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A review of anode materials for sodium ion batteries
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作者 Syed Ali Riza XU Ri-gan +6 位作者 LIU Qi muhammad hassan YANG Qiang MU Dao-bin LI Li WU Feng CHEN Ren-jie 《新型炭材料(中英文)》 SCIE EI CAS CSCD 北大核心 2024年第5期743-769,共27页
Lithium-ion batteries(LIBs)are used in electric vehicles and portable smart devices,but lithium resources are dwindling and there is an increasing demand which has to be catered for.Sodium ion batteries(SIBs),which ar... Lithium-ion batteries(LIBs)are used in electric vehicles and portable smart devices,but lithium resources are dwindling and there is an increasing demand which has to be catered for.Sodium ion batteries(SIBs),which are less costly,are a promising replacement for LIBs because of the abundant natural reserves of sodium.The anode of a SIB is a necessary component of the battery but is less understood than the cathode.This review outlines the development of various types of anodes,including carbonbased,metallic and organic,which operate using different reaction mechanisms such as intercalation,alloying and conversion,and considers their challenges and prospects.Strategies for modifying their structures by doping and coating,and also modifying the solid electrolyte interface are discussed.In addition,this review also discusses the challenges encountered by the anode of SIBs and the solutions. 展开更多
关键词 Sodium ion batteries ANODE Carbon material Metallic compound ORGANIC
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微量元素Fe^(2+)、Co^(2+)、Ni^(2+)对麦秸与鸡粪混合厌氧发酵的影响 被引量:2
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作者 王文鑫 丁为民 +2 位作者 熊佳定 muhammad hassan 孙元昊 《太阳能学报》 EI CAS CSCD 北大核心 2021年第6期462-468,共7页
以麦秸与鸡粪为原料,采用批次式中温厌氧发酵方式,探究微量元素Fe^(2+)、Co^(2+)、Ni^(2+)对混合厌氧发酵的影响。实验结果表明:Fe^(2+)、Co^(2+)、Ni^(2+)最佳浓度分别为210、32、32 mg/L,当Fe^(2+)、Co^(2+)、Ni^(2+)的添加浓度在适... 以麦秸与鸡粪为原料,采用批次式中温厌氧发酵方式,探究微量元素Fe^(2+)、Co^(2+)、Ni^(2+)对混合厌氧发酵的影响。实验结果表明:Fe^(2+)、Co^(2+)、Ni^(2+)最佳浓度分别为210、32、32 mg/L,当Fe^(2+)、Co^(2+)、Ni^(2+)的添加浓度在适宜范围内时,可显著(p<0.05)提高发酵系统产CH4潜力及CODs去除率;当Fe^(2+)浓度为210 mg/L、Co^(2+)浓度为32 mg/L、Ni^(2+)浓度为32 mg/L时,其CH4累积产量分别为322.21、331.19、357.10 mL/(g VS),相比于对照组为245.35 mL/(g VS)显著(p<0.05)提高31.33%、34.99%、45.54%,CODs去除率依次为61.83%、57.01%、63.63%,提高CH4产量的排序为Ni^(2+)>Co^(2+)>Fe^(2+),Ni^(2+)对CH4累积产量的提高最明显,同时也有最高的CODs去除率,且各实验组pH值均稳定在适宜范围内,厌氧发酵稳定运行,可为麦秸与家禽粪便的沼气工程提供技术参考。 展开更多
关键词 微量元素 厌氧发酵 甲烷 麦秸 鸡粪
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E-cigarettes and arterial health:A review of the link between vaping and atherosclerosis progression
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作者 muhammad hassan Julia Vinagolu-Baur +4 位作者 Vivian Li Kelly Frasier Grace Herrick Tiffany Scotto Erica Rankin 《World Journal of Cardiology》 2024年第12期707-719,共13页
Recent studies have suggested an evolving understanding of the association be-tween vaping,specifically electronic cigarette(e-cigarette)use,and the progre-ssion of atherosclerosis,a significant contributor to cardiov... Recent studies have suggested an evolving understanding of the association be-tween vaping,specifically electronic cigarette(e-cigarette)use,and the progre-ssion of atherosclerosis,a significant contributor to cardiovascular disease.Des-pite the prevailing perception of vaping as a safer alternative to traditional toba-cco smoking,accumulating evidence suggests that the aerosols emitted by e-cigarettes contain harmful constituents that may promote endothelial dysfunction,oxidative stress,inflammation,and dyslipidemia—key mechanisms implicated in atherosclerosis pathogenesis.While past research,including experimental studies and clinical investigations,has shed light on the potential cardiovascular risks associated with vaping,gaps in knowledge persist.Future research endeavors should focus on interpreting the long-term effects of vaping on atherosclerosis development and progression,exploring the impact of different e-cigarette formu-lations and user demographics,and identifying effective strategies for mitigating the cardiovascular consequences of vaping.By identifying and addressing these research gaps,we can enhance our understanding of the cardiovascular implica-tions of vaping and inform evidence-based interventions and policies to safe-guard public health.Core Tip:E-cigarette use has been linked to various cardiovascular risks,including the progression of atherosclerosis.Despite the perception of vaping as a safer alternative to smoking,evidence suggests that e-cigarette aerosols contain harmful substances that contribute to endothelial dysfunction,oxidative stress,inflammation,and dyslipidemia.These mechanisms are crucial in the development and progression of atherosclerosis.This review explores multiple facets of e-cigarettes and arterial health,focusing on the connection between vaping and atherosclerosis progression.It presents up-to-date evidence on pathophysiology and significant clinical implications,the impact of various constituents,and discusses contemporary public health strategies. 展开更多
关键词 E-cigarettes Vaping ATHEROSCLEROSIS Cardiovascular disease DYSLIPIDEMIA Oxidative stress Nicotine
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Improving Growth Performance of Jatropha curcas by Inducing Polyploidy through Colchicine Treatment
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作者 Syed Amir Manzoor Asim Riaz +11 位作者 Tanzeela Zafar muhammad hassan Hafiz muhammad Imran Umar Javed hassan Waseem Alam Saleh muhammad Mudassir Mahmood Hamza Sohail Tanveer Aslam Feehan hassan Fahim Abbas muhammad Faseeh Iqbal 《American Journal of Plant Sciences》 2016年第6期769-772,共4页
This study was planned to assess genetic variation in Jatropha curcas as affected by colchichine treatments. During the experiment, seeds of Jatropha curcas were collected from mature and healthy Jatropha plants and w... This study was planned to assess genetic variation in Jatropha curcas as affected by colchichine treatments. During the experiment, seeds of Jatropha curcas were collected from mature and healthy Jatropha plants and were soaked in different concentrations of colchicines. The second treatment was that of time of soaking (seeds were soaked in different concentrations for different time durations). The results clearly revealed that by increasing the concentration of colchicine treatment, parameters like stomatal density, and size of the guard cells were reduced. 展开更多
关键词 JATROPHA POLYPLOIDY COLCHICINE BIOFUEL
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Gene Action Studies in the Inheritance of Economic Traits in Diallel Cross of Lentil (Lens culinaris Medik)
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作者 Fahim Abbas Asim Riaz +10 位作者 Tanzeela Zafar muhammad hassan Hafiz muhammad Imran Umar Javed hassan Waseem Alam Saleh muhammad Mudassir Mahmood Hamza Sohail Usman Ali Tiwana muhammad Tayyab Iqbal muhammad Bilal 《American Journal of Plant Sciences》 2016年第6期756-768,共13页
The present study was conducted in 4 × 4 half diallel cross fashion using the genotypes named as NL-2002, NL-2006, Punjab Masoor-2009 and Markaz-2009 for the evaluation of gene action in the inheritance of econom... The present study was conducted in 4 × 4 half diallel cross fashion using the genotypes named as NL-2002, NL-2006, Punjab Masoor-2009 and Markaz-2009 for the evaluation of gene action in the inheritance of economic traits of lentil by following the Griffing (1956) Method of analysis. Minirap 13.1 Copyright<sup>&copy;</sup> 2000, Minitab inc. Method II, Model I was used for the analysis and gene action was computed by variance component analysis using Mixed Model with GLM (general linear model) procedure. The F<sub>1</sub> direct crosses along with the parental genotypes were then evaluated by framing the experiment in RCBD in 3 replications. The data were recorded for the characters which are under the study are, plant height (cm), number of primary branches, number of secondary branches, number of pods per plant, number of seed per pod, seed yield per plant, biomass (gram), 100 seeds weight (gram), harvest index (%), yield per plant. The simple ANOVA for all the characters revealed that difference among genotypes was highly significant. As significant differences were present between the genotypes, it permitted subsequent analysis of the data. The Combining Ability (CA) results showed that value of variance for GCA (General Combining Ability) was significantly higher than that of those of the values of variance of SCA (Specific Combining Ability). Hence current results clearly depicted the role of additive type of gene action governing the characters under study. 展开更多
关键词 LENTIL DIALLEL Gene Action Studies
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热过氧化氢预处理对花生秸秆酶解的影响 被引量:3
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作者 熊佳定 丁为民 +3 位作者 王文鑫 muhammad hassan 孙元昊 李志伟 《太阳能学报》 EI CAS CSCD 北大核心 2018年第9期2569-2575,共7页
以花生秸秆为原料,通过单因素试验探究热H2O2预处理对花生秸秆酶解的影响,结果表明所有试验组均显著(p〈0.05)可提高酶解还原糖产量,进一步设计正交试验对预处理条件进行优化,结果表明:100℃,2h,6%H2O2可作为最优预处理条件... 以花生秸秆为原料,通过单因素试验探究热H2O2预处理对花生秸秆酶解的影响,结果表明所有试验组均显著(p〈0.05)可提高酶解还原糖产量,进一步设计正交试验对预处理条件进行优化,结果表明:100℃,2h,6%H2O2可作为最优预处理条件,在该预处理条件下酶解还原糖产率相比于未处理秸秆,提高154.56%。分别对预处理前后花生秸秆成分、化学特性以及物理结构进行测定,并分析热H2O2能有效提高花生秸秆酶解效率的原因。 展开更多
关键词 过氧化氢 热处理 酶解 结构特征 花生秸秆
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基于BP神经网络的农机化发展水平影响因素研究 被引量:6
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作者 吐尔逊.买买提 米斯卡力.居马瓦依 +1 位作者 张学军 muhammad hassan 《农机化研究》 北大核心 2018年第8期21-25,31,共6页
为了明确各因素对农业机械化发展水平的影响程度,基于误差反向传播神经网络(Back propagation neural network,BPNN)和平均影响值(Mean impact value,MIV)方法建立了影响因素量化BPNN-MIV模型。以新疆1 4地州2 0 0 1-2 0 1 5年农机化发... 为了明确各因素对农业机械化发展水平的影响程度,基于误差反向传播神经网络(Back propagation neural network,BPNN)和平均影响值(Mean impact value,MIV)方法建立了影响因素量化BPNN-MIV模型。以新疆1 4地州2 0 0 1-2 0 1 5年农机化发展影响因素作为网络输入,农业机械化发展水平作为网络输出,量化了各因素MIV。结果表明:农业机械化发展水平各一级指标对发展水平的影响强度的顺序为综合保障能力、农业机械化程度、综合效益水平。所得出的结论与新疆农机化发展实际较为接近,表明BPNN-MIV方法在量化属性影响程度方面有较大的优势。 展开更多
关键词 农业机械化发展水平 神经网络 平均影响值
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Ginkgolide B promotes the proliferation and differentiation of neural stem cells following cerebral ischemia/reperfusion injury,both in vivo and in vitro 被引量:22
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作者 Pei-Dong Zheng Rajneesh Mungur +3 位作者 Heng-Jun Zhou muhammad hassan Sheng-Nan Jiang Jie-Sheng Zheng 《Neural Regeneration Research》 SCIE CAS CSCD 2018年第7期1204-1211,共8页
Neural stem cells have great potential for the development of novel therapies for nervous system diseases.However,the proliferation of endogenous neural stem cells following brain ischemia is insufficient for central ... Neural stem cells have great potential for the development of novel therapies for nervous system diseases.However,the proliferation of endogenous neural stem cells following brain ischemia is insufficient for central nervous system self-repair.Ginkgolide B has a robust neuroprotective effect.In this study,we investigated the cell and molecular mechanisms underlying the neuroprotective effect of ginkgolide B on focal cerebral ischemia/reperfusion injury in vitro and in vivo.Neural stem cells were treated with 20,40 and 60 mg/L ginkgolide B in vitro.Immunofluorescence staining was used to assess cellular expression of neuron-specific enolase,glial fibrillary acid protein and suppressor of cytokine signaling 2.After treatment with 40 and 60 mg/L ginkgolide B,cells were large,with long processes.Moreover,the proportions of neuron-specific enolase-,glial fibrillary acid protein-and suppressor of cytokine signaling 2-positive cells increased.A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion.Six hours after ischemia,ginkgolide B(20 mg/kg) was intraperitoneally injected,once a day.Zea Longa's method was used to assess neurological function.Immunohistochemistry was performed to evaluate the proportion of nestin-,neuron-specific enolase-and glial fibrillary acid protein-positive cells.Real-time quantitative polymerase chain reaction was used to measure m RNA expression of brain-derived neurotrophic factor and epidermal growth factor.Western blot assay was used to analyze the expression levels of brain-derived neurotrophic factor and suppressor of cytokine signaling 2.Ginkgolide B decreased the neurological deficit score,increased the proportion of nestin-,neuron-specific enolase-and glial fibrillary acid protein-positive cells,increased the m RNA expression of brain-derived neurotrophic factor and epidermal growth factor,and increased the expression levels of brain-derived neurotrophic factor and suppressor of cytokine signaling 2 in the ischemic penumbra.Together,the in vivo and in vitro findings suggest that ginkgolide B improves neurological function by promoting the proliferation and differentiation of neural stem cells in rats with cerebral ischemia/reperfusion injury. 展开更多
关键词 nerve regeneration brain-derived neurotrophic factor epidermal growth factor suppressor of cytokine signaling 2 neuron-specific enolase glial fibrillary acid protein nestin bromodeoxyuridine neurological function middle cerebral artery occlusion astrocytes neural regeneration
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The Effects of a Backward Bifurcation on a Continuous Time Markov Chain Model for the Transmission Dynamics of Single Strain Dengue Virus 被引量:1
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作者 Adnan Khan muhammad hassan Mudassar Imran 《Applied Mathematics》 2013年第4期663-674,共12页
Global incidence of dengue, a vector-borne tropical disease, has seen a dramatic increase with several major outbreaks in the past few decades. We formulate and analyze a stochastic epidemic model for the transmission... Global incidence of dengue, a vector-borne tropical disease, has seen a dramatic increase with several major outbreaks in the past few decades. We formulate and analyze a stochastic epidemic model for the transmission dynamics of a single strain of dengue virus. The stochastic model is constructed using a continuous time Markov chain (CTMC) and is based on an existing deterministic model that suggests the existence of a backward bifurcation for some values of the model parameters. The dynamics of the stochastic model are explored through numerical simulations in this region of bistability. The mean of each random variable is numerically estimated and these are compared to the dynamics of the deterministic model. It is observed that the stochastic model also predicts the co-existence of a locally asymptotically stable disease-free equilibrium along with a locally stable endemic equilibrium. This co-existence of equilibria is important from a public health perspective because it implies that dengue can persist in populations even if the value of the basic reproduction number is less than unity. 展开更多
关键词 EPIDEMIOLOGY DENGUE FEVER BACKWARD BIFURCATION Stochastic Model
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Role of Clonal Integration among Different Environmental Conditions (A Review) 被引量:1
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作者 Wajahat Husain Jaafry Dezhi Li +1 位作者 Syeda Amber Fatima muhammad hassan 《Natural Science》 2016年第11期475-486,共12页
Most of the ecosystems are dominated by clonal species. The most unique feature of clonal plants is their capability for clonal integration (translocation of vital resources among connected ramets), implying that inte... Most of the ecosystems are dominated by clonal species. The most unique feature of clonal plants is their capability for clonal integration (translocation of vital resources among connected ramets), implying that integration may play an essential role in their success. However, a general effect of clonal integration on plant performance is lacking. We conducted a text review on the effects of clonal integration on different habitats and species. Overall, clonal integration increased performance of clonal plants in different habitats. However clonal integration has also some limitations under stressful environments. Benefits of clonal integration may lack somehow when environmental stress increases. But connected ramets placed in unfavorable patches benefited more from integration compared to severed ramet placed in nutrient rich patches. Climate change and temperature increase have positive effects on biomass of clonal species. 展开更多
关键词 Clonal Integration HABITATS Clonal Plants
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多孔碳包覆氧化硅的制备及电化学性能研究
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作者 梁道伟 丁旭丽 +1 位作者 赵洪达 muhammad hassan 《江苏科技大学学报(自然科学版)》 CAS 北大核心 2022年第1期39-46,共8页
二氧化硅(SiO_(2))作为锂离子电池负极材料时理论比容量可达1965 mA·h·g^(-1),其储量丰富、价格低廉,是下一代锂离子电池负极材料的有力竞争者.文中选取多孔碳(Pc)包覆SiO_(2)(Diatomite)复合材料(SiO_(2)@Pc)作为锂离子电池... 二氧化硅(SiO_(2))作为锂离子电池负极材料时理论比容量可达1965 mA·h·g^(-1),其储量丰富、价格低廉,是下一代锂离子电池负极材料的有力竞争者.文中选取多孔碳(Pc)包覆SiO_(2)(Diatomite)复合材料(SiO_(2)@Pc)作为锂离子电池负极材料,研究了不同SiO_(2)@Pc复合比例对电池首次库伦效率及循环性能的影响.与未包覆的SiO_(2)相比(首效29.9%),SiO_(2)@Pc为1∶2时首次库伦效率可以提高到45%,其循环稳定性明显提高,在100圈后容量保持较高的稳定状态.通过XPS和TG等表征分析确定了SiO_(2)@Pc复合物中各组分的化学形态和百分含量,通过电化学阻抗谱及不同扫描速率下的循环伏安曲线拟合,结果表明:Pc与SiO_(2)恰当比例的复合可以提高SiO_(2)@Pc材料中的Li^(+)的扩散能力;有利于推动SiO_(2)作为锂离子电池负极材料的应用,为低成本高比能的锂离子电池负极材料的研究提供了新的思路. 展开更多
关键词 二氧化硅 多孔碳 首次库伦效率 负极材料 锂离子电池
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Organic geochemistry and source rock potential assessment of Late Paleocene Patala Formation in Margalla Hill Range,North Pakistan
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作者 Shams M.Kamran WANG Pujun +1 位作者 Nasar Khan muhammad hassan 《Global Geology》 2021年第4期213-225,共13页
Black shales of the Paleocene Patala Formation are proven source rocks for conventional hydrocarbons in southern Potwar Basin of Pakistan and are assumed to be effective source rocks towards north in the Margalla Hill... Black shales of the Paleocene Patala Formation are proven source rocks for conventional hydrocarbons in southern Potwar Basin of Pakistan and are assumed to be effective source rocks towards north in the Margalla Hill Range of Pakistan.In this regard,the current study focuses on source rock geochemistry of the Paleocene Patala Formation to assess its source rock potential,organic matter types and thermal maturity levels in the Margalla Hill Range of North Pakistan.Source rock generative potential,kerogen types and thermal maturation of the analysed rock samples were unraveled by using Rock-Eval pyrolysis T_(max),TOC(total organic carbon)and vitrinite reflectance(R_(0))analyses.TOC analysis coupled with S_(2) yield revealed poor to fair source rock quality encountered within the formation.The pyrolysis T_(max) vs Hydrogen Index(HI),showed mostly Type Ⅲ kerogen dominated by thermally immature to mature organic matter.The HI and genetic potential is low and revealed poor hydrocarbon generation potential of the formation.The S_(1) vs TOC plots confirm the indigenous nature of the hydrocarbons hosted by Patala Formation.The vitrinite reflectance outcomes indicated immature to mature source rock beds lying in dry gas zone.The HI and OI signatures and abundance of Type Ⅲ kerogen are indicating dominance of terrestrial organic matter within the formation.Overall,the investigated Patala Formation exposed at the studied section of Margalla Hill Range,Pakistan acts as a poor source rock unit for liquid hydrocarbon generation but holds prospects for dry gas generation in the study area. 展开更多
关键词 Patala Formation organic geochemistry thermal maturity Margalla Hill Range North Pakistan eastern Tethys
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Exploring the first occurrence of Scincomorpha lizard from Nenjiang Formation(lower Campanian)of Jilin,Northeast China:a follow-up study
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作者 muhammad hassan WU Wenhao YANG Jinyue 《Global Geology》 2023年第4期199-210,共12页
In a region where lizard fossils are rare,this study explores a groundbreaking discovery of squamate lizard materials from the upper part of Nenjiang Formation(early Campanian)in Jilin Province,Northeast China.Despite... In a region where lizard fossils are rare,this study explores a groundbreaking discovery of squamate lizard materials from the upper part of Nenjiang Formation(early Campanian)in Jilin Province,Northeast China.Despite the fragmentary nature of the dentaries,they exhibit distinct tooth morphological characteristics of squamate lizards,suggesting insectivorous and omnivorous diets for these small reptiles.This finding not only represents a significant addition to the squamate lizard fossil records from the Late Cre-taceous in Northeast China but also contributes to our understanding of the paleogeographic distribution of squamate lizards.Furthermore,it sheds new light on the terrestrial vertebrate fauna of the Cretaceous Songliao Basin. 展开更多
关键词 squamates Late Cretaceous Nenjiang Formation Songliao Basin
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Determination of water content in corn stover silage using near-infrared spectroscopy 被引量:6
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作者 Maoqun Zhang Chao Zhao +4 位作者 Qianjun Shao Zidong Yang Xuefen Zhang Xiaofeng Xu muhammad hassan 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2019年第6期143-148,共6页
The aim of this study was to evaluate the feasibility of utilizing near-infrared spectroscopy to determine the water content of corn stover silage across a wide range.The water contents of 208 samples were measured,an... The aim of this study was to evaluate the feasibility of utilizing near-infrared spectroscopy to determine the water content of corn stover silage across a wide range.The water contents of 208 samples were measured,and their corresponding near-infrared spectra were simultaneously collected.The effects of different preprocessing methods,such as derivation,standard normal variety(SNV),multiplicative scatter correction(MSC),and non-preprocessing methods for the obtained near-infrared spectra on the performance of calibration models were compared.The calibration models were established by modified partial least squares(MPLS)regression.The results showed that the calibration model developed from the successive preprocessing of MSC and first-order derivation(1-D)achieved the optimal performance.The correlation coefficients of the calibration and validation subset were 0.974 and 0.949,respectively,and the standard errors of the calibration and cross validation were 4.249% and 4.256%,respectively.External validation was performed on 60 samples.The correlation coefficient between the measured and predicted values of the calibration model was 0.973 and the prediction model’s relative percent deviation was 4.317.This indicated that the mathematical model of near-infrared spectroscopy predicted the water content in corn stover silage with high accuracy.The study showed that the near-infrared spectroscopy technology can be used for rapid and non-destructive testing across a wide range of water contents in the corn stover silage. 展开更多
关键词 near-infrared spectroscopy WATER non-destructive measurement corn stover silage
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Heavy metals in a typical city-river-reservoir system of East China:Multi-phase distribution,microbial response and ecological risk 被引量:3
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作者 Jun Yang Mingrui Zhou +3 位作者 Kaifeng Yu Karina Yew-Hoong Gin muhammad hassan Yiliang He 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2022年第2期343-354,共12页
The rapid construction of artificial reservoirs in metropolises has promoted the emergence of city-river-reservoir systems worldwide.This study investigated the environmental behaviors and risks of heavy metals in the... The rapid construction of artificial reservoirs in metropolises has promoted the emergence of city-river-reservoir systems worldwide.This study investigated the environmental behaviors and risks of heavy metals in the aquatic environment of a typical system composed of main watersheds in Suzhou and Jinze Reservoir in Shanghai.Results shown that Mn,Zn and Cu were the dominant metals detected in multiple phases.Cd,Mn and Zn were mainly presented in exchangeable fraction and exhibited high bioavailability.Great proportion and high mobility of metals were found in suspended particulate matter(SPM),suggesting that SPM can greatly affect metal multi-phase distribution process.Spatially,city system(Ci S)exhibited more serious metal pollution and higher ecological risk than river system(Ri S)and reservoir system(Re S)owing to the diverse emission sources.Ci S and Re S were regarded as critical pollution source and sink,respectively,while Ri S was a vital transportation aisle.Microbial community in sediments exhibited evident spatial variation and obviously modified by exchangeable metals and nutrients.In particular,Bacteroidetes and Firmicutes presented significant positive correlations with most exchangeable metals.Risk assessment implied that As,Sb and Ni in water may pose potential carcinogenic risk to human health.Nevertheless,Re S was in a fairly safe state.Hg was the main risk contributor in SPM,while Cu,Zn,Ni and Sb showed moderate risk in sediments.Overall,Hg,Sb and Ci S were screened out as priority metals and system,respectively.More attention should be paid to these priority issues to promote the sustainable development of the watershed. 展开更多
关键词 Heavy metal MULTI-PHASE Chemical fraction City-river-reservoir system Microbial community
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Estimating the basic reproduction number for single-strain dengue fever epidemics 被引量:3
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作者 Adnan Khan muhammad hassan Mudassar Imran 《Infectious Diseases of Poverty》 SCIE 2014年第1期100-116,共17页
Background:Dengue,an infectious tropical disease,has recently emerged as one of the most important mosquito-borne viral diseases in the world.We perform a retrospective analysis of the 2011 dengue fever epidemic in Pa... Background:Dengue,an infectious tropical disease,has recently emerged as one of the most important mosquito-borne viral diseases in the world.We perform a retrospective analysis of the 2011 dengue fever epidemic in Pakistan in order to assess the transmissibility of the disease.We obtain estimates of the basic reproduction number R0 from epidemic data using different methodologies applied to different epidemic models in order to evaluate the robustness of our estimate.Results:We first estimate model parameters by fitting a deterministic ODE vector-host model for the transmission dynamics of single-strain dengue to the epidemic data,using both a basic ordinary least squares(OLS)as well as a generalized least squares(GLS)scheme.Moreover,we perform the same analysis for a direct-transmission ODE model,thereby allowing us to compare our results across different models.In addition,we formulate a direct-transmission stochastic model for the transmission dynamics of dengue and obtain parameter estimates for the stochastic model using Markov chain Monte Carlo(MCMC)methods.In each of the cases we have considered,the estimate for the basic reproduction number R0 is initially greater than unity leading to an epidemic outbreak.However,control measures implemented several weeks after the initial outbreak successfully reduce R0 to less than unity,thus resulting in disease elimination.Furthermore,it is observed that there is strong agreement in our estimates for the pre-control value of R0,both across different methodologies as well across different models.However,there are also significant differences between our estimates for the post-control value of the basic reproduction number across the two different models.Conclusion:In conclusion,we have obtained robust estimates for the value of the basic reproduction number R0 associated with the 2011 dengue fever epidemic before the implementation of public health control measures.Furthermore,we have shown that there is close agreement between our estimates for the post-control value of R0 across the different methodologies.Nevertheless,there are also significant differences between the estimates for the post-control value of R0 across the two different models. 展开更多
关键词 EPIDEMIOLOGY Dengue fever Statistical inference Stochastic model Markov chain Monte Carlo
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Stability and protection of nanowire devices in air 被引量:1
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作者 Zhen He muhammad hassan +6 位作者 Huan-Xin Ju Rui Wang Jin-Long Wang Jia-Fu Chen Jun-Fa Zhu Jian-Wei Liu Shu-Hong Yu 《Nano Research》 SCIE EI CAS CSCD 2018年第6期3353-3361,共9页
Nanowire devices have attracted considerable attention because of their unique structure and novel properties, and have opened up significant development opportunities. However, not many studies have focused on their ... Nanowire devices have attracted considerable attention because of their unique structure and novel properties, and have opened up significant development opportunities. However, not many studies have focused on their stability and durability under practical conditions, which limits the rapid development of real applications. Herein, we systematically investigate three different treatments, polymer coating, inert atmosphere protection, and thickness-induced self-protection, to protect the tellurium nanowire devices from oxidation when exposed to open air. The degree of oxidation was monitored by examining changes in the valence states of tellurium element and in the morphology of the nanowires~ After the protective treatments, the tellurium nanowire devices showed improved stability and remained stable even after 800 days of storage. This work highlights the importance of investigating the stability of nanowire devices, especially for their practical applications. 展开更多
关键词 STABILITY PROTECTION TELLURIUM NANOWIRES nanowire devices assembly
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Oxygen/Sulfur Atom Exchange Copolymerization of Carbon Disulfide and Propylene Oxide by a Highly Effective Heterogeneous Berlin Green Catalyst
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作者 Munir Ullah KHAN Safir Ullah KHAN +6 位作者 CAO Xiaohan muhammad USMAN muhammad Naeem SHAH Abdul GHAFFAR muhammad hassan ZHANG Chengjian ZHANG Xinghong 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2023年第5期790-796,共7页
In this study,we report that Berlin Green(FeFe-BG)framework exhibits superior performance in the catalytic coupling of carbon disulfide(CS_(2))and propylene oxide(PO)to generate a random copolymer containing thioether... In this study,we report that Berlin Green(FeFe-BG)framework exhibits superior performance in the catalytic coupling of carbon disulfide(CS_(2))and propylene oxide(PO)to generate a random copolymer containing thioether,propylene monothiocarbonate and ether units.Oxygen and sulfur atom exchange was detected in polymeric and cyclic thiocarbonate byproducts and utilized to modulate the copolymerization of CS_(2)and propylene oxide.The coupling of PO and CS_(2)was selective for copolymer formation under various reaction conditions.^(1)H and^(13)C NMR spectroscopy determined two distinct polymer linkages and two cyclic byproducts.Copolymer number average molecular weights ranged from 6.4 kg/mol to 10.5 kg/mol,with a comparatively low polydispersity of 1.3-1.7.The CS_(2)/PO molar feed ratio had a significant impact on the O/S exchange process;the ratio of cyclic thiocarbonate byproducts could be efficiently regulated by tuning the CS_(2)molar feed ratio. 展开更多
关键词 Carbon disulfide COPOLYMERIZATION Prussian Blue analogue Heterogeneous catalysis Berlin Green
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