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Target recognition based on modified combination rule 被引量:16
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作者 Chen Tianlu Que Peiwen 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第2期279-283,共5页
Evidence theory is widely used in the field of target recognition. The invalidation problem of this theory when dealing with highly conflict evidences is a research hotspot. Several alternatives of the combination rul... Evidence theory is widely used in the field of target recognition. The invalidation problem of this theory when dealing with highly conflict evidences is a research hotspot. Several alternatives of the combination rule are analyzed and compared. A new combination approach is proposed. Calculate the reliabilities of evidence sources using existing evidences. Construct reliabilities judge matrixes and get the weights of each evidence source. Weight average all inputted evidences. Combine processed evidences with D-S combination rule repeatedly to identify a target. The application in multi-sensor target reeognition as well as the comparison with typical alternatives all validated that this approach can dispose highly conflict evidences efficiently and get reasonable reeognition results rapidly. 展开更多
关键词 evidence theory combination rule conflict evidences target recognition data fusion.
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Effects of water intrusion and loading rate on mechanical properties of and crack propagation in coal–rock combinations 被引量:12
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作者 陈田 姚强岭 +4 位作者 卫斐 种照辉 周健 王常彬 李静 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第2期423-431,共9页
Tackling the problems of underground water storage in collieries in arid regions requires knowledge of the effect of water intrusion and loading rate on the mechanical properties of and crack development in coal–rock... Tackling the problems of underground water storage in collieries in arid regions requires knowledge of the effect of water intrusion and loading rate on the mechanical properties of and crack development in coal–rock combinations. Fifty-four coal–rock combinations were prepared and split equally into groups containing different moisture contents(dry, natural moisture and saturated) to conduct acoustic emission testing under uniaxial compression with loading rates ranging from 0.1 mm/min to 0.6 mm/min. The results show that the peak stress and strength-softening modulus, elastic modulus, strain-softening modulus, and post-peak modulus partly decrease with increasing moisture content and loading rate. In contrast, peak strain increases with increasing moisture content and fluctuates with rising loading rate. More significantly, the relationship between stiffness and stress, combined with accumulated counts of acoustic emission, can be used to precisely predict all phases of crack propagation. This is helpful in studying the impact of moisture content and loading rate on crack propagation and accurately calculating mechanical properties. We also determined that the stress thresholds of crack closure, crack initiation, and crack damage do not vary with changes of moisture content and loading rate, constituting 15.22%, 32.20%, and 80.98% of peak stress, respectively. These outcomes assist in developing approaches to water storage in coal mines, determining the necessary width of waterproof coal–rock pillars, and methods of supporting water-enriched roadways, while also advances understanding the mechanical properties of coal–rock combinations and laws of crack propagation. 展开更多
关键词 water intrusion loading rate mechanical properties coal-rock combination crack propagation stress threshold
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Active fraction combination from Liuwei Dihuang decoction(LW-AFC) ameliorates corticosterone-induced long-term potentiation impairment in mice in vivo 被引量:4
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作者 HUANG Yan LI Dong +3 位作者 CHENG Bin LIU Gang ZHANG Yong-xiang ZHOU Wen-xia 《中国药理学与毒理学杂志》 CAS 北大核心 2019年第6期436-437,共2页
Liuwei Dihuang decoction(LW), a classic formula in traditional Chinese medicine(TCM), has been used for nearly one thousand years for various diseases with characteristic features of kidney yin deficiency. LW consists... Liuwei Dihuang decoction(LW), a classic formula in traditional Chinese medicine(TCM), has been used for nearly one thousand years for various diseases with characteristic features of kidney yin deficiency. LW consists of 6herbs including Dihuang[prepared root of Rehmannia glutinosa(Gaertn) DC], Shanyao(rhizome of Dioscorea polystachya Turcz), Shanzhuyu(fruit of Cornus officinalis Siebold Zucc), Mudanpi(root bark of Paeonia × suffruticosa Andrews),Zexie(rhizome of Alisma plantago-aquatica L) and Fuling(scleorotia of Wolfiporia extensa(Peck) Ginns)LW-active fraction combination(LW-AFC) is extracted from LW, it is effective for the treatment of kidney yin deficiency in many animal models. There are 3 fractions in LW-AFC, a polysaccharide fraction(LWB-B), a glycoside fraction(LWD-b) and an oligosaccharide fraction(CA-30). Our previous results indicate that LW-AFC has similar pharmacological effects to LW, modulating the balance of the NIM network. LW-AFC has positive effects in many animal models of kidney deficiency or disturbance of the NIM network. LW-AFC could improve the cognitive ability in Alzheimer′s disease(AD) animal models(APP/PS1, SAMP8), where modulating immune function and balancing the NIM network may play an important role in its cognition improving effects. Our study also showed that LW-AFC had protective effects on stress-induced disturbances of the NIM network. However, the underlying mechanisms remain elusive and need further investigation. OBJECTIVE This study evaluated the effects of LW-AFC and the active fractions(polysaccharide, LWB-B;glycoside, LWD-b;oligosaccharide,CA-30) on corticosterone(Cort)-induced long-term potentiation(LTP) impairment in vivo. METHODS LTP was used to evaluate the synaptic plasticity. LW-AFC was orally administered for seven days. The active fractions were given by either chronic administration(ig, ip, 7 d) or single administration(icv, ig, ip). Cort was injected subcutaneously 1 h before the high-frequency stimulation(HFS) to induce LTP impairment. Moreover, in order to research on the possible effective pathways, an antibiotic cocktail and an immunosuppressant were also used. RESULTS Chronic administration(ig) of LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment. Single administration(icv, ig, ip) of any of the active fractions had no effect on Cort-induced LTP impairment, while chronic administration(ig, ip) of LWB-B or LWD-b showed positive effects against Cort. Interestingly, CA-30 only showed protective effects via ig administration,and there was little effect when CA-30 was administered ip In addition, when the intestinal microbiota was disrupted by application of the antibiotic cocktail, CA-30 showed little protective effects against Cort. The effects of LW-AFC were also abolished when the immune function was inhibited. In the hippocampal tissue, Cort treatment increased corticosterone and glutamate, and LW-AFC could inhibit the Cort-induced elevation of corticosterone and glutamate;there was little change in D-serine in Cort-treated animals, but LW-AFC could increase the D-serine levels. CONCLUSION LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment. Their protective effects are unlikely by a direct way, and immune modulation might be the common pathway. CA-30 could protect LTP from impairment via modulating the intestinal microbiota. Decreasing corticosterone and glutamate and increasing D-serine in the Cort-treated animals’ hippocampal tissue might be one of the mechanisms for the neural protective effects of LW-AFC. Further study is needed to understand the underlying mechanisms. 展开更多
关键词 LW-active fraction combination ACTIVE FRACTIONS CORTICOSTERONE long-term POTENTIATION SYNAPTIC plasticity stress
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On units combination and commitment optimization for electric power production 被引量:1
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作者 谭忠富 何永秀 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2004年第1期12-18,共7页
Electric power system is one of the most important and complex engineering in modern society, supplying main and general power for social production and social life. Meanwhile, since it is a productive system with bo... Electric power system is one of the most important and complex engineering in modern society, supplying main and general power for social production and social life. Meanwhile, since it is a productive system with both high input and output, it has an obvious economic significance to improve its operating efficiency. For an example, an unit is 10 GW scale, if its standard coal consumption can be decreased with 1 g/kW·h, it can save about 5 000 tons standard coal per year. It will be discussed mainly that how to establish optimization model and its numerical algorithm for operating management of the electric power system. The idea on establishing optimization model is how to dispatch work state of units or power plants, so that total cost of fuel consumption for generation is reduced to the minimum. Here the dispatch is to decide which unit or plant to operate, which unit or plant to stop running, how much power should be generated for those operating units or plants at each given time interval. 展开更多
关键词 units combination units commitment OPTIMIZATION plants combination interconnection system
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Evidence combination method in time domain based on reliability and importance 被引量:2
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作者 LUO Chengkun CHEN Yunxiang +2 位作者 XIANG Huachun WANG Weijia WANG Zezhou 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第6期1308-1316,共9页
In order to achieve the information fusion in the time domain based on the evidence theory, an evidence combination method in the time domain based on reliability and importance is proposed according to the idea of ev... In order to achieve the information fusion in the time domain based on the evidence theory, an evidence combination method in the time domain based on reliability and importance is proposed according to the idea of evidence discount. Firstly, the distortion of the time-domain evidence is judged based on single exponential smoothing. The real-time reliability of the evidence at the adjacent time is obtained by the real-time reliability assessment method of the evidence based on the credibility decay model.Then, the relative importance of the evidence at the adjacent time is obtained by comprehensively considering improved conflict degree and uncertainty. Finally, based on the criterion of evidence discount and the Dempster’s rule of combination, the evidence combination is carried out to achieve the sequential combination of time-domain evidence. The numerical simulation and analysis show that this method has fully embodied the dynamic characteristics of time-domain evidence combination, and it has strong processing ability for conflict information and anti-disturbing ability.The proposed method has good applicability to information fusion in the time domain. 展开更多
关键词 evidence theory time-domain evidence combination evidence discount RELIABILITY IMPORTANCE
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Temporal evidence combination method for multi-sensor target recognition based on DS theory and IFS 被引量:4
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作者 Ju Wang Fuxian Liu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第6期1114-1125,共12页
In order to effectively deal with the conflict temporal evidences without affecting the sequential and dynamic characteristics in the multi-sensor target recognition(MSTR) system at the decision making level, this pap... In order to effectively deal with the conflict temporal evidences without affecting the sequential and dynamic characteristics in the multi-sensor target recognition(MSTR) system at the decision making level, this paper proposes a Dempster-Shafer(DS) theory and intuitionistic fuzzy set(IFS) based temporal evidence combination method(DSIFS-TECM). To realize the method,the relationship between DS theory and IFS is firstly analyzed. And then the intuitionistic fuzzy possibility degree of intuitionistic fuzzy value(IFPD-IFV) is defined, and a novel ranking method with isotonicity for IFV is proposed. Finally, a calculation method for relative reliability factor(RRF) is designed based on the proposed ranking method. As a proof of the method, numerical analysis and experimental simulation are performed. The results indicate DSIFS-TECM is capable of dealing with the conflict temporal evidences and sensitive to the changing of time. Furthermore, compared with the existing methods, DSIFS-TECM has stronger ability of anti-interference. 展开更多
关键词 Dempster-Shafer(DS) theory intuitionistic fuzzy set(IFS) temporal evidence combination relative reliability factor
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Combination effect of seasonal freezing and artificial freezing on frost heave of silty clay 被引量:7
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作者 于琳琳 徐学燕 马琛 《Journal of Central South University》 SCIE EI CAS 2010年第1期163-168,共6页
To investigate the frost-heave properties of silty clay under the combination action of seasonal freezing and artificial freezing, and verify the feasibility of combined freezing, eight combined freezing experiments w... To investigate the frost-heave properties of silty clay under the combination action of seasonal freezing and artificial freezing, and verify the feasibility of combined freezing, eight combined freezing experiments were performed on silty clay with water content (mass fraction) of 23.5% and 28.0%, through developed frost-heave test apparatus, in closed or open system. Two sorts of freezing temperature models, namely, constant and sine models, were applied to artificial freezing. The experimental results indicate that the frost-heave degree in seasonal freezing stage accounts for over 90% of the total in open system and it is up to 95% in closed system; the change of artificial sine-freezing temperature has no influence on the frost-heave degree in closed system, however, slight influence in open system. It is found that the variation of temperature gradient of sine-freezing specimen lags behind that of sine-freezing temperature with half phase; sine-freezing temperature model can reduce frost-heave degree of soil. Brand new technology is proposed for the application of artificial ground freezing and new study field of artificial freezing is created. 展开更多
关键词 seasonal freezing artificial freezing combined freezing sine-freezing freezing-temperature models frost-heave degree
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Nonlinear dynamics of flexible rotor system supported on fixed-tilting pad combination journal bearing 被引量:4
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作者 吕延军 张永芳 +1 位作者 于杨冰 虞烈 《Journal of Central South University》 SCIE EI CAS 2011年第3期610-617,共8页
Based on the Reynolds equation with Reynolds boundary conditions, the Castelli method was employed to solve the Reynolds equation for oil lubrication upon bearings. By doing so, a profile of nonlinear oil film force o... Based on the Reynolds equation with Reynolds boundary conditions, the Castelli method was employed to solve the Reynolds equation for oil lubrication upon bearings. By doing so, a profile of nonlinear oil film force of single-pad journal bearings is established. According to the structure of combination journal bearings, nonlinear oil film force of combination journal bearing is obtained by retrieval, interpolation and assembly techniques. As for symmetrical flexible Jeffcott rotor systems supported by combination journal bearings, the nonlinear motions of the center of the rotor are calculated by the self-adaptive Runge-Kutta method and Poincar6 mapping with different rotational speeds. The numerical results show that the system performance is slightly better when the pivot ratio changes from 0.5 to 0.6, and reveals nonlinear phenomena of periodic, period-doubing, quasi-periodic motion, etc. 展开更多
关键词 fixed-tilting pad combination journal bearings nonlinear analysis DYNAMICS BIFURCATION
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Characterization of stereostructure by X-ray and technology of extracting in combination hydrolysis in situ of acankoreanogenin from leaves of Acanthopanax gracilistylus W.W.Smith 被引量:1
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作者 戴玲 刘向前 +1 位作者 谢霞 刘恒言 《Journal of Central South University》 SCIE EI CAS 2014年第8期3063-3070,共8页
To study the stereostructure by X-ray and the technology of extracting acankoreanogenin from the leaves of Acanthopanax graeilistylus W. W. Smith (AGS), the crystal structure was measured with a Bruker APEX-Ⅱ area-... To study the stereostructure by X-ray and the technology of extracting acankoreanogenin from the leaves of Acanthopanax graeilistylus W. W. Smith (AGS), the crystal structure was measured with a Bruker APEX-Ⅱ area-detector diffractometer instrument and the technology of extracting in combination hydrolysis in situ (ECHS) was compared with these of traditional methods. The crystal belongs to the monoclinic system, space group P2b with unit cell parameters: a=(8.3652±0.0006) nm, b=(24.721±0.002) nm, and c=(14.5587±0.0011) nm, α=90°, β=97.850 (4) °, γ=90 °, V=2982.51 nm3, Dc= 1.179 mg/m3, and the molecular number (Z) of elementary structures was 2. The comparisons show that the extraction rate of acankoreanogenin with ECHS methods is much higher than that of traditional methods. Then, central composite design-response surface methodology (CCD-RSM) was adopted for optimizing the extraction rate of ECHS methods. The optimized values of extraction parameters are as follows: for the for extraction process of acid hydrolysis are that extraction time 110.8 min, solvent-herb ratio 11.5 and acid content 5.25%; the best extraction process of basic hydrolysis are that extract time 120 min, solvent-herb ratio 8.7 and the alkali content 8.79%. Finally, the extracts were purified with decolorizing carbon after alkali solution and acid-isolation and purity of acankoreanogenin was 98.7%. 展开更多
关键词 acankoreanogenin extraction in combination hydrolysis in situ Acanthopanax gracilistylus W. W. Smith (AGS) centralcomposite design-response surface methodology
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Analysis on the combination ability and stability of rice restore line Yihui1577
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作者 BAO Lingfeng LIN Gang ZHAO Deming LI Yunwu HE Bing 《Journal of Northeast Agricultural University(English Edition)》 CAS 2007年第4期301-305,共5页
Yihui1577 was bred after over 10 generations by crossing RI6 and Yunnan purple rice. Many new hybrid rice varieties had been bred with Yihui 1577, of which Gangyou 1577, Ⅱ you1577, Nyou 1577 and Yixiang1577 were cert... Yihui1577 was bred after over 10 generations by crossing RI6 and Yunnan purple rice. Many new hybrid rice varieties had been bred with Yihui 1577, of which Gangyou 1577, Ⅱ you1577, Nyou 1577 and Yixiang1577 were certified by Sichuan Province Crop Variety Release Committee, Gangyou1577 and Yixiang1577 were certified by National Crop Variety Release Committee. The series varieties bred with Yihui1577 had been used widely with accumulated areas of 1 200 000 hm2. By using Yihui1577 as breeding material, an excellent restore line Yihui 3003 and some other restore lines, such as Yihui 1979, Yihui 315 with good rice quality and good combination ability had been bred. Analysis of combination ability and stability about restore line Yihui 1577 was made by using agricultural experimentation and statistical approach. The combination ability analysis was made in complete dual crossing method with 4 CMS lines and 6 restorer lines. It showed that the general combination ability effect value of Yihui1577 was 0.226, while Minghui63 was -0.113. So the general combination ability ofYihui1577 was prior to that of Minghui 63. Stability analysis showed that the F value of Gangyou1577 was 1.81378, while Sanyou 63 was 1.40327, both didn't reach significant level. So Gangyou1577 had the same stability as Sanyou 63. The same conclusion had got in the stability analysis of the breeds of Ⅱ you 1577, Yixiang 1577, Nyou 1577 and so on. 展开更多
关键词 RICE restore line Yihui 1577 combination ability STABILITY
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Combination Method for Parallel Computation in ODEs
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作者 Song Xiaoqiu(Beijing Institute of Computer Application and Simulation Technology ) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1996年第4期19-26,共8页
In this paper, a 3rd order combination method with three processes and a 4th order combination method with five processes for solving ODEs are discussed. These methods are the Runge-Kutta method combined with a linear... In this paper, a 3rd order combination method with three processes and a 4th order combination method with five processes for solving ODEs are discussed. These methods are the Runge-Kutta method combined with a linear multistep method, which overcomes the defect of the 3rd order parallel Runge-Kutta method discussed in [1]. 展开更多
关键词 SOFTWARE RELIABILITY Numerical analysis combination method Parallel Computation ODEs.
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Mechanisms of active fraction combination from Liuwei Dihuang Decoction(LW-AFC) on long-term potentiation impairment in vivo
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作者 HUANG Yan LI Dong +3 位作者 CHENG Bin LIU Gang ZHANG Yong-xiang ZHOU Wen-xia 《中国药理学与毒理学杂志》 CAS 北大核心 2019年第9期665-665,共1页
OBJECTIVE Liuwei Dihuang Decoction(LW)-active fraction combination(LW-AFC,consist of 3 fractions polysaccharide,LWB-B;glycoside,LWD-b;oligosaccharide,CA-30)is extracted from LW,it is effective for the treatment of kid... OBJECTIVE Liuwei Dihuang Decoction(LW)-active fraction combination(LW-AFC,consist of 3 fractions polysaccharide,LWB-B;glycoside,LWD-b;oligosaccharide,CA-30)is extracted from LW,it is effective for the treatment of kidney yin deficiency in many animal models.This study evaluated the effects and mechanisms of LW-AFC and the active fractions on corticosterone(Cort)-induced long-term potentiation(LTP)impairment in vivo.METHODS LTP was used to evaluate the synaptic plasticity.LW-AFC was orally administered for seven days.The active fractions were given by either chronic administration(ig,ip,7 d)or single administration(icv,ig,ip).Cort was injected subcutaneously 1h before the high-frequency stimulation(HFS)to induce LTP impairment.Moreover,in order to research on the possible effective pathways,an antibiotic cocktail and an immunosuppressant were also used.RESULTS Chronic administration(ig)of LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment.Single administration(icv,ig,ip)of any of the active fractions had no effect on Cort-induced LTP impairment,while chronic administration(ig,ip)of LWB-B or LWD-b showed positive effects against Cort.Interestingly,CA-30 only showed protective effects via ig administration,and there was little effect when CA-30 was administered ip In addition,when the intestinal microbiota was disrupted by application of the antibiotic cocktail,CA-30 showed little protective effects against Cort.The effects of LW-AFC were also abolished when the immune function was inhibited.In the hippocampal tissue,Cort treatment increased Cort and glutamate,and LW-AFC could inhibit the Cort-induced elevation of Cort and glutamate;there was little change in D-serine in Cort-treated animals,but LW-AFC could increase the D-serine levels.CONCLUSION LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment.Their protective effects are unlikely by a direct way,and immune modulation might be the common pathway.CA-30 could protect LTP from impairment via modulating the intestinal microbiota.Decreasing Cort and glutamate and increasing D-serine in the Cort-treated animals'hippocampal tissue might be one of the mechanisms for the neural protective effects of LW-AFC.Further study is needed to understand the underlying mechanisms. 展开更多
关键词 LW-active fraction combination active fractions CORTICOSTERONE long-term potentiation synaptic plasticity stress
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Trust evolvement method of Web service combination based on network behavior
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作者 刘济波 向占宏 朱培栋 《Journal of Central South University of Technology》 EI 2008年第4期558-563,共6页
Based on the problem that the service entity only has the partial field of vision in the network environment,a trust evolvement method of the macro self-organization for Web service combination was proposed.In the met... Based on the problem that the service entity only has the partial field of vision in the network environment,a trust evolvement method of the macro self-organization for Web service combination was proposed.In the method,the control rule of the trust degree in the Dempster-Shafer(D-S)rule was utilized based on the entity network interactive behavior,and a proportion trust control rule was put up.The control rule could make the Web service self-adaptively study so as to gradually form a proper trust connection with its cooperative entities and to improve the security performance of the whole system.The experimental results show that the historical successful experience is saved during the service combination alliance,and the method can greatly improve the reliability and success rate of Web service combination. 展开更多
关键词 network behavior Web service combination trust evolvement Dempster-Shafer rule
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A Strategy Toward Convergent Combination Immunotherapy for SARS
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作者 Wayne A. Marasco 《中国实验动物学报》 CAS CSCD 2005年第S1期12-,共1页
关键词 A Strategy Toward Convergent combination Immunotherapy for SARS
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Reliability sensitivity analysis based on multi-hyperplane combination method 被引量:1
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作者 Yu-ge DONG Hai-tao LU Ling-ling LI 《Defence Technology(防务技术)》 SCIE EI CAS 2014年第4期354-359,共6页
For a nonlinear limit state function, the first-order reliability method(FORM) may cause large errors in the computation of not only the reliability index or failure probability but also the reliability sensitivity. I... For a nonlinear limit state function, the first-order reliability method(FORM) may cause large errors in the computation of not only the reliability index or failure probability but also the reliability sensitivity. In order to obtain more the accurate results of the reliability sensitivity analysis, a number of hyperplanes are built near the design point by first-order Tayler series expansion, which replace the known nonlinear limit state hypersurface, and an equivalent computational method is utilized to construct an equivalent hyperplane of the obtained hyperplanes. And the reliability sensitivities can be estimated more accurately by the derived equations based on the equivalent hyperplane. An example shows that the method is effective and feasible. 展开更多
关键词 可靠性指标 灵敏度分析 超平面 极限状态函数 可靠性灵敏度 泰勒级数展开 可靠度方法 失效概率
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Research on Strong Pulsed Electromagnetic Field Test Method by Time-frequency Combination 被引量:4
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作者 TANG Shiping CAI Mingjuan LI Jianxuan 《高电压技术》 EI CAS CSCD 北大核心 2013年第10期2471-2476,共6页
Many conventional methods of testing strong and pulsed electromagnetic fields,the ones used in radars for example,had deficiencies due to the difficulty in obtaining simultaneous information about the electromagnetic ... Many conventional methods of testing strong and pulsed electromagnetic fields,the ones used in radars for example,had deficiencies due to the difficulty in obtaining simultaneous information about the electromagnetic field's peak both in the time domain and in the frequency domain.With regard to this problem,after analyzing the time-domain and the frequency-domain characteristics of radar pulsed signals,we propose a new time-frequency combination test method based on the correction of the test parameters,as well as its correction method at different bandwidths.The test method is applied in a quick test of a high-power pulsed radar signal,and the corrected results have error less than 1 dB in both the time domain and the frequency domain,which indicates that the proposed time-frequency combined method is effective in testing strong and pulsed electromagnetic fields. 展开更多
关键词 脉冲电磁场 测试方法 时频 频域特性 雷达信号 高功率脉冲 传统方法 脉冲信号
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W-band folded-waveguide traveling-wave tube with dual electron beams and H-plane power combining
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作者 Wang Huanyu Duan Jingrui +5 位作者 Wang Zhanliang Tang Haichen Lu Zhigang Wang Shaomeng Gong Huarong Gong Yubin 《强激光与粒子束》 北大核心 2025年第12期19-25,共7页
[Background]Traveling-wave tubes(TWTs)are widely applied in radar,imaging,and military systems owing to their excellent amplification characteristics.Miniaturization and integration are critical to the future of TWTs,... [Background]Traveling-wave tubes(TWTs)are widely applied in radar,imaging,and military systems owing to their excellent amplification characteristics.Miniaturization and integration are critical to the future of TWTs,with multi-channel slow-wave structures(SWSs)forming the foundation for their realization in high-power vacuum electronic devices.[Purpose]To provide design insights for multi-channel TWTs and simultaneously enhance their output power,a W-band folded-waveguide TWT with dual electron beams and H-plane power combining was proposed.[Methods]Three-dimensional electromagnetic simulations in CST were conducted to verify the highfrequency characteristics,electric field distribution,and amplification performance of the proposed SWS,thereby confirming the validity of the design.[Results]Results indicate that the designed TWT achieves a transmission bandwidth of 10 GHz.With an electron beam voltage of 17.9 kV and a current of 0.35 A,the output power reaches 450 W at 94 GHz,corresponding to an efficiency of 7.18%and a gain of 23.5 dB.Moreover,under fixed beam voltage and current,the TWT delivers over 200 W output power across 91–99 GHz,with a 3 dB bandwidth of 91–98.5 GHz.The particle voltage distribution after modulation further validates the mode analysis.[Conclusions]These results demonstrate the feasibility of compact dual-beam power-combining structures and provide useful guidance for the design of future multi-channel TWTs. 展开更多
关键词 double electron beam folded waveguide slow-wave structure power combining beam-wave interaction W-BAND
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Holistic Cognition and Meanings of Restricted Combinations
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作者 Wang Ping 《学术界》 CSSCI 北大核心 2012年第10期267-272,共6页
A restricted combination is a kind of language phenomena.It is important in language.It is relatively-stationary phrase.Though it is conposed of more than one word,its meaning isn't only literal meaning expressed ... A restricted combination is a kind of language phenomena.It is important in language.It is relatively-stationary phrase.Though it is conposed of more than one word,its meaning isn't only literal meaning expressed by the words,but holistic.The whole isn't equal to the part.In the process of understanding restricted combinations,holistic congnition can play an important role. 展开更多
关键词 英文摘要 优秀文摘 中国 历史文化
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Design and optimization of the RGB beam combiner in micro display using entropy weight-TOPSIS method
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作者 ZHENG Yu ZHAO Yan-bing +4 位作者 ZOU Xin-jie WANG Ji-rong JIANG Xiang LIU Jian-zhe DUAN Ji-an 《Journal of Central South University》 2025年第2期483-494,共12页
Red-green-blue(RGB)beam combiners are widely used in scenarios such as augmented reality/virtual reality(AR/VR),laser projection,biochemical detection,and other fields.Optical waveguide combiners have attracted extens... Red-green-blue(RGB)beam combiners are widely used in scenarios such as augmented reality/virtual reality(AR/VR),laser projection,biochemical detection,and other fields.Optical waveguide combiners have attracted extensive attention due to their advantages of small size,high multiplexing efficiency,convenient mass production,and low cost.An RGB beam combiner based on directional couplers is designed,with a core-cladding relative refractive index difference of 0.75%.The RGB beam combiner is optimized from the perspective of parameter optimization.Using the beam propagation method(BPM),the relationship between the performance of the RGB beam combiner and individual parameters is studied,achieving preliminary optimization of the device’s performance.The key parameters of the RGB beam combiner are optimized using the entropy weight-technique for order preference by similarity to an ideal solution TOPSIS method,establishing the optimal parameter scheme and further improving the device’s performance indicators.The results show that after optimization,the multiplexing efficiencies for red,green,and blue lights,as well as the average multiplexing efficiency,reached 99.17%,99.76%,96.63%and 98.52%,respectively.The size of the RGB beam combiner is 4.768 mm×0.062 mm. 展开更多
关键词 optical waveguide combiners red-green-blue beam combiner beam propagation method entropy weight TOPSIS method multiplexing efficiency
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On the Construction of Knowledge Ecology Models in the Strategic Change from Traditional Enterprises to Innovative Enterprises from the Perspective of Combination Innovation
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作者 Liu Yan Li Yuntao 《学术界》 CSSCI 北大核心 2015年第7期282-286,共5页
The paper expounds the extensive ecological process of knowledge creation in the strategic change from traditional enterprises to innovative enterprises from the perspective of integrating innovation,analyzes the syst... The paper expounds the extensive ecological process of knowledge creation in the strategic change from traditional enterprises to innovative enterprises from the perspective of integrating innovation,analyzes the systematic integration process of the three links including knowledge preparation,knowledge production and knowledge diffusion in the two different change paths of integrated innovation and digestive absorption innovation,and establishes the knowledge ecology models in different paths. 展开更多
关键词 传统企业 知识创造 创新型 生态模式 生态学模型 生态过程 集成过程 知识扩散
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