乙型肝炎病毒(hepatitis B virus,HBV)是一种小环型部分双链DNA病毒,属于嗜肝病毒属。HBV没有直接的肝细胞毒性,其感染后宿主免疫系统与病毒之间复杂的相互作用引发的免疫性肝损伤是其致病的重要机制。天然免疫是机体抵抗病原微生物入...乙型肝炎病毒(hepatitis B virus,HBV)是一种小环型部分双链DNA病毒,属于嗜肝病毒属。HBV没有直接的肝细胞毒性,其感染后宿主免疫系统与病毒之间复杂的相互作用引发的免疫性肝损伤是其致病的重要机制。天然免疫是机体抵抗病原微生物入侵的第一道防线,病原体相关分子模式(pathogen associated molecular patterns,PAMPs)被病原体识别受体(pathogens recognition receptors,PRRs)识别并启动天然免疫应答。肝细胞上表达的PRRs介导的天然免疫应答在HBV感染相关的免疫效应中发挥重要作用。HBV在与宿主免疫系统的博弈过程中已经进化出逃避天然免疫识别的主动策略,或主动干扰天然免疫信号通路诱导免疫抑制,从而有利于自身复制。充分理解肝细胞介导的天然免疫应答在参与控制HBV感染过程中的作用及其调控机制,有助于设计新的免疫治疗策略来预防并根除病毒。展开更多
A lab-scale anaerobic-anoxic-oxic (A2O) process used to treat a synthetic brewage wastewater was investigated. The objectives of the study were to identify the existence of denitrifying phosphorus removing bacteria (D...A lab-scale anaerobic-anoxic-oxic (A2O) process used to treat a synthetic brewage wastewater was investigated. The objectives of the study were to identify the existence of denitrifying phosphorus removing bacteria (DPB), evaluate the contribution of DPB to biological nutrient removal and enhance the denitrifying phosphorus removal in A2O bioreactors. Sludge analysis confirmed that the average anoxic P uptake accounted for approximately 70% the total amount of P uptake, and the ratio of anoxic P uptake rate to aerobic P uptake rate was 69%. In addition, nitrate concentration in the anoxic phase and different organic substrate introduced into the anaerobic phase had significant effect on the anoxic P uptake. Compared with conventional A2O processes, good removal efficiencies of COD, phosphorus, ammonia and total nitrogen (92.3%, 95.5%, 96% and 79.5%, respectively) could be achieved in the anoxic P uptake system, and aeration energy consumption was saved 25%. By controlling the nitrate recirculation flow in the anoxic zone, anoxic P uptake could be enhanced, which solved the competition for organic substrates among poly-P organisms and denitrifiers successfully under the COD limiting conditions. Therefore, in wastewater treatment plants the control system should be applied according to the practical situation to optimize the operation.展开更多
The analytical method (AM) for separation of composite waves is presented based on the Hilbert transform. It is applicable to both regular and irregular trains; of waves. The wave data series measured with two wave ga...The analytical method (AM) for separation of composite waves is presented based on the Hilbert transform. It is applicable to both regular and irregular trains; of waves. The wave data series measured with two wave gauges in the experiments are separated into two series of incident and reflected waves. Then, the reflection coefficient can be easily obtained. The arrival of reflected waves can also be detected for improvement of the accuracy of the reflection coefficient. The reflection performance of the physical model can be estimated exactly without calculation of wave height and phase difference. Numerical samples developed to test the method are proved to be accurate. Physical experiments are conducted and compared with Goda's method and satisfactory results are obtained.展开更多
Objective: This study was designed to detect the expression of bcl-2 and p53 proteins in colorectal carcinomas and to determine their association with the patient survival and stage of the diseases. Methods: Immunohis...Objective: This study was designed to detect the expression of bcl-2 and p53 proteins in colorectal carcinomas and to determine their association with the patient survival and stage of the diseases. Methods: Immunohistochemistry method was used to detect the expression of bcl-2 and p53 proteins in 93 cases of colorectal carcinoma. The stain results were obtained by analyzing the clinic-pathological characteristics of patients. Results: Fifty-seven percent (53/93) of the colorectal carcinomas were bcl-2 protein positive. The positive rate of bcl-2 protein in lymph node involvement cases was lower (15/37) than the cases without node involvement (38/58, P<0.01). The positive rate of p53 protein was 43% (40/93) in colon-rectum carcinomas. No significant correlation was observed between p53 protein expression and clinic-pathological manifestations (P>0.05) but the survival was significantly worse (P=0.0001) in the p53 protein positive cases. Neither bcl-2 nor p53 alone was correlated with stage of the disease. When combined bcl-2/p53 status was analyzed, a group with bcl-2(+) and p53(?) had the best prognosis. This group was significantly associated with earlier Dukes’ stages (P=0.1763). In multivariate Cox regression analysis, lymph node involvement and p53 protein expression were two independent factors correlated with survival time. Conclusion: The expression of bcl-2 and p53 represent biological characteristics of colorectal carcinomas. Assessment of both bcl-2 and p53 status may be valuable in predicting the prognosis of patients.展开更多
Based on schematically formulation of the vibrations induced by moving trains, this paper analyses the waveforms along the Datong-Qinhuangdao railroad in Northern China recorded in the suburban Huairou district of Be...Based on schematically formulation of the vibrations induced by moving trains, this paper analyses the waveforms along the Datong-Qinhuangdao railroad in Northern China recorded in the suburban Huairou district of Beijing on March 8, 2003. It is illustrated that vibrations induced by train, except traditional recognized noises and interfer- ence effects, could be used as a seismic source to detect crustal structures with its advantage of abundant frequency spectrum, repeatability and no additional harm to the environment. It will bring lights to the traditional exploration seismology with the further studies of signal processing and interpretation methods, and related models and new observing systems.展开更多
Energy regeneration during braking is an important technique for hybrid electric vehicle (HEV) to improve their fuel economy and extend their driving range. Due to the effect of regenerative braking torque which is ad...Energy regeneration during braking is an important technique for hybrid electric vehicle (HEV) to improve their fuel economy and extend their driving range. Due to the effect of regenerative braking torque which is added by electric motor, the braking torque distribution between front and rear axles should be changed and the control logic of anti-lock braking system (ABS) ought to be adjusted according to the regenerative braking torque. This paper put forward a braking control strategy for hybrid electric vehicle; the control strategy is implemented with eight DOFs (Degree-of-Freedom) nonlinear vehicle forward simulation model which is built under the environment of Matlab/Simulink. Based on target wheel slip ratio, a fuzzy logic approach was applied to maintain the optimal target slip ratio so that best compromise between hydraulic torque and regenerative torque can be obtained for the vehicle.展开更多
In the paper, nano-hydroxyapatite was synthesized by hydrothermal treatment. The crystal morphology and compositions of the synthetic HA were investigated using TEM, IR, XRD and XPS techniques and were compared with t...In the paper, nano-hydroxyapatite was synthesized by hydrothermal treatment. The crystal morphology and compositions of the synthetic HA were investigated using TEM, IR, XRD and XPS techniques and were compared with those of porcine femoral bone apatite. The results showed that the synthetic HA is nanometer rod crystal similar to the bone apatite, and the average crystal sizes calculated by Scherrer equation for the four samples (HA dried at 80℃, unburned bone apatite, HA calcined at 750℃ and bone apatite calcined at 750℃) are 20.6, 21.7, 22.5 and 27.6nm, respectively. Moreover, the essential compositions for the synthetic HA and bone apatite are almost the same.展开更多
The preservation and sustainable development of soil and water resources isone of the basic principles for the development of China. Throughout the course of history, all thesocial improvement and economic development...The preservation and sustainable development of soil and water resources isone of the basic principles for the development of China. Throughout the course of history, all thesocial improvement and economic development are deeply concerned with soil loss and ecologicalenvironmental protection. It is now a common sense that soil and water conservation is the safetyinsurance for national ecology and its development. For the past long period of time, soil and waterloss has been recognized as 'the No.1 killer' to the ecological environment. The nation is on thestags of the critical conditions for its development. China has massive mountain and upland areawith complicated geological conditions and accelerated human destruction and serious soil and waterloss. Based on rich historical documents, renovating experience and detailed analysis of the datacollected in field experiments and field surveys for soil and water conservation, this paper aims toreview the general characteristics of soil and water loss, to explore the relationship between soiland water conservation and sustainable economic development, and to provide relevant strategies forsoil and water conservation in China.展开更多
Various process parameters exert different effects in stamping process. In order to study the relationships among the process parameters of box stamping process, including the blank holder force, friction coefficient,...Various process parameters exert different effects in stamping process. In order to study the relationships among the process parameters of box stamping process, including the blank holder force, friction coefficient, depth of drawbead, offset and length of drawbead, the decision tree algorithm C4.5 was performed to generate the decision tree using the result data of the box stamping simulation. The design and improvement methods of the decision tree were presented. Potential and valuable rules were generated by traversing the decision tree, which plays an instructive role on the practical design. The rules show that the correct combination of blank holder force and setting of drawbead are the dominant contribution for controlling the cracking and wrinkling in box stamping process. In order to validate the rules, the stamping process for box was also performed. The experiment results show good agreement with the generated rules.展开更多
The second-order nonlinear system with delay x ' (t) + f(x(t),x ' (t)) + g(x(t),x ' (t))psi (x(t-tau)) = p(t) being considered. Four theorems on the stability of zero solution, the boundedness of the solut...The second-order nonlinear system with delay x ' (t) + f(x(t),x ' (t)) + g(x(t),x ' (t))psi (x(t-tau)) = p(t) being considered. Four theorems on the stability of zero solution, the boundedness of the solutions, the existence of the periodic solutions, the existence and uniqueness of the stationary oscillation are obtained by means of the Liapunov's second method, The conclusion in the literatures are generalized.展开更多
The technique of IP traceback may effectively block DOS (Denial Of Service) and meet the requirement of the computer forensic, but its accuracy depends upon that condition that each node in the Internet must support I...The technique of IP traceback may effectively block DOS (Denial Of Service) and meet the requirement of the computer forensic, but its accuracy depends upon that condition that each node in the Internet must support IP packet marking or detected agents. So far, this requirement is not satisfied. On the basis of traditional traceroute,this paper investigates the efficiency of discovering path methods from aspects of the size and order of detecting packets, and the length of paths.It points out that the size of padding in probed packets has a slight effect on discovering latency, and the latency with the method of bulk sending receiving is much smaller than one with the traditional traceroute. Moreover, the loss rate of packets with the technique of TTL (Time To Live) which increases monotonously is less than that with the technique of TTL which decreases monotonously. Lastly,OS (Operating System) passive fingerprint is used as heuristic to predict the length of the discovered path so as to reduce disturbance in network traffic.展开更多
基金Supported by Key Technology Research and Development Program of the Tenthfive-year plan (2001BA610A-09), the NationalNatural Science Foundation of China (No. 50478040) and 863 Hi-Technology Research and Development Program of China(No.2004AA601020)
文摘A lab-scale anaerobic-anoxic-oxic (A2O) process used to treat a synthetic brewage wastewater was investigated. The objectives of the study were to identify the existence of denitrifying phosphorus removing bacteria (DPB), evaluate the contribution of DPB to biological nutrient removal and enhance the denitrifying phosphorus removal in A2O bioreactors. Sludge analysis confirmed that the average anoxic P uptake accounted for approximately 70% the total amount of P uptake, and the ratio of anoxic P uptake rate to aerobic P uptake rate was 69%. In addition, nitrate concentration in the anoxic phase and different organic substrate introduced into the anaerobic phase had significant effect on the anoxic P uptake. Compared with conventional A2O processes, good removal efficiencies of COD, phosphorus, ammonia and total nitrogen (92.3%, 95.5%, 96% and 79.5%, respectively) could be achieved in the anoxic P uptake system, and aeration energy consumption was saved 25%. By controlling the nitrate recirculation flow in the anoxic zone, anoxic P uptake could be enhanced, which solved the competition for organic substrates among poly-P organisms and denitrifiers successfully under the COD limiting conditions. Therefore, in wastewater treatment plants the control system should be applied according to the practical situation to optimize the operation.
基金This project was financially supported by the Trans-Century Training Program Fund for the Talent,Ministry of Education of China.
文摘The analytical method (AM) for separation of composite waves is presented based on the Hilbert transform. It is applicable to both regular and irregular trains; of waves. The wave data series measured with two wave gauges in the experiments are separated into two series of incident and reflected waves. Then, the reflection coefficient can be easily obtained. The arrival of reflected waves can also be detected for improvement of the accuracy of the reflection coefficient. The reflection performance of the physical model can be estimated exactly without calculation of wave height and phase difference. Numerical samples developed to test the method are proved to be accurate. Physical experiments are conducted and compared with Goda's method and satisfactory results are obtained.
文摘Objective: This study was designed to detect the expression of bcl-2 and p53 proteins in colorectal carcinomas and to determine their association with the patient survival and stage of the diseases. Methods: Immunohistochemistry method was used to detect the expression of bcl-2 and p53 proteins in 93 cases of colorectal carcinoma. The stain results were obtained by analyzing the clinic-pathological characteristics of patients. Results: Fifty-seven percent (53/93) of the colorectal carcinomas were bcl-2 protein positive. The positive rate of bcl-2 protein in lymph node involvement cases was lower (15/37) than the cases without node involvement (38/58, P<0.01). The positive rate of p53 protein was 43% (40/93) in colon-rectum carcinomas. No significant correlation was observed between p53 protein expression and clinic-pathological manifestations (P>0.05) but the survival was significantly worse (P=0.0001) in the p53 protein positive cases. Neither bcl-2 nor p53 alone was correlated with stage of the disease. When combined bcl-2/p53 status was analyzed, a group with bcl-2(+) and p53(?) had the best prognosis. This group was significantly associated with earlier Dukes’ stages (P=0.1763). In multivariate Cox regression analysis, lymph node involvement and p53 protein expression were two independent factors correlated with survival time. Conclusion: The expression of bcl-2 and p53 represent biological characteristics of colorectal carcinomas. Assessment of both bcl-2 and p53 status may be valuable in predicting the prognosis of patients.
基金National Natural Science Foundations of China (No. 40234038 and 40174014).
文摘Based on schematically formulation of the vibrations induced by moving trains, this paper analyses the waveforms along the Datong-Qinhuangdao railroad in Northern China recorded in the suburban Huairou district of Beijing on March 8, 2003. It is illustrated that vibrations induced by train, except traditional recognized noises and interfer- ence effects, could be used as a seismic source to detect crustal structures with its advantage of abundant frequency spectrum, repeatability and no additional harm to the environment. It will bring lights to the traditional exploration seismology with the further studies of signal processing and interpretation methods, and related models and new observing systems.
基金863 National Project EQ7200HEV hybridelectric vehicle (2001AA501200,2003AA501200)
文摘Energy regeneration during braking is an important technique for hybrid electric vehicle (HEV) to improve their fuel economy and extend their driving range. Due to the effect of regenerative braking torque which is added by electric motor, the braking torque distribution between front and rear axles should be changed and the control logic of anti-lock braking system (ABS) ought to be adjusted according to the regenerative braking torque. This paper put forward a braking control strategy for hybrid electric vehicle; the control strategy is implemented with eight DOFs (Degree-of-Freedom) nonlinear vehicle forward simulation model which is built under the environment of Matlab/Simulink. Based on target wheel slip ratio, a fuzzy logic approach was applied to maintain the optimal target slip ratio so that best compromise between hydraulic torque and regenerative torque can be obtained for the vehicle.
文摘In the paper, nano-hydroxyapatite was synthesized by hydrothermal treatment. The crystal morphology and compositions of the synthetic HA were investigated using TEM, IR, XRD and XPS techniques and were compared with those of porcine femoral bone apatite. The results showed that the synthetic HA is nanometer rod crystal similar to the bone apatite, and the average crystal sizes calculated by Scherrer equation for the four samples (HA dried at 80℃, unburned bone apatite, HA calcined at 750℃ and bone apatite calcined at 750℃) are 20.6, 21.7, 22.5 and 27.6nm, respectively. Moreover, the essential compositions for the synthetic HA and bone apatite are almost the same.
基金State Key Basic Research and Development Plan of China No.G2000018605+4 种基金 National Natural Science Foundation of China No.40171063 No.40371076 The Science Foundation of the State Key Laboratory of Soil Erosion and Dry Farming CAS
文摘The preservation and sustainable development of soil and water resources isone of the basic principles for the development of China. Throughout the course of history, all thesocial improvement and economic development are deeply concerned with soil loss and ecologicalenvironmental protection. It is now a common sense that soil and water conservation is the safetyinsurance for national ecology and its development. For the past long period of time, soil and waterloss has been recognized as 'the No.1 killer' to the ecological environment. The nation is on thestags of the critical conditions for its development. China has massive mountain and upland areawith complicated geological conditions and accelerated human destruction and serious soil and waterloss. Based on rich historical documents, renovating experience and detailed analysis of the datacollected in field experiments and field surveys for soil and water conservation, this paper aims toreview the general characteristics of soil and water loss, to explore the relationship between soiland water conservation and sustainable economic development, and to provide relevant strategies forsoil and water conservation in China.
文摘Various process parameters exert different effects in stamping process. In order to study the relationships among the process parameters of box stamping process, including the blank holder force, friction coefficient, depth of drawbead, offset and length of drawbead, the decision tree algorithm C4.5 was performed to generate the decision tree using the result data of the box stamping simulation. The design and improvement methods of the decision tree were presented. Potential and valuable rules were generated by traversing the decision tree, which plays an instructive role on the practical design. The rules show that the correct combination of blank holder force and setting of drawbead are the dominant contribution for controlling the cracking and wrinkling in box stamping process. In order to validate the rules, the stamping process for box was also performed. The experiment results show good agreement with the generated rules.
文摘The second-order nonlinear system with delay x ' (t) + f(x(t),x ' (t)) + g(x(t),x ' (t))psi (x(t-tau)) = p(t) being considered. Four theorems on the stability of zero solution, the boundedness of the solutions, the existence of the periodic solutions, the existence and uniqueness of the stationary oscillation are obtained by means of the Liapunov's second method, The conclusion in the literatures are generalized.
文摘The technique of IP traceback may effectively block DOS (Denial Of Service) and meet the requirement of the computer forensic, but its accuracy depends upon that condition that each node in the Internet must support IP packet marking or detected agents. So far, this requirement is not satisfied. On the basis of traditional traceroute,this paper investigates the efficiency of discovering path methods from aspects of the size and order of detecting packets, and the length of paths.It points out that the size of padding in probed packets has a slight effect on discovering latency, and the latency with the method of bulk sending receiving is much smaller than one with the traditional traceroute. Moreover, the loss rate of packets with the technique of TTL (Time To Live) which increases monotonously is less than that with the technique of TTL which decreases monotonously. Lastly,OS (Operating System) passive fingerprint is used as heuristic to predict the length of the discovered path so as to reduce disturbance in network traffic.
