期刊文献+
共找到130篇文章
< 1 2 7 >
每页显示 20 50 100
Effect of Certain Toxicants on Gonadotropin-Induced Ovarian Non-Esterified Cholesterol Depletion and Steroidogenic Enzyme Stimulation of the Common Carp Cyprinus carpio in vitro 被引量:1
1
作者 DILIP MUKHERJEE DHRITI GUHA VINOD KUMAR 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1992年第2期92-98,共7页
Isolated ovarian tissues from the common carp, Cyprinus carpio were incubated in vitro to obtain a discrete effect of four common toxicants of industrial origin, namely phenol, sulfide, mercuric chloride and cadmium c... Isolated ovarian tissues from the common carp, Cyprinus carpio were incubated in vitro to obtain a discrete effect of four common toxicants of industrial origin, namely phenol, sulfide, mercuric chloride and cadmium chloride, on gonadotropin-induced alteration of nonesterified and esterified cholesterol and steroidogenic enzymes, △5-3β-HSD and 17β-HSD activity. Stage II ovarian tissue containing 30-40% mature oocytes were shown to be most responsive to gonadotropins in depleting only nonesterified cholesterol moiety and stimulating the activity of both. Safe doses of above mentioned toxicants when added separately to stage II ovarian tissue with oLH (1 μg/incubation) gonadotropin-induced depletion of nonesterified cholesterol and gonadotropin-induced stimulation of the activity of both enzymes was significantly inhibited. Esterified cholesterol remained almost unaltered. Findings clearly indicate the impairment of gonadotropin induced fish ovarian steroidogenesis by the four toxicants separately. 展开更多
关键词 effect of Certain Toxicants on Gonadotropin-Induced Ovarian Non-Esterified Cholesterol depletion and Steroidogenic Enzyme Stimulation of the Common Carp Cyprinus carpio in vitro
下载PDF
Biologically effective radiation of solar ultraviolet radiation and the depletion of stratospheric ozone
2
作者 Wang Shaobin Su Weihan(Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences),Beijing 100085,China) Wei Dingwen(Institute of Atmospheric Physics,Chinese Academy or Sciences),Beijing 100029,China) 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1994年第3期373-381,共9页
Based on the biological action spectra and total UV-B radiation in the atmosphere,the effective UV-dose for DNA, erythema,and plant at different seasons in the last decade,and their future change in Beijing area were ... Based on the biological action spectra and total UV-B radiation in the atmosphere,the effective UV-dose for DNA, erythema,and plant at different seasons in the last decade,and their future change in Beijing area were calculated.Computation results indicate that the maxi- mum of biologically effective radiation dose at noontime is in July and the minimum is in January. From 1980 to 1989 biologically effective radiation dose have increased with the average rates of about 0.6,0.7 and 1.1 mW/m ̄2 per year for January, April and October,while in July the trend of radiation dose is not ln evidence. For 1% reduction of ozone concentration radiation amplification factor for DNA,erythema and plant are 2.3,2.3 and 1.4 and for 30% reduction of ozone concentration the RAF for DNA,erythema and plant are 4.2,4.0 and 2.1,respectively. 展开更多
关键词 UV-B ozone depletion biological effects solar radiation.
下载PDF
Enhanced effect of dimension of receptor-ligand complex and depletion effect on receptor-mediated endocytosis of nanoparticles
3
作者 刘野 高庆庆 +4 位作者 刘益军 赵闯 毛宗良 胡林 刘艳辉 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第12期48-54,共7页
We present an extended analytical model including the depletion effect and the dimension of ligand-receptor complex, aiming to elucidate their influences on endocytosis of spherocylindrical nanoparticles (NPs). It i... We present an extended analytical model including the depletion effect and the dimension of ligand-receptor complex, aiming to elucidate their influences on endocytosis of spherocylindrical nanoparticles (NPs). It is found that the dimension of ligand-receptor complex (δ) and the depletion effect interrelatedly govern the optimal conditions of NP endocytosis. The endocytosis phase diagram constructed in the space of NP radius and relative aspect ratio indicates that the endocytosis of NP is enhanced evidently by reducing the optimal radius and the threshold radius of endocytosed NP. Meanwhile, through thermodynamic and kinetic analysis of the diffusion of receptors, the dependence of diffusion length on depletion effect and the dimension of ligand-receptor complex can be identified in great detail. For small aspect ratio, diffusion length decreases with increasing concentration c of small bioparticles in cellular environment. Endocytosis speed corresponding to large radius R and high concentration c of small bioparticles strongly depends on the increasing (2r-δ). These results may show some highlights into the conscious design of NPs for diagnostic agents and therapeutic drug delivery applications. 展开更多
关键词 cellular uptake depletion effect dimension of receptor-ligand complex elasticity theory
下载PDF
Simultaneous Impedance Analysis of Three Parallel Piezoelectric Quartz Crystals for Electrochemical Depletion Layer Effect Study
4
作者 HuiYanLIU QingJiXIE 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第5期563-566,共4页
Simultaneous impedance analysis of three one-face sealed resonating piezoelectric quartz crystals (PQCs) in parallel is proposed through admittance measurements of the three PQCs on one impedance analyzer and then non... Simultaneous impedance analysis of three one-face sealed resonating piezoelectric quartz crystals (PQCs) in parallel is proposed through admittance measurements of the three PQCs on one impedance analyzer and then non-linear fitting according to the parallel combination of three Butterworth-Van Dyke circuits. Responses of each PQC obtained from the three-PQC mode agreed well with those measured separately in series sucrose aqueous solutions. This novel method has been used for the study of depletion-layer effect during ferri-/ferrocyanide electrochemical reactions. 展开更多
关键词 Three-PQC impedance analysis electrochemical depletion layer effect ferri-/ferrocyanide.
下载PDF
Coupling effects of depletion interactions in a three-sphere colloidal system
5
作者 陈泽顺 戴刚 +1 位作者 高海峡 肖长明 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第5期587-590,共4页
In a three-sphere system, the middle sphere is acted upon by two opposite depletion forces from the other two spheres. It is found that, in this system, the two depletion forces are coupled with each other and result ... In a three-sphere system, the middle sphere is acted upon by two opposite depletion forces from the other two spheres. It is found that, in this system, the two depletion forces are coupled with each other and result in a strengthened depletion force. So the difference of the depletion forces of the three-sphere system and its corresponding two two-sphere systems is introduced to describe the coupling effect of the depletion interactions. The numerical results obtained by Monte- Carlo simulations show that this coupling effect is affected by both the concentration of small spheres and the geometrical confinement. Meanwhile, it is also found that the mechanisms of the coupling effect and the effect on the depletion force from the ~eometry factor are the same. 展开更多
关键词 three-sphere system coupling effect of depletion interactions
下载PDF
Coupling Effects of Depletion Interactions in Colloidal Suspensions
6
作者 Haixia Gao Zeshun Chen +1 位作者 Chunshu Li Changming Xiao 《Journal of Modern Physics》 2012年第9期918-922,共5页
The depletion interactions of the three-sphere system in which the three spheres are on one line are studied by Monte Carlo simulations. The depletion interactions are determined by ARM, and the coupling effect was pr... The depletion interactions of the three-sphere system in which the three spheres are on one line are studied by Monte Carlo simulations. The depletion interactions are determined by ARM, and the coupling effect was proved by the numerical result that the depletion interactions in the three-sphere system are larger than that of the corresponding two-sphere system. Furthermore, we find that the mechanisms of the coupling effect and the effect on depletion force from the geometry factor are the same. In addition, the numerical results also show that this coupling effect will be affected by both the volume fraction and separation of three-sphere system. 展开更多
关键词 Three-Sphere SYSTEM COUPLING effect of depletion INTERACTIONS
下载PDF
Coupling Effects of Depletion Interactions in Three-Sphere Systems with Different Size Ratio of Large- to Small-Sphere
7
作者 Zhouan Zhou Dai Gang Changming Xiao 《Journal of Modern Physics》 2013年第6期761-765,共5页
The coupling effects of depletion interactions in three-sphere systems with different size ratio of large- to small-sphere are studied by Monte Carlosimulations in this paper. The numerical results show that this coup... The coupling effects of depletion interactions in three-sphere systems with different size ratio of large- to small-sphere are studied by Monte Carlosimulations in this paper. The numerical results show that this coupling effect is affected by the size ratio of large- to small-sphere: the larger the size ratio is, the larger the coupling effect will be. 展开更多
关键词 Coupling effects of depletion INTERACTIONS Three-Sphere SYSTEMS SIZE RATIO
下载PDF
Causes of Ozone Layer Depletion and Its Effects on Human: Review 被引量:2
8
作者 Fakhra Anwar Fahad Nazir Chaudhry +2 位作者 Saiqa Nazeer Noshila Zaman Saba Azam 《Atmospheric and Climate Sciences》 2016年第1期129-134,共6页
This study was conducted at University of Gujrat during 2014-2015 as a term paper for Master of Philosophy. The data regarding effect of ozone depletion on human was reviewed and compiled as a review paper from variou... This study was conducted at University of Gujrat during 2014-2015 as a term paper for Master of Philosophy. The data regarding effect of ozone depletion on human was reviewed and compiled as a review paper from various published articles of international reputed journals, annual/environmental reports of recognized organization and e-books. The causes, mechanism and bio-effects of ozone layer depletion on humans were addressed. It is revealed that introduction of Chloroflourocarbons (CFCs) in the environment is the most rated cause of said depiction. Ozone depletion is allowing the UV radiation to earth surface. The exposure to these radiations is severely affecting all life forms on earth, especially the humans. Permanent or temporary blindness, skin cancer and immunity suppression are the main effects of these radiations reported by various researchers on humans. The prospects of ozone recovery are still undiscovered. The current situation of ozone depiction demands urgent remedial measures to protect lives on this earth. 展开更多
关键词 OZONE Ozone depletion Chloroflourocarbons (CFCs) Ultra Violet (UV) Radiations Bio-effects
下载PDF
Impact of back-gate bias on the hysteresis effect in partially depleted SOI MOSFETs
9
作者 罗杰馨 陈静 +4 位作者 周建华 伍青青 柴展 余涛 王曦 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第5期473-478,共6页
The hysteresis effect in the output characteristics,originating from the floating body effect,has been measured in partially depleted(PD) silicon-on-insulator(SOI) MOSFETs at different back-gate biases.I D hystere... The hysteresis effect in the output characteristics,originating from the floating body effect,has been measured in partially depleted(PD) silicon-on-insulator(SOI) MOSFETs at different back-gate biases.I D hysteresis has been developed to clarify the hysteresis characteristics.The fabricated devices show the positive and negative peaks in the I D hysteresis.The experimental results show that the I D hysteresis is sensitive to the back gate bias in 0.13-渭m PD SOI MOSFETs and does not vary monotonously with the back-gate bias.Based on the steady-state Shockley-Read-Hall(SRH) recombination theory,we have successfully interpreted the impact of the back-gate bias on the hysteresis effect in PD SOI MOSFETs. 展开更多
关键词 floating body effect hysteresis effect back gate bias partially depleted (PD) SOl
下载PDF
耗尽区调制对氢化MILC Poly-Si TFT热产生漏电的影响
10
作者 朱臻 《微电子学与计算机》 CSCD 北大核心 2011年第2期43-46,共4页
研究了热载流子应力下耗尽区调制效应对氢化金属诱导横向结晶多晶硅薄膜晶体管热产生漏电的影响.从理论上论证了热载流子应力下氢化金属诱导横向结晶多晶硅薄膜晶体管热产生漏电中的耗尽区调制效应的存在.并利用正、反向测量模式,从实... 研究了热载流子应力下耗尽区调制效应对氢化金属诱导横向结晶多晶硅薄膜晶体管热产生漏电的影响.从理论上论证了热载流子应力下氢化金属诱导横向结晶多晶硅薄膜晶体管热产生漏电中的耗尽区调制效应的存在.并利用正、反向测量模式,从实验上进一步确认这种效应对氢化金属诱导横向结晶多晶硅薄膜晶体管热产生漏电的影响.发现在热载流子应力下,正、反向测量模式时,氢化金属诱导横向结晶多晶硅薄膜晶体管热产生漏电均随应力时间的增加而减小.但由于漏极和源极附近沟道区的表面势受热空穴注入影响的程度不同,热载流子应力下,正、反向测量模式的热产生漏电减小程度不同.理解热载流子应力下耗尽区调制效应对氢化金属诱导横向结晶多晶硅薄膜晶体管热产生漏电的影响,有助于成功设计电路. 展开更多
关键词 金属诱导横向结晶 多晶硅薄膜晶体管 热载流子应力 热产生漏电 耗尽区调制效应
下载PDF
Heteromaterial-gate line tunnel field-effect transistor based on Si/Ge heterojunction
11
作者 Shuqin Zhang Renrong Liang +2 位作者 Jing Wang Zhen Tan Jun Xu 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第1期557-562,共6页
A Si/Ge heterojunction line tunnel field-effect transistor (LTFET) with a symmetric heteromaterial gate is proposed. Compared to single-material-gate LTFETs, the heteromaterial gate LTFET shows an off-state leakage ... A Si/Ge heterojunction line tunnel field-effect transistor (LTFET) with a symmetric heteromaterial gate is proposed. Compared to single-material-gate LTFETs, the heteromaterial gate LTFET shows an off-state leakage current that is three orders of magnitude lower, and steeper subthreshold characteristics, without degradation in the on-state current. We reveal that these improvements are due to the induced local potential barrier, which arises from the energy-band profile modulation effect. Based on this novel structure, the impacts of the physical parameters of the gap region between the pocket and the drain, including the work-function mismatch between the pocket gate and the gap gate, the type of dopant, and the doping concentration, on the device performance are investigated. Simulation and theoretical calculation results indicate that the gap gate material and n-type doping level in the gap region should be optimized simultaneously to make this region fully depleted for further suppression of the off-state leakage current. 展开更多
关键词 line tunnel field-effect transistor heteromaterial gate fully depleted
下载PDF
22nm全耗尽型绝缘体上硅器件单粒子瞬态效应的敏感区域
12
作者 张博翰 梁斌 +1 位作者 刘小年 方亚豪 《国防科技大学学报》 EI CAS CSCD 北大核心 2024年第2期146-152,共7页
基于3D-TCAD模拟,研究了22 nm全耗尽型绝缘体上硅(fully depleted silicon-on-insulator,FDSOI)器件单粒子瞬态(single-event transient,SET)效应的敏感性区域。对比了使用单管和使用反相器来研究器件SET敏感性区域的方法,从而分析实际... 基于3D-TCAD模拟,研究了22 nm全耗尽型绝缘体上硅(fully depleted silicon-on-insulator,FDSOI)器件单粒子瞬态(single-event transient,SET)效应的敏感性区域。对比了使用单管和使用反相器来研究器件SET敏感性区域的方法,从而分析实际电路中重离子轰击位置对22 nm FDSOI器件SET敏感性的影响,并从电荷收集机制的角度进行了解释。深入分析发现寄生双极放大效应对重粒子轰击位置敏感是造成器件不同区域SET敏感性不同的原因。而单管漏极接恒压源造成漏极敏感性增强是导致单管与反相器中器件SET敏感区域不同的原因。修正了FDSOI工艺下器件SET敏感性区域的研究方法,与单管相比,采用反相器进行仿真,结果更符合实际情况,这将为器件SET加固提供理论指导。 展开更多
关键词 单粒子瞬态 电荷收集 双极放大效应 敏感区域 全耗尽型绝缘体上硅
下载PDF
Surface depletion field in 2D perovskite microplates: Structural phase transition, quantum confinement and Stark effect 被引量:2
13
作者 Wancai Li Chen Fang +6 位作者 Haizhen Wang Shuai Wang Junze Li Jiaqi Ma Jun Wang Hongmei Luo Dehui Li 《Nano Research》 SCIE EI CAS CSCD 2019年第11期2858-2865,共8页
Surface depletion field would introduce the depletion region near surface and thus could significantly alter the optical,electronic and optoelectronic properties of the materials,especially low-dimensional materials.T... Surface depletion field would introduce the depletion region near surface and thus could significantly alter the optical,electronic and optoelectronic properties of the materials,especially low-dimensional materials.Two-dimensional(2D)organic—inorganic hybrid perovskites with van der Waals bonds in the out-of-plane direction are expected to have less influence from the surface depletion field;nevertheless,studies on this remain elusive.Here we report on how the surface depletion field affects the structural phase transition,quantum confinement and Stark effect in 2D(BA)2PbI4 perovskite microplates by the thickness-,temperature-and power-dependent photoluminescence(PL)spectroscopy.Power dependent PL studies suggest that high-temperature phase(HTP)and low-temperature phase(LTP)can coexist in a wider temperature range depending on the thickness of the 2D perovskite microplates.With the decrease of the microplate thickness,the structural phase transition temperature first gradually decreases and then increases below 25 nm,in striking contrast to the conventional size dependent structural phase transition.Based on the thickness evolution of the emission peaks for both high-temperature phase and low-temperature phase,the anomalous size dependent phase transition could probably be ascribed to the surface depletion field and the surface energy difference between polymorphs.This explanation was further supported by the temperature dependent PL studies of the suspended microplates and encapsulated microplates with graphene and boron nitride flakes.Along with the thickness dependent phase transition,the emission energies of free excitons for both HTP and LTP with thickness can be ascribed to the surface depletion induced confinement and Stark effect. 展开更多
关键词 two-dimensional(2D)perovskite thickness surface depletion field structural phase transition quantum confinement Stark effect
原文传递
中国ODS的排放及其对温室效应的贡献 被引量:11
14
作者 徐建华 胡建信 张剑波 《中国环境科学》 EI CAS CSSCI CSCD 北大核心 2003年第4期363-366,共4页
分析了消耗臭氧层物质(ODS)在中国的消费状况和逐步淘汰的进程.选择1999年为基准年,列出了中国ODS的排放清单,根据各物质作不同用途的排放特点,计算了这些物质的实际排放量的臭氧消耗潜势(ODP)值和全球变暖潜势(GWP)值.结果表明,1999年... 分析了消耗臭氧层物质(ODS)在中国的消费状况和逐步淘汰的进程.选择1999年为基准年,列出了中国ODS的排放清单,根据各物质作不同用途的排放特点,计算了这些物质的实际排放量的臭氧消耗潜势(ODP)值和全球变暖潜势(GWP)值.结果表明,1999年中国排放的ODS的ODP值约43496t,按照GWP值折算,相当于约60.4106t当量碳.削减和淘汰ODS,不仅能够保护臭氧层,对控制全球变暖也有很大贡献. 展开更多
关键词 ODS ODP GWP 排放 温室效应
下载PDF
滤除白细胞的血液成分质量与临床应用研究 被引量:21
15
作者 李聚林 罗志 +3 位作者 谢苇 何伟兰 刘振北 潘汉站 《中国输血杂志》 CAS CSCD 北大核心 2009年第2期121-124,共4页
目的探讨滤除白细胞(滤白)血液成分,尤其是悬浮少白细胞红细胞的品质及临床应用效果。方法随机收集全血91袋、滤白细胞全血90袋、悬浮红细胞(悬红)76袋和悬浮少白细胞红细胞(少白悬红)82袋(无缝接驳法34袋、连袋法48袋),检测并比较全血... 目的探讨滤除白细胞(滤白)血液成分,尤其是悬浮少白细胞红细胞的品质及临床应用效果。方法随机收集全血91袋、滤白细胞全血90袋、悬浮红细胞(悬红)76袋和悬浮少白细胞红细胞(少白悬红)82袋(无缝接驳法34袋、连袋法48袋),检测并比较全血与滤白全血、2种方法制备的滤白全血、悬红与少白悬红的理化指标;随机收集4家医院近10年间的145名输注悬红与329名输注少白悬红(包括2种方法制备的少白悬红)患者的输血资料,对疗效做对比分析。结果滤白全血未见红细胞溶血现象,其血浆FHb和血液pH、K+、Na+较全血无明显变化[分别为(0.19±0.10)g/L、6.88±0.06、(19.78±4.01)mmol/L和(141.62±8.10)mmol/L];无缝接驳法与连袋法制备的滤白全血的血浆FHb分别为(0.10±0.097)、(0.16±0.13)g/L(P>0.05);无缝接驳法、连袋法制备的少白悬红及悬红三者的容量和Hct比较:分别为(144.01±11.54)、(152.45±15.39)和(158.71±10.69)m l,0.48±0.03、0.50±0.03、0.53±0.05,差异具统计学意义(P<0.05);过滤法白细胞清除率高达3 log10,残余白细胞可低至10-6。内科、外科和非出血性等输血患者比较,输注少白悬红者与输注悬红者的输后RBC和Hb的中位数(M)分别为(0.55vs0.42)、(0.37vs0.28)、(0.62vs0.50)×1012/L和(14.5vs13.5)、(12vs8)、(18.43vs15.86)g/L。结论无缝接驳法与连袋滤器法制备的滤白全血和少白悬红品质稳定可靠,少白悬红细胞的输注效果好于悬红。 展开更多
关键词 滤除白细胞 悬浮红细胞 去白细胞血制品 质量 输血效果
下载PDF
低氘白酒对人肺腺癌细胞的抑制作用 被引量:2
16
作者 张亚茹 沈才洪 +3 位作者 郑有丽 卢中明 敖宗华 丛峰松 《食品科学》 EI CAS CSCD 北大核心 2013年第11期278-284,共7页
目的:探讨低氘白酒在体内外对肺腺癌的抑制作用。方法:在体外,采用MTT法检测白酒、低氘水(DDW)和低氘白酒(DDA)抑制人肺癌A549细胞的增殖情况;采用TUNEL法和流式细胞仪分别检测白酒、DDW和DDA诱导人肺癌A549细胞的凋亡率。在体内,建立... 目的:探讨低氘白酒在体内外对肺腺癌的抑制作用。方法:在体外,采用MTT法检测白酒、低氘水(DDW)和低氘白酒(DDA)抑制人肺癌A549细胞的增殖情况;采用TUNEL法和流式细胞仪分别检测白酒、DDW和DDA诱导人肺癌A549细胞的凋亡率。在体内,建立肺癌移植瘤模型,造模当日给药。9d后,开始测量瘤体生长曲线。21d后,断颈处死小鼠,称体质量及瘤质量,固定小鼠瘤组织及肝肺组织,HE染色检测病理变化。结果:在体外,72h、180mmol/L DDA能明显抑制A549增殖,细胞增殖率为(70.58±2.73)%,与空白组及白酒组相比较,具有显著性差异(P<0.05);TUNEL法检测A549细胞凋亡率,表明DDA能促进细胞凋亡,与空白组、DDW组、白酒组相比较,具有显著性差异(P<0.05);流式细胞仪检测到DDA能促进细胞凋亡。在体内,DDA组与DDW组肿瘤抑制率分别为31.014%和27.639%,与空白组相比较,具有显著性差异(P<0.05)。HE染色结果显示,DDW组与DDA低剂量组,肿瘤细胞排列松散,周围有坏死组织。同时,DDW及DDA对裸鼠的肝肺组织无影响。结论:低剂量DDA在体外能抑制肺腺癌A549细胞增殖,在体内能抑制人肺腺癌H460裸鼠皮下移植瘤生长,并诱导癌细胞凋亡。 展开更多
关键词 低氘水 低氘白酒 肺癌 抑制作用
下载PDF
社会排斥对自我损耗的影响:自我觉知的克服作用 被引量:12
17
作者 张野 张珊珊 王佳名 《心理科学》 CSSCI CSCD 北大核心 2016年第5期1210-1215,共6页
实验1采用打破习惯范式任务和单词搜索任务考察自我觉知对自我损耗的克服作用。实验2采用社会排斥情境任务考察自我觉知在社会排斥中对自我损耗的影响。结果发现:(1)在自我损耗条件下,自我觉知启动组被试Stroop任务成绩显著好于无启动组... 实验1采用打破习惯范式任务和单词搜索任务考察自我觉知对自我损耗的克服作用。实验2采用社会排斥情境任务考察自我觉知在社会排斥中对自我损耗的影响。结果发现:(1)在自我损耗条件下,自我觉知启动组被试Stroop任务成绩显著好于无启动组;(2)在社会排斥情境下,接受组和控制组被试Stroop任务成绩显著好于排斥组。在自我觉知启动条件下,排斥组、接受组和控制组被试的Stroop任务成绩无显著差异。结果证实了自我觉知在社会排斥中对自我损耗的克服作用。 展开更多
关键词 社会排斥 自我损耗 自我觉知 克服作用
下载PDF
聚合物驱不可及孔隙体积对渗流规律的影响 被引量:13
18
作者 李爱芬 宋浩鹏 谢昊君 《油气地质与采收率》 CAS CSCD 北大核心 2016年第2期70-75,共6页
聚合物溶液在多孔介质中流动存在不可及孔隙体积和吸附滞留现象,以往研究聚合物溶液在多孔介质中的渗流规律时,常忽略不可及孔隙体积的影响。为此,通过实验测定了聚合物驱不可及孔隙体积、聚合物溶液的流变性和在多孔介质中的有效粘度;... 聚合物溶液在多孔介质中流动存在不可及孔隙体积和吸附滞留现象,以往研究聚合物溶液在多孔介质中的渗流规律时,常忽略不可及孔隙体积的影响。为此,通过实验测定了聚合物驱不可及孔隙体积、聚合物溶液的流变性和在多孔介质中的有效粘度;通过建立考虑不可及孔隙体积的并联毛细管模型,分析不同渗透率岩心的不可及孔隙体积对聚合物溶液阻力系数、有效粘度、剪切速率和衰竭层效应的影响。结果表明,对聚合物累积质量曲线求导得到的不可及孔隙体积更准确;不可及孔隙体积会使聚合物溶液阻力系数和有效粘度降低,剪切速率和衰竭层厚度增加;岩心渗透率越小,不可及孔隙体积越大,对阻力系数、有效粘度、剪切速率和衰竭层厚度的计算误差越大。 展开更多
关键词 聚合物溶液 不可及孔隙体积 多孔介质 有效粘度 衰竭层效应
下载PDF
Realizing High Breakdown Voltage SJ-LDMOS on Bulk Silicon Using a Partial n-Buried Layer 被引量:1
19
作者 陈万军 张波 李肇基 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第3期355-360,共6页
A new design concept is proposed to eliminate the substrate-assisted depletion effect that significantly degrades the breakdown voltage (BV) of conventional super junction-LDMOS. The key feature of the new concept i... A new design concept is proposed to eliminate the substrate-assisted depletion effect that significantly degrades the breakdown voltage (BV) of conventional super junction-LDMOS. The key feature of the new concept is that a partial buried layer is implemented which compensates for the charge interaction between the p-substrate and SJ region,realizing high breakdown voltage and low on-resistance. Numerical simulation results indicate that the proposed device features high breakdown voltage,low on-resistance,and reduced sensitivity to doping imbalance in the pillars. In addition, the proposed device is compatible with smart power technology. 展开更多
关键词 super junction LDMOS breakdown voltage substrate-assisted depletion effect
下载PDF
稠油油藏泡沫油渗流数学模型的建立 被引量:8
20
作者 李文会 刘鹏程 +1 位作者 吴永彬 李秀峦 《油气地质与采收率》 CAS CSCD 北大核心 2016年第2期108-114,共7页
针对目前泡沫油渗流数学模型存在的问题,借鉴拟泡点模型和过饱和模型中拟泡点压力及弛豫时间的概念,通过对3组长岩心衰竭实验进行分析,建立了泡沫油渗流数学模型。模型中将泡沫油视为拟单相流,通过实验分析在泡沫油流动过程中流动介质... 针对目前泡沫油渗流数学模型存在的问题,借鉴拟泡点模型和过饱和模型中拟泡点压力及弛豫时间的概念,通过对3组长岩心衰竭实验进行分析,建立了泡沫油渗流数学模型。模型中将泡沫油视为拟单相流,通过实验分析在泡沫油流动过程中流动介质的有效渗透率与降压速度、原油粘度和含气饱和度的变化规律,提出有效渗透率的数学表达式;认为泡沫油的粘度与相同条件下饱和油的粘度近似相等;将泡沫油的压缩系数视为油相与气相压缩系数的线性组合;同时在模型建立过程中考虑了泡沫油的过饱和现象。为了验证所建模型的正确性,分别将泡沫油渗流数学模型、拟泡点模型、过饱和模型及黑油模型计算结果与实验结果进行对比,结果表明泡沫油渗流数学模型与实验结果吻合程度较好,而其他模型计算偏差较大。 展开更多
关键词 泡沫油 数学模型 衰竭实验 拟单相流 有效渗透率 热力学不平衡
下载PDF
上一页 1 2 7 下一页 到第
使用帮助 返回顶部