Aluminum-selenium(Al-Se)batteries,which possess a high theoretical specific capacity of 1357 mA h g^(-1),represent a promising energy storage technology.However,they suffer from significant attenuation of capacity and...Aluminum-selenium(Al-Se)batteries,which possess a high theoretical specific capacity of 1357 mA h g^(-1),represent a promising energy storage technology.However,they suffer from significant attenuation of capacity and low cycle life due to the shuttle effect.To mitigate the shuttle effect induced by soluble selenium chloroaluminate compound that tends to migrate towards the negative electrode,a quasi-solid-state Al-Se battery was fabricated through the synthesis of a multi-aperture structure quasisolid-state electrolyte(MOF@GPE)based on metal-organic framework(MOF)material and gel-polymer electrolyte(GPE).The high ionic conductivity(1.13×10^(-3)S cm^(-1))of MOF@GPE at room temperature,coupled with its wide electrochemical stability window(2.45 V),can facilitate ion transport kinetics and enhance the electrochemical performance of Al-Se batteries.The MOF@GPE-based quasi-solidstate Al-Se batteries exhibit outstanding long-life cycling stability,delivering a high specific discharge capacity of 548 mA h g^(-1)with a maintained discharge specific capacity of 345 mA h g^(-1)after 500 cycles at a current density of 200 mA g^(-1).The stable ion transmission and high ion transport kinetics in MOF@GPE can be attributed to the stable structure and permeable channel of MOF,which effectively captures the soluble selenium chloroaluminate compound and further restrains the shuttle effect,resulting in improved cycling performance.展开更多
Plants typically exhibit the purple phenomenon as a result of an increase in flavonoids and anthocyanins.A new tea germplasm'P113'was recently selected from Camellia tachangensis,which is purple in tender shoo...Plants typically exhibit the purple phenomenon as a result of an increase in flavonoids and anthocyanins.A new tea germplasm'P113'was recently selected from Camellia tachangensis,which is purple in tender shoots.In the present study,integrated transcriptome and metabolome were used to analyze the flavonoid metabolite components and the genes involved in flavonoid biosynthesis in'P113'.A total of 86 flavonoid metabolites were identified,including 70 significantly differential metabolites(p<0.05)and they were enriched to the three metabolic pathways of ko00941,ko00942 and ko00944 through KEGG pathway analysis.A total of 136 flavonoid involved genes were obtained from transcriptomic study,of which 53 were significantly differentially expressed in developmental shoots.The correlation between metabolite profiling and transcriptome,transcriptome and protein interactions suggested that transcription factor MYB12 and glycosyltransferase UGT78D2 had a good facilitation on purple tender shoots.The metabolic pathways and potential genes that underlie the coloration of the shoots in'P113'are clarified in this study.It also lays the groundwork for identifying potential genes involved in color variation and offers a theoretical framework for the creation and use of distinctive genetic resources and the breeding of new cultivars.展开更多
目的了解上海市男男性行为人群(men who have sex with men,MSM)亚硝酸盐吸入剂(rush popper)使用情况及其相关因素,为制定和实施MSM相关的干预措施提供理论依据。方法于2019—2020年实施横断面调查,对招募的MSM进行面对面的无记名调查...目的了解上海市男男性行为人群(men who have sex with men,MSM)亚硝酸盐吸入剂(rush popper)使用情况及其相关因素,为制定和实施MSM相关的干预措施提供理论依据。方法于2019—2020年实施横断面调查,对招募的MSM进行面对面的无记名调查。收集调查对象的年龄、民族、文化程度、婚姻状况等社会人口学信息,最近6个月的rush popper使用情况及性行为特征,并进行HIV和梅毒血清学检测。采用χ^(2)经验或Fisher确切概率法比较rush popper使用和非使用者人口学和性行为特征的差异。多因素Logistic回归分析影响rush popper使用的因素。结果共调查479名MSM,最近半年rush popper使用率为45.3%(217/479),HIV阳性率为13.4%,梅毒阳性率为6.1%。多因素Logistic分析显示,与rush popper使用相关的因素包括:月收入6000~9999元(aOR=2.379,95%CI:1.056~5.356);外地户籍(aOR=1.968,95%CI:1.267~3.050);通过网络或交友软件寻找男性性伴(aOR=2.583,95%CI:1.067~6.254);同性性行为方式为肛交(aOR=3.426,95%CI:1.486~7.895);肛交角色为被动方(aOR=1.879,95%CI:1.092~3.232);半年内与7人及以上发生性行为(aOR=3.161,95%CI:1.532~6.519);与配偶发生性行为时从未使用安全套(aOR=2.747,95%CI:1.101~6.856);有时使用安全套(aOR=2.846,95%CI:1.171~6.917);HIV阳性(aOR=2.310,95%CI:1.247~4.279)。结论上海市MSM rush popper使用率较高,其使用与导致HIV感染的高危性行为有较强的相关性。制定有针对性的干预措施,减少rush popper在MSM中的使用对于防治艾滋病具有重要的意义。展开更多
在水温22.8～30.1℃下,2017年4月15日—10月15日,分3次测定体质量分别为20.10～47.03 g、30.61～70.22 g和34.52～88.57 g 3组2龄黄喉拟水龟的背甲长(x_1)、背甲宽(x_2)、背甲高(x_3)、腹甲长(x_4)、腹甲宽(x_5)、甲桥长(x_6)、喉盾宽(x...在水温22.8～30.1℃下,2017年4月15日—10月15日,分3次测定体质量分别为20.10～47.03 g、30.61～70.22 g和34.52～88.57 g 3组2龄黄喉拟水龟的背甲长(x_1)、背甲宽(x_2)、背甲高(x_3)、腹甲长(x_4)、腹甲宽(x_5)、甲桥长(x_6)、喉盾宽(x_7)、肱盾宽(x_8)、胸盾宽(x_9)、股盾宽(x_(10))、肛盾宽(x_(11))、喉盾缝长(x_(12))、肱盾缝长(x_(13))、胸盾缝长(x_(14))、腹盾缝长(x_(15))、股盾缝长(x_(16))、肛盾缝长(x_(17))18个形态性状,每个体质量组测定340只,通过相关分析、通径分析和回归分析,研究了形态性状对体质量(y)的影响。试验结果表明,20.10～47.03 g、30.61～70.22 g、34.52～88.57 g 3组中个体对体质量直接作用较大的形态性状分别为背甲长和背甲高、腹甲长、背甲长和喉盾缝长。利用逐步回归分析方法,以体质量为依变量(y),形态性状为自变量(x_1～x_(17)),建立了3组黄喉拟水龟的最优多元线性回归方程:y_1=-48.209+7.557x_(10)+5.994x_3+4.553x_1,y_2=-26.398+9.326x_4+9.510x_3,y_3=-46.413+11.098x_1+40.039x_(12)。该研究结果为黄喉拟水龟良种选育提供了重要参考指标。展开更多
An optimization method is introduced to design the aerodynamic parameters of a dual-spin twodimensional guided projectile with the canards for trajectory correction. The nose guidance component contains two pairs of c...An optimization method is introduced to design the aerodynamic parameters of a dual-spin twodimensional guided projectile with the canards for trajectory correction. The nose guidance component contains two pairs of canards which can provide lift and despin with the projectile for stability. The optimal design algorithm is developed to decide the profiles both of the steering and spinning canards,and their deflection angles are also simulated to meet the needs of trajectory correction capabilities.Finally, the aerodynamic efficiency of the specific canards is discussed according to the CFD simulations.Results that obtained here can be further applied to the exterior ballistics design.展开更多
Surface-functionalized nitrogen/carbon co-doped polymorphic TiO_(2) phase junction nanoparticles uniformly distributed in porous carbon matrix were synthesized by a simple one-step pyrolysis of titanium based metal-or...Surface-functionalized nitrogen/carbon co-doped polymorphic TiO_(2) phase junction nanoparticles uniformly distributed in porous carbon matrix were synthesized by a simple one-step pyrolysis of titanium based metal-organic framework(MOF),NH_(2)-MIL^(-1)25(Ti) at 700℃ under water vapour atmosphere.Introducing water vapour during the pyrolysis of NH_(2)-MIL^(-1)25(Ti) not only functionalizes the derived porous carbon matrix with carboxyl groups but also forms additional oxygen-rich N like interstitial/intraband states lying above the valence band of TiO2 along with the self-doped carbo n,which further narrows the energy band gaps of polymorphic TiO2 nanoparticles that enhance photocatalytic charge transfer efficiency.Without co-catalyst,sample N-C-TiO2/CArW demonstrates H_(2) evolution activity of 426 μmol gcat-1h^(-1),which remarkably outperforms commercial TiO_(2)(P-25) and N-C-TiO_(2)/CAr with a 5-fold and 3-fold H_(2) generation,respectively.This study clearly shows that water vapour atmosphere during the pyrolysis increases the hydrophilicity of the Ti-MOF derived composites by functionalizing porous carbon matrix with carboxylic groups,as well as enhancing the electrical conductivity and charge transfer efficiency due to the formation of additional localized oxygen-rich N like interstitial/intraband states.This work also demonstrates that by optimizing the anatase-rutile phase composition of the TiO2 polymorphs,tuning the energy band gaps by N/C co-doping and functionalizing the porous carbon matrix in the N-C-TiO2/C nanocomposites,the photocatalytic H_(2) generation activity can be further enhanced.展开更多
Cloud computing has been exploited in managing large-scale IoT systems.IoT cloud servers usually handle a large number of requests from various IoT devices.Due to the fluctuant and heavy workload,the servers require t...Cloud computing has been exploited in managing large-scale IoT systems.IoT cloud servers usually handle a large number of requests from various IoT devices.Due to the fluctuant and heavy workload,the servers require the cloud to provide high scalability,stable performance,low price and necessary functionalities.However,traditional clouds usually offer computing service with the abstraction of virtual machine(VM),which can hardly meet these requirements.Meanwhile,different cloud vendors provide different performance stabilities and price models,which fluctuate according to the dynamic workload.A single cloud cannot satisfy all the requirements of the IoT scenario well.The JointCloud computing model empowers the cooperation among multiple public clouds.However,it is still difficult to dynamically schedule the workload on different clouds based on the VM abstraction.This paper introduces HCloud,a trusted JointCloud platform for IoT systems using serverless computing model.HCloud allows an IoT server to be implemented with multiple serverless functions and schedules these functions on different clouds based on a schedule policy.The policy is specified by the client and includes the required functionalities,execution resources,latency,price and so on.HCloud collects the status of each cloud and dispatches serverless functions to the most suitable cloud based on the schedule policy.By leveraging the blockchain technology,we further enforce that our system can neither fake the cloud status nor wrongly dispatch the target functions.We have implemented a prototype of HCloud and evaluated it by simulating multiple cloud providers.The evaluation results show that HCloud can greatly improve the performance of serverless workloads with negligible costs.展开更多
基金supported by the National Natural Science Foundation of China(51874019 and 51725401)the China Postdoctoral Science Foundation(2020M680347 and 2021T140051)the Fundamental Research Funds for the Central Universities(FRFTP-20-045A1)。
文摘Aluminum-selenium(Al-Se)batteries,which possess a high theoretical specific capacity of 1357 mA h g^(-1),represent a promising energy storage technology.However,they suffer from significant attenuation of capacity and low cycle life due to the shuttle effect.To mitigate the shuttle effect induced by soluble selenium chloroaluminate compound that tends to migrate towards the negative electrode,a quasi-solid-state Al-Se battery was fabricated through the synthesis of a multi-aperture structure quasisolid-state electrolyte(MOF@GPE)based on metal-organic framework(MOF)material and gel-polymer electrolyte(GPE).The high ionic conductivity(1.13×10^(-3)S cm^(-1))of MOF@GPE at room temperature,coupled with its wide electrochemical stability window(2.45 V),can facilitate ion transport kinetics and enhance the electrochemical performance of Al-Se batteries.The MOF@GPE-based quasi-solidstate Al-Se batteries exhibit outstanding long-life cycling stability,delivering a high specific discharge capacity of 548 mA h g^(-1)with a maintained discharge specific capacity of 345 mA h g^(-1)after 500 cycles at a current density of 200 mA g^(-1).The stable ion transmission and high ion transport kinetics in MOF@GPE can be attributed to the stable structure and permeable channel of MOF,which effectively captures the soluble selenium chloroaluminate compound and further restrains the shuttle effect,resulting in improved cycling performance.
基金supported by the Project of the National key R&D plan(2021YFD1200203-1)Science and Technology Plan Project of Guizhou province,in RP China([2019]1404)+2 种基金Project of the National Science Foundation,in RP China(32060700),Project of the key field project of Natural Science Foundation of Guizhou Provincial Department of education(KY[2021]042)Science and Technology Plan Project of Guizhou province,in RP China([2021]General Project 126)Project of the National key R&D plan(2021YFD1100307)。
文摘Plants typically exhibit the purple phenomenon as a result of an increase in flavonoids and anthocyanins.A new tea germplasm'P113'was recently selected from Camellia tachangensis,which is purple in tender shoots.In the present study,integrated transcriptome and metabolome were used to analyze the flavonoid metabolite components and the genes involved in flavonoid biosynthesis in'P113'.A total of 86 flavonoid metabolites were identified,including 70 significantly differential metabolites(p<0.05)and they were enriched to the three metabolic pathways of ko00941,ko00942 and ko00944 through KEGG pathway analysis.A total of 136 flavonoid involved genes were obtained from transcriptomic study,of which 53 were significantly differentially expressed in developmental shoots.The correlation between metabolite profiling and transcriptome,transcriptome and protein interactions suggested that transcription factor MYB12 and glycosyltransferase UGT78D2 had a good facilitation on purple tender shoots.The metabolic pathways and potential genes that underlie the coloration of the shoots in'P113'are clarified in this study.It also lays the groundwork for identifying potential genes involved in color variation and offers a theoretical framework for the creation and use of distinctive genetic resources and the breeding of new cultivars.
文摘目的了解上海市男男性行为人群(men who have sex with men,MSM)亚硝酸盐吸入剂(rush popper)使用情况及其相关因素,为制定和实施MSM相关的干预措施提供理论依据。方法于2019—2020年实施横断面调查,对招募的MSM进行面对面的无记名调查。收集调查对象的年龄、民族、文化程度、婚姻状况等社会人口学信息,最近6个月的rush popper使用情况及性行为特征,并进行HIV和梅毒血清学检测。采用χ^(2)经验或Fisher确切概率法比较rush popper使用和非使用者人口学和性行为特征的差异。多因素Logistic回归分析影响rush popper使用的因素。结果共调查479名MSM,最近半年rush popper使用率为45.3%(217/479),HIV阳性率为13.4%,梅毒阳性率为6.1%。多因素Logistic分析显示,与rush popper使用相关的因素包括:月收入6000~9999元(aOR=2.379,95%CI:1.056~5.356);外地户籍(aOR=1.968,95%CI:1.267~3.050);通过网络或交友软件寻找男性性伴(aOR=2.583,95%CI:1.067~6.254);同性性行为方式为肛交(aOR=3.426,95%CI:1.486~7.895);肛交角色为被动方(aOR=1.879,95%CI:1.092~3.232);半年内与7人及以上发生性行为(aOR=3.161,95%CI:1.532~6.519);与配偶发生性行为时从未使用安全套(aOR=2.747,95%CI:1.101~6.856);有时使用安全套(aOR=2.846,95%CI:1.171~6.917);HIV阳性(aOR=2.310,95%CI:1.247~4.279)。结论上海市MSM rush popper使用率较高,其使用与导致HIV感染的高危性行为有较强的相关性。制定有针对性的干预措施,减少rush popper在MSM中的使用对于防治艾滋病具有重要的意义。
文摘在水温22.8～30.1℃下,2017年4月15日—10月15日,分3次测定体质量分别为20.10～47.03 g、30.61～70.22 g和34.52～88.57 g 3组2龄黄喉拟水龟的背甲长(x_1)、背甲宽(x_2)、背甲高(x_3)、腹甲长(x_4)、腹甲宽(x_5)、甲桥长(x_6)、喉盾宽(x_7)、肱盾宽(x_8)、胸盾宽(x_9)、股盾宽(x_(10))、肛盾宽(x_(11))、喉盾缝长(x_(12))、肱盾缝长(x_(13))、胸盾缝长(x_(14))、腹盾缝长(x_(15))、股盾缝长(x_(16))、肛盾缝长(x_(17))18个形态性状,每个体质量组测定340只,通过相关分析、通径分析和回归分析,研究了形态性状对体质量(y)的影响。试验结果表明,20.10～47.03 g、30.61～70.22 g、34.52～88.57 g 3组中个体对体质量直接作用较大的形态性状分别为背甲长和背甲高、腹甲长、背甲长和喉盾缝长。利用逐步回归分析方法,以体质量为依变量(y),形态性状为自变量(x_1～x_(17)),建立了3组黄喉拟水龟的最优多元线性回归方程:y_1=-48.209+7.557x_(10)+5.994x_3+4.553x_1,y_2=-26.398+9.326x_4+9.510x_3,y_3=-46.413+11.098x_1+40.039x_(12)。该研究结果为黄喉拟水龟良种选育提供了重要参考指标。
文摘An optimization method is introduced to design the aerodynamic parameters of a dual-spin twodimensional guided projectile with the canards for trajectory correction. The nose guidance component contains two pairs of canards which can provide lift and despin with the projectile for stability. The optimal design algorithm is developed to decide the profiles both of the steering and spinning canards,and their deflection angles are also simulated to meet the needs of trajectory correction capabilities.Finally, the aerodynamic efficiency of the specific canards is discussed according to the CFD simulations.Results that obtained here can be further applied to the exterior ballistics design.
基金EPSRC CDT in Metamaterials at University of Exeter and Leverhulme Trust(RPG-2018-320) for financial support。
文摘Surface-functionalized nitrogen/carbon co-doped polymorphic TiO_(2) phase junction nanoparticles uniformly distributed in porous carbon matrix were synthesized by a simple one-step pyrolysis of titanium based metal-organic framework(MOF),NH_(2)-MIL^(-1)25(Ti) at 700℃ under water vapour atmosphere.Introducing water vapour during the pyrolysis of NH_(2)-MIL^(-1)25(Ti) not only functionalizes the derived porous carbon matrix with carboxyl groups but also forms additional oxygen-rich N like interstitial/intraband states lying above the valence band of TiO2 along with the self-doped carbo n,which further narrows the energy band gaps of polymorphic TiO2 nanoparticles that enhance photocatalytic charge transfer efficiency.Without co-catalyst,sample N-C-TiO2/CArW demonstrates H_(2) evolution activity of 426 μmol gcat-1h^(-1),which remarkably outperforms commercial TiO_(2)(P-25) and N-C-TiO_(2)/CAr with a 5-fold and 3-fold H_(2) generation,respectively.This study clearly shows that water vapour atmosphere during the pyrolysis increases the hydrophilicity of the Ti-MOF derived composites by functionalizing porous carbon matrix with carboxylic groups,as well as enhancing the electrical conductivity and charge transfer efficiency due to the formation of additional localized oxygen-rich N like interstitial/intraband states.This work also demonstrates that by optimizing the anatase-rutile phase composition of the TiO2 polymorphs,tuning the energy band gaps by N/C co-doping and functionalizing the porous carbon matrix in the N-C-TiO2/C nanocomposites,the photocatalytic H_(2) generation activity can be further enhanced.
基金supported by the National Key Research&Development Program(No.2016YFB1000104).
文摘Cloud computing has been exploited in managing large-scale IoT systems.IoT cloud servers usually handle a large number of requests from various IoT devices.Due to the fluctuant and heavy workload,the servers require the cloud to provide high scalability,stable performance,low price and necessary functionalities.However,traditional clouds usually offer computing service with the abstraction of virtual machine(VM),which can hardly meet these requirements.Meanwhile,different cloud vendors provide different performance stabilities and price models,which fluctuate according to the dynamic workload.A single cloud cannot satisfy all the requirements of the IoT scenario well.The JointCloud computing model empowers the cooperation among multiple public clouds.However,it is still difficult to dynamically schedule the workload on different clouds based on the VM abstraction.This paper introduces HCloud,a trusted JointCloud platform for IoT systems using serverless computing model.HCloud allows an IoT server to be implemented with multiple serverless functions and schedules these functions on different clouds based on a schedule policy.The policy is specified by the client and includes the required functionalities,execution resources,latency,price and so on.HCloud collects the status of each cloud and dispatches serverless functions to the most suitable cloud based on the schedule policy.By leveraging the blockchain technology,we further enforce that our system can neither fake the cloud status nor wrongly dispatch the target functions.We have implemented a prototype of HCloud and evaluated it by simulating multiple cloud providers.The evaluation results show that HCloud can greatly improve the performance of serverless workloads with negligible costs.
