On the software module, this paper proposes a visual specification language(VSL). Based on decomposition, the language imitates men's thinking procedure that decomposes aproblem into smaller ones, then independent...On the software module, this paper proposes a visual specification language(VSL). Based on decomposition, the language imitates men's thinking procedure that decomposes aproblem into smaller ones, then independently solves the results of every small problem to get theresult of original problem (decomposition and synthesis). Besides, the language mixes visual withspecification. With computer supporting, we can implement the software module automatically. It willgreatly improve the quality of software and raise the efficiency of software development. Thesimple definition of VSL, the principle of auto-generation, an example and the future research areintroduced.展开更多
Hepatitis C virus（HCV）-specific CD8^＋ T cells play an important role in the resolution of HCV infection. Nevertheless, during chronic hepatitis C these cells lack their effector functions and fail to control the vi...Hepatitis C virus（HCV）-specific CD8^＋ T cells play an important role in the resolution of HCV infection. Nevertheless, during chronic hepatitis C these cells lack their effector functions and fail to control the virus. HCV has developed several mechanisms to escape immune control. One of these strategies is the upregulation of negative co-stimulatory molecules such us programmed death-1 （PD-1）. This molecule is upregulated on intrahepatic and peripheral HCV-specific cytotoxic T cells during acute and chronic phases of the disease, whereas PD-1 expression is low in resolved infection. PD-1 expressing HCV-specific CD8^＋ T cells are exhausted with impairment of several effector mechanisms, such as： type-1 cytokine production, expansion ability after antigen encounter and cytotoxic ability. However, PD-1 associated exhaustion can be restored by blocking the interaction between PD-1 and its ligand （PD-L1）. After this blockade, HCV-specific CD8^＋ T cells reacquire their functionality. Nevertheless, functional restoration depends on PD-1 expression level. High PD-l-expressing intrahepatic HCV-specific CD8^＋ T cells do not restore their effector abilities after PD-1/ PD-L1 blockade. The mechanisms by which HCV is able to induce PD-1 up-regulation to escape immune control are unknown. Persistent TCR stimulation by a high level of HCV antigens could favour early PD-1 induction, but the interaction between HCV core protein and gClq receptor could also participate in this process. The PD-1/PD-L1 pathway modulation could be a therapeutic strategy, in conjunction with the regulation of others co-stimulatory pathways, in order to restore immune response aclainst HCV to succeed in clearing the infection.展开更多
A series of Ru/FeOx catalysts were synthesized for the selective hydrogenation of CO2to CO.Detailed characterizations of the catalysts through X‐ray diffraction,X‐ray photoelectron spectroscopy,transmission electron...A series of Ru/FeOx catalysts were synthesized for the selective hydrogenation of CO2to CO.Detailed characterizations of the catalysts through X‐ray diffraction,X‐ray photoelectron spectroscopy,transmission electron microscopy,and temperature‐programmed techniques were performed to directly monitor the surface chemical properties and the catalytic performance to elucidate the reaction mechanism.Highly dispersed Ru species were observed on the surface of FeOx regardless of the initial Ru loading.Varying the Ru loading resulted in changes to the Ru coverage over the FeOx surface,which had a significant impact on the interaction between Ru and adsorbed H,and concomitantly,the H2activation capacity via the ability for H2dissociation.FeOx having0.01%of Ru loading exhibited100%selectivity toward CO resulting from the very strong interaction between Ru and adsorbed H,which limits the desorption of the activated H species and hinders over‐reduction of CO to CH4.Further increasing the Ru loading of the catalysts to above0.01%resulted in the adsorbed H to be easily dissociated,as a result of a weaker interaction with Ru,which allowed excessive CO reduction to produce CH4.Understanding how to selectively design the catalyst by tuning the initial loading of the active phase has broader implications on the design of supported metal catalysts toward preparing liquid fuels from CO2.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences toward preparing liquid fuels from CO2.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.展开更多
With the increasing popularity of cloud computing, there is an increased de mand for cloud resources in cloud. It has be come even more urgent to find solutions to improve resource utilization. From the per spective o...With the increasing popularity of cloud computing, there is an increased de mand for cloud resources in cloud. It has be come even more urgent to find solutions to improve resource utilization. From the per spective of a cloud consumer, a cloud applica tion processes a large information flow in volving user actions that access resources, but little work has so far been devoted to research from the perspective of the interaction be tween the user and the cloud application. In this paper, we analyze the interaction in detail, and propose a general mathematical interac tion model to formulate the challenge pertain ing to storage resource allocation as an opti mization problem, focusing on minimizing both the user＇s cost and server＇s consumption. A potential response mechanism is then de signed based on the interaction model. Fur thermore, the proposed model is used to ex plore strategies when multiple users access the same file simultaneously. Additionally, an improved queuing system, namely M/ G~ oo queue with standby, is introduced. Finally, an evaluation is presented to verify the interac- tion model.展开更多
The 0.4 nm molecular sieve supported Cu-Ni bimetal catalysts for direct synthesis of dimethyl carbonate (DMC) from CO 2 and CH 3 OH were prepared and investigated. The synthesized catalysts were fully characterized by...The 0.4 nm molecular sieve supported Cu-Ni bimetal catalysts for direct synthesis of dimethyl carbonate (DMC) from CO 2 and CH 3 OH were prepared and investigated. The synthesized catalysts were fully characterized by BET, XRD (X-ray diffraction), TPR (temperature programmed reduction), IR (infra-red adsorption), NH 3-TPD (temperature programmed desorption) and CO 2-TPD (temperature programmed desorption) techniques. The results showed that the surface area of catalysts decreased with increasing metal content, and the metals as well as Cu-Ni alloy co-existed on the reduced catalyst surface. There existed interaction between metal and carrier, and moreover, metal particles affected obviously the acidity and basicity of carrier. The large amount of basic sites facilitated the activation of methanol to methoxyl species and their subsequent reaction with activated carbon dioxide. The catalysts were evaluated in a continuous tubular fixed-bed micro-gaseous reactor and the catalyst with bimetal loading of 20% (by mass) had best catalytic activities. Under the conditions of 393 K, 1.1 MPa, 5 h and gas space velocity of 510 h 1 , the selectivity and yield of DMC were higher than 86.0 % and 5.0 %, respectively.展开更多
Expanded bed adsorption(EBA),a promising and practical separation technique,has been widely studied in the past two decades.The development of adsorbents for EBA process is a challenging course,with the special design...Expanded bed adsorption(EBA),a promising and practical separation technique,has been widely studied in the past two decades.The development of adsorbents for EBA process is a challenging course,with the special design and preparation according to the target molecules and specific expanded bed systems.Many types of supporting matrices for expanded bed adsorbents have been developed,and their preparation methods are being consummated gradually.These matrices are activated and then coupled with ligands to form functionalized adsorbents,including ion-exchange adsorbents,affinity adsorbents,mixed mode adsorbents,hydrophobic charge induction chromatography adsorbents and others.In this review,the preparation of the matrices for EBA process is summa-rized,and the coupling of ligands to the matrices to prepare functionalized adsorbents is discussed as well.展开更多
Curling results from the temperature differential across the concrete slab thickness and may induce undue stresses in newly placed slab. This study deals with the finite element （FE） analysis of curling, curling str...Curling results from the temperature differential across the concrete slab thickness and may induce undue stresses in newly placed slab. This study deals with the finite element （FE） analysis of curling, curling stresses, field measurement of curling on a newly built jointed plain concrete pavement, and comparison of its long-term performance using both Mechanistic-Empirical Pavement Design Guide （MEPDG） and HIPERPAVII software. The FE analysis was performed with a software program, ANSYS. The test section was modeled as a three-layer system with 300 mm concrete slab, 100 mm treated drainable base, and 150 mm lime-treated subgrade. All layers were assumed to be linear elastic. Temperature data was collected at five different depth locations across the concrete slab with digital data loggers. Curling was measured on five different days with a simple setup. The effect of temperature nonlinearities across the slab thickness was also examined. The results show that both upward and downward curling increase as the temperature differential increases. The maximum stress resulting from the combined effect of curling and traffic loading due to positive temperature differential is higher than that due to the negative temperature differential of the same magnitude. Since temperature differential has a significant influence on curling, both curling and curling stresses can be mitigated at an early age with temperature control, namely via enhanced curing. Both MEPDG and HIPERPAVII showed approximately the same performance for the PCC thickness ranging from 215 mm to 300 mm for this project. Performance prediction from HIPERPAVII is very sensitive to the change in PCC thickness less than 230 mm whereas MEPDG prediction is not as sensitive to the thickness change as with HIPERPAV 1I.展开更多
Thin films of tin and copper oxide forming heterojunction are being studied for applications in photovoltaic systems. The procedure for obtaining such a film was based on the technique of spray pyrolysis with working ...Thin films of tin and copper oxide forming heterojunction are being studied for applications in photovoltaic systems. The procedure for obtaining such a film was based on the technique of spray pyrolysis with working temperature of 600 ℃. The XRD （X-ray diffraction） showed the formation of tin oxides （SnO2） and copper （Cu2O） and its structural parameters are a, b and c, 4.7534 A^°, 4.7534 A^°, 3.1998 A^° （tetragonal form） and 4.2580 A^°, 4.2580 A^°, 4.2580 A^° （cubic form）, respectively. Highseore Plus program was used for phase identification and DBWSTool2.4 program used for refinement. The grain size was estimated by Williamson-Hall.展开更多
文摘On the software module, this paper proposes a visual specification language(VSL). Based on decomposition, the language imitates men's thinking procedure that decomposes aproblem into smaller ones, then independently solves the results of every small problem to get theresult of original problem (decomposition and synthesis). Besides, the language mixes visual withspecification. With computer supporting, we can implement the software module automatically. It willgreatly improve the quality of software and raise the efficiency of software development. Thesimple definition of VSL, the principle of auto-generation, an example and the future research areintroduced.
基金Supported by Grants from "Fiscam" J.C.C.M (Ayuda para proyectos de investigación en salud PI-2007/32)+5 种基金"Fundación de Investigación Médica Mutua Madrileń a" (Beca Ayudas a la Investigación FMMM 2548/2008) from SpainBenito-Martínez S was supported by a research grant from "Fiscam" J.C.C.M ("Perfeccionamiento y movilidad de investigadores" MOV-2007_JI/18), SpainCalvino M was supported by a research grant from "Instituto de Salud Carlos III" (Contrato de apoyo a la investigación en el SNS’’ CA07/00157), Spain
文摘Hepatitis C virus（HCV）-specific CD8^＋ T cells play an important role in the resolution of HCV infection. Nevertheless, during chronic hepatitis C these cells lack their effector functions and fail to control the virus. HCV has developed several mechanisms to escape immune control. One of these strategies is the upregulation of negative co-stimulatory molecules such us programmed death-1 （PD-1）. This molecule is upregulated on intrahepatic and peripheral HCV-specific cytotoxic T cells during acute and chronic phases of the disease, whereas PD-1 expression is low in resolved infection. PD-1 expressing HCV-specific CD8^＋ T cells are exhausted with impairment of several effector mechanisms, such as： type-1 cytokine production, expansion ability after antigen encounter and cytotoxic ability. However, PD-1 associated exhaustion can be restored by blocking the interaction between PD-1 and its ligand （PD-L1）. After this blockade, HCV-specific CD8^＋ T cells reacquire their functionality. Nevertheless, functional restoration depends on PD-1 expression level. High PD-l-expressing intrahepatic HCV-specific CD8^＋ T cells do not restore their effector abilities after PD-1/ PD-L1 blockade. The mechanisms by which HCV is able to induce PD-1 up-regulation to escape immune control are unknown. Persistent TCR stimulation by a high level of HCV antigens could favour early PD-1 induction, but the interaction between HCV core protein and gClq receptor could also participate in this process. The PD-1/PD-L1 pathway modulation could be a therapeutic strategy, in conjunction with the regulation of others co-stimulatory pathways, in order to restore immune response aclainst HCV to succeed in clearing the infection.
基金supported by the National Natural Science Foundation of China(21476145,91645117)China Postdoctoral Science Foundation(2016M600221)~~
文摘A series of Ru/FeOx catalysts were synthesized for the selective hydrogenation of CO2to CO.Detailed characterizations of the catalysts through X‐ray diffraction,X‐ray photoelectron spectroscopy,transmission electron microscopy,and temperature‐programmed techniques were performed to directly monitor the surface chemical properties and the catalytic performance to elucidate the reaction mechanism.Highly dispersed Ru species were observed on the surface of FeOx regardless of the initial Ru loading.Varying the Ru loading resulted in changes to the Ru coverage over the FeOx surface,which had a significant impact on the interaction between Ru and adsorbed H,and concomitantly,the H2activation capacity via the ability for H2dissociation.FeOx having0.01%of Ru loading exhibited100%selectivity toward CO resulting from the very strong interaction between Ru and adsorbed H,which limits the desorption of the activated H species and hinders over‐reduction of CO to CH4.Further increasing the Ru loading of the catalysts to above0.01%resulted in the adsorbed H to be easily dissociated,as a result of a weaker interaction with Ru,which allowed excessive CO reduction to produce CH4.Understanding how to selectively design the catalyst by tuning the initial loading of the active phase has broader implications on the design of supported metal catalysts toward preparing liquid fuels from CO2.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences toward preparing liquid fuels from CO2.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.
基金supported in part by the National Natural Science Foundation of China under Grant No. 61271199the Fundamental Research Funds in Beijing Jiaotong University under Grant No. W11JB00630
文摘With the increasing popularity of cloud computing, there is an increased de mand for cloud resources in cloud. It has be come even more urgent to find solutions to improve resource utilization. From the per spective of a cloud consumer, a cloud applica tion processes a large information flow in volving user actions that access resources, but little work has so far been devoted to research from the perspective of the interaction be tween the user and the cloud application. In this paper, we analyze the interaction in detail, and propose a general mathematical interac tion model to formulate the challenge pertain ing to storage resource allocation as an opti mization problem, focusing on minimizing both the user＇s cost and server＇s consumption. A potential response mechanism is then de signed based on the interaction model. Fur thermore, the proposed model is used to ex plore strategies when multiple users access the same file simultaneously. Additionally, an improved queuing system, namely M/ G~ oo queue with standby, is introduced. Finally, an evaluation is presented to verify the interac- tion model.
基金Supported by the National High Technology Research and Development Program of China (2008AA03Z3472294,2009AA302410)the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme (2010)+1 种基金the Guangdong Province Sci & Tech Bureau (2006B12401006, 2008A080800024)the Chinese Universities Basic Research Founding
文摘The 0.4 nm molecular sieve supported Cu-Ni bimetal catalysts for direct synthesis of dimethyl carbonate (DMC) from CO 2 and CH 3 OH were prepared and investigated. The synthesized catalysts were fully characterized by BET, XRD (X-ray diffraction), TPR (temperature programmed reduction), IR (infra-red adsorption), NH 3-TPD (temperature programmed desorption) and CO 2-TPD (temperature programmed desorption) techniques. The results showed that the surface area of catalysts decreased with increasing metal content, and the metals as well as Cu-Ni alloy co-existed on the reduced catalyst surface. There existed interaction between metal and carrier, and moreover, metal particles affected obviously the acidity and basicity of carrier. The large amount of basic sites facilitated the activation of methanol to methoxyl species and their subsequent reaction with activated carbon dioxide. The catalysts were evaluated in a continuous tubular fixed-bed micro-gaseous reactor and the catalyst with bimetal loading of 20% (by mass) had best catalytic activities. Under the conditions of 393 K, 1.1 MPa, 5 h and gas space velocity of 510 h 1 , the selectivity and yield of DMC were higher than 86.0 % and 5.0 %, respectively.
基金Supported by the National Natural Science Foundation of China （20876139, 20776129） and the National Basic Research Program of China （2007CB707805）.
文摘Expanded bed adsorption(EBA),a promising and practical separation technique,has been widely studied in the past two decades.The development of adsorbents for EBA process is a challenging course,with the special design and preparation according to the target molecules and specific expanded bed systems.Many types of supporting matrices for expanded bed adsorbents have been developed,and their preparation methods are being consummated gradually.These matrices are activated and then coupled with ligands to form functionalized adsorbents,including ion-exchange adsorbents,affinity adsorbents,mixed mode adsorbents,hydrophobic charge induction chromatography adsorbents and others.In this review,the preparation of the matrices for EBA process is summa-rized,and the coupling of ligands to the matrices to prepare functionalized adsorbents is discussed as well.
文摘Curling results from the temperature differential across the concrete slab thickness and may induce undue stresses in newly placed slab. This study deals with the finite element （FE） analysis of curling, curling stresses, field measurement of curling on a newly built jointed plain concrete pavement, and comparison of its long-term performance using both Mechanistic-Empirical Pavement Design Guide （MEPDG） and HIPERPAVII software. The FE analysis was performed with a software program, ANSYS. The test section was modeled as a three-layer system with 300 mm concrete slab, 100 mm treated drainable base, and 150 mm lime-treated subgrade. All layers were assumed to be linear elastic. Temperature data was collected at five different depth locations across the concrete slab with digital data loggers. Curling was measured on five different days with a simple setup. The effect of temperature nonlinearities across the slab thickness was also examined. The results show that both upward and downward curling increase as the temperature differential increases. The maximum stress resulting from the combined effect of curling and traffic loading due to positive temperature differential is higher than that due to the negative temperature differential of the same magnitude. Since temperature differential has a significant influence on curling, both curling and curling stresses can be mitigated at an early age with temperature control, namely via enhanced curing. Both MEPDG and HIPERPAVII showed approximately the same performance for the PCC thickness ranging from 215 mm to 300 mm for this project. Performance prediction from HIPERPAVII is very sensitive to the change in PCC thickness less than 230 mm whereas MEPDG prediction is not as sensitive to the thickness change as with HIPERPAV 1I.
文摘Thin films of tin and copper oxide forming heterojunction are being studied for applications in photovoltaic systems. The procedure for obtaining such a film was based on the technique of spray pyrolysis with working temperature of 600 ℃. The XRD （X-ray diffraction） showed the formation of tin oxides （SnO2） and copper （Cu2O） and its structural parameters are a, b and c, 4.7534 A^°, 4.7534 A^°, 3.1998 A^° （tetragonal form） and 4.2580 A^°, 4.2580 A^°, 4.2580 A^° （cubic form）, respectively. Highseore Plus program was used for phase identification and DBWSTool2.4 program used for refinement. The grain size was estimated by Williamson-Hall.
