期刊文献+
共找到6,121篇文章
< 1 2 250 >
每页显示 20 50 100
Understanding the correlation between energy-state mismatching and open-circuit voltage loss in bulk heterojunction solar cells
1
作者 Hyun-Seock Yang Danbi Kim +7 位作者 Chang-Mok Oh Vellaiappillai Tamilavan Pesi MHangoma Hojun Yi Bo RLee Insoo Shin In-Wook Hwang Sung Heum Park 《Carbon Energy》 SCIE EI CAS CSCD 2024年第5期164-174,共11页
Photoinduced intermolecular charge transfer(PICT)determines the voltage loss in bulk heterojunction(BHJ)organic photovoltaics(OPVs),and this voltage loss can be minimized by inducing efficient PICT,which requires ener... Photoinduced intermolecular charge transfer(PICT)determines the voltage loss in bulk heterojunction(BHJ)organic photovoltaics(OPVs),and this voltage loss can be minimized by inducing efficient PICT,which requires energy-state matching between the donor and acceptor at the BHJ interfaces.Thus,both geometrically and energetically accessible delocalized state matching at the hot energy level is crucial for achieving efficient PICT.In this study,an effective method for quantifying the hot state matching of OPVs was developed.The degree of energy-state matching between the electron donor and acceptor at BHJ interfaces was quantified using a mismatching factor(MF)calculated from the modified optical density of the BHJ.Furthermore,the correlation between the open-circuit voltage(Voc)of the OPV device and energy-state matching at the BHJ interface was investigated using the calculated MF.The OPVs with small absolute MF values exhibited high Voc values.This result clearly indicates that the energy-state matching between the donor and acceptor is crucial for achieving a high Voc in OPVs.Because the MF indicates the degree of energy-state matching,which is a critical factor for suppressing energy loss,it can be used to estimate the Voc loss in OPVs. 展开更多
关键词 bulk heterojunction open circuit voltage organic photovoltaics photoinduced charge transfer voltage loss
下载PDF
On Fuzzy Regularly Closed Filters in Michálek Fuzzy Topological Space
2
作者 Puthenpurackal Ratnakumar Neethu Bloomy Joseph 《Advances in Pure Mathematics》 2024年第10期779-784,共6页
C.L. Chang’s introduction of fuzzy topology in 1981 opened up new avenues for parallel theories in topology. However, Chang’s work appears to focus more on the topology of fuzzy sets rather than fuzzy topology itsel... C.L. Chang’s introduction of fuzzy topology in 1981 opened up new avenues for parallel theories in topology. However, Chang’s work appears to focus more on the topology of fuzzy sets rather than fuzzy topology itself. In 1975, Michálek presented a functional definition of ordinary topology and later developed fuzzy topology as a distinct extension of this idea, setting it apart from Chang’s approach. While there has been significant research on Chang’s fuzzy topology, Michálek’s version has not received as much attention. This paper introduces the concept of fuzzy regularly closed filters, or FRCM filters, within Michálek’s fuzzy topological space and explores some properties of FRCM ultrafilters. 展开更多
关键词 TOPOLOGY Fuzzy Topology Michálek’s Fuzzy Topological Space Fuzzy closed Fuzzy open FILTERS
下载PDF
OPEN表和CLOSED表的合一 被引量:2
3
作者 冯乃勤 王岁花 +1 位作者 郑延斌 冯国燚 《计算机工程与应用》 CSCD 北大核心 2003年第16期100-101,125,共3页
在人工智能传统的搜索方法中,一直是将OPEN表和CLOSED表分开的。这不仅增加了搜索算法的复杂性,久而久之,也许禁锢了人们的思想。文章试图改变这种状况,提出了一种与众不同的新思路,巧妙地将OPEN表和CLOSED表合二为一,减少了一些工作量... 在人工智能传统的搜索方法中,一直是将OPEN表和CLOSED表分开的。这不仅增加了搜索算法的复杂性,久而久之,也许禁锢了人们的思想。文章试图改变这种状况,提出了一种与众不同的新思路,巧妙地将OPEN表和CLOSED表合二为一,减少了一些工作量,在一定程度上降低了算法的复杂性。 展开更多
关键词 搜索 0PEN表 closed 算法复杂性
下载PDF
Closed circle DNA algorithm of change positive-weighted Hamilton circuit problem 被引量:5
4
作者 Zhou Kang Tong Xiaojun Xu Jin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第3期636-642,共7页
Chain length of closed circle DNA is equal. The same closed circle DNA's position corresponds to different recognition sequence, and the same recognition sequence corresponds to different foreign DNA segment, so clos... Chain length of closed circle DNA is equal. The same closed circle DNA's position corresponds to different recognition sequence, and the same recognition sequence corresponds to different foreign DNA segment, so closed circle DNA computing model is generalized. For change positive-weighted Hamilton circuit problem, closed circle DNA algorithm is put forward. First, three groups of DNA encoding are encoded for all arcs, and deck groups are designed for all vertices. All possible solutions are composed. Then, the feasible solutions are filtered out by using group detect experiment, and the optimization solutions are obtained by using group insert experiment and electrophoresis experiment. Finally, all optimization solutions are found by using detect experiment. Complexity of algorithm is concluded and validity of DNA algorithm is explained by an example. Three dominances of the closed circle DNA algorithm are analyzed, and characteristics and dominances of group delete experiment are discussed. 展开更多
关键词 closed circle DNA computing model change positive-weighted Hamilton circuit problem group insert experiment group delete experiment.
下载PDF
Using Automation Controller System and Simulation Program for Testing Closed Circuits of Mini-Sprinkler Irrigation System 被引量:2
5
作者 Hani A. Mansour Hany M. Mehanna +1 位作者 Mohamed E. El-Hagarey Ahmehd S. Hassan 《Open Journal of Modelling and Simulation》 2013年第2期14-23,共10页
The field experiments were conducted at the experimental farm of Faculty of agricultural, southern Illinois University SIUC, USA. The project makes the irrigation automated. With the use of low cost sensors and the si... The field experiments were conducted at the experimental farm of Faculty of agricultural, southern Illinois University SIUC, USA. The project makes the irrigation automated. With the use of low cost sensors and the simple circuitry makes currently project a low cost product, which can be bought even by a poor farmer. This research work is best suited for places where water is scares and has to be used in limited quantity and this proposal is a model to modernize the agriculture industries at a mass scale with optimum expenditure. In the field of agricultural engineering, use of sensor method of irrigation operation is important and it is well known that closed circuits of Mini-sprinkler irrigation system are very economical and efficient. Closed circuits are considered one of the modifications of Mini-sprinkler irrigation system, and added advantages to Mini-sprinkler irrigation system because it can relieve low operating pressures problem at the end of the lateral lines. In the conventional closed circuits of Mini-sprinkler irrigation system, the farmer has to keep watch on irrigation timetable, which is different for different crops. Using this system, one can save manpower, water to improve production and ultimately profit. The data could be summarized in following: Irrigation methods under study when using lateral length 60 mcould be ranked in the following ascending order according the values of the predicted and measured head losses CM1M-SIS CM2M-SIS.The correlation (Corr.) coefficients were used to compare the predicted and measured head losses along the lateral lines of all the closed circuits designs. Generally, the values of correlation analysis were (>0.90) were obtained with 0% field slope60 mlength (experimental conditions) for all closed circuits.The interaction between irrigation methods: at the start there are significant differences between CM2M-SIS and CM1M-SIS. 展开更多
关键词 Automation Controller Simulation Program Mini-Sprinkler IRRIGATION LATERAL closed circuitS
下载PDF
Energy and water saving by using modified closed circuits of drip irrigation system 被引量:1
6
作者 Hani Abdel-Ghani Mansour Mohamed Yousif Tayel +1 位作者 David A. Lightfoot Abdel-Ghany Mohamed El-Gindy 《Agricultural Sciences》 2010年第3期154-177,共24页
The aim of this research was determine the en- ergy and water use efficiencies under the modification of closed circuit drip irrigation systems designs. Field experiments carried out on transgenic maize (GDH, LL3), (Z... The aim of this research was determine the en- ergy and water use efficiencies under the modification of closed circuit drip irrigation systems designs. Field experiments carried out on transgenic maize (GDH, LL3), (Zea Mays crop) under two types of closed circuits: a) One manifold for lateral lines or Closed circuits with One Manifold of Drip Irrigation System (CM1DIS);b) Closed circuits with Two Manifolds of Drip Irrigation System (CM2DIS), and c) Traditional Drip Irrigation System (TDIS) as a control. Three lengths of lateral lines were used, 40, 60, and 80 meters. PE tubes lateral lines: 16 mm diameter;30 cm emitters distance, and GR built-in emitters 4 lph when operating pressure 1 bar under Two levels slope conditions 0% and 2%. Experiments were conducted at the Agric. Res. Fields., Soil and Plant & Agric. System Dept., Agric. Faculty, Southern Illinois University, Car- bondale (SIUC), Illinois, USA. Under 0% level slope when using CM2DIS the increase percent of Energy Use Efficiency (EUE) were 32.27, 33.21, and 34.37% whereas with CM1DIS were 30.84, 28.96, and 27.45% On the other hand when level slope 2% were with CM2DIS 31.57, 33.14, and 34.25 while CM1DIS were 30.15, 28.98, and 27.53 under lateral lengths 40, 60 and 80 m respectively relative to TDIS. Water Use Efficiency (WUE) when level slope 0% under CM2DIS were 1.67, 1.18, and 0.87 kg/m3 compared to 1.65, 1.16, and 0.86 kg/m3 with CM1DIS and 1.35, 1.04, and 0.75 kg/m3 with TDIS whereas with level slope 2% when using CM2DIS were 1.76, 1.29, and 0.84 kg/m3 compared to 1.77, 1.30, and 0.87 kg/m3 with CM1DIS and 1.41, 1.12, and 0.76 kg/m3 (for lateral lengths 40, 60, and 80 meters respectively). Water saving percent varied widely within individual lateral lengths and between circuit types relative to TDIS. Under slope 0% level CM2DIS water saving percent values were 19.26, 12.48, and 14.03%;with CM1DIS they were 18.51, 10.50, and 12.78%;and under slope level 2% with CM2DIS they were 19.93, 13.26, and 10.38% and CM1DIS were 20.49, 13.96, and 13.23% (for lateral lengths 40, 60, 80 meters respectively). The energy use efficiency and water saving were observed under CM2DIS and CM1DIS when using the shortest lateral length 40 meters, then lateral length 60 meters, while the lowest value was observed when using lateral length 80 meters this result depends on the physical and hydraulic characteristics of the emitters, lateral line uniformity, and friction losses. CM2DIS was more energy use efficiency, EUE, water saving, and WUE than either CM1DIS or TDIS. 展开更多
关键词 DRIP IRRIGATION closed circuitS Energy USE EFFICIENCY Water USE EFFICIENCY
下载PDF
Internal Lateral Sphincterotomy in Yaounde: Comparative Short-Term Results of Open versus Closed Techniques 被引量:1
7
作者 Georges Bwelle Motto Yannick Mahamat Ekani Boukar +4 位作者 Guy Aristide Bang Joseph Cyrille Chopkeng Ngoumfe Fabrice Tientcheu Tim Arthur Essomba Maurice Aurélien Sosso 《Surgical Science》 2021年第11期374-380,共7页
<b><span style="font-family:Verdana;">Background:</span></b><span style="font-family:Verdana;"></span><b> </b><span style="font-family:Verdan... <b><span style="font-family:Verdana;">Background:</span></b><span style="font-family:Verdana;"></span><b> </b><span style="font-family:Verdana;">Chronic anal fissure is a benign disorder which is associated with considerable discomfort. </span><span style="font-family:Verdana;"><b></b></span><b><b><span style="font-family:Verdana;">Aim of the Work:</span></b><span style="font-family:;" "=""><span style="font-family:Verdana;"></span></span></b><b> </b><span style="font-family:;" "=""><span style="font-family:Verdana;">The aim of this study was to compare the post-operative results of open and closed internal lateral sphincterotomies in the short and medium term.</span><b> </b></span><span style="font-family:Verdana;"><b></b></span><b><b><span style="font-family:Verdana;">Patient and Methods:</span></b><span style="font-family:;" "=""><span style="font-family:Verdana;"></span></span></b><b> </b><span style="font-family:Verdana;">We carried out a prospective randomized comparative study in the digestive and visceral surgery departments of Central Hospital of Yaounde over a period of 15</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">months. Patients were evaluated for each technique by several variables, including duration of surgery, post-operative pain, recurrence, surgical wound infection, gas and/or stool incontinence, and healing time with follow-up up to 12</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">months postoperatively.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;"><b></b></span><b><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:;" "=""><span style="font-family:Verdana;"></span></span></b><b> </b><span style="font-family:Verdana;">A total of 63 patients underwent surgery within them we had 32 open lateral internal sphincterotom</span><span style="font-family:Verdana;">ies</span><span style="font-family:Verdana;"> (group 1) and 31 closed lateral internal sphincterotom</span><span style="font-family:Verdana;">ies</span><span style="font-family:Verdana;"> (group 2). There were 35 men and 28 women with a sex ratio of 1.25. The mean age was 35.36 ± 10.16 years with extremes ranging from 19 to 62 years. The typical presentation was pain on defecation. The majority of fissures were located at the posterior commissure. The average duration of the procedure was longer in patients in group 1 (15.34 minutes) compared to 5.22 minutes in patients in group 2. We found 3.12% of surgical wound infections in patients in group 1 and neither patient in group 2. Gas incontinence was 6.45% in group 2 patients and 28.12% in group 1.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">The mean intensity of pain at 24 hours post-operative was between</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">4 and 6 on </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">visual analogue scale in patients in group 2 and between 7 and 10 in group 1. Wound healing time was 8.9 days in group </span><span style="font-family:Verdana;">1</span><span style="font-family:Verdana;"> and 4 days in group 2 patients. The hospital stay was 24 hours for both groups of patients. No recurrence was noted during the 6-month</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">follow-up period.</span><b> </b></span><span style="font-family:;" "=""><span style="font-family:Verdana;"><b></b></span><b><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"></span></b></span><b> </b><span style="font-family:Verdana;">Closed lateral internal anal sphincterotomy is the treatment of choice for chronic anal fissures because it is effective and associated with </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">lower complication rate than the open sphincterotomy technique.</span> 展开更多
关键词 Anal Fissure Internal Lateral Sphincterotomy open Technique close Technique
下载PDF
Open-closed Loop ILC Corrected with Angle Relationship of Output Vectors for Tracking Control of Manipulator 被引量:8
8
作者 WANG Hong-Bin WANG Yan 《自动化学报》 EI CSCD 北大核心 2010年第12期1758-1765,共8页
关键词 ILC 自动化 跟踪控制 仿真
下载PDF
Open-plus-closed-loop control for chaotic motion of 3D rigid pendulum 被引量:2
9
作者 戈新生 邹奎 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2014年第4期403-412,共10页
An open-plus-closed-loop (OPCL) control problem for the chaotic motion of a 3D rigid pendulum subjected to a constant gravitationM force is studied. The 3D rigid pendulum is assumed to be consist of a rigid body sup... An open-plus-closed-loop (OPCL) control problem for the chaotic motion of a 3D rigid pendulum subjected to a constant gravitationM force is studied. The 3D rigid pendulum is assumed to be consist of a rigid body supported by a fixed and frictionless pivot with three rotational degrees. In order to avoid the singular phenomenon of Euler's angular velocity equation, the quaternion kinematic equation is used to describe the motion of the 3D rigid pendulum. An OPCL controller for chaotic motion of a 3D rigid pendulum at equilibrium position is designed. This OPCL controller contains two parts: the open-loop part to construct an ideal trajectory and the closed-loop part to stabilize the 3D rigid pendulum. Simulation results show that the controller is effective and efficient. 展开更多
关键词 3D rigid pendulum QUATERNION chaotic motion Poincar section open-plus-closed-loop (OPCL) control
下载PDF
Value of negative pressure sealing drainage on wound healing of Gustilo IIIB and IIIC open fractures
10
作者 Bo Fang Yong-Sheng Wang +2 位作者 Wei Li Kai Ying Gang Zong 《World Journal of Clinical Cases》 SCIE 2024年第20期4199-4205,共7页
BACKGROUND Gustilo III fractures have a high incidence and are difficult to treat.Patients often experience difficulty in wound healing.Negative pressure drainage technology can help shorten wound healing time and has... BACKGROUND Gustilo III fractures have a high incidence and are difficult to treat.Patients often experience difficulty in wound healing.Negative pressure drainage technology can help shorten wound healing time and has positive value in improving patient prognosis.AIM To explore the clinical value of the negative pressure sealing drainage technique in wound healing of Gustilo IIIB and IIIC open fractures.METHODS Eighty patients with Gustilo IIIB and IIIC open fractures with skin and soft tissue injuries who were treated in the Second People’s Hospital of Dalian from March 2019 to December 2021 were selected as the research subjects.They were divided into a study group(n=40,healed with negative pressure closed drainage)and a control group(n=40,healed with conventional dressing changes)according to the variation in the healing they received.The efficacy of the clinical interventions,the variations in the regression indicators(time to wound healing,time to fracture healing,time to hospitalization),and the conversion and healing of bacterial wounds were compared 1-3 mo after the intervention.RESULTS The total effective rate of patients among the study group was 95.00%(38/40),which was notably higher than 75.00%(30/40)among the control group(P<0.05).The wound healing time,fracture healing time,and hospital stay of the patients in the study group was shorter than the control group(P<0.05).After the intervention,the negative bacterial culture at the wound site rate and wound healing rate of the patients among the study group increased compared to the control group(P<0.05).CONCLUSION Negative pressure sealing and drainage technology has a good therapeutic effect on patients with Gustilo IIIB and IIIC open fracture wounds with skin and soft tissue injury.It can notably enhance the wound healing rate and the negative rate of bacteria on the wound surface and help to speed up the recovery process of patients. 展开更多
关键词 Negative pressure closed drainage Gustilo type III open fracture Wound healing Clinical outcome Research value
下载PDF
TRANSFER OPEN OR CLOSED SETVALUED MAPPING AND GENERALIZ-ATION OF H-KKM THEOREM WITH APPLICATIONS
11
作者 李秉友 苏家宝 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1994年第10期981-987,共7页
In this paper ,we introduce a class of generalized mapping called transfer open orclosed valued mapping to generalize the KKM theorem on H-space.Then asapplications,using our H-KKM theorem,we prove some coincidence th... In this paper ,we introduce a class of generalized mapping called transfer open orclosed valued mapping to generalize the KKM theorem on H-space.Then asapplications,using our H-KKM theorem,we prove some coincidence theorems.matching theorems and vector valued minimax inequalities which generalize slightly thecorresponding results in[1,2,4,5,6,7]. 展开更多
关键词 transfer closed or open setvalued mapping coincidence theorem.H-KKM mapping matching theorem
下载PDF
Effect of closed circuits drip irrigation system and lateral lines length on growth, yield, quality and water use efficiency of soybean crop
12
作者 Mohamed Yousif Tayel Hani Abdel-Ghani Mansour Sabreen Khalil Pibars 《Agricultural Sciences》 2013年第2期85-90,共6页
Field experiment was conducted for one growing season (2012) in clay loam soil at the Experimental Farm of Faculty of Agriculture, Southern Illinois University at Carbondale (SIUC), USA on soybean crop to study the ef... Field experiment was conducted for one growing season (2012) in clay loam soil at the Experimental Farm of Faculty of Agriculture, Southern Illinois University at Carbondale (SIUC), USA on soybean crop to study the effect of: 1) the closed drip irrigation system: closed circuits with one and two a manifolds for lateral lines (CM1DIS;CM2DIS) and traditional drip irrigation system (TDIS) as a control;and 2) lateral lines length (LLL): LLL1, LLL2 and LLL3 (40, 60,80 m) on soybean growth, yield, oil, protein content and water use efficiency. Plants were drip irrigated every 4 days. N, K2O and P2O5 fertilizers were added via irrigation water. Data obtained could be outlined as follows: 1) According to the mean values of soybean crop growth (leaf area;plant height), yield (grain and straw), both oil and protein content and water use efficiency, the treatment used could be ranked in the following ascending orders: TDIS < CM1DIS < CM2DIS and LLL3 < LLL2 < LLL1;2) Differences in the means of the studied data among treatments used were significant at the 1% level;3) The effects of the DIC × LLL on the data obtained were significant at the 1 % level;And 4) the highest values of the obtained data and the lowest ones were achieved in the following interactions: CM2DIS × LLL1;TDIS × LLL3, respectively. 展开更多
关键词 closed circuits DRIP IRRIGATION Lateral Lines SOYBEAN WUE
下载PDF
Modification of water application uniformity among closed circuit trickle irrigation systems
13
作者 Hani A.-G. Mansour Mohamed Yousif Tayel +2 位作者 Mohamed A. Abd El-Hady David A. Lightfoot Abdel-Ghany Mohamed El-Gindy 《Agricultural Sciences》 2010年第1期1-9,共9页
The aim of this research was determine the ma- ximum application uniformity of closed circuit trickle irrigation systems designs. Laboratory tests carried out for Two types of closed circuits: a) One manifold for late... The aim of this research was determine the ma- ximum application uniformity of closed circuit trickle irrigation systems designs. Laboratory tests carried out for Two types of closed circuits: a) One manifold for lateral lines or Closed circuits with One Manifold of Trikle Irrigation System (COMTIS);b) Closed circuits with Two Manifolds of Trikle Irrigation System (CTMTIS), and c) Traditional Trikle Irrigation System (TTIS) as a control. Three lengths of lateral lines were used, 40, 60, and 80 meters. PE tubes lateral lines: 16 mm diameter;30 cm emitters distance, and GR built-in emitters 4 lph when operating pressure 1 bar. Experiments were conducted at the Agric. Eng. Res. Inst., ARC, MALR, Egypt. With COMTIS the emitter flow rate was 4.07, 3.51, and 3.59 lph compared to 4.18, 3.72, and 3.71 lph with CTMTIS and 3.21, 2.6, and 2.16 lph with TTIS (lateral lengths 40, 60, and 80 meters respectively). Uniformity varied widely within individual lateral lengths and between circuit types. Under CTMTIS uniformity values were 97.74, 95.14, and 92.03 %;with COMTIS they were 95.73, 89.45, and 83.25 %;and with TTIS they were 88.27, 84.73, and 80.53 % (for lateral lengths 40, 60, 80 meters respectively). The greatest uniformity was observed under CTMTIS and COMTIS when using the shortest lateral length 40 meters, then lateral length 60 meters, while the lowest value was observed when using lateral length 80 meters this result depends on the physical and hydraulic characteristics of the emitter and lateral line. CTMTIS was more uniform than either COMTIS or TTIS. Friction losses were decreased with CTMTIS in the emitter laterals at lengths 40 meters compared to TTIS and COMTIS. Therefore, differences may be related to increased friction losses when using TDIS and COMDIS. 展开更多
关键词 Trickle IRRIGATION closed circuitS MANIFOLD LATERAL Flow Rate UNIFORMITY
下载PDF
A screw dislocation near one open inhomogeneity and another closed inhomogeneity both permitting constant interior stresses
14
作者 Xu WANG Ping YANG P.SCHIAVONE 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2021年第2期173-182,共10页
We prove that the interior stresses within both a non-parabolic open inhomogeneity and another interacting non-elliptical closed inhomogeneity can still remain constant when the matrix is simultaneously under the acti... We prove that the interior stresses within both a non-parabolic open inhomogeneity and another interacting non-elliptical closed inhomogeneity can still remain constant when the matrix is simultaneously under the action of a screw dislocation and uniform remote anti-plane stresses.The constancy of interior stresses is realized through the construction of a conformal mapping function for the doubly connected domain occupied by the surrounding matrix.The mapping function is endowed with the information describing the screw dislocation via the incorporation of two specifically defined logarithmic terms.The constant interior stress fields are observed to be independent of the specific open and closed shapes of the two inhomogeneities and the existence of the screw dislocation.In contrast,the existence of the neighboring screw dislocation significantly affects the open and closed shapes of the two inhomogeneities. 展开更多
关键词 constant stress field open inhomogeneity closed inhomogeneity screw dislocation conformal mapping
下载PDF
The effect of different inflation volumes of laryngeal mask airway on efficacy of closed circuit controlled ventilation in pediatric cancer patients
15
作者 Magda S.Azer Ayman A.Ghoneim Hossam Z.Ghobrial 《The Chinese-German Journal of Clinical Oncology》 CAS 2013年第12期596-601,共6页
Objective: The laryngeal mask airway (LMA) is an established way for airway control during spontaneous ventila- tion. Its ability to deliver positive pressure ventilation without leakage especially in low flow stat... Objective: The laryngeal mask airway (LMA) is an established way for airway control during spontaneous ventila- tion. Its ability to deliver positive pressure ventilation without leakage especially in low flow states is still controversy. The aim of this study is to test the possibility of using LMA in pediatric closed circuit controlled ventilation, and to find out the optimum cuff volume to perform closed system ventilation. Methods: Twenty children scheduled for elective surgeries were enrolled in a crossover study. Laryngeal mask airway was used. In stage I, the cuff was inflated with the maximum volume of air as rec- ommended by the manufacturers. Adjustment of volume of air inflated into the LMA cuff to the minimum volume to obtain the effective seal was done at stage II. The leak pressure, intracuff pressure and the leak volume were measured in both stages. Results: The cuff filling volume was significantly lower compared to the maximum cuff inflation volume in stage I. Leakage values showed significantly less values in stage II of the study with smaller cuff inflation volumes. The airway leakage pressure was significantly lower in stage fl in comparison to stage I. Cuff inflation pressure in stage I showed marked elevation which dropped significantly after adjustment of cuff volume in stage I1. Conclusion: Laryngeal mask airway is an effective tool to provide closed circuit controlled ventilation in pediatrics. Inflation of the cuff by the minimum volume of air needed to reach the just sealing pressure is suggested to minimize the leakage volume. 展开更多
关键词 laryngeal mask airway (LMA) PEDIATRIC controlled ventilation closed circuit intracuff volume leak pressure
下载PDF
Dynamic modeling and analysis of the closed-circuit grinding-classification process
16
作者 YunfeiChu WenliXu WeihanWan 《Journal of University of Science and Technology Beijing》 CSCD 2005年第2期111-115,共5页
Mathematical models of the grinding process are the basis of analysis, simulation and control. Most existent models in- cluding theoretical models and identification models are, however, inconvenient for direct analy... Mathematical models of the grinding process are the basis of analysis, simulation and control. Most existent models in- cluding theoretical models and identification models are, however, inconvenient for direct analysis. In addition, many models pay much attention to the local details in the closed-circuit grinding process while overlooking the systematic behavior of the process as a whole. From the systematic perspective, the dynamic behavior of the whole closed-circuit grinding-classification process is consid- ered and a first-order transfer function model describing the dynamic relation between the raw material and the product is established. The model proves that the time constant of the closed-circuit process is lager than that of the open-circuit process and reveals how physical parameters affect the process dynamic behavior. These are very helpful to understand, design and control the closed-circuit grinding-classification process. 展开更多
关键词 closed-circuit grinding-classification process open-circuit grinding process dynamic model transfer function time constant pole analysis disturbance rejection
下载PDF
Free torsion of thin-walled structural members of open-and closed-sections
17
作者 Long-yuan LI D.EASTERBROOK 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2014年第1期25-32,共8页
Free torsion of thin-walled structures of open- and closed-sections is a classical elastic mechanics problem, which, in literature, is often solved by the method of membrane analogy. The method of membrane analogy, ho... Free torsion of thin-walled structures of open- and closed-sections is a classical elastic mechanics problem, which, in literature, is often solved by the method of membrane analogy. The method of membrane analogy, however, can be only applied to structures of a single material. If the structure consists of both open- and closed-sections, the method of membrane analogy is difficult to be applied. In this paper, a new method is presented for solving the free torsion of thin-walled structures of open- and/or closed- sections with multiple materials. By utilizing a simple statically indeterminate concept, torsional equations are derived based on the equilibrium and compatibility conditions. The method presented here not only is very simple and easy to understand but also can be applied to thin-walled structures of combined open- and closed-sections with multiple materials. 展开更多
关键词 TORSION THIN-WALLED open-section closed-section shear flow shear stress
下载PDF
A Comparative Study on Open Circuit Voltage Models for Lithium-ion Batteries 被引量:10
18
作者 Quan-Qing Yu Rui Xiong +1 位作者 Le-Yi Wang Cheng Lin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第4期84-91,共8页
The current research of state of charge(SoC) online estimation of lithium-ion battery(LiB) in electric vehicles(EVs)mainly focuses on adopting or improving of battery models and estimation filters. However, little att... The current research of state of charge(SoC) online estimation of lithium-ion battery(LiB) in electric vehicles(EVs)mainly focuses on adopting or improving of battery models and estimation filters. However, little attention has been paid to the accuracy of various open circuit voltage(OCV) models for correcting the SoC with aid of the ampere-hour counting method. This paper presents a comprehensive comparison study on eighteen OCV models which cover the majority of models used in literature. The low-current OCV tests are conducted on the typical commercial LiFePO/graphite(LFP) and LiNiMnCoO/graphite(NMC) cells to obtain the experimental OCV-SoC curves at different ambient temperature and aging stages. With selected OCV and SoC points from experimental OCV-SoC curves, the parameters of each OCV model are determined by curve fitting toolbox of MATLAB 2013. Then the fitting OCV-SoC curves based on diversified OCV models are also obtained. The indicator of root-mean-square error(RMSE) between the experimental data and fitted data is selected to evaluate the adaptabilities of these OCV models for their main features, advantages,and limitations. The sensitivities of OCV models to ambient temperatures, aging stages, numbers of data points,and SoC regions are studied for both NMC and LFP cells. Furthermore, the influences of these models on SoC estimation are discussed. Through a comprehensive comparison and analysis on OCV models, some recommendations in selecting OCV models for both NMC and LFP cells are given. 展开更多
关键词 State of charge open circuit voltage model Lithium-ion battery NMC LFP
下载PDF
Changes in neurological and pathological outcomes in a modified rat spinal cord injury model with closed canal 被引量:1
19
作者 Xin Sun Xing-Zhen Liu +4 位作者 Jia Wang Hai-Rong Tao Tong Zhu Wen-Jie Jin Kang-Ping Shen 《Neural Regeneration Research》 SCIE CAS CSCD 2020年第4期697-704,共8页
Most animal spinal cord injury models involve a laminectomy,such as the weight drop model or the transection model.However,in clinical practice,many patients undergo spinal cord injury while maintaining a relatively c... Most animal spinal cord injury models involve a laminectomy,such as the weight drop model or the transection model.However,in clinical practice,many patients undergo spinal cord injury while maintaining a relatively complete spinal canal.Thus,open spinal cord injury models often do not simulate real injuries,and few previous studies have investigated whether having a closed spinal canal after a primary spinal cord injury may influence secondary processes.Therefore,we aimed to assess the differences in neurological dysfunction and pathological changes between rat spinal cord injury models with closed and open spinal canals.Sprague-Dawley rats were randomly divided into three groups.In the sham group,the tunnel was expanded only,without inserting a screw into the spinal canal.In the spinal cord injury with open canal group,a screw was inserted into the spinal canal to cause spinal cord injury for 5 minutes,and then the screw was pulled out,leaving a hole in the vertebral plate.In the spinal cord injury with closed canal group,after inserting a screw into the spinal canal for 5 minutes,the screw was pulled out by approximately 1.5 mm and the flat end of the screw remained in the hole in the vertebral plate so that the spinal canal remained closed;this group was the modified model,which used a screw both to compress the spinal cord and to seal the spinal canal.At 7 days post-operation,the Basso-Beattie-Bresnahan scale was used to measure changes in neurological outcomes.Hematoxylin-eosin staining was used to assess histopathology.To evaluate the degree of local secondary hypoxia,immunohistochemical staining and western blot assays were applied to detect the expression of hypoxia-inducible factor 1α(HIF-1α)and vascular endothelial growth factor(VEGF).Compared with the spinal cord injury with open canal group,in the closed canal group the Basso-Beattie-Bresnahan scores were lower,cell morphology was more irregular,the percentage of morphologically normal neurons was lower,the percentages of HIF-1α-and VEGF-immunoreactive cells were higher,and HIF-1αand VEGF protein expression was also higher.In conclusion,we successfully established a rat spinal cord injury model with closed canal.This model could result in more serious neurological dysfunction and histopathological changes than in open canal models.All experimental procedures were approved by the Institutional Animal Care Committee of Shanghai Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine,China(approval No.HKDL201810)on January 30,2018. 展开更多
关键词 Basso-Beattie-Bresnahan scores closed SPINAL CANAL HIF-1α hypoxia MODEL nerve regeneration open SPINAL CANAL rat secondary INJURY SPINAL cord INJURY VEGF
下载PDF
Effect of Valence Band Tail Width on the Open Circuit Voltage of P3HT:PCBM Bulk Heterojunction Solar Cell:AMPS-1D Simulation Study 被引量:5
20
作者 Bushra Mohamed Omer 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第8期216-220,共5页
The effect of the valence band tail width on the open circuit voltage of P3HT:PCBM bulk heterojunction solar cell is investigated by using the AMPS-1D computer program. An effective medium model with exponential vale... The effect of the valence band tail width on the open circuit voltage of P3HT:PCBM bulk heterojunction solar cell is investigated by using the AMPS-1D computer program. An effective medium model with exponential valence and conduction band tail states is used to simulate the photovoltaic cell. The simulation result shows that the open circuit voltage depends Iinearly on the logarithm of the generation rate and the slope depends on the width of the valence band tail. The open circuit voltage decreases with the increasing width of the band tail. The dark and light ideality factors increase with the width of the valence band tail. 展开更多
关键词 Effect of Valence Band Tail Width on the open circuit Voltage of P3HT:PCBM Bulk Heterojunction Solar Cell:AMPS-1D Simulation Study HT
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部