The education and management of party members is the basic and regular work of the party building, which is crucial to improving the quality of the party members and maintaining the advanced nature and purity of the p...The education and management of party members is the basic and regular work of the party building, which is crucial to improving the quality of the party members and maintaining the advanced nature and purity of the party members. College student Party members are an important part of Party members, and it is of great significance to do a good job in educating college student Party members. Based on the exploration of the weak links in the education process of college student party members, this paper puts forward targeted solutions to improve the pertinence and effectiveness of college student party members education.展开更多
Based on the“three box”exergy analysis model,a black box-gray box hierarchical exergy analysis and evaluation method is put forward in this paper,which is applied to evaluate the power generation technology of diffe...Based on the“three box”exergy analysis model,a black box-gray box hierarchical exergy analysis and evaluation method is put forward in this paper,which is applied to evaluate the power generation technology of differential pressure produced by natural gas expansion.By using the exergy analysis theory,the black box-gray box hierarchical exergy analysis models of three differential pressure power generation technologies are established respectively.Firstly,the“black box”analysis models of main energy consuming equipment are established,and then the“gray box”analysis model of the total system is established.Based on the calculation results of exergy analysis indexes,the weak energy consumption equipment in the whole power generation process is accurately located.Taking a gas field in southwest China as an example,the comprehensive energy consumption evaluation of the three power generation technologies is carried out,and the technology with the best energy consumption condition among the three technologies is determined.Finally,the rationalization improvement measures are put forward from improving the air tightness,replacing the deflector and reducing the flow loss.展开更多
The Josephson effect of Bose condensates with a weak link created by superposing a far-off-resonant red-detuned laser beam on a double-well potential is theoretically considered. The numerical simulations show that th...The Josephson effect of Bose condensates with a weak link created by superposing a far-off-resonant red-detuned laser beam on a double-well potential is theoretically considered. The numerical simulations show that there would be c/ear Josephson effect for this sort of three-well system. The present work gives a feasible scheme to study a new type of weak link which is crucial to investigate experimentally the Josephson effect.展开更多
A modified spark plasma sintering（SPS） technique was developed for the fabrication of Bi2Sr2CaCu2Ox（Bi-2212）superconducting bulks with better intergrain connections. The influences of the modified SPS process on t...A modified spark plasma sintering（SPS） technique was developed for the fabrication of Bi2Sr2CaCu2Ox（Bi-2212）superconducting bulks with better intergrain connections. The influences of the modified SPS process on the microstructures, intergrain connections, and related superconducting properties were systematically analyzed. The modified SPS process can not only increase the final density of the bulk samples but also enhance the texture structures. Clean grain boundaries were obtained instead of the intergrain amorphous layers. Therefore the intergranular properties were obviously improved. Due to the better intergrain connections and the stronger flux pinning properties, the critical current densities of the Bi-2212 bulks obtained via the modified SPS process were greatly increased. The obtained improvements imply the possibility for the modified SPS technique to be used for enhancing the superconducting properties of the Bi-2212 tapes.展开更多
YBa 2Cu 3O 7-δ weak link junctions with width from 0.1 mm to 0.3 mm and length from 0.2 mm to 0.5 mm was made by hand with a razor blade. The current voltage characteristics of the microbridges show, under...YBa 2Cu 3O 7-δ weak link junctions with width from 0.1 mm to 0.3 mm and length from 0.2 mm to 0.5 mm was made by hand with a razor blade. The current voltage characteristics of the microbridges show, under microwave irradiation, pronounced Shapiro steps up to transition temperature. A careful measurement of the dependence of the critical supercurrent on the external magnetic field and laser light is presented.展开更多
N−1 security is an important criterion for the development and planning of distribution networks.The existing N−1 contingency analysis methods of distribution networks are primarily based on the unit of components,and...N−1 security is an important criterion for the development and planning of distribution networks.The existing N−1 contingency analysis methods of distribution networks are primarily based on the unit of components,and the faults of each component are analyzed and verified one by one.The calculation process of these methods is complicated,and the positioning effect of the weak links needed for distribution network planning is insufficient.For this reason,this paper proposes a method of N−1 contingency parallel analysis for main transformers based on the incidence matrix.First,the main transformer incidence matrix is established,and the load transfer process is classified into three types,according to different transfer modes,and the contact matrices are then established respectively.Second,considering the capacity constraint of main transformers and tie-lines,the corresponding capacity matrices are established.The maximum transfer capability(MTC)of the distribution network in the case of each main transformer fault is calculated by contact matrices and capacity matrices,and the N−1 contingency analysis result is obtained by comparing MTC with the load that needs transferring.Meanwhile,the transfer margin of the main transformers and tie-lines after transferring can be obtained in the process of N−1 contingency analysis,so as to find any weak links.An example is given to verify the correctness and effectiveness of the proposed method.In this paper,the N−1 contingency analysis results of all main transformers in the distribution network are expressed analytically through matrices operations,and the weak links can then be intuitively identified.The cumbersome operation of checking each component is avoided,and the computational efficiency is improved.展开更多
In this paper,we propose a simple model of opinion dynamics to construct social networks,based on the algorithm of link rewiring of local attachment(RLA)and global attachment(RGA).Generality,the system does reach a st...In this paper,we propose a simple model of opinion dynamics to construct social networks,based on the algorithm of link rewiring of local attachment(RLA)and global attachment(RGA).Generality,the system does reach a steady state where all individuals'opinion and the complex network structure are fixed.The RGA enhances the ability of consensus of opinion formation.Furthermore,by tuning a model parameter p,which governs the proportion of RLA and RGA,we find the formation of hierarchical structure in the social networks for p>p_(c).Here,p_(c) is related to the complex network size N and the minimal coordination number 2K.The model also reproduces many features of large social networks,including the“weak links”property.展开更多
文摘The education and management of party members is the basic and regular work of the party building, which is crucial to improving the quality of the party members and maintaining the advanced nature and purity of the party members. College student Party members are an important part of Party members, and it is of great significance to do a good job in educating college student Party members. Based on the exploration of the weak links in the education process of college student party members, this paper puts forward targeted solutions to improve the pertinence and effectiveness of college student party members education.
基金financially supported by the National Natural Science Foundation of China(52074089 and 51534004)Natural Science Foundation of Heilongjiang Province of China(LH2019E019)。
文摘Based on the“three box”exergy analysis model,a black box-gray box hierarchical exergy analysis and evaluation method is put forward in this paper,which is applied to evaluate the power generation technology of differential pressure produced by natural gas expansion.By using the exergy analysis theory,the black box-gray box hierarchical exergy analysis models of three differential pressure power generation technologies are established respectively.Firstly,the“black box”analysis models of main energy consuming equipment are established,and then the“gray box”analysis model of the total system is established.Based on the calculation results of exergy analysis indexes,the weak energy consumption equipment in the whole power generation process is accurately located.Taking a gas field in southwest China as an example,the comprehensive energy consumption evaluation of the three power generation technologies is carried out,and the technology with the best energy consumption condition among the three technologies is determined.Finally,the rationalization improvement measures are put forward from improving the air tightness,replacing the deflector and reducing the flow loss.
基金Supported by the National Natural Science Foundation of China under Grant No 10474119, the National Basic Research Programme of China under Grant No 2005CB724508, and the Funds from Chinese Academy of Sciences.
文摘The Josephson effect of Bose condensates with a weak link created by superposing a far-off-resonant red-detuned laser beam on a double-well potential is theoretically considered. The numerical simulations show that there would be c/ear Josephson effect for this sort of three-well system. The present work gives a feasible scheme to study a new type of weak link which is crucial to investigate experimentally the Josephson effect.
基金Project supported by the National Basic Research Program of China(Grant No.2011CBA00104)the National Natural Science Foundation of China(Grant No.51472206)+1 种基金the ITER Project of China(Grant No.2013GB110001)the Program for Innovative Research Team in Shaanxi Province,China(Grant No.2013KCT-07)
文摘A modified spark plasma sintering（SPS） technique was developed for the fabrication of Bi2Sr2CaCu2Ox（Bi-2212）superconducting bulks with better intergrain connections. The influences of the modified SPS process on the microstructures, intergrain connections, and related superconducting properties were systematically analyzed. The modified SPS process can not only increase the final density of the bulk samples but also enhance the texture structures. Clean grain boundaries were obtained instead of the intergrain amorphous layers. Therefore the intergranular properties were obviously improved. Due to the better intergrain connections and the stronger flux pinning properties, the critical current densities of the Bi-2212 bulks obtained via the modified SPS process were greatly increased. The obtained improvements imply the possibility for the modified SPS technique to be used for enhancing the superconducting properties of the Bi-2212 tapes.
文摘YBa 2Cu 3O 7-δ weak link junctions with width from 0.1 mm to 0.3 mm and length from 0.2 mm to 0.5 mm was made by hand with a razor blade. The current voltage characteristics of the microbridges show, under microwave irradiation, pronounced Shapiro steps up to transition temperature. A careful measurement of the dependence of the critical supercurrent on the external magnetic field and laser light is presented.
基金supported in part by National Key Research and Development Program of China under Grant 2020YFB0906000in part by National Natural Science Foundation of China under Grant 51977140,Grant U1866207 and Grant 51207101in part by Natural Science Foundation of Tianjin under Grant 19JCYBJC21300。
文摘N−1 security is an important criterion for the development and planning of distribution networks.The existing N−1 contingency analysis methods of distribution networks are primarily based on the unit of components,and the faults of each component are analyzed and verified one by one.The calculation process of these methods is complicated,and the positioning effect of the weak links needed for distribution network planning is insufficient.For this reason,this paper proposes a method of N−1 contingency parallel analysis for main transformers based on the incidence matrix.First,the main transformer incidence matrix is established,and the load transfer process is classified into three types,according to different transfer modes,and the contact matrices are then established respectively.Second,considering the capacity constraint of main transformers and tie-lines,the corresponding capacity matrices are established.The maximum transfer capability(MTC)of the distribution network in the case of each main transformer fault is calculated by contact matrices and capacity matrices,and the N−1 contingency analysis result is obtained by comparing MTC with the load that needs transferring.Meanwhile,the transfer margin of the main transformers and tie-lines after transferring can be obtained in the process of N−1 contingency analysis,so as to find any weak links.An example is given to verify the correctness and effectiveness of the proposed method.In this paper,the N−1 contingency analysis results of all main transformers in the distribution network are expressed analytically through matrices operations,and the weak links can then be intuitively identified.The cumbersome operation of checking each component is avoided,and the computational efficiency is improved.
基金supported by the National Natural Science Foundation of China(Grant Nos.10647125,10635020,10975057 and 10975062)the Programme of Introducing Talents of Discipline to Universities under Grant No.B08033.
文摘In this paper,we propose a simple model of opinion dynamics to construct social networks,based on the algorithm of link rewiring of local attachment(RLA)and global attachment(RGA).Generality,the system does reach a steady state where all individuals'opinion and the complex network structure are fixed.The RGA enhances the ability of consensus of opinion formation.Furthermore,by tuning a model parameter p,which governs the proportion of RLA and RGA,we find the formation of hierarchical structure in the social networks for p>p_(c).Here,p_(c) is related to the complex network size N and the minimal coordination number 2K.The model also reproduces many features of large social networks,including the“weak links”property.
