期刊文献+
共找到626篇文章
< 1 2 32 >
每页显示 20 50 100
Man-machine Function Allocation Based on Uncertain Linguistic Multiple Attribute Decision Making 被引量:13
1
作者 ZHANG An TANG Zhili ZHANG Chao 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2011年第6期816-822,共7页
Function allocation is one of the necessary stages in the design course of man-machine systems since appropriate function allocation makes the whole system more effective, reliable and inexpensive. Therefore, our rese... Function allocation is one of the necessary stages in the design course of man-machine systems since appropriate function allocation makes the whole system more effective, reliable and inexpensive. Therefore, our research mainly focuses on the problems of function allocation between man and machine in man-machine systems, analyses each capability advantage of man and machine according to their respective inherent characteristics and makes a comparison between them. In view of highly uncertain characteristics of decision attribute value in the practical process, we introduce the uncertain linguistic multiple attribute decision making (ULMADM) method in the function allocation process. Meanwhile, we also use the uncertain extended weighted arithmetic averaging (UEWAA) method to determine the automation level range of the operator functions. Then, we eventually estab- lish the automation level of man-machine function allocation by using the multi-attribute decision making algorithm, which is combined by UEWAA and uncertain linguistic hybrid aggregation (ULHA) operators. Finally, an example about function allocation is given, that is, fault diagnosis in the cockpit of civil aircraft. The final result of the example demonstrates that the proposed method about function allocation is feasible and effective. 展开更多
关键词 man-machine systems function allocation uncertain linguistic multiple attribute decision making levels of automa tion fault detection cockpits RELIABILITY
原文传递
Generalized Gr?tzsch ring function and generalized elliptic integrals 被引量:1
2
作者 MA Xiao-yan QIU Song-liang TU Guo-yan 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2016年第4期458-468,共11页
Abstract. In this paper, we study the quotient of hypergeometric functions μα (r) in the theory of Ramanujan's generalized modular equation for α ∈(0, 1/2]. Several new inequalities are given for this and rela... Abstract. In this paper, we study the quotient of hypergeometric functions μα (r) in the theory of Ramanujan's generalized modular equation for α ∈(0, 1/2]. Several new inequalities are given for this and related functions. Our main results complement and generalize some known results in the literature. 展开更多
关键词 Gaussian hypergeometric function generalized GrStzsch ring function generalized elliptic func-tion.
在线阅读 下载PDF
Real-Valued Functions and Some Covering Properties 被引量:2
3
作者 Erguang YANG Li WANG 《Journal of Mathematical Research with Applications》 CSCD 2016年第5期561-567,共7页
In the paper [properties defined with semi-continuous functions and some related spaces', Houston J. Math., 2015, 41(3): 1097-1106] properties (UL)m^wl, (UL)mK and (UL)m were defined and it was shown that sp... In the paper [properties defined with semi-continuous functions and some related spaces', Houston J. Math., 2015, 41(3): 1097-1106] properties (UL)m^wl, (UL)mK and (UL)m were defined and it was shown that spaces having these properties coincide with countably paracompact spaces, countably mesocompact spaces and countably metacompact spaces, respectively. In this paper, we continue with the study on the relationship between properties defined with real-valued functions and some covering properties. Some characterizations of countably compact spaces and pseudo-compact spaces in terms of real-valued functions are obtained. 展开更多
关键词 real-valued functions countably compact spaces pseudo-compact spaces inser-tion theorems
原文传递
The Homotopic Probability Distribution and the Partition Function for the Entangled System Around a Ribbon Segment Chain
4
作者 QIAN Shang-Wu GU Zhi-Yu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2001年第12期691-694,共4页
Using the Feynman's path integral with topological constraints arising from the presence of one singular line, we find the homotopic probability distribution PnL for the winding number n and the partition function... Using the Feynman's path integral with topological constraints arising from the presence of one singular line, we find the homotopic probability distribution PnL for the winding number n and the partition function PL of the entangled system around a ribbon segment chain. We find that when the width of the ribbon segment chain 2a increases,the partition function exponentially decreases, whereas the free energy increases an amount, which is proportional to the square of the width. When the width tends to zero we obtain the same results as those of a single chain with one singular point. 展开更多
关键词 Feynman's path integral with TOPOLOGICAL constraints homotopic probability distribution parti tion function ENTANGLED system around a RIBBON SEGMENT CHAIN
在线阅读 下载PDF
Command functions of open loop galvanometer scanners with optimized duty cycles
5
作者 V.F.Duma 《Theoretical & Applied Mechanics Letters》 CAS 2012年第4期34-39,共6页
The paper approaches the problem of the command functions of galvanometer-based scanners (GS) that are necessary to produce the linear plus parabolic scanning function of the GS, which we have proved previously to p... The paper approaches the problem of the command functions of galvanometer-based scanners (GS) that are necessary to produce the linear plus parabolic scanning function of the GS, which we have proved previously to produce the highest possible duty cycle (i.e., time efficiency) of the device. We have completed this theoretical aspect (which contradicted what has been stated previously in the literature, where it has been considered that the linear plus sinusoidal scanning function was the best) with the experimental study of the most used scanning functions of the GSs (sawtooth, sinusoidal and triangular), with applications in biomedical imaging, in particular in optical coherence tomography, demonstrating that the triangular function is always the best one to be applied, from both an optical and a mechanical point of view. In the present study the input voltage/command function which should be applied to the GS to produce the desired triangular scanning function (with controlled non-linearity for the fastest possible stop-and-turn portions) was determined analytically, in relationship with the active torque that drives the device. This command function is analyzed with regard to the specific, respectively required parameters of the GS: natural frequency and damping factor, respectively scan speed and amplitude. The modeling in an open loop control structure of the GS is finally discussed as a trade-off between using the highest possible duty cycle and minimizing the maximum peaks of the input voltage. 展开更多
关键词 scanners galvanometer scanner optomechatronics scanning functions command func-tions duty cycle driving torque
在线阅读 下载PDF
ANALYSIS TO NEYMAN-PEARSON CLASSIFICATION WITH CONVEX LOSS FUNCTION
6
作者 Min Han Dirong Chen Zhaoxu Sun 《Analysis in Theory and Applications》 2008年第1期18-28,共11页
Neyman-Pearson classification has been studied in several articles before. But they all proceeded in the classes of indicator functions with indicator function as the loss function, which make the calculation to be di... Neyman-Pearson classification has been studied in several articles before. But they all proceeded in the classes of indicator functions with indicator function as the loss function, which make the calculation to be difficult. This paper investigates Neyman- Pearson classification with convex loss function in the arbitrary class of real measurable functions. A general condition is given under which Neyman-Pearson classification with convex loss function has the same classifier as that with indicator loss function. We give analysis to NP-ERM with convex loss function and prove it's performance guarantees. An example of complexity penalty pair about convex loss function risk in terms of Rademacher averages is studied, which produces a tight PAC bound of the NP-ERM with convex loss function. 展开更多
关键词 Neyman-Pearson lemma convex loss function Neyman-Pearson classifica-tion NP-ERM Rademacher average
在线阅读 下载PDF
Single-pulse chaotic dynamics of functionally graded materials plate
7
作者 Yu-Gao Huangfu Fang-Qi Chen 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2013年第4期593-601,共9页
Single-pulse chaos are studied for a functionally graded materials rectangular plate. By means of the global perturbation method, explicit conditions for the existence of a SiZnikov-type homoclinic orbit are obtained ... Single-pulse chaos are studied for a functionally graded materials rectangular plate. By means of the global perturbation method, explicit conditions for the existence of a SiZnikov-type homoclinic orbit are obtained for this sys- tem, which suggests that chaos are likely to take place. Then, numerical simulations are given to test the analytical predic- tions. And from our analysis, when the chaotic motion oc- curs, there are a quasi-period motion in a two-dimensional subspace and chaos in another two-dimensional supplemen- tary subspace. 展开更多
关键词 functionally graded materials ~ Single-pulse ~Melnikov's method ~ Homoclinic orbit ~ Numerical simula-tion
在线阅读 下载PDF
“5E”康复护理联合间歇导尿术在脊髓损伤神经源性膀胱患者中的应用
8
作者 孔培培 翟清华 +2 位作者 张会 李树强 刘晓辉 《中国实用神经疾病杂志》 2026年第1期85-89,共5页
目的探讨“5E”康复护理联合间歇导尿术在脊髓损伤后神经源性膀胱患者中的应用效果。方法选取2022-03—2025-02郑州大学第二附属医院康复医学科2个病区收治的42例脊髓损伤后神经源性膀胱患者为研究对象,随机分为对照组和观察组,各21例... 目的探讨“5E”康复护理联合间歇导尿术在脊髓损伤后神经源性膀胱患者中的应用效果。方法选取2022-03—2025-02郑州大学第二附属医院康复医学科2个病区收治的42例脊髓损伤后神经源性膀胱患者为研究对象,随机分为对照组和观察组,各21例。对照组实施间歇导尿术和常规护理,观察组在间歇导尿术和常规护理基础上联合“5E”康复护理干预。干预4周后,比较2组最大膀胱安全容量、排尿期最大膀胱内压、残余尿量、尿道括约肌功能、汉密尔顿焦虑量表(HAMA)评分及世界卫生组织生活质量简表(WHOQOL-BREF)评分,记录并发症发生情况。结果干预后,观察组与对照组最大膀胱安全容量、排尿期最大膀胱内压、残余尿量比较,差异均有统计学意义(P<0.05)。干预后,观察组与对照组尿道括约肌松弛患者及尿道括约肌痉挛或失协调患者排尿期最大尿道压力比较,差异均有统计学意义(P<0.05)。干预后,观察组与对照组HAMA评分、WHOQOL-BREF评分比较,差异均有统计学意义(P<0.05)。结论“5E”康复护理协同间歇导尿术管理神经源性膀胱,可改善脊髓损伤患者的排尿功能及尿道括约肌功能,改善负面情绪和生活质量。 展开更多
关键词 脊髓损伤 神经源性膀胱 “5E”康复护理 间歇导尿术 排尿功能 负面情绪 尿路感染
暂未订购
Selection of Measured Signals in the Navigation Measuring Complex 被引量:1
9
作者 柯芳 Andrey PROLETARSKY Konstantin NEUSIPIN 《Journal of Measurement Science and Instrumentation》 CAS 2011年第4期346-348,共3页
To increase accuracy of navigation parameters,a perspective measuring complex with intellectual components is developed.Conception of synthesis optimal structure of the measuring complex is realized basing on a select... To increase accuracy of navigation parameters,a perspective measuring complex with intellectual components is developed.Conception of synthesis optimal structure of the measuring complex is realized basing on a selective method using principles of the functional systems.Selection of measured information is finished by original numeric criterion of observation level of state vector components.Prediction is realized by algorithm of self-organization that makes synthesis of the optimal complication.Therefore mechanism of self-regulation is realized and accuracy of the selective navigation complex is increased. 展开更多
关键词 selected navigation complex functional systems intellectual components observation level selforganiza tion
在线阅读 下载PDF
Electroacupuncture improves microcirculation and neuronal morphology in the spinal cord of a rat model of intervertebral disc extrusion 被引量:10
10
作者 Dai-xun Jiang Zhi-song Lu +4 位作者 Ge-bin Li Sheng-yong Sun Xiang Mu Peter Lee Wu Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第2期237-243,共7页
Most studies on spinal cord neuronal injury have focused on spinal cord tissue histology and the expression of nerve cell damage and repair-related genes. The importance of the microcirculation is often ignored in spi... Most studies on spinal cord neuronal injury have focused on spinal cord tissue histology and the expression of nerve cell damage and repair-related genes. The importance of the microcirculation is often ignored in spinal cord injury and repair research. Therefore, in this study, we established a rat model of intervertebral disc extrusion by inserting a silica gel pad into the left ventral sur-face of T13. Electroacupuncture was used to stimulate the bilateralZusanlipoint (ST36) and Neiting point (ST44) for 14 days. Compared with control animals, blood lfow in the ifrst lumbar vertebra (L1) was noticeably increased in rats given electroacupuncture. Microvessel density in the T13 segment of the spinal cord was increased significantly as well. The number of normal neurons was higher in the ventral horn of the spinal cord. In addition, vacuolation in the white matter was lessened. No obvious glial cell proliferation was visible. Furthermore, hindlimb motor function was improved signiifcantly. Collectively, our results suggest that electroacupuncture can improve neuronal morphology and microcirculation, and promote the recovery of neurological functions in a rat model of intervertebral disc extrusion. 展开更多
关键词 nerve regeneration ELECTROACUPUNCTURE intervertebral disc blood circulation inflamma-tion neuroprotection motor function neurons NSFC grants neural regeneration
暂未订购
MULTIPLE POSITIVE SOLUTIONS OF A SINGULAR (n-1,1) CONJUGATE BOUNDARY VALUE PROBLEM WITH DELAY 被引量:2
11
作者 Weng Peixuan\ Tian YanlingDept. of Math.,South China Normal Univ.,Guangzhou 51 0 631 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2000年第2期128-136,共9页
This paper discusses the singular ( n\|1,1 ) conjugate boundary value problem as follows by using a fixed point index theorem in cones[HL(2:1,Z;2,Z]u (n) (t)+a(t)f(u(w(t)))=0,(0<t<1), u(t)=φ(t),(-τ≤t&l... This paper discusses the singular ( n\|1,1 ) conjugate boundary value problem as follows by using a fixed point index theorem in cones[HL(2:1,Z;2,Z]u (n) (t)+a(t)f(u(w(t)))=0,(0<t<1), u(t)=φ(t),(-τ≤t<0), u (j) (0)=u(1)=0,(1≤j≤n-2).Effort is devoted to give some sufficient conditions for which the equation has at least two positive solutions.An example to illustrate the application of this theorem is given. [FQ(6*2。39,X-W] 展开更多
关键词 Conjugate boundary value problem functional differential equation multiple positive solution.Keywords:Conjugateboundaryvalueproblem functionaldifferentialequation multiplepositivesolu-tion.
在线阅读 下载PDF
Laplace Transformation and Ergodic Potential Kernel for q-Process in Random Environment 被引量:2
12
作者 LU Ping HU Dihe 《Wuhan University Journal of Natural Sciences》 CAS 2007年第2期218-224,共7页
This paper introduces some concepts such as q- process in random environment, Laplace transformation, ergodic potential kernel, error function and some basic lemmas.We study the continuity and Laplace transformation o... This paper introduces some concepts such as q- process in random environment, Laplace transformation, ergodic potential kernel, error function and some basic lemmas.We study the continuity and Laplace transformation of random transition function. Finally, we give the sufficient condition for the existence of ergodic potential kernel for homogeneous q- processes in random environments. 展开更多
关键词 random transition function transition density func-tion in random environment q-process in random environment Laplace transformation ergodic potential kernel
在线阅读 下载PDF
APPLICATIONS OF HYPERGEOMETRIC SUMMATION THEOREMS OF KUMMER AND DIXON INVOLVING DOUBLE SERIES 被引量:1
13
作者 H.M.SRIVASTAVA M.I.QURESHI +1 位作者 Kaleem A.QURAISHI Ashish ARORA 《Acta Mathematica Scientia》 SCIE CSCD 2014年第3期619-628,共10页
Using series iteration techniques identities and apply each of these identities in we derive a number of general double series order to deduce several hypergeometric reduction formulas involving the Srivastava-Daoust ... Using series iteration techniques identities and apply each of these identities in we derive a number of general double series order to deduce several hypergeometric reduction formulas involving the Srivastava-Daoust double hypergeometric function. The results presented in this article are based essentially upon the hypergeometric summation theorems of Kummer and Dixon. 展开更多
关键词 Pochhammer's symbol Gamma function series identities hypergeometric re-duction formulas Srivastava-Daoust double and multiple hypergeometric func-tions Legendre's duplication formula Gauss-Legendre multiplication formula Kummer's theorem Dixon's theorem
在线阅读 下载PDF
Resource selection of moose(Alces alces cameloides) and their response to human disturbances in the northwestern slope of Lesser Khingan Mountains, northeastern China
14
作者 HU Suxian JIANG Guangshun +2 位作者 MA Jianzhang ZHANG Minghai LIU Hui 《Journal of Forestry Research》 SCIE CAS CSCD 2013年第4期727-734,共8页
Moose (Alces alces cameloides) is typically representative of the fauna of the frigid temperate zone and has been put on the Chinese second priority list of protected animals. The moose of northeast China is on the ... Moose (Alces alces cameloides) is typically representative of the fauna of the frigid temperate zone and has been put on the Chinese second priority list of protected animals. The moose of northeast China is on the southern most edge of its distribution in Asia. To study resource selection characteristics of moose and their response to human distur- bances and forest resource variables, the field work was conducted in Heilongiiang Provincial Shengshan Forestry Farm, which is located in the northwestern slope of Lesser Khingan Mountains, northeastern China, from January to March in both 2006 and 2007. A total of 428 plots were examined within the study area. Signs of moose use were found in 19 plots. Based on the analysis of resource selection function, we found that moose selected areas with higher densities of mixed deciduous broadleaf patch and mixed coniferous and broad leaf patch, and a higher NDVI value. Moose avoided settlement 6 km away and remained low probability of occurrence within 3 km from roads, 展开更多
关键词 Alces alces cameloides human disturbances resource selec-tion function Kappa statistic
在线阅读 下载PDF
口咽初乳滴注联合微生态制剂治疗喂养不耐受早产儿效果及对胃肠激素及免疫功能影响 被引量:1
15
作者 程凤娜 王小娟 张莉莉 《中国计划生育学杂志》 2025年第2期341-345,共5页
目的:探讨口咽初乳滴注联合微生态制剂对喂养不耐受早产儿胃肠激素及免疫功能的影响。方法:选取2021年1月-2023年12月在本院新生儿科进行治疗的对喂养不耐受早产儿135例,简单随机分为联合组(n=68)和参照组(n=67),两组均给予早产儿微生... 目的:探讨口咽初乳滴注联合微生态制剂对喂养不耐受早产儿胃肠激素及免疫功能的影响。方法:选取2021年1月-2023年12月在本院新生儿科进行治疗的对喂养不耐受早产儿135例,简单随机分为联合组(n=68)和参照组(n=67),两组均给予早产儿微生态制剂治疗,联合组同时行口咽初乳滴注干预。比较喂养不耐受早产儿治疗效果,治疗前后免疫功能指标及胃肠激素水平[胃动素(MTL)、胃泌素(GAS)]。结果:联合组治疗总有效率(97.1%)高于对照组(88.1%),两组免疫指标CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+)均升高,CD8^(+)下降且联合组变化幅度大于对照组,两组胃肠激素MTL、GAS水平均升高且联合组(365.61±50.47 ng/L、136.52±25.32 ng/L)高于对照组(316.78±49.53 ng/L、119.26±19.84 ng/L)(均P<0.05)。结论:口咽初乳滴注联合微生态制剂治疗喂养不耐受早产儿效果提高,可促进患儿机体免疫功能及胃肠功能提高。 展开更多
关键词 喂养不耐受早产儿 初乳 口咽滴注 微生态制剂 胃肠激素 免疫功能
暂未订购
百令胶囊联合紫杉醇+顺铂化疗在非小细胞肺癌合并肺结核患者中的应用效果 被引量:1
16
作者 孙冰 杨亚勤 +1 位作者 黄健 崔秀琴 《癌症进展》 2025年第8期936-939,共4页
目的探讨百令胶囊联合紫杉醇^(+)顺铂化疗在非小细胞肺癌(NSCLC)合并肺结核患者中的应用效果。方法依据治疗方式的不同将150例NSCLC合并肺结核患者分为对照组(n=72)和观察组(n=78),两组患者均接受标准方案肺结核治疗,在此基础上,对照组... 目的探讨百令胶囊联合紫杉醇^(+)顺铂化疗在非小细胞肺癌(NSCLC)合并肺结核患者中的应用效果。方法依据治疗方式的不同将150例NSCLC合并肺结核患者分为对照组(n=72)和观察组(n=78),两组患者均接受标准方案肺结核治疗,在此基础上,对照组患者接受紫杉醇^(+)顺铂治疗,观察组患者接受百令胶囊联合紫杉醇^(+)顺铂治疗。比较两组患者的临床疗效、免疫功能指标(CD4^(+)、CD8^(+)、CD4^(+)/CD8^(+))、凝血功能指标[D-二聚体(D-D)、纤维蛋白原(FIB)]、不良反应发生情况及生活质量[欧洲癌症研究与治疗组织生命质量测定量表(EORTC QLQ-C30)]。结果观察组患者的治疗总有效率为58.97%,高于对照组患者的40.28%,差异有统计学意义(P﹤0.05)。治疗后,两组患者CD4^(+)水平及CD4^(+)/CD8^(+)均高于本组治疗前,CD8^(+)水平均低于本组治疗前,观察组患者CD4^(+)水平及CD4^(+)/CD8^(+)均高于对照组,CD8^(+)水平低于对照组,差异均有统计学意义(P﹤0.05)。治疗后,两组患者D-D、FIB水平均低于本组治疗前,观察组患者D-D、FIB水平均低于对照组,差异均有统计学意义(P﹤0.05)。治疗后,两组患者EORTC QLQ-C30各维度评分均高于本组治疗前,观察组患者EORTC QLQ-C30各维度评分均高于对照组,差异均有统计学意义(P﹤0.05)。观察组患者的不良反应总发生率为39.74%,低于对照组患者的56.94%,差异有统计学意义(P﹤0.05)。结论百令胶囊联合紫杉醇^(+)顺铂化疗可有效提高NSCLC合并肺结核患者的免疫功能,改善凝血功能指标,降低不良反应发生率,提高患者的生活质量。 展开更多
关键词 百令胶囊 非小细胞肺癌 肺结核 免疫功能 凝血功能 不良反应 生活质量
暂未订购
Periodic Wave Solutions and Solitary Wave Solutions of the (2+1)-Dimensional Korteweg-de-Vries Equatio
17
作者 Liangwei He Shuanghong Chen 《American Journal of Computational Mathematics》 2021年第4期327-339,共13页
In this paper, we investigate the periodic wave solutions and solitary wave solutions of a (2+1)-dimensional Korteweg-de Vries (KDV) equation</span><span style="font-size:10pt;font-family:"">... In this paper, we investigate the periodic wave solutions and solitary wave solutions of a (2+1)-dimensional Korteweg-de Vries (KDV) equation</span><span style="font-size:10pt;font-family:""> </span><span style="font-size:10pt;font-family:"">by applying Jacobi elliptic function expansion method. Abundant types of Jacobi elliptic function solutions are obtained by choosing different </span><span style="font-size:10.0pt;font-family:"">coefficient</span><span style="font-size:10.0pt;font-family:"">s</span><span style="font-size:10pt;font-family:""> <i>p</i>, <i>q</i> and <i>r</i> in the</span><span style="font-size:10pt;font-family:""> </span><span style="font-size:10pt;font-family:"">elliptic equation. Then these solutions are</span><span style="font-size:10pt;font-family:""> </span><span style="font-size:10pt;font-family:"">coupled into an auxiliary equation</span><span style="font-size:10pt;font-family:""> </span><span style="font-size:10pt;font-family:"">and substituted into the (2+1)-dimensional KDV equation. As <span>a result,</span></span><span style="font-size:10pt;font-family:""> </span><span style="font-size:10pt;font-family:"">a large number of complex Jacobi elliptic function solutions are ob</span><span style="font-size:10pt;font-family:"">tained, and many of them have not been found in other documents. As</span><span style="font-size:10pt;font-family:""> </span><span style="font-size:10.0pt;font-family:""><span></span></span><span style="font-size:10pt;font-family:"">, some complex solitary solutions are also obtained correspondingly.</span><span style="font-size:10pt;font-family:""> </span><span style="font-size:10pt;font-family:"">These solutions that we obtained in this paper will be helpful to understand the physics of the (2+1)-dimensional KDV equation. 展开更多
关键词 Nonlinear Evolution Equations Jacobi Elliptic function (2+1)-Dimensional KDV Periodic Wave Solutions Solitary Wave Solu-tions
在线阅读 下载PDF
不同干旱条件下区域抗旱水源优化配置研究
18
作者 郭溪 梁鹏辉 +2 位作者 吴泽宁 何晨涛 曹欠欠 《水利学报》 北大核心 2025年第9期1228-1239,共12页
干旱是全球最常见和最严重的自然灾害之一,高温极端干旱事件对国家水安全保障构成了严重威胁。针对不同干旱条件下的抗旱水源配置原则、约束条件、目标函数及模型构建等问题,基于不同干旱条件对抗旱水源配置系统的结构破坏和功能损失机... 干旱是全球最常见和最严重的自然灾害之一,高温极端干旱事件对国家水安全保障构成了严重威胁。针对不同干旱条件下的抗旱水源配置原则、约束条件、目标函数及模型构建等问题,基于不同干旱条件对抗旱水源配置系统的结构破坏和功能损失机理,分别构建一般干旱与特大干旱条件下的区域抗旱水源优化配置准则、目标函数、约束条件和方案生成方法,建立了不同干旱条件下区域抗旱水源优化配置模型,并以楚雄州为例进行应用验证。结果表明:经抗旱水源优化配置后,一般干旱条件下,楚雄州社会总缺水量降至1883.01万m3,经济损失减少4.4亿元;特大干旱条件下,楚雄州缺水损伤程度下降至14.54%,水源工程总体破坏程度降至11.26%。综上,区域抗旱水源优化配置模型可有效降低旱灾损失及供需水系统破坏程度,提高各用水户的供水保证率,可为区域整体干旱应对能力提升提供技术支撑。 展开更多
关键词 干旱 特大干旱 供用水系统结构-功能损伤 优化配置模型 抗旱水源
在线阅读 下载PDF
有序屋脊状质构表面的接触模型研究
19
作者 张新宝 阳香铭 吕子劲 《机械设计与制造》 北大核心 2025年第6期246-252,共7页
为了改善船舶轴系中结合面及滑动轴承的接触特性,提出了一种基于有限元方法和统计学方法的有序屋脊状质构结合面的接触模型,能准确地表征有序屋脊状质构表面的接触特性。该模型基于有限元法,构建了单个质构单元的接触模型。在此基础上,... 为了改善船舶轴系中结合面及滑动轴承的接触特性,提出了一种基于有限元方法和统计学方法的有序屋脊状质构结合面的接触模型,能准确地表征有序屋脊状质构表面的接触特性。该模型基于有限元法,构建了单个质构单元的接触模型。在此基础上,对质构高度分布函数进行修正来解决基体变形的相互影响的问题。通过MATLAB仿真实验,分析了不同法向变形情况下,结合面的接触压力、真实接触面积等接触特性。结果表明软硬基体变形、质构单元的高度分布是影响结合面接触特性的重要因素,可为结合面接触特性的预测和微观表面设计提供了更准确、有效的方案。 展开更多
关键词 接触特性 屋脊状质构 有限元分析 基体变形 分布函数修正
在线阅读 下载PDF
经翼点入路与额下入路切除术对鞍区肿瘤患者视功能及并发症的影响
20
作者 徐志明 隋岩永 +1 位作者 周勇 王永意 《中国实用神经疾病杂志》 2025年第5期598-602,共5页
目的探究经翼点入路与额下入路切除术对鞍区肿瘤患者视功能、并发症的影响。方法回顾性分析青岛市市立医院2021-02—2023-02收治的鞍区肿瘤患者的临床资料,翼点入路的37例患者纳入翼点组,额下入路的36例患者纳入额下组。比较术后2组患... 目的探究经翼点入路与额下入路切除术对鞍区肿瘤患者视功能、并发症的影响。方法回顾性分析青岛市市立医院2021-02—2023-02收治的鞍区肿瘤患者的临床资料,翼点入路的37例患者纳入翼点组,额下入路的36例患者纳入额下组。比较术后2组患者肿瘤切除程度、视功能、生活质量[卡诺夫斯基表现量表(KPS)]、神经功能[格拉斯哥昏迷评分量表(GCS)],记录患者并发症发生率和肿瘤复发情况。结果组间肿瘤切除程度差异无统计学意义(χ^(2)=1.333,P=0.248);术后2周时,额下组视功能改善率(32.43%比66.67%)显著高于翼点组(χ^(2)=8.665,P=0.013);2组患者KPS、GCS评分均显著升高,且额下组高于翼点组(t=2.613、12.993、P=0.011、<0.001);翼点组并发症发生率(16.22%比66.67%)显著低于额下组(χ^(2)=19.185,P<0.001),组间复发率差异无统计学意义(χ^(2)=0.245,P=0.620)。结论经翼点入路与额下入路在鞍区肿瘤患者中具有相同的切除效果,而额下入路对视功能的改善效果更好,有助于提高患者的生活质量和神经功能,但翼点入路安全性较高。 展开更多
关键词 鞍区肿瘤 翼点入路 额下入路 视功能 并发症
暂未订购
上一页 1 2 32 下一页 到第
使用帮助 返回顶部