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Evolution of boundary layer ozone in Shijiazhuang,a suburban site on the North China Plain
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作者 Wei Zhao Guiqian Tang +10 位作者 Huan Yu Yang Yang Yinghong Wang Lili Wang Junlin An Wenkang Gao Bo Hu Mengtian Cheng Xingqin An Xin Li Yuesi Wang 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第9期152-160,共9页
The structure of the boundary layer affects the evolution of ozone(O3), and research into this structure will provide important insights for understanding photochemical pollution.In this study, we conducted a one-mont... The structure of the boundary layer affects the evolution of ozone(O3), and research into this structure will provide important insights for understanding photochemical pollution.In this study, we conducted a one-month observation(from June 15 to July 14, 2016) of the boundary layer meteorological factors as well as O3 and its precursors in Luancheng County,Shijiazhuang(37°53′N, 114°38′E). Our research showed that photochemical pollution in Shijiazhuang is serious, and the mean hourly maximum and mean 8-hr maximum O3 concentrations are 97.9 ± 26.1 and 84.4 ± 22.4 ppbV, respectively. Meteorological factors play a significant role in the formation of O3. High temperatures and southeasterly winds lead to elevated O3 values, and at moderate relative humidity(40%–50%) and medium boundary layer heights(1200–1500 m), O3 production sensitivity occurred in the transitional region between volatile organic compounds(VOC) and nitrogen oxides(NOx) limitations,and the O3 concentration was the highest. The vertical profiles of O3 were also measured by a tethered balloon. The results showed that a large amount of O3 was stored in the residual layer, and the concentration was positively correlated with the O3 concentration measured the previous day. During the daytime of the following day, the contribution of O3 stored in the residual layer to the boundary layer reached 27%± 7% on average. 展开更多
关键词 OZONE Boundary LAYER RESIDUAL LAYER Vertical EVOLUTION Sensitivity
A stable artificial protective layer for high capacity dendrite-free lithium metal anode
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作者 Zhipeng Wen Yueying Peng +5 位作者 Jianlong Cong Haiming Hua Yingxin Lin Jian Xiong Jing Zeng Jinbao Zhao 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第10期2535-2542,共8页
The metallic lithium(Li)is considered as the most promising anode material for high-e nergy batteries.Nevertheless,the uncon trollable growth of Li den drite and un stable electrolyte/electrode in terface still hin de... The metallic lithium(Li)is considered as the most promising anode material for high-e nergy batteries.Nevertheless,the uncon trollable growth of Li den drite and un stable electrolyte/electrode in terface still hin der the developme nt of Li-based battery.In this work,a no vel strategy has been proposed to stabilize Li anode by in-situ polymerizing polypyrrole(PPy)layer on Ni foam(PPy@Ni foam)as an artificial protective layer.The PPy protective layer can effectively decrease the contact between Li metal and electrolyte during cycling.In addition,the morphology characterization shows that the PPy layer can help the even Li deposition undemeath the layer,leading to a dendrite-free Li anode.As a result,when deposited 2 mAh-cm-2 Li metal,the PPy@Ni foam can keep stable Coulombic efficiency(99%)during nearly 250 cycles,much better than the pure Ni foam(100 cycles).Even in the case of the Li capacity of 10 mAh-cm-2,the stable cycling performance for 60 cycles can still be achieved.Furthermore,when assembled with LiFePO4 material as the cathode for a full cell,the PPy@Ni foam can keep high capacity retention of 85.5%at 500 cycles.In our work,we provide a simple and effective method to enhanee the electrochemical performances of Li metal-based batteries,and reveal a new avenue to design three-dimensional(3D)metallic curre nt collector for protecting the Li metal ano de. 展开更多
关键词 high capacity polypyrrole layer Li metal artificial protective layer dendrite-free anode
Discriminating performance of macular ganglion cellinner plexiform layer thicknesses at different stages of glaucoma
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作者 Melih Ustaoglu Nilgun Solmaz Feyza Onder 《国际眼科杂志:英文版》 SCIE CAS 2019年第3期464-471,共8页
AIM: To determine the discriminating performance of the macular ganglion cell-inner plexiform layer(GCIPL) parameters between all the consecutive stages of glaucoma(from healthy to moderate-to-severe glaucoma), and to... AIM: To determine the discriminating performance of the macular ganglion cell-inner plexiform layer(GCIPL) parameters between all the consecutive stages of glaucoma(from healthy to moderate-to-severe glaucoma), and to compare it with the discriminating performances of the peripapillary retinal nerve fiber layer(RNFL) parameters and optic nerve head(ONH) parameters.METHODS: Totally 147 eyes(40 healthy, 40 glaucoma suspects, 40 early glaucoma, and 27 moderate-to-severe glaucoma) of 133 subjects were included. Optical coherence tomography(OCT) was obtained using Cirrus HD-OCT 5000. The diagnostic performances of GC-IPL, RNFL, and ONH parameters were evaluated by determining the area under the curve(AUC) of the receiver operating characteristics. RESULTS: All GC-IPL parameters discriminated glaucoma suspect patients from subjects with healthy eyes and moderate-to-severe glaucoma from early glaucoma patients(P<0.017, for all). Also, minimum, inferotemporal and inferonasal GC-IPL parameters discriminated early glaucoma patients from glaucoma suspects, whereas no RNFL or ONH parameter could discriminate between the two. The best parameters to discriminate glaucoma suspects from subjects with healthy eyes were superonasal GC-IPL, superior RNFL and average c/d ratio(AUC=0.746, 0.810 and 0.746, respectively). Discriminating performances of all the parameters for early glaucoma vs glaucoma suspect comparison were lower than that of the other consecutive group comparisons, with the bestGC-IPL parameters being minimum and inferotemporal(AUC=0.669 and 0.662, respectively). Moreover, minimum GC-IPL, average RNFL, and rim area(AUC=0.900, 0.858, 0.768, respectively) were the best parameters for discriminating moderate-to-severe glaucoma patients from early glaucoma patients.CONCLUSION: GC-IPL parameters can discriminate glaucoma suspect patients from subjects with healthy eyes, and also all the consecutive stages of glaucoma from each other(from glaucoma suspect to moderate-tosevere glaucoma). Further, the discriminating performa 展开更多
关键词 retinal NERVE fiber LAYER optic NERVE head cirrus HD-OCT ganglion cell-inner PLEXIFORM LAYER GLAUCOMA SUSPECT
Layer by Layer Assembly of Poly(Allylamine Hydrochloride)/Phosphate Ions and Poly(Sodium 4-Styrene Sulfonate) Membrane for Forward Osmosis Application 预览
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作者 ZHOU Wen YU Li +2 位作者 LI Yiming GAO Baoyu WANG Zhining 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第3期743-749,共7页
Based on the layer by layer(Lb L)assembly technology,the nano-scale composite membrane with excellent structure can be prepared by changing the polyelectrolyte and controlling the deposition conditions.Polyamines and ... Based on the layer by layer(Lb L)assembly technology,the nano-scale composite membrane with excellent structure can be prepared by changing the polyelectrolyte and controlling the deposition conditions.Polyamines and phosphate ions(Pi)can be self-organized to form supramolecular systems which could be exploited to stabilize the interfacial architecture.The LbL membrane was made of the positively charged poly(allylamine hydrochloride)(PAH)self-organized with Pi and the negatively charged poly(sodium 4-styrene sulfonate)(PSS)alternatively on top of a poly(acrylonitrile)(PAN)substrate.Compared to the membrane without Pi,the membrane assembled by PAH/Pi improved forward of flux and reduced flux of salt.The concentration of PAH and PSS,deposition time,pH and number of layers showed significant influences on the performance of the membrane.In this experiment,we systematically investigated the preparation conditions and under the optimized conditions the prepared membrane exhibited high water fluxes of 13.5 L m^-2 h^-1 with corresponding salt to water flux,Js/Jv,ratio of 0.07 g L^-1 tested by forward osmosis when DI water as feed solution and 2 mol L^-1 MgCl2 as draw solution. 展开更多
关键词 forward osmosis LAYER by layer(LbL) POLYELECTROLYTE phosphate ions
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Experimental Study of Air Layer Drag Reduction with Bottom Cavity for A Bulk Carrier Ship Model 预览
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作者 WU Hao OU Yong-peng 《中国海洋工程:英文版》 SCIE EI CSCD 2019年第5期554-562,共9页
Air lubrication by means of a bottom cavity is a promising method for ship drag reduction. The characteristics of the bottom cavity are sensitive to the flow field around the ship hull and the effect of drag reduction... Air lubrication by means of a bottom cavity is a promising method for ship drag reduction. The characteristics of the bottom cavity are sensitive to the flow field around the ship hull and the effect of drag reduction, especially the depth of the bottom cavity. In this study, a ship model experiment of a bulk carrier is conducted in a towing tank using the method of air layer drag reduction (ALDR) with different bottom cavity depths. The shape of the air layer is observed, and the changes in resistance are measured. The model experiments produce results of approximately 20% for the total drag reduction at the ship design speed for a 25-mm cavity continuously supplied with air at Cq = 0.224 in calm water, and the air layer covers the whole cavity when the air flow rate is suitable. In a regular head wave, the air layer is easily broken and reduces the drag reduction rate in short waves, particularly when λ/Lw1 is close to one;however, it still has a good drag reduction effect in the long waves. 展开更多
关键词 AIR LAYER drag reduction BULK CARRIER model test DEPTH of CAVITY AIR LAYER shape
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Numerical Study of Boundary Layer Structure and Rainfall after Landfall of Typhoon Fitow(2013):Sensitivity to Planetary Boundary Layer Parameterization 预览
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作者 Meiying DONG Chunxiao JI +1 位作者 Feng CHEN Yuqing WANG 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第4期431-450,共20页
The boundary layer structure and related heavy rainfall of Typhoon Fitow(2013),which made landfall in Zhejiang Province,China,are studied using the Advanced Research version of the Weather Research and Forecasting mod... The boundary layer structure and related heavy rainfall of Typhoon Fitow(2013),which made landfall in Zhejiang Province,China,are studied using the Advanced Research version of the Weather Research and Forecasting model,with a focus on the sensitivity of the simulation to the planetary boundary layer parameterization.Two groups of experiments—one with the same surface layer scheme and including the Yonsei University(YSU),Mellor–Yamada–Nakanishi–Niino Level 2.5,and Bougeault and Lacarrere schemes;and the other with different surface layer schemes and including the Mellor–Yamada–Janjic and Quasi-Normal Scale Elimination schemes—are investigated.For the convenience of comparative analysis,the simulation with the YSU scheme is chosen as the control run because this scheme successfully reproduces the track,intensity and rainfall as a whole.The maximum deviations in the peak tangential and peak radial winds may account for 11% and 33% of those produced in the control run,respectively.Further diagnosis indicates that the vertical diffusivity is much larger in the first group,resulting in weaker vertical shear of the tangential and radial winds in the boundary layer and a deeper inflow layer therein.The precipitation discrepancies are related to the simulated track deflection and the differences in the simulated low-level convergent flow among all tests.Furthermore,the first group more eciently transfers moisture and energy and produces a stronger ascending motion than the second,contributing to a deeper moist layer,stronger convection and greater precipitation. 展开更多
关键词 planetary BOUNDARY LAYER PARAMETERIZATION landfalling TYPHOON BOUNDARY LAYER structure RAINFALL
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Analysis and Simulation of the Stratospheric Quasi-zero Wind Layer over Korla, Xinjiang Province, China 预览
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作者 Rui YANG Lingkun RAN +1 位作者 Yuli ZHANG Yi LIU 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第10期1143-1155,共13页
The stratospheric quasi-zero wind layer (QZWL) is a transition region with low zonal wind speeds in the lower stratosphere at an altitude of ~20 km. The zonal wind direction above the QZWL layer is opposite to that be... The stratospheric quasi-zero wind layer (QZWL) is a transition region with low zonal wind speeds in the lower stratosphere at an altitude of ~20 km. The zonal wind direction above the QZWL layer is opposite to that below the QZWL layer and the north –south wind component is small. The atmospheric wind field near the stratospheric QZWL is an important factor affecting the flight altitude and dynamic control of stratospheric airships. It is therefore necessary to study the stratospheric QZWL to provide better environmental information for these aircraft. High-resolution radiosonde data were used to analyze the characteristics of the stratospheric QZWL over Korla, Xinjiang Province, China. A weak wind layer in which the wind direction suddenly reversed from westerly to easterly was observed at ~20 km in the lower stratosphere, characteristic of the stratospheric QZWL. The Weather Research and Forecasting model was used to simulate the profiles of the horizontal wind speed and direction over Korla. The forcing effect of each diagnostic term in the equation on the zonal wind speed was analyzed. The results showed that the advection term was the dominant factor forcing the zonal wind speed. The wave term had a secondary forcing role, although the forcing effect of the wave term on the zonal wind speed was significant in some regions. 展开更多
关键词 numerical simulation radiosonde STRATOSPHERIC AIRSHIPS STRATOSPHERIC quasi-zero WIND LAYER
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Fenlong Tillage System by the Theory of "Natural Forces" and Possibility of "Fenlong Agriculture" Establishment 预览
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作者 Wei Benhui 《气象与环境研究:英文版》 CAS 2019年第1期59-63,69共6页
"Natural forces"——core theory of Fenlong technique is explored in this paper. We break through key core technique of farming and agriculture, and invent new method of Fenlong tillage. Broad-spectrum Fenlon... "Natural forces"——core theory of Fenlong technique is explored in this paper. We break through key core technique of farming and agriculture, and invent new method of Fenlong tillage. Broad-spectrum Fenlong tillage technique system based on "full-layer and bottom-layer super-deep tillage without disturbance of soil layer" is established, which provides the possibility for establishing "modern Fenlong agriculture". When applied in 35 kinds of crops in 24 provinces of China, yield could be increased by 10%-50%, and even 1 times. In the transformation of severe saline-alkali land, corn yield could increase by 73.0%, and Na, Cl and Mg ions in grain decrease by 20.81%, 1.47%, and 9.36% respectively. The newly developed "scarification tillage (reclamation) in the bottom area" could cover "bottom tillage" of dryland, paddy field, degraded grassland, perennial sugarcane, forest and fruit land, traditional Chinese medicine land, and ecological reconstruction of desertification land. It is point out that if Fenlong technique is used in 666 666.67 km 2 of farmland, 200 000 km 2 of saline-alkali land, 666 666.67 km 2 of degraded grassland, and fisheries in rivers and offshore waters are used, trillion yuan of Fenlong economy could be formed, and the nationals will walk towards a healthier new era. Fenlong technique involves agriculture, forestry, water, grass, environment and other aspects, and its global promotion could improve eco-environment and change world development pattern. 展开更多
关键词 Fenlong series of TILLAGE Super-deep without DISTURBANCE soil layer YIELD and quality improvement SALINE-ALKALI land transformation Modern AGRICULTURE
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flash系列剧制作的研究 预览
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作者 黄淑玲 《计算机时代》 2019年第2期67-68,共2页
从场景结构、时间轴结构、字幕图层、多图层动画、元件的使用、静音图层等多方面对flash制作系列剧进行了全方位的研究。使得制作的flash作品更有协调性、合理性、可行性而且能大大提高制作的效率。
关键词 图层 场景 时间轴 FLASH动画
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某热电厂玻璃钢烟囱内筒的铺层设计及现场制作 预览
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作者 刘会平 《华电技术》 CAS 2019年第6期72-75,共4页
以某2×350 MW机组热电联产项目为例,说明玻璃钢烟囱内筒在火电厂湿法烟气脱硫烟囱中应用的适应性,根据该电厂的实际工况,设计了2种不同的铺层并在现场制作了2种铺层的玻璃钢烟囱内筒管段,对管段进行取样并通过第三方检测机构测试... 以某2×350 MW机组热电联产项目为例,说明玻璃钢烟囱内筒在火电厂湿法烟气脱硫烟囱中应用的适应性,根据该电厂的实际工况,设计了2种不同的铺层并在现场制作了2种铺层的玻璃钢烟囱内筒管段,对管段进行取样并通过第三方检测机构测试其力学性能,对比它们的原材料成本,为火电厂湿法脱硫后烟囱玻璃钢内筒的铺层设计提供参考。 展开更多
关键词 玻璃钢 热电厂 烟气脱硫 烟囱 热电联产 湿法烟气脱硫 铺层
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Key structure in laminar-turbulent transition of boundary layer with streaky structures 预览
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作者 Joe Yoshikawa Yu Nishio +1 位作者 Seiichiro Izawa Yu Fukunishi 《力学快报:英文版》 CAS CSCD 2019年第1期32-35,I0005共5页
A numerical simulation is performed to find out a key vortical structure in the laminar-turbulent transition. A low-speed streak is generated inside a laminar boundary layer using an isolated cuboid roughness, aimed a... A numerical simulation is performed to find out a key vortical structure in the laminar-turbulent transition. A low-speed streak is generated inside a laminar boundary layer using an isolated cuboid roughness, aimed at providing an environment unstable to outer disturbances. Then, a short duration jet is issued into the boundary layer. When the jet velocity is low, some vortices appear in the boundary layer, but the transition of the boundary layer does not take place. However, when the jet velocity exceeds a certain threshold, two vortices newly appear above the elongated legs of a V-shaped vortex and only one of them is stretched and survives. After that, vortices are generated one after another around the survived one. By comparing the decayed and the survived vortices, it is found that the difference in their heights is the key characteristic which leads to the transition. 展开更多
关键词 Turbulent ONSET KEY vortical STRUCTURE Laminar-turbulent transition Boundary layer Streaky STRUCTURES Short DURATION jet Numerical simulation
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Swelling-induced finite bending of functionally graded pH-responsive hydrogels: a semi-analytical method 预览
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作者 M. SHOJAEIFARD M. R. BAYAT M. BAGHANI 《应用数学和力学:英文版》 SCIE EI CSCD 2019年第5期679-694,共16页
Abstract Recently, pH-sensitive hydrogels have been utilized in the diverse applications including sensors, switches, and actuators. In order to have continuous stress and defor- mation fields, a new semi-analytical a... Abstract Recently, pH-sensitive hydrogels have been utilized in the diverse applications including sensors, switches, and actuators. In order to have continuous stress and defor- mation fields, a new semi-analytical approach is developed to predict the swelling induced finite bending for a functionally graded (FG) layer composed of a pH-sensitive hydrogel, in which the cross-link density is continuously distributed along the thickness direction under the plane strain condition. Without considering the intermediary virtual reference, the initial state is mapped into the deformed configuration in a circular shape by utilizing a total deformation gradient tensor stemming from the inhomogeneous swelling of an FG layer in response to the variation of the pH value of the solvent. To enlighten the capabil- ity of the presented analytical method, the finite element method (FEM) is used to verify the accuracy of the analytical results in some case studies. The perfect agreement con- firms the accuracy of the presented method. Due to the applicability of FG pH-sensitive hydrogels, some design factors such as the semi-angle, the bending curvature, the aspect ratio, and the distributions of deformation and stress fields are studied. Furthermore, the tangential free-stress axes are illustrated in deformed configuration. 展开更多
关键词 PH-SENSITIVE HYDROGEL functionally graded (FG) layer FINITE BENDING semi- analytical solution FINITE element method (FEM)
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Flat-plate hypersonic boundary-layer flow instability and transition prediction considering air dissociation 预览
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作者 Yufeng HAN Wei CAO 《应用数学和力学:英文版》 SCIE EI CSCD 2019年第5期719-736,共18页
The effects of air dissociation on flat-plate hypersonic boundary-layer flow instability and transition prediction are studied. The air dissociation reactions are as- sumed to be in the chemical equilibrium. Based on ... The effects of air dissociation on flat-plate hypersonic boundary-layer flow instability and transition prediction are studied. The air dissociation reactions are as- sumed to be in the chemical equilibrium. Based on the flat-plate boundary layer, the flow stability is analyzed for the Mach numbers from 8 to 15. The results reveal that the con- sideration of air dissociation leads to a decrease in the unstable region of the first-mode wave and an increase in the maximum growth rate of the second mode. High frequencies appear earlier in the third mode than in the perfect gas model, and the unstable region moves to a lower frequency region. When the Mach number increases, the second-mode wave dominates the transition process, and the third-mode wave has little effect on the transition. Moreover, when the Mach number increases from 8 to 12, the N-factor enve- lope becomes higher, and the transition is promoted. However, when the Mach number exceeds 12, the N-factor envelope becomes lower, and the transition is delayed. The N- factor envelope decreases gradually with the increase in the altitude or Mach number. 展开更多
关键词 AIR DISSOCIATION TRANSITION prediction BOUNDARY layer
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Effect of Leading-Edge Optimization on the Loss Characteristics in a Low-Pressure Turbine Linear Cascade
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作者 CUI Tao WANG Songtao +2 位作者 TANG Xiaolei WEN Fengbo WANG Zhongqi 《热科学学报:英文版》 SCIE EI CAS CSCD 2019年第5期886-904,共19页
This paper presents a numerical study on the aerodynamics loss reduction characteristics after the leading-edge(LE) optimization in a low-pressure turbine linear cascade. The LE was optimized with a simple and practic... This paper presents a numerical study on the aerodynamics loss reduction characteristics after the leading-edge(LE) optimization in a low-pressure turbine linear cascade. The LE was optimized with a simple and practical method of "Class Function/Shape Function Transformation Technique"(CST). The simulation conditions, covering the whole working range, were independently determined by incidence, Reynolds number and Mach number. Quantitative loss analyses were carried out with a loss breakdown method based on volumetric integration of entropy production rates. To understand the reason of loss reduction, the local sources at different operating points were identified with entropy production rates. The results showed that LE optimization with the CST method played a positive role in decreasing the total losses, and the working range with lower loss was extended. The profile loss and the endwall loss were significantly reduced by the LE optimization, which were also verified to be the major causes of the total loss reduction by loss breakdown. The decrease of profile loss can be attributed to the boundary layer near the LE region and the boundary layer of downstream at off-design incidence. The reduction mostly came from the pressure side at negative incidence, while came from the suction side at the positive incidence. The endwall loss was decreased markedly about 2.5%–5% by the LE optimization at the incidence of-12°, which was 1% at the incidence of 12°. The mechanism for the endwall loss reduction at different incidences was different from each other. At negative incidence, the LE optimization diminished the corner separation vortex on the pressure side. While at positive incidence, the benefits came from three aspects, i.e., reduced suction LE separation bubbles close to the endwall, reduced passage vortex strength, and weakened shear process between passage vortex and trailing shed vortex. The loss of the downstream zone was relatively lower than that of the profile losses and the endwall losses. The effect 展开更多
关键词 low pressure TURBINE LEADING edge LOSS BREAKDOWN LOSS AUDIT boundary layer entropy production rates
Evaluation of spectral domain optical coherence tomography parameters in discriminating preperimetric glaucoma from high myopia
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作者 Xiao-Yu Xu Hui Xiao +1 位作者 Jing-Yi Luo Xing Liu 《国际眼科杂志:英文版》 SCIE CAS 2019年第1期58-65,共8页
AIM: To evaluate the diagnostic ability of macular ganglion cell-inner plexiform layer(GCIPL) thickness obtained by spectral-domain optical coherence tomography(SD-OCT) in discriminating non-highly myopic eyes with pr... AIM: To evaluate the diagnostic ability of macular ganglion cell-inner plexiform layer(GCIPL) thickness obtained by spectral-domain optical coherence tomography(SD-OCT) in discriminating non-highly myopic eyes with preperimetric glaucoma(PPG) from highly myopic healthy eyes. METHODS: A total of 254 eyes, including 76 normal controls(NC), 116 eyes with high myopia(HM) and 62 non-highly myopic eyes with PPG were enrolled. The diagnostic ability of OCT parameters was accessed by the areas under the receiver operating characteristic(AUROC) curve in two distinguishing groups: PPG eyes with nonglaucomatous eyes including NC and HM(Group 1), and PPG eyes with HM eyes(Group 2). Differences in diagnostic performance between GCIPL and RNFL parameters were evaluated. RESULTS: The minimum(AUROC curve of 0.782), inferotemporal(0.758) and inferior(0.705) GCIPL thickness were the top three GCIPL parameters in discriminating PPG from non-glaucomatous eyes, all of which had statistically significant lower diagnostic ability than average RNFL thickness(0.847). In discriminating PPG from HM, the best GCIPL parameter was minimum(0.689), statistically significant lower in diagnostic ability than average RNFL thickness(0.789) and three other RNFL thickness parameters of temporal and inferotemporal clock-hour sectors. CONCLUSION: The minimum GCIPL thickness is the best GCIPL parameter to detect non-highly myopic PPG from highly myopic eyes, whose diagnostic ability is inferiorto that of average RNFL thickness and RNFL thickness of several temporal and inferotemporal clock-hour sectors. The average RNFL thickness is recommended for discriminating PPG from highly myopic healthy eyes in current clinical practice in a Chinese population. 展开更多
关键词 GANGLION cell-inner PLEXIFORM layer DIAGNOSTIC ability preperimetric GLAUCOMA high myopia.
Efficient organic-inorganic hybrid cathode interfacial layer enabled by polymeric dopant and its application in large-area polymer solar cells
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作者 Sheng Dong Kai Zhang +4 位作者 Xiang Liu Qingwu Yin Hin-Lap Yip Fei Huang Yong Cao 《中国科学:化学英文版》 SCIE EI CAS CSCD 2019年第1期67-73,共7页
An organic-inorganic hybrid cathode interfacial layer(CIL) was developed by doping ZnO with the naphthalene-diimide based derivative NDI-PFNBr. It was found the resulting organic-inorganic hybrid CIL showed apparently... An organic-inorganic hybrid cathode interfacial layer(CIL) was developed by doping ZnO with the naphthalene-diimide based derivative NDI-PFNBr. It was found the resulting organic-inorganic hybrid CIL showed apparently improved conductivity and could act as an effective cathode interlayer to modify indium tin oxide(ITO) transparent electrodes. As a result, by employing the blend of PTB7-Th:PC71BM as the photoactive layer, the inverted polymer solar cells(PSCs) exhibited a remarkable enhancement of power conversion efficiency(PCE) from 8.52% for the control device to 10.04% for the device fabricated with the hybrid CIL. Moreover, all device parameters were simultaneously improved by using this hybrid CIL. The improved open-circuit voltage(VOC) was attributed to the reduced work function of the ITO cathode, whereas the enhancements in fill factor(FF) and short-circuit current density(JSC) were assigned to the increased conductivity and more effective charge extraction and collection at interface. Encouragingly, when the thickness of the hybrid CIL was increased to 80 nm, the resulting device could still keep a PCE of 8.81%, exhibiting less thickness dependence. Considering these advantages, 16 and 93 cm2large-area PSCs modules were successfully fabricated from the hybrid CIL by using doctor-blade coating techniques and yielded a remarkable PCE of8.05% and 4.49%, respectively. These results indicated that the hybrid CIL could be a promising candidate to serve as the cathode interlayer for high-performance large-area inverted PSCs. 展开更多
关键词 hybrid CATHODE INTERFACIAL layer LARGE-AREA module doctor-blade coating polymer solar cells
Mechanical properties and associated seismic isolation effects of foamed concrete layer in rock tunnel 预览
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作者 Shaosen Ma Weizhong Chen Wusheng Zhao 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第1期159-171,共13页
Foamed concrete has a good energy absorption capability and can be used as seismic isolation material for tunnels.This study aims to investigate the mechanical properties and associated seismic isolation effects of fo... Foamed concrete has a good energy absorption capability and can be used as seismic isolation material for tunnels.This study aims to investigate the mechanical properties and associated seismic isolation effects of foamed concrete layer in rock tunnel.For this,a series of uniaxial/triaxial compression tests was conducted to understand the effects of concrete density,confining stress and strain rate on the mechanical properties of foamed concrete.The direct shear tests were also performed to investigate the effects of concrete density and normal stress on the nonlinear behaviors of foamed concrete layer-lining interface.The test results showed that the mechanical properties of foamed concrete are significantly influenced by the concrete density.The foamed concrete also has high volumetric compressibility and strain-rate dependence.The peak stress,residual stress,shear stiffness and residual friction coefficient of the foamed concrete layer-lining interface are influenced by the foamed concrete density and normal stress applied.Then,a crushable foam constitutive model was constructed using ABAQUS software and a composite exponential model was also established to study the relationship between shear stress and shear displacement of the interface,in which their parameters were fitted based on the experimental results.Finally,a parametric analysis using the finite element method(FEM)was conducted to understand the influence of foamed concrete layer properties on the seismic isolation effect,including the density and thickness of the layer as well as the shear stiffness and residual friction coefficient of the interface.It was revealed that lower density and greater thickness in addition to smaller shear stiffness or residual friction coefficient of the foamed concrete layer could yield better seismic isolation effect,and the influences of the first two tend to be more significant. 展开更多
关键词 ROCK TUNNEL Foamed concrete SEISMIC ISOLATION LAYER SEISMIC ISOLATION mechanism
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Rotating electroosmotic flows in soft parallel plate microchannels 预览
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作者 Yongbo LIU Yongjun JIAN 《应用数学和力学:英文版》 SCIE EI CSCD 2019年第7期1017-1028,共12页
We present a theoretical investigation of rotating electroosmotic flows(EOFs) in soft parallel plate microchannels. The soft microchannel, also called as the polyelectrolyte-grafted microchannel, is denoted as a rigid... We present a theoretical investigation of rotating electroosmotic flows(EOFs) in soft parallel plate microchannels. The soft microchannel, also called as the polyelectrolyte-grafted microchannel, is denoted as a rigid microchannel coated with a polyelectrolyte layer(PEL) on its surface. We compare the velocity in a soft microchannel with that in a rigid one for different rotating frequencies and find that the PEL has a trend to lower the velocities in both directions for a larger equivalent electrical double layer(EDL) thickness λFCL(λFCL = 0.3) and a smaller rotating frequency ω(ω < 5).However, for a larger rotating frequency ω(ω = 5), the main stream velocity u far away from the channel walls in a soft microchannel exceeds that in a rigid one. Inspired by the above results, we can control the EOF velocity in micro rotating systems by imparting PELs on the microchannel walls, which may be an interesting application in biomedical separation and chemical reaction. 展开更多
关键词 ROTATING ELECTROOSMOTIC flow (EOF) SOFT MICROCHANNEL POLYELECTROLYTE layer (PEL) thickness
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Comparison of mixing layer height inversion algorithms using lidar and a pollution case study in Baoding, China
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作者 Xiangguang Ji Cheng Liu +8 位作者 Zhouqing Xie Qihou Hu Yunsheng Dong Guangqiang Fan Tianshu Zhang Chengzhi Xing Zhuang Wang Zeeshan Javed Jianguo Liu 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第5期81-90,共10页
Beijing–Tianjin–Hebei area is suffering from atmospheric pollution from a long time. The understanding of the air pollution mechanism is of great importance for officials to design strategies for the environmental g... Beijing–Tianjin–Hebei area is suffering from atmospheric pollution from a long time. The understanding of the air pollution mechanism is of great importance for officials to design strategies for the environmental governance. Mixing layer height(MLH) is a key factor influencing the diffusion of air pollutants. It plays an important role on the evolution of heavy pollution events. Light detection and ranging(lidar), is an effective remote-sensing tool, which can retrieve high spatial and temporal evolution process within mixing layer(ML), especially the variation of MLH. There are many methods to retrieve MLH, but each method has its own applicable limitations. The Mie-lidar data in Beijing was firstly used to compare three different algorithms which are widely used under different pollution levels.We find that the multi-layer structure near surface may cause errors in the detection of mixing layer. The MLH retrieved based on image edge detection was better than another two methods especially under heavy polluted episode. Then we applied this method to investigate the evolution of the mixing layer height during a pollution episode in December2016. MLH at Gucheng county showed the positive correlation with the concentration of particulate matters during the start of this pollution episode. The elevated pollution level in Gucheng was not associated with MLH’s decrease, and the significantly increased particulate matters raised the boundary layer, which trapped the pollutants near the surface. 展开更多
关键词 MIXING layer Beijing–Tianjin–Hebei area SEVERE HAZE
Direct numerical simulation of turbulent boundary layer over an anisotropic compliant wall 预览
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作者 Qian-Jin Xia Wei-Xi Huang Chun-Xiao Xu 《力学学报:英文版》 SCIE EI CAS CSCD 2019年第2期384-400,共17页
Direct numerical simulation of a spatially developing turbulent boundary layer over a compliant wall with anisotropic wall material properties is performed. The Reynolds number varies from 300 to approximately 860 alo... Direct numerical simulation of a spatially developing turbulent boundary layer over a compliant wall with anisotropic wall material properties is performed. The Reynolds number varies from 300 to approximately 860 along the streamwise direction, based on the external flow velocity and the momentum thickness. Eight typical cases are selected for numerical investigation under the guidance of the monoharmonic analysis. The instantaneous flow fields exhibit the traveling wavy motion of the compliant wall, and the frequency-wavenumber power spectrum of wall pressure fluctuation is computed to quantify the mutual influence of the wall compliance and the turbulent flow at different wave numbers. It is shown that the Reynolds shear stress and the pressure fluctuation are generally enhanced by the wall compliance with the parameters considered in the present study. A dynamical decomposition of the skin-friction coefficient is derived, and a new term (CW) appears due to the wall-induced Reynolds shear stress. The influence of the anisotropic compliant wall motion on the turbulent boundary layer through the wall-induced negative Reynolds shear stress is discussed. To elucidate the underlying mechanism, the budget analysis of the Reynolds stresses transportation is further carried out. The impact of the wall compliance on the turbulent flow is disclosed by examining the variations of the diffusion and velocity-pressure correlation terms. It is shown that increase of the Reynolds stresses inside the flow domain is caused by enhancement of the velocity-pressure correlation term, possibly through the long-range influence of the wall compliance on the pressure field, rather than diffusion of the wall-induced Reynolds shear stress into the fluid flow. 展开更多
关键词 TURBULENT boundary layer ANISOTROPIC compliant WALL Direct numerical simulation Skin-friction coefficient REYNOLDS shear stress
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