KeLa-2 gas reservoir is the largest uncompartimentalized gas field so far discovered in China, with a reserve of hundreds of billions of cubic meters of dry gas. It has such features as extremely long interval (550m)...KeLa-2 gas reservoir is the largest uncompartimentalized gas field so far discovered in China, with a reserve of hundreds of billions of cubic meters of dry gas. It has such features as extremely long interval (550m), high pressure (74.5MPa) and pressure coefficient (2.022). Gas reservoirs with a pressure coefficient of over 2.0 are not commonly found. The abnormal high-pressure reservoirs are quite different in characteristic and performance during the process of depletion exploitation. Therefore, it is necessary to know the property of pressure sensitivity for this abnormal high-pressure reservoir. The aim of this paper is to test the reservoir pressure sensitivity and to analyze its effect on the deliverability of gas. Through some experiments, the permeability change with the confining pressure of rock samples from KeLa-2 abnormal high-pressure gas reservoir is measured. A power function is used to match the measured data, and to derive an empirical equation to describe the change of permeability through the change of the reservoir pressure or effective overburden pressure. Considering the permeability change during the development of reservoirs, a conventional deliverability equation is modified, and the deliverability curve for KeLa-2 gas reservoir is predicted. The research indicates that the extent of the pressure sensitivity of rock samples from KeLa-2 is higher than that from the Daqing oilfield. KeLa-2 reservoir rock has the feature of an undercompaction state. The pressure sensitivity of a reservoir may decrease the well deliverability. It is concluded that for KeLa-2 reservoir the predicted absolute open flow (AOF), when the pressure sensitivity is taken into account, is approximately 70% of the AOF when permeability is constant and does not change with pressure.展开更多
Recombinant bacteria secreting the transmembrane-truncated region of white spot syndrome virus （WSSV） envelope protein VP28 named DhpVB were constructed, using live Escherichia coli as a deliverer and a con- stituti...Recombinant bacteria secreting the transmembrane-truncated region of white spot syndrome virus （WSSV） envelope protein VP28 named DhpVB were constructed, using live Escherichia coli as a deliverer and a con- stitutive secretory expression plasmid as the expression vector. With the ability to deliver recombinant pro- tein products outside, DhpVB could make VP28 directly interact with the shrimp when injected into shrim- p. In order to test the protection potential, live DhpVB were injected into the marine shrimp Exopalamon carincauda Holthuis for three times and WSSV challenge was performed twice simultaneously at the last two injections of the bacteria. The results showed that DhpVB displayed statistically significant advantage over bacteria without VP28 after the second challenge with an average RI （Resistance index） of 0.67±0.08, compared with 0.41±0.09 of bacteria without VP28 （P 〈0.05）. The data suggested that a quasi-immune response may exist in E. carincauda and live bacteria carrying VP28 could enhance the shrimp resistance against WSSV.展开更多
Mr.Chairman,Ladies and Gentlemen,It is a great honour and pleasure for me tohave the opportunity to deliver this lecture on“How Acupuncture-Moxibustion Should Go For-ward into the 21st Century”.In 1978,the Internati...Mr.Chairman,Ladies and Gentlemen,It is a great honour and pleasure for me tohave the opportunity to deliver this lecture on“How Acupuncture-Moxibustion Should Go For-ward into the 21st Century”.In 1978,the International Conference onPrimary Health Care held in Alma-Ata recog-nized the potential of traditional medicine in ex-tending primary health care to underserved pop-ulations.In many developing countries,in fact,people have always used both traditional展开更多
It is of great significance to forecast high yield of CBM wells and analyze dynamic production by having an overall study on the characteristics of the produced CBM and determining the main factors influencing the pro...It is of great significance to forecast high yield of CBM wells and analyze dynamic production by having an overall study on the characteristics of the produced CBM and determining the main factors influencing the productivity of CBM. With the test report and the related geological parameters of a single well, methods of combining the productivity data and typical production curves were used to analyze different geological factors and how to influence the capacity of a single layer. Then, the paper proposed a new understanding about capacity characteristics of the study area and geological control factors： First, the Shanxi formation production capacity characteristics was divided into two-stages, showing signs of gas and gas break- through for 100 days. Second, two parameters, which include potential of gas production and gas production capacity, were bet- ter than the single parameter, such as gas content, coal thickness, and penetration to analyze affecting factors of single well pro- duction. Finally, comprehensive analysis concluded that the ratio of critical desorption pressure to reservoir pressure has greater influence on the production of vertical CBM wells. Besides, the potential of gas production capacity has greater impact at stage of showing gas signs; the coal reservoir pressure and gas production capacity have greater impact at stage of gas breakthrough for 100 days. Thus, to seek the coal bed methane with high ratio of critical desorption pressure to reservoir pressure and high yield of gas will be important guarantee to the success of the coal bed methane exploration and development.展开更多
A brand new treatment was reported to cure the cancer triumphantly using the combination of photo-thermal therapy inducing by nitrogen doped carbon dots(N-CDs)and chemotherapy of the doxorubicin(Dox).The experiment re...A brand new treatment was reported to cure the cancer triumphantly using the combination of photo-thermal therapy inducing by nitrogen doped carbon dots(N-CDs)and chemotherapy of the doxorubicin(Dox).The experiment results demonstrated that the as-synthesized N-CDs had excellent photo-thermal effect inducing the temperature enhancement as high as about 10℃.Furthermore,the as-prepared N-CDs could load Dox availably and achieve a pH-controlled drug release.Thus,the multifunctional N-CDs-Dox nanocomposites could perform the synergetic effect of photo-thermal therapy and chemotherapy to tumor cells.展开更多
Opportunistic networks are random networks and do not communicate with each other among respective communication areas.This situation leads to great difficulty in message transfer.This paper proposes a reducing energy...Opportunistic networks are random networks and do not communicate with each other among respective communication areas.This situation leads to great difficulty in message transfer.This paper proposes a reducing energy consumption optimal selection of path transmission(OSPT) routing algorithm in opportunistic networks.This algorithm designs a dynamic random network topology,creates a dynamic link,and realizes an optimized selected path.This algorithm solves a problem that nodes are unable to deliver messages for a long time in opportunistic networks.According to the simulation experiment,OSPT improves deliver ratio,and reduces energy consumption,cache time and transmission delay compared with the Epidemic Algorithm and Spray and Wait Algorithm in opportunistic networks.展开更多
With the development of the Tazhong No. 1 carbonate gas condensate reservoir in China, it has become more and more important to study the characteristics of gas condensate well deliverability. A single-well radial sim...With the development of the Tazhong No. 1 carbonate gas condensate reservoir in China, it has become more and more important to study the characteristics of gas condensate well deliverability. A single-well radial simulator for dual-permeability reservoirs was established to study the influences of fluid properties, permeability, and pressure drawdown on well deliverability with and without the capillary number effect. The simulation shows that well deliverability basically maintains its initial value and is not affected by the capillary number when the formation pressure is higher than dew-point pressure. However, well deliverability drops rapidly when the formation pressure is lower than dew-point pressure. Even if the condensate dropout is very low, well deliverability without the capillary number effect reduces to 50 percent of its initial value when reservoir pressure declines to 95 percent of dew-point pressure, but well deliverability is significantly improved if the capillary number effect exists. The capillary number effect is most significant when reservoir pressure is just lower than dew point pressure, then the effect decreases; the reduction of well deliverability is mainly caused by the reduction of gas relative permeability of the matrix system near the wellbore.展开更多
Hydrogen has emerged as a promising alternative to meet the growing demand for sustainable and renewable energy sources.Underground hydrogen storage(UHS)in depleted gas reservoirs holds significant potential for large...Hydrogen has emerged as a promising alternative to meet the growing demand for sustainable and renewable energy sources.Underground hydrogen storage(UHS)in depleted gas reservoirs holds significant potential for large-scale energy storage and the seamless integration of intermittent renewable energy sources,due to its capacity to address challenges associated with the intermittent nature of renewable energy sources,ensuring a steady and reliable energy supply.Leveraging the existing infrastructure and well-characterized geological formations,depleted gas reservoirs offer an attractive option for large-scale hydrogen storage implementation.However,significant knowledge gaps regarding storage performance hinder the commercialization of UHS operation.Hydrogen deliverability,hydrogen trapping,and the equation of state are key areas with limited understanding.This literature review critically analyzes and synthesizes existing research on hydrogen storage performance during underground storage in depleted gas reservoirs;it then provides a high-level risk assessment and an overview of the techno-economics of UHS.The significance of this review lies in its consolidation of current knowledge,highlighting unresolved issues and proposing areas for future research.Addressing these gaps will advance hydrogen-based energy systems and support the transition to a sustainable energy landscape.Facilitating efficient and safe deployment of UHS in depleted gas reservoirs will assist in unlocking hydrogen’s full potential as a clean and renewable energy carrier.In addition,this review aids policymakers and the scientific community in making informed decisions regarding hydrogen storage technologies.展开更多
The Film Copy Deliverer Problem (FDP),much more difficult than TSP,is a new problem in the combination optimization. In this paper,a new algorithm is introduced. First,the FDP is converted to TSP. Then an evolutionary...The Film Copy Deliverer Problem (FDP),much more difficult than TSP,is a new problem in the combination optimization. In this paper,a new algorithm is introduced. First,the FDP is converted to TSP. Then an evolutionary algorithm based on inversion operator is adopted. Compared with other Genetic Algorithms,it is not only more simple and easier to realize but also faster and more accurate.展开更多
4-ary pulse amplitude modulation(4PAM) signals with 33% and 50% return-to-zero(RZ) clocks are generated for passive optical network(PON). We demonstrate that RZ-4PAM signals with duty cycles of 33% and 50% after trans...4-ary pulse amplitude modulation(4PAM) signals with 33% and 50% return-to-zero(RZ) clocks are generated for passive optical network(PON). We demonstrate that RZ-4PAM signals with duty cycles of 33% and 50% after transmission over 20-km-long single mode fiber(SMF) at 10 Gbit/s can be directly detected by using one photo detector,and the original data can also be restored by one M-ary threshold detector and one 4PAM sequence decoder. The optical spectra of 33% and 50% RZ-4PAM signals are measured,and their eye-diagrams before and after transmission are also analyzed. Simulation results show that 33% and 50% RZ-4PAM downlink signals can be received effectively,and the received power values are-15.1 d Bm and-13.8 d Bm when the bit error rate(BER) is 10^(-6). Moreover,33% RZ-4PAM optical signals have better reception performance than 50% RZ-4PAM optical signals.展开更多
The flowing mechanism of a low permeability gas reservoir is different from a conventional gas reservoir,especially for that with higher irreducible water saturation the threshold pressure gradient exists. At present,...The flowing mechanism of a low permeability gas reservoir is different from a conventional gas reservoir,especially for that with higher irreducible water saturation the threshold pressure gradient exists. At present,in all the deliverability equation,the additional pressure drop caused by the threshold pressure gradient is viewed as constant,but this method has big error in the practical application. Based on the non-Darcy steady flow equation,the limited integral of the additional pressure drop is solved in this paper and it is realized that the additional pressure drop is not a constant but has something to do with production data,and a new deliverability equation is derived,with the relevant processing method for modified isochronal test data. The new deliverability equation turns out to be practical through onsite application.展开更多
Medical education is associated with significant costs[1].These costs have led to a growing interest in how to deliver high quality or high quantity education on a limited budget.This in turn has led to an interest in...Medical education is associated with significant costs[1].These costs have led to a growing interest in how to deliver high quality or high quantity education on a limited budget.This in turn has led to an interest in how best to measure quantity,quality and cost and how to track these variables over time.The ultimate aim of the interest in cost and value in medical education is to展开更多
Standards digitalization is a priority of future standardization work in China,as the National Standardization Development Outline puts forward“promoting the transformation of standardization in a digital,networked a...Standards digitalization is a priority of future standardization work in China,as the National Standardization Development Outline puts forward“promoting the transformation of standardization in a digital,networked and smart way”.When delivering a report at the National Standardization Work Conference earlier this year.展开更多
The development of novel drug delivery systems is an essential step toward controlled site-specific administration of therapeutics within the body. It is desirable for delivery vehicles to be introduced into the body ...The development of novel drug delivery systems is an essential step toward controlled site-specific administration of therapeutics within the body. It is desirable for delivery vehicles to be introduced into the body through minimally invasive means and, these vehicles should be capable of releasing drug to their intended location at a controlled rate. Furthermore, it is desirable to develop drug delivery systems that are capable of in vivo to suffer degradation and to deliver the drug completely, avoiding the need to surgically remove the vehicle at the end of its useful lifetime. Hydrogels are of particular interest for drug delivery applications due to their ability to address these needs in addition to their good biocompatibility, tunable network structure to control the diffusion of drugs and, tunable affinity for drugs. However, hydrogels are also limited for drug delivery applications due to the often quick elution of drug from their highly swollen polymer matrices as well as the difficulty inherent in the injection of macroscopic hydrogels into the body. This paper presents an overview to the advances in hydrogels based drug delivery. Different types of hydrogels can be used for drug delivery to specific sites in the gastrointestinal tract ranging from the oral cavity to the colon. These novel systems exhibit a range of several peculiar properties which make them attractive as controlled drug release formulations. Moreover, such materials are biocompatible and can be formulated to give controlled, pulsed, and triggered drug release profiles in a variety of tissues.展开更多
A discrete event heuristic feedback control system fo r a steel plate storage at Odense Steel Shipyard Ltd is developed and implemente d in a computer-based simulation model. The plant is subject to stochastic dist ur...A discrete event heuristic feedback control system fo r a steel plate storage at Odense Steel Shipyard Ltd is developed and implemente d in a computer-based simulation model. The plant is subject to stochastic dist urbances. The control system is able to handle this stochastic behaviour bec ause of the feedback design. The present simulation results indicate that a bene fit in the range of 30%～40% is reachable by modifying the plant. Plant description The steel plate storage is located at Odense Steel Shipyard Ltd, Denmark. The st eel plate storage contains steel plates used to build ship sections. The size of the storage is 600x35 meters. It consists of 32x8 stacks of plates. Plates are delivered and removed dynamically. The plate storage contains 5.000 steel plates in average. Over time, new plates delivered to the storage replace plates removed from the storage. The maximum si ze of a plate is 17x4 meters with a weight of up to 22 tons. The plates are uniq ue and dedicated to a specific purpose but in average the 5 000 plates consist o f 2 500 types. Plates are transported around the plate storage by two portal cranes. The cranes drive on a common rail and hence they cannot overtake each other. The cranes us e magnetic force to lift the plates. The crane can deliver the lifted plate to a conveyor belt or to another stack depending on whether the plate has been order ed for the current day or later. The plant is subject to different kinds of disturbances. The processes performed at the plant are stochastic. Furthermore, the due dates of the plates are frequ ently changed and hence the effect of previously sorting might be lost. The control task is to dispatch movements of plates to the two cranes. The overa ll goal is to minimize the costs at the plate storage and hence the two cranes a re used for executing the movements as fast as possible without colliding and re spect other physical constraints. Problem solution Different approaches have been investigated to solve the problem. A discrete eve nt heuristic feedback controller is used as an online algorithm. The controller is combined with a local search heuristic for improving the initial plan deliver ed by the controller. The improved plan is used as a reference for another feedb ack controller. To indicate the size of the problem, consider an example where the online algori thm is used for executing 600 movements for one day. Through the day the algorit hm finds the locally optimal movement between 20 executable movements. Then the number of different solutions is 20 600! Notice that the possibility of cho osing another destination for the plates to be moved is not taken into account! Results Without time disturbances the controller using an optimised plan as a reference supply the best performance. Nevertheless, when time disturbances are introduces the discrete event heuristic feedback controller performs as well. The comparis on depends on the size of the disturbances. When the disturbances reach a certai n level the discrete event heuristic feedback controller supply the best perform ance and robustness. If the performance is compared with the working system of today, it seems realis tic that a 30%～40% reduction in time is reachable.展开更多
Recombinant vaccinia virus has many advantagesover more restricted vectors like retrovirus andadenovirus. The proven safety of vaccinia virus, which isrestricted to local and transitory infection, favors clinicalappli...Recombinant vaccinia virus has many advantagesover more restricted vectors like retrovirus andadenovirus. The proven safety of vaccinia virus, which isrestricted to local and transitory infection, favors clinicalapplication of vaccinia virus to deliver cytokines locally.展开更多
In recent years, great enthusiasm is given to theresearches of cancer gene therapy, which seems to bea promising novel strategy for cancer treatment.There are several strategies to deliver target genes intobodies. Amo...In recent years, great enthusiasm is given to theresearches of cancer gene therapy, which seems to bea promising novel strategy for cancer treatment.There are several strategies to deliver target genes intobodies. Among them, adenovirus-mediated genetransfection exhibits great advantages including highgene transfer efficiency and high expression level. Butthe optimal route of gene delivery is still uncertain.展开更多
文摘KeLa-2 gas reservoir is the largest uncompartimentalized gas field so far discovered in China, with a reserve of hundreds of billions of cubic meters of dry gas. It has such features as extremely long interval (550m), high pressure (74.5MPa) and pressure coefficient (2.022). Gas reservoirs with a pressure coefficient of over 2.0 are not commonly found. The abnormal high-pressure reservoirs are quite different in characteristic and performance during the process of depletion exploitation. Therefore, it is necessary to know the property of pressure sensitivity for this abnormal high-pressure reservoir. The aim of this paper is to test the reservoir pressure sensitivity and to analyze its effect on the deliverability of gas. Through some experiments, the permeability change with the confining pressure of rock samples from KeLa-2 abnormal high-pressure gas reservoir is measured. A power function is used to match the measured data, and to derive an empirical equation to describe the change of permeability through the change of the reservoir pressure or effective overburden pressure. Considering the permeability change during the development of reservoirs, a conventional deliverability equation is modified, and the deliverability curve for KeLa-2 gas reservoir is predicted. The research indicates that the extent of the pressure sensitivity of rock samples from KeLa-2 is higher than that from the Daqing oilfield. KeLa-2 reservoir rock has the feature of an undercompaction state. The pressure sensitivity of a reservoir may decrease the well deliverability. It is concluded that for KeLa-2 reservoir the predicted absolute open flow (AOF), when the pressure sensitivity is taken into account, is approximately 70% of the AOF when permeability is constant and does not change with pressure.
基金The National Basic Research Program of China (973 Program) under contract No. 2012CB114403General Program of National Natural Science Foundation of China to Dr. Fuhua Li under contract No. 31072203+1 种基金National Hightech Research and Development Program under contract Nos 2012AA10A404 and 2012AA092205China Agriculture Research System under contract No. CARS-47
文摘Recombinant bacteria secreting the transmembrane-truncated region of white spot syndrome virus （WSSV） envelope protein VP28 named DhpVB were constructed, using live Escherichia coli as a deliverer and a con- stitutive secretory expression plasmid as the expression vector. With the ability to deliver recombinant pro- tein products outside, DhpVB could make VP28 directly interact with the shrimp when injected into shrim- p. In order to test the protection potential, live DhpVB were injected into the marine shrimp Exopalamon carincauda Holthuis for three times and WSSV challenge was performed twice simultaneously at the last two injections of the bacteria. The results showed that DhpVB displayed statistically significant advantage over bacteria without VP28 after the second challenge with an average RI （Resistance index） of 0.67±0.08, compared with 0.41±0.09 of bacteria without VP28 （P 〈0.05）. The data suggested that a quasi-immune response may exist in E. carincauda and live bacteria carrying VP28 could enhance the shrimp resistance against WSSV.
文摘Mr.Chairman,Ladies and Gentlemen,It is a great honour and pleasure for me tohave the opportunity to deliver this lecture on“How Acupuncture-Moxibustion Should Go For-ward into the 21st Century”.In 1978,the International Conference onPrimary Health Care held in Alma-Ata recog-nized the potential of traditional medicine in ex-tending primary health care to underserved pop-ulations.In many developing countries,in fact,people have always used both traditional
文摘It is of great significance to forecast high yield of CBM wells and analyze dynamic production by having an overall study on the characteristics of the produced CBM and determining the main factors influencing the productivity of CBM. With the test report and the related geological parameters of a single well, methods of combining the productivity data and typical production curves were used to analyze different geological factors and how to influence the capacity of a single layer. Then, the paper proposed a new understanding about capacity characteristics of the study area and geological control factors： First, the Shanxi formation production capacity characteristics was divided into two-stages, showing signs of gas and gas break- through for 100 days. Second, two parameters, which include potential of gas production and gas production capacity, were bet- ter than the single parameter, such as gas content, coal thickness, and penetration to analyze affecting factors of single well pro- duction. Finally, comprehensive analysis concluded that the ratio of critical desorption pressure to reservoir pressure has greater influence on the production of vertical CBM wells. Besides, the potential of gas production capacity has greater impact at stage of showing gas signs; the coal reservoir pressure and gas production capacity have greater impact at stage of gas breakthrough for 100 days. Thus, to seek the coal bed methane with high ratio of critical desorption pressure to reservoir pressure and high yield of gas will be important guarantee to the success of the coal bed methane exploration and development.
文摘A brand new treatment was reported to cure the cancer triumphantly using the combination of photo-thermal therapy inducing by nitrogen doped carbon dots(N-CDs)and chemotherapy of the doxorubicin(Dox).The experiment results demonstrated that the as-synthesized N-CDs had excellent photo-thermal effect inducing the temperature enhancement as high as about 10℃.Furthermore,the as-prepared N-CDs could load Dox availably and achieve a pH-controlled drug release.Thus,the multifunctional N-CDs-Dox nanocomposites could perform the synergetic effect of photo-thermal therapy and chemotherapy to tumor cells.
基金Supported by the National Natural Science Foundation of China(No.61379057,61073186,61309001,61379110,61103202)Doctoral Fund of Ministry of Education of China(No.20120162130008)the National Basic Research Program of China(973 Program)(No.2014CB046305)
文摘Opportunistic networks are random networks and do not communicate with each other among respective communication areas.This situation leads to great difficulty in message transfer.This paper proposes a reducing energy consumption optimal selection of path transmission(OSPT) routing algorithm in opportunistic networks.This algorithm designs a dynamic random network topology,creates a dynamic link,and realizes an optimized selected path.This algorithm solves a problem that nodes are unable to deliver messages for a long time in opportunistic networks.According to the simulation experiment,OSPT improves deliver ratio,and reduces energy consumption,cache time and transmission delay compared with the Epidemic Algorithm and Spray and Wait Algorithm in opportunistic networks.
基金Project "973",a national fundamental research development program,for its financial support
文摘With the development of the Tazhong No. 1 carbonate gas condensate reservoir in China, it has become more and more important to study the characteristics of gas condensate well deliverability. A single-well radial simulator for dual-permeability reservoirs was established to study the influences of fluid properties, permeability, and pressure drawdown on well deliverability with and without the capillary number effect. The simulation shows that well deliverability basically maintains its initial value and is not affected by the capillary number when the formation pressure is higher than dew-point pressure. However, well deliverability drops rapidly when the formation pressure is lower than dew-point pressure. Even if the condensate dropout is very low, well deliverability without the capillary number effect reduces to 50 percent of its initial value when reservoir pressure declines to 95 percent of dew-point pressure, but well deliverability is significantly improved if the capillary number effect exists. The capillary number effect is most significant when reservoir pressure is just lower than dew point pressure, then the effect decreases; the reduction of well deliverability is mainly caused by the reduction of gas relative permeability of the matrix system near the wellbore.
基金supporting this work and funding research through the project Enabling Large-Scale Hydrogen Underground Storage in Porous Media(21.RP2.0091)。
文摘Hydrogen has emerged as a promising alternative to meet the growing demand for sustainable and renewable energy sources.Underground hydrogen storage(UHS)in depleted gas reservoirs holds significant potential for large-scale energy storage and the seamless integration of intermittent renewable energy sources,due to its capacity to address challenges associated with the intermittent nature of renewable energy sources,ensuring a steady and reliable energy supply.Leveraging the existing infrastructure and well-characterized geological formations,depleted gas reservoirs offer an attractive option for large-scale hydrogen storage implementation.However,significant knowledge gaps regarding storage performance hinder the commercialization of UHS operation.Hydrogen deliverability,hydrogen trapping,and the equation of state are key areas with limited understanding.This literature review critically analyzes and synthesizes existing research on hydrogen storage performance during underground storage in depleted gas reservoirs;it then provides a high-level risk assessment and an overview of the techno-economics of UHS.The significance of this review lies in its consolidation of current knowledge,highlighting unresolved issues and proposing areas for future research.Addressing these gaps will advance hydrogen-based energy systems and support the transition to a sustainable energy landscape.Facilitating efficient and safe deployment of UHS in depleted gas reservoirs will assist in unlocking hydrogen’s full potential as a clean and renewable energy carrier.In addition,this review aids policymakers and the scientific community in making informed decisions regarding hydrogen storage technologies.
文摘The Film Copy Deliverer Problem (FDP),much more difficult than TSP,is a new problem in the combination optimization. In this paper,a new algorithm is introduced. First,the FDP is converted to TSP. Then an evolutionary algorithm based on inversion operator is adopted. Compared with other Genetic Algorithms,it is not only more simple and easier to realize but also faster and more accurate.
基金supported by the National Natural Science Foundation of China(No.61107064)the Chongqing University Innovation Team Founding(No.KJTD201320)+3 种基金the Natural Science Foundation of Chongqing Science & Technology Commission(Nos.cstc2014jcyj A40046 and cstc2016jcyj A1233)the Science and Technology Special Funds of Wanzhou District in Chongqing Citythe Chongqing Graduate Student Research Innovation Project(No.CYS15225)the Chongqing Three Gorges University Graduate Scientific Research Innovation Project
文摘4-ary pulse amplitude modulation(4PAM) signals with 33% and 50% return-to-zero(RZ) clocks are generated for passive optical network(PON). We demonstrate that RZ-4PAM signals with duty cycles of 33% and 50% after transmission over 20-km-long single mode fiber(SMF) at 10 Gbit/s can be directly detected by using one photo detector,and the original data can also be restored by one M-ary threshold detector and one 4PAM sequence decoder. The optical spectra of 33% and 50% RZ-4PAM signals are measured,and their eye-diagrams before and after transmission are also analyzed. Simulation results show that 33% and 50% RZ-4PAM downlink signals can be received effectively,and the received power values are-15.1 d Bm and-13.8 d Bm when the bit error rate(BER) is 10^(-6). Moreover,33% RZ-4PAM optical signals have better reception performance than 50% RZ-4PAM optical signals.
基金National Basic Research Program of China(2007CB209506)
文摘The flowing mechanism of a low permeability gas reservoir is different from a conventional gas reservoir,especially for that with higher irreducible water saturation the threshold pressure gradient exists. At present,in all the deliverability equation,the additional pressure drop caused by the threshold pressure gradient is viewed as constant,but this method has big error in the practical application. Based on the non-Darcy steady flow equation,the limited integral of the additional pressure drop is solved in this paper and it is realized that the additional pressure drop is not a constant but has something to do with production data,and a new deliverability equation is derived,with the relevant processing method for modified isochronal test data. The new deliverability equation turns out to be practical through onsite application.
文摘Medical education is associated with significant costs[1].These costs have led to a growing interest in how to deliver high quality or high quantity education on a limited budget.This in turn has led to an interest in how best to measure quantity,quality and cost and how to track these variables over time.The ultimate aim of the interest in cost and value in medical education is to
文摘Standards digitalization is a priority of future standardization work in China,as the National Standardization Development Outline puts forward“promoting the transformation of standardization in a digital,networked and smart way”.When delivering a report at the National Standardization Work Conference earlier this year.
基金This work was financially supported by a Grant(Praxis SFRH/BD/48324/2008)from FCT(Fundacao para a Ciencia e a Tecnologia,Portugal).
文摘The development of novel drug delivery systems is an essential step toward controlled site-specific administration of therapeutics within the body. It is desirable for delivery vehicles to be introduced into the body through minimally invasive means and, these vehicles should be capable of releasing drug to their intended location at a controlled rate. Furthermore, it is desirable to develop drug delivery systems that are capable of in vivo to suffer degradation and to deliver the drug completely, avoiding the need to surgically remove the vehicle at the end of its useful lifetime. Hydrogels are of particular interest for drug delivery applications due to their ability to address these needs in addition to their good biocompatibility, tunable network structure to control the diffusion of drugs and, tunable affinity for drugs. However, hydrogels are also limited for drug delivery applications due to the often quick elution of drug from their highly swollen polymer matrices as well as the difficulty inherent in the injection of macroscopic hydrogels into the body. This paper presents an overview to the advances in hydrogels based drug delivery. Different types of hydrogels can be used for drug delivery to specific sites in the gastrointestinal tract ranging from the oral cavity to the colon. These novel systems exhibit a range of several peculiar properties which make them attractive as controlled drug release formulations. Moreover, such materials are biocompatible and can be formulated to give controlled, pulsed, and triggered drug release profiles in a variety of tissues.
文摘A discrete event heuristic feedback control system fo r a steel plate storage at Odense Steel Shipyard Ltd is developed and implemente d in a computer-based simulation model. The plant is subject to stochastic dist urbances. The control system is able to handle this stochastic behaviour bec ause of the feedback design. The present simulation results indicate that a bene fit in the range of 30%～40% is reachable by modifying the plant. Plant description The steel plate storage is located at Odense Steel Shipyard Ltd, Denmark. The st eel plate storage contains steel plates used to build ship sections. The size of the storage is 600x35 meters. It consists of 32x8 stacks of plates. Plates are delivered and removed dynamically. The plate storage contains 5.000 steel plates in average. Over time, new plates delivered to the storage replace plates removed from the storage. The maximum si ze of a plate is 17x4 meters with a weight of up to 22 tons. The plates are uniq ue and dedicated to a specific purpose but in average the 5 000 plates consist o f 2 500 types. Plates are transported around the plate storage by two portal cranes. The cranes drive on a common rail and hence they cannot overtake each other. The cranes us e magnetic force to lift the plates. The crane can deliver the lifted plate to a conveyor belt or to another stack depending on whether the plate has been order ed for the current day or later. The plant is subject to different kinds of disturbances. The processes performed at the plant are stochastic. Furthermore, the due dates of the plates are frequ ently changed and hence the effect of previously sorting might be lost. The control task is to dispatch movements of plates to the two cranes. The overa ll goal is to minimize the costs at the plate storage and hence the two cranes a re used for executing the movements as fast as possible without colliding and re spect other physical constraints. Problem solution Different approaches have been investigated to solve the problem. A discrete eve nt heuristic feedback controller is used as an online algorithm. The controller is combined with a local search heuristic for improving the initial plan deliver ed by the controller. The improved plan is used as a reference for another feedb ack controller. To indicate the size of the problem, consider an example where the online algori thm is used for executing 600 movements for one day. Through the day the algorit hm finds the locally optimal movement between 20 executable movements. Then the number of different solutions is 20 600! Notice that the possibility of cho osing another destination for the plates to be moved is not taken into account! Results Without time disturbances the controller using an optimised plan as a reference supply the best performance. Nevertheless, when time disturbances are introduces the discrete event heuristic feedback controller performs as well. The comparis on depends on the size of the disturbances. When the disturbances reach a certai n level the discrete event heuristic feedback controller supply the best perform ance and robustness. If the performance is compared with the working system of today, it seems realis tic that a 30%～40% reduction in time is reachable.
文摘Recombinant vaccinia virus has many advantagesover more restricted vectors like retrovirus andadenovirus. The proven safety of vaccinia virus, which isrestricted to local and transitory infection, favors clinicalapplication of vaccinia virus to deliver cytokines locally.
文摘In recent years, great enthusiasm is given to theresearches of cancer gene therapy, which seems to bea promising novel strategy for cancer treatment.There are several strategies to deliver target genes intobodies. Among them, adenovirus-mediated genetransfection exhibits great advantages including highgene transfer efficiency and high expression level. Butthe optimal route of gene delivery is still uncertain.
