up. He later developed progressive difficulty in walking which was initially attributed to as secondary to vasovagal syncope and postural hypotension. He eventually presented to us with intractable nausea and vomiting, worsening headache and ataxia. He had an urgent CT head which showed significant growth in the lesion with compression of the surrounding structures and obstructive hydrocephalus. He was given steroids which improved his nausea and vomiting, followed by undergoing surgery in regional center leading to significant improvement in his gait within few days of surgery. He unfortunately continued to have a degree of ataxia and facial numbness. This case illustrates a rare presentation of CPA tumor with symptoms of nausea and vomiting as a result of mass effect of the growing tumor. In addition, this review also shows the importance of regularly following up the patients with suspected CPA lesions on initial scans which will help with identifying the increase in size of lesion promptly and potentially preventing advanced complications of CPA tumors. We suggest regular monitoring of these patients to timely manage the lesion and avoid the potential life-threatening complications.展开更多
The present article deals with thermally stratified stagnation-point flow saturated in porous medium on surface of variable thickness along with more convincing and reliable surface condition termed as melting heat tr...The present article deals with thermally stratified stagnation-point flow saturated in porous medium on surface of variable thickness along with more convincing and reliable surface condition termed as melting heat transfer.Homogeneous–heterogeneous reaction and radiative effects have been further taken into account to reconnoiterproperties of heat transfer.Melting heat transfer and phenomenon of homogeneous–heterogeneous reaction have engrossed widespread utilization in purification of metals,welding process,electroslag melting,biochemical systems,catalysis and several industrial developments.Suitable transformations are utilized to attain a scheme of ordinary differential equations possessing exceedingly nonlinear nature.Homotopic process is employed to develop convergent solutions of the resulting problem.Discussion regarding velocity,thermal field and concentration distribution for several involved parameters is pivotal part.Graphical behaviors of skin friction coefficient and Nusselt number are also portrayed.Concentration of the reactants is found to depreciate as a result of strength of both heterogeneous and homogeneous reaction parameters.With existence of melting phenomenon,declining attitude of fluid temperature is observed for higher radiation parameter.展开更多
Wheat(Triticum aestivum L.)exhibits a greater capacity for cadmium(Cd)absorption compared to other cereal crops,leading to elevated daily Cd intake,and posing a significant threat to public health.For the mitigation of...Wheat(Triticum aestivum L.)exhibits a greater capacity for cadmium(Cd)absorption compared to other cereal crops,leading to elevated daily Cd intake,and posing a significant threat to public health.For the mitigation of Cd stress in sustainable and environmentally friendly way,a pot study was designed by using exogenous application of various biostimulants,i.e.,Nigella sativa and Ocimum sanctum extracts:0%,10%,and 20%in combination with the chelating agent ethylenediaminetetraacetic acid(EDTA)using 0 and 5 mg kg^(-1) under various levels of Cd stress(i.e.,0,5,10,and 15 mg kg^(-1) soil).Results revealed that Cd stress significantly reduced the seed emergence,growth,root,and allometric characters and yield-related parameters of wheat crops.The most observable reduc-tion was documented in wheat plants exposed to a higher Cd concentration(15 mg kg^(-1)),followed by the lower Cd level(control).The combined application of bio-stimulants and EDTA minimized the negative impacts of Cd stress.The highest increase in seedling emergence(5.44%),leaf area(50.60%),number of tillers(31.02%),grain yield per plant(24.28%),biological yield(13.97%),and decrease in Cd levels in grains(40%)was noticed where 20%foliar application of N.sativa and 10%of O.sanctum biostimulants were done using 5 mg kg^(-1) of soil-applied EDTA.This intervention demonstrated a notable reduction in Cd-induced negative effects,highlighting the potential of these substances in promoting sustainable wheat cultivation in contaminated environments.Moreover,it is an eco-friendly and approachable method at thefield level able to ensure food safety.展开更多
文摘Wireless sensor networks (WSNs) offer an attractive solution to many environmental,security,and process monitoring problems.However,one barrier to their fuller adoption is the need to supply electrical power over extended periods of time without the need for dedicated wiring.Energy harvesting provides a potential solution to this problem in many applications.This paper reviews the characteristics and energy requirements of typical sensor network nodes,assesses a range of potential ambient energy sources,and outlines the characteristics of a wide range of energy conversion devices.It then proposes a method to compare these diverse sources and conversion mechanisms in terms of their normalised power density.
基金supported by the National Basic Research Program of China (973 Program Grant No. 2015CB943000)+1 种基金the National Natural Science Foundation of China (Grant Nos. 91519333 and 31471225)the Fundamental Research Funds for the Central Universities (Grant No. WK2070000034)
文摘An enormous amount of long non-coding RNAs（lnc RNAs） transcribed from eukaryotic genome are important regulators in different aspects of cellular events. Cytoplasm is the residence and the site of action for many lncRNAs. The cytoplasmic lncRNAs play indispensable roles with multiple molecular mechanisms in animal and human cells. In this review, we mainly talk about functions and the underlying mechanisms of lncRNAs in the cytoplasm. We highlight relatively well-studied examples of cytoplasmic lncRNAs for their roles in modulating mRNA stability,regulating m RNA translation, serving as competing endogenous RNAs, functioning as precursors of microRNAs, and mediating protein modifications. We also elaborate the perspectives of cytoplasmic lncRNA studies.
文摘Volatile organic compounds(VOCs)released from the waste treatment facilities have become a significant issue because they are not only causing odor nuisance but may also hazard to human health.Non-thermal plasma(NTP)technologies are newly developed methods and became a research trend in recent years regarding the removal of VOCs from the air stream.Due to its unique characteristics,such as rapid response at room temperature,bulk homogenized volume,high reaction efficiency,dielectric barrier discharge(DBD)plasma technology is considered one of the most promising techniques of NTP.This paper reviews recent progress of DBD plasma technology for abatement of VOCs.The principle of plasma generation in DBD and its configurations(electrode,discharge gap,dielectric barrier material,etc.)are discussed in details.Based on previously published literature,attention has been paid on the effect of DBD configuration on the removal of VOCs.Effect of various process parameters such as initial concentration,gas feeding rate,oxygen content and input power on VOCs removal are also considered.Moreover,the role of catalysis and inhibitors in VOCs removal by DBD system are presented.Finally,a modified configuration of the DBD reactor,i.e.double dielectric barrier discharge(DDBD)for the abatement of VOCs is discussed.It was suggested that the DDBD plasma reactor could be used for higher conversion efficiency as well as for avoiding solid residue deposition on the electrode.These depositions can interfere with the performance of the reactor.
基金supported by the Doctoral Program of Higher Education(20130142120075)the Fundamental Research Funds for the Central Universities(HUST:2016YXMS032)National Key Research and Development Program of China(Grant No.2016YFB0700702)
文摘Metal halide perovskites are crystalline materials originally developed out of scientific curiosity. They have shown great potential as active materials in optoelectronic applications. In the last 6 years, their certified photovoltaic efficiencies have reached 22.1%. Compared to bulk halide perovskites, low-dimensional ones exhibited novel physical properties. The photoluminescence quantum yields of perovskite quantum dots are close to 100%. The external quantum efficiencies and current efficiencies of perovskite quantum dot light-emitting diodes have reached 8% and 43 cd A^(-1),respectively, and their nanowire lasers show ultralow-threshold room-temperature lasing with emission tunability and ease of synthesis. Perovskite nanowire photodetectors reached a responsivity of 10 A W^(-1)and a specific normalized detectivity of the order of 10^(12 )Jones. Different from most reported reviews focusing on photovoltaic applications, we summarize the rapid progress in the study of low-dimensional perovskite materials, as well as their promising applications in optoelectronic devices. In particular, we review the wide tunability of fabrication methods and the state-of-the-art research outputs of low-dimensional perovskite optoelectronic devices. Finally, the anticipated challenges and potential for this exciting research are proposed.
基金This research was supported by theAgricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2018-RIP-O7).
文摘Sweet and sour are the most important taste of blueberries,and they are produced by sugar and acid,respectively.Their contributions to the taste depend not only on the levels of sugar and acid,but also on the types and relative proportions of sugar and acid.Therefore,it is very important to evaluate the composition and levels of sugar and acid in blueberries.Regional differences and variety diversity also affect the sugar and acid characteristics of fruits.Therefore,this study selected two main producing regions in northern China(Weihai and Yingkou)to examine the sugar and acid characteristics of 11 common blueberry cultivars.The indexes measured included soluble sugars,organic acids,soluble solid content and titratable acidity.The results showed that glucose and fructose were the major sugars,and citric acid and quinic acid were the major organic acids.Correlation analysis showed that glucose,fructose,and sucrose were positively correlated with total sugar content;the citric acid content was positively correlated with the titratable acidity and total organic acids.Titratable acidity,glucose,fructose,sucrose,total sugar content,citric acid,shikimic acid and total acid content of the blueberries varied significantly between regions(P<0.05).In general,compared with Weihai blueberries,Yingkou blueberries had higher sugar content and lower acid content.The results of this study may provide useful references for the evaluation of sweet and sour flavors and cultivar selection of blueberries.
基金Higher Education Commission of Pakistan for funding the experiments
文摘Background High temperature stress at peak flowering stage of cotton is a major hindrance for crop potential.This study aimed to increase genetic divergence regarding heat tolerance in newly developed cultivars and hybrids.Fifty cotton genotypes and 40 F1(hybrids)were tested under field conditions following the treatments,viz.,high temperature stress and control at peak flowering stage in August and October under April and June sowing,respectively.Results The mean squares revealed significant differences among genotypes,treatments,genotype×treatment for relative cell injury,chlorophyll contents,canopy temperature,boll retention and seed cotton yield per plant.The genetic diversity among 50 genotypes was analyzed through cluster analysis and heat susceptibility index(HSI).The heat tolerant genotypes including FH-Noor,NIAB-545,FH-466,FH-Lalazar,FH-458,NIAB-878,IR-NIBGE-8,Weal-AGShahkar,and heat sensitive,i.e.,CIM-602,Silky-3,FH-326,SLH-12 and FH-442 were hybridized in line×tester fashion to produce F1 populations.The breeding materials’populations(40 F1)revealed higher specific combining ability variances along with dominance variances,decided the non-additive type gene action for all the traits.The best general combining ability effects for most of the traits were displayed by the lines,i.e.,FH-Lalazar,NIAB-878 along with testers FH-326 and Silky-3.Specific combining ability effects and better-parent heterosis were showed by the crosses,viz.,FH-Lalazar×Silky-3,FH-Lalazar×FH-326,NIAB-878×Silky-3,and NIAB-878×FH-326 for seed cotton yield and yield contributing traits under high temperature stress.Conclusion Heterosis breeding should be carried out in the presence of non-additive type gene action for all the studied traits.The best combiner parents with better-parent heterosis may be used in crossing program to develop high yielding cultivars,and hybrids for high temperature stress tolerance.
基金supported by The Scientific and Technological Research Council of Turkey [TüBITAK Project No.112M297]
文摘2,6-Dimethylnaphthalene(2,6-DMN) is a commercially important chemical for the production of polyethylenenaphthalate and polybutylene naphthalate. However, its complex synthesis procedure and high production cost significantly reduce the use of 2,6-DMN. In this study, the synthesis of 2,6-DMN was investigated with methylation of 2-methylnaphthalene(2-MN) over metal-loaded beta zeolite catalysts including beta zeolite, Cu-impregnated beta zeolite and Zr-impregnated beta zeolite. The experiments were performed in a fixed-bed reactor at atmospheric pressure under a nitrogen atmosphere. The reactor was operated at a temperature range of 400–500 °C and varying weight hourly space velocity between 1 and 3 h^(-1).The results demonstrated that 2,6-DMN can be synthesized by methylation of 2-MN over beta type zeolite catalysts.Besides 2,6-DMN, the product stream also contained other DMN isomers such as 2,7-DMN, 1,3-DMN, 1,2-DMN and 2,3-DMN. The activity and selectivity of beta zeolite catalyst were remarkably enhanced by Zr impregnation, whereas Cu modification of beta zeolite catalyst had an insignificant effect on its selectivity. The highest conversion of 2-MN reached81%, the highest ratio of 2,6-DMN/2,7-DMN reached 2.6 and the highest selectivity of 2,6-DMN was found to be 20% by using Zr-modified beta zeolite catalyst.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0603)the National Natural Science Foundation of China(41971153 and 42171086)+1 种基金the Science and Technology Department of Tibet Program(XZ202301ZY0016G)the Chinese Committee on International Centre for Integrated Mountain Development(CNICIMOD)。
基金This work is financially supported by the National Key Research of Development Program of China(Grant No.2016YFD0702004)the National Natural Science Foundation of China(Grant No.51605196)+3 种基金the Jiangsu Key Research and Development Program of China(Grant No.BE2016356)the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20160532)the National Science Foundation for Post-doctoral Scientists of China(Grant No.2016M591788)Natural Science Foundation of the Higher Education Institutions of Jiangsu Province,China(Grant No.17KJB416003).
文摘Mechanical shear resistance of wheat grain is a significant concern for the designers and researchers related to the design of threshing,handling and processing machinery of the field crops.The grain mechanical properties directly affect the machine geometry and its operational parameters.The present study was carried out to determine the shear resistance of five wheat varieties(Locally names;TD-02,Sindhu-1105,Benazir,China and SKD-118)influenced by moisture content(16.7%,18.7%and 19.5%)and loading rate(3 mm/s,6 mm/s and 9 mm/s).However,some physio-dimensional properties(length,width,thickness,slenderness ratio,surface area and sphericity)were obtained at different moisture contents.The results showed that the shear resistance reduced by increasing the moisture content and loading rate.The average shear resistance decreased from 10.45 N to 3.74 N for 3-9 mm/s loading rate at moisture content of 16.7%to 19.5%.Thus,the maximum correlation(r=0.905)of shear resistance obtained at 16.7%,whereas minimum correlation(r=0.692)obtained at 19.5%.The shear resistance of wheat grain was highly significant(p<0.05)at 9 mm/s for 19.5%.Shear resistance decreased with an increase in the moisture content in the grain whereas deformation is increasing with the increase of moisture content.However,the maximum bulk density of wheat grain obtained at 19.5%for SKD-118,while the minimum obtained at 16.7%for TD-02.It is recommended that the design and modification of wheat grain processing equipment should be executed on the physio-mechanical properties of grain varieties.
文摘The effect of cold rolling and post-rolling heat treatment on the microstructural and electrochemical properties of the 316L stainless steel was investigated.Two-pass and four-pass cold-rolled stainless steel specimens were heat-treated by annealing at 900℃followed by quenching in water.During the cold rolling,the microstructure of the as-received specimen transformed from austenite to strain-inducedα′-martensite due to significant plastic deformation that also resulted in significant grain elongation(i.e.,~33%and 223%increases in the grain elongation after two and four rolling passes,respectively).The hardness of the heat-treated as-received specimen decreased from HV 190 to 146 due to the recovery and recrystallization of the austenite grain structure.The cyclic polarization scans of the as-rolled and heat-treated specimens were obtained in 0.9wt%NaCl solution.The pitting potential of the four-pass rolled specimen was significantly increased from 322.3 to 930.5 mV after post-rolling heat treatment.The beneficial effect of the heat treatment process was evident from~10-times-lower corrosion current density and two-orders-of-magnitude-lower passive current density of the heat-treated specimens compared with those of the as-rolled specimens.Similarly,appreciably lower corrosion rate(3.302×10^(−4)mm/a)and higher pitting resistance(1115.5 mV)were exhibited by the postrolled heat-treated specimens compared with the as-rolled 316L stainless steel specimens.
文摘Hypophosphataemia is defined as low level of phosphate in the blood (normal range 0.8 - 1.4 mmol/l), which can be drug-induced such as uniphyline. We present a case of elderly female patient with known chronic obstructive pulmonary disease, admitted with acute respiratory failure and low serum phosphate level, her clinical signs and serum phosphate level did not improve with conventional therapy and intravenous phosphate replacement, until her recently commenced uniphyline was discontinued. This highlights the importance of awareness amongst the clinicians about this rare but potential side effect of uniphyline. We suggest monitoring phosphate levels in patients admitted with acute respiratory failure especially those on extended bronchodilator therapy.
文摘Cerebellopontine angle (CPA) lesions account for up to 10% of all intracranial tumors. Most CPA tumors are benign, but can cause nerve damage or compress the surrounding structures if left untreated. The typical presentation is with adult-onset sensorineural hearing loss or non-pulsatile tinnitus. In some patients, this goes unnoticed, and presentation is delayed until the lesion is much larger and presents with symptoms related to mass effect. We present the case study of 63 years old gentleman, who had suspected left CPA lesion on CT head done few years ago for dizziness and left-sided facial numbness. MRI could not be done at that time due to his MRI incompatible pacemaker leading to delay in his management eventually causing loss of patient to the follow up. He later developed progressive difficulty in walking which was initially attributed to as secondary to vasovagal syncope and postural hypotension. He eventually presented to us with intractable nausea and vomiting, worsening headache and ataxia. He had an urgent CT head which showed significant growth in the lesion with compression of the surrounding structures and obstructive hydrocephalus. He was given steroids which improved his nausea and vomiting, followed by undergoing surgery in regional center leading to significant improvement in his gait within few days of surgery. He unfortunately continued to have a degree of ataxia and facial numbness. This case illustrates a rare presentation of CPA tumor with symptoms of nausea and vomiting as a result of mass effect of the growing tumor. In addition, this review also shows the importance of regularly following up the patients with suspected CPA lesions on initial scans which will help with identifying the increase in size of lesion promptly and potentially preventing advanced complications of CPA tumors. We suggest regular monitoring of these patients to timely manage the lesion and avoid the potential life-threatening complications.
文摘The present article deals with thermally stratified stagnation-point flow saturated in porous medium on surface of variable thickness along with more convincing and reliable surface condition termed as melting heat transfer.Homogeneous–heterogeneous reaction and radiative effects have been further taken into account to reconnoiterproperties of heat transfer.Melting heat transfer and phenomenon of homogeneous–heterogeneous reaction have engrossed widespread utilization in purification of metals,welding process,electroslag melting,biochemical systems,catalysis and several industrial developments.Suitable transformations are utilized to attain a scheme of ordinary differential equations possessing exceedingly nonlinear nature.Homotopic process is employed to develop convergent solutions of the resulting problem.Discussion regarding velocity,thermal field and concentration distribution for several involved parameters is pivotal part.Graphical behaviors of skin friction coefficient and Nusselt number are also portrayed.Concentration of the reactants is found to depreciate as a result of strength of both heterogeneous and homogeneous reaction parameters.With existence of melting phenomenon,declining attitude of fluid temperature is observed for higher radiation parameter.
基金The authors would like to extend their sincere appreciation to the Researchers Supporting Project Number(RSP2024R356),King Saud University,Riyadh,Saudi Arabia.
文摘Wheat(Triticum aestivum L.)exhibits a greater capacity for cadmium(Cd)absorption compared to other cereal crops,leading to elevated daily Cd intake,and posing a significant threat to public health.For the mitigation of Cd stress in sustainable and environmentally friendly way,a pot study was designed by using exogenous application of various biostimulants,i.e.,Nigella sativa and Ocimum sanctum extracts:0%,10%,and 20%in combination with the chelating agent ethylenediaminetetraacetic acid(EDTA)using 0 and 5 mg kg^(-1) under various levels of Cd stress(i.e.,0,5,10,and 15 mg kg^(-1) soil).Results revealed that Cd stress significantly reduced the seed emergence,growth,root,and allometric characters and yield-related parameters of wheat crops.The most observable reduc-tion was documented in wheat plants exposed to a higher Cd concentration(15 mg kg^(-1)),followed by the lower Cd level(control).The combined application of bio-stimulants and EDTA minimized the negative impacts of Cd stress.The highest increase in seedling emergence(5.44%),leaf area(50.60%),number of tillers(31.02%),grain yield per plant(24.28%),biological yield(13.97%),and decrease in Cd levels in grains(40%)was noticed where 20%foliar application of N.sativa and 10%of O.sanctum biostimulants were done using 5 mg kg^(-1) of soil-applied EDTA.This intervention demonstrated a notable reduction in Cd-induced negative effects,highlighting the potential of these substances in promoting sustainable wheat cultivation in contaminated environments.Moreover,it is an eco-friendly and approachable method at thefield level able to ensure food safety.
