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123篇 您的检索式:作者名="HE XueFeng"
    题名 作者 年代 出处 被引量
1A Regional Ocean Reanalysis System for Coastal Waters of China and Adjacent Seas显示文摘A regional ocean reanalysis system for the coastal waters of China and adjacent seas has been developed by the National Marine Data and Information Service(NMDIS).It produces a dataset package called CORA (China ocean reanalysis).The regional ocean model used is based on the Princeton Ocean Model with a generalized coordinate system(POMgcs).The model is parallelized by NMDIS with the addition of the wave breaking and tidal mixing processes into model parameterizations.Data assimilation is a sequential three-dimensional variational(3D-Var) scheme implemented within a multigrid framework.Observations include satellite remote sensing sea surface temperature(SST),altimetry sea level anomaly(SLA),and temperature/salinity profiles.The reanalysis fields of sea surface height,temperature,salinity,and currents begin with January 1986 and are currently updated every year. Error statistics and error distributions of temperature,salinity and currents are presented as a primary evaluation of the reanalysis fields using sea level data from tidal gauges,temperature profiles,as well as the trajectories of Argo floats.Some case studies offer the opportunity to verify the evolution of certain local circulations.These evaluations show that the reanalysis data produced provide a good representation of the ocean processes and phenomena in the coastal waters of China and adjacent seas.Guijun Han Wei Li Xuefeng Zhang Dong Li Zhongjie He Xidong Wang Xinrong Wu Ting Yu Jirui Ma 2011Advances in Atmospheric Sciences2011,28,3:27
2Immune response,stress resistance and bacterial challenge in juvenile rainbow trouts Oncorhynchus mykiss fed diets containing chitosan-oligosaccharides显示文摘Effects of dietary supplementation of chitosan-oligosaccharides(COS)on the growth performance,immune response,stress resistance,and disease resistance of juvenile rainbow trout Oncorhynchus mykiss were studied.Four experimental diets containing 0,20,40,or 60 mg/kg COS(COS0,COS20,COS40,and COS60,respectively)were fed to juvenile rainbow trout(initial weight=5.2±0.3 g)for 8 weeks.By the end of the feeding trial,representative groups of fish from each dietary treatment were challenged with stressor(30 sec air exposure)and pathogen exposure(intraperitoneal injection with Aeromonas hydrophila).Results showed that supplementation of COS in diets did not affect production performance and body composition of rainbow trout.However,fish fed the COS40 diet demonstrated improved phagocytic activities,respiratory burst activities and decreased serum cortisol level.Additionally,survival following A.hydrophila challenge was significant higher among fish fed the COS-supplemented feeds,although there was no difference based on the level of supplementation.The present study suggests that COS can be used as an immuno-stimulant in rainbow trout feeds.Lin LUO Xuefeng CAI Chuan HE Min XUE Xiufeng WU Haining CAO 2009Current Zoology2009,55,6:22
3PepperHub, an Informatics Hub for the Chili Pepper Research Community显示文摘Feng Liu Huiyang Vu Yingtian Deng Jingyuan Zheng Minglei Liu Lijun Ou Bozhi Yang Xiongze Dai Yanqing Ma Shengyu Feng Shuang He Xuefeng Li Zhuqing Zhang Wenchao Chen Shudong Zhou Rong Chen Minmin Liu Sha Yang Ruimin Wei Huadong Li Feng Li Bo Ouyang Xuexiao Zou 2017Molecular Plant2017,10,8:13
4Insight-HXMT observations of the first binary neutron star merger GW170817显示文摘Finding the electromagnetic(EM) counterpart of binary compact star merger, especially the binary neutron star(BNS) merger,is critically important for gravitational wave(GW) astronomy, cosmology and fundamental physics. On Aug. 17, 2017,Advanced LIGO and Fermi/GBM independently triggered the first BNS merger, GW170817, and its high energy EM counterpart,GRB 170817 A, respectively, resulting in a global observation campaign covering gamma-ray, X-ray, UV, optical, IR, radio as well as neutrinos. The High Energy X-ray telescope(HE) onboard Insight-HXMT(Hard X-ray Modulation Telescope) is the unique high-energy gamma-ray telescope that monitored the entire GW localization area and especially the optical counterpart(SSS17 a/AT2017 gfo) with very large collection area(~1000 cm^2) and microsecond time resolution in 0.2-5 MeV. In addition,Insight-HXMT quickly implemented a Target of Opportunity(ToO) observation to scan the GW localization area for potential X-ray emission from the GW source. Although Insight-HXMT did not detect any significant high energy(0.2-5 MeV) radiation from GW170817, its observation helped to confirm the unexpected weak and soft nature of GRB 170817 A. Meanwhile,Insight-HXMT/HE provides one of the most stringent constraints(~10^(-7) to 10^(-6) erg/cm^2/s) for both GRB170817 A and any other possible precursor or extended emissions in 0.2-5 MeV, which help us to better understand the properties of EM radiation from this BNS merger. Therefore the observation of Insight-HXMT constitutes an important chapter in the full context of multi-wavelength and multi-messenger observation of this historical GW event.TiPei Li ShaoLin Xiong ShuangNan Zhang FangJun Lu LiMing Song XueLei Cao Zhi Chang Gang Chen Li Chen TianXiang Chen Yong Chen YiBao Chen YuPeng Chen Wei Cui WeiWei Cui JingKang Deng YongWei Dong YuanYuan Du MinXue Fu GuanHua Gao He Gao Min Gao MingYu Ge YuDong Gu Ju Guan ChengCheng Guo DaWei Han Wei Hu Yue Huang Jia Huo ShuMei Jia LuHua Jiang WeiChun Jiang Jing Jin YongJie Jin Bing Li ChengKui Li Gang Li MaoShun Li Wei Li Xian Li XiaoBo Li XuFang Li YanGuo Li ZiJian Li ZhengWei Li XiaoHua Liang JinYuan Liao CongZhan Liu GuoQing Liu HongWei Liu ShaoZhen Liu XiaoJing Liu Yuan Liu YiNong Liu Bo Lu XueFeng Lu Tao Luo Xiang Ma Bin Meng Yi Nang JianYin Nie Ge OU JinLu Qu Na Sai Liang Sun Yin Tan Lian Tao WenHui Tao YouLi Tuo GuoFeng Wang HuanYu Wang Juan Wang WenShuai Wang YuSa Wang XiangYang Wen BoBing WU Mei Wu GuangCheng Xiao He Xu YuPeng Xu LinLi Yan JiaWei Yang Sheng Yang YanJi Yang AiMei Zhang ChunLei Zhang ChengMo Zhang Fan Zhang HongMei Zhang Juan Zhang Qiang Zhang Shu Zhang Tong Zhang Wei Zhang WanChang Zhang WenZhao Zhang Yi Zhang Yue Zhang YiFei Zhang YongJie Zhang Zhao Zhang ZiLiang Zhang HaiSheng Zhao JianLing Zhao XiaoFan Zhao ShiJie Zheng Yue Zhu YuXuan Zhu ChangLin Zou 2018Science China(Physics,Mechanics & Astronomy)2018,61,3:12
5Characteristics of internal-wave and internal-tide deposits and their hydrocarbon potential显示文摘内部波浪、内部潮的存款的学习在最后十年期间是 sedimentology 上的一个新研究领域。内部波浪和内部潮导致的深海的拖拉水流在现代的海地板上被开发,它能形成不仅各种小规模和疏开深海的拖拉水流存款,而且在 km 尺寸的大规模沉积波浪可伸缩。在这篇论文,在海洋学的内部波浪和内部潮的概念和特征被介绍,并且特征,沉积序列,沉积 microfacies 和沉积在深海底部发现的内部波浪、内部潮的存款和大规模沉积波浪的起源当模特儿被总结。在内部波浪、内部潮的存款和石油之间的关系被讨论,并且最后内部波浪、内部潮的存款被显示是为石油探索的一个新潜在的领域。He Youbin Gao Zhenzhong Luo Jinxiong Luo Shunshe Liu Xuefeng 2008Petroleum Science2008,5,1:9
6THE CONSTRUCTION OF WAVELET-BASED TRUNCATED CONICAL SHELL ELEMENT USING B-SPLINE WAVELET ON THE INTERVAL显示文摘在间隔(BSWI ) 上基于 B 花键小浪,截断的圆锥形的壳元素的二个班被构造解决 axisymmetric 问题,即 BSWI 薄截断的圆锥形的壳元素和 BSWI 有独立斜坡变丑插值的中等厚的截断的圆锥形的壳元素。在基于小浪的元素的构造,而不是传统的多项式插值, BSWI 的可伸缩的功能被采用经由变化原则通过构造元素的转变矩阵,然后构造 BSWI 元素形成形状功能。不同于把小浪 Galerkin 方法加在一起的直接小浪的进程,小浪扩大的系数代表的元素的排水量域经由构造转变矩阵被转变成边和内部模式。BSWI 元素为结构的分析联合 B 花键功能近似和各种各样的基于小浪的元素的精确性。圆锥形的壳的一些静态、动态的数字例子被学习比传统的元素与更高的效率和精确表明现在的元素。Xiang Jiawei He Zhengjia Chen Xuefeng 2006Acta Mechanica Solida Sinica2006,19,4:7
7Fiber damage analysis model for RC beam-column based on EEP super-convergent computation显示文摘A new numerical strategy to model nonlinear damage behavior of RC beam-column member based on level of material and superconvergent computation is presented in this paper. A fiber damage analysis model (FDAM) for RC beam-column member is established by analyzing section of fiber beam column element with the uniaxial damage constitutive relations of con-crete. The damage index of RC member through statistical analysis of concrete fibers damage is defined in the extreme section of beam elements, which can describe the nonlinear damage behavior of RC beam-column member under any loadings. The newly proposed element energy projection (EEP) method is applied to the inelastic analysis of FDAM. EEP superconvergent formulas for section forces and deformations of beam-column are established, and general algorithm and numerical strategy adopting EEP super-convergent computation for section deformation increment are proposed in the classical Newton-Raphson process. Both analysis and numerical test show that the EEP method can effectively find out the nonlinear feature of the distribution, and accurately obtain the damage distribution of RC beamcolumn. The proposed numerical scheme in this paper proves to be effective and convenient in its use and can be easily integrated into the present inelastic FEM programs of structure analysis.TENG Jun LI ZuoHua OU JinPing HE XueFeng 2011Science China(Technological Sciences)2011,54,10:6
8Prediction of nitrogen and phosphorus contents in citrus leaves based on hyperspectral imaging显示文摘The nutritional status of citrus leaves is very important to the determining of fertilization plans.The spectrum technique is a quick,un-injured method and is becoming widely used for plant nutrient estimation.The possibility and method of using spectrum technique to estimate the nutrient of citrus leaf was explored in this study.A total amount of 135 leaves from the mature spring shoots of navel orange trees(C.sinensis Osbeck,“Newhall”)were collected and randomly grouped into two sets of samples:100 leaves for the calibration set and 35 leaves for the prediction set.The hyperspectral images were scanned upper and lower side of each leaf and then the total nitrogen(N)and phosphorus(P)contents of each leaf were measured.The raw spectra data were extracted to generate average spectra curves,preprocessed with five different methods,and was used to build N and P content prediction models.The performances of the five preprocessing methods,i.e.,Savitzky-Golay smoothing(SGS),standard normal variate(SNV),multiplicative scatter correction(MSC),first-derivative(1-Der)and second-derivative(2-Der),were tested with linear partial least squares(PLS)models and nonlinear least squares-support vector machine(LS-SVM)models.The results showed that the SG-PLS and PLS were the best for the N predicting(Rp=0.9049,RMSEP=0.1041)and P(Rp=0.9235,RMSEP=0.0514)in citrus leaves,respectively;the hyperspectral image data from leaf‟s upper side predicting better for the contents of N and P.The study suggested that the hyperspectral image data from the upper side of the citrus leaves are suitable for nondestructive estimation of nutrient content.Liu Yanli Lyu Qiang He Shaolan Yi Shilai Liu Xuefeng Xie Rangjin Zheng Yongqiang Deng Lie 2015International Journal of Agricultural and Biological Engineering2015,8,2:5
9The principle of second generation wavelet for milling cutter breakage detection显示文摘Performance degradation or failure of manufacturing equipment will badly influence machining quality.Because of discontinuousness of the milling process,dynamic signals produced in the milling process become non-stationary.This paper indicates that the essence of SGW(second generation wavelet) transform in non-stationary signal processing is the mathematics principle of inner product transform of a dynamic signal with basis functions.Namely,by means of the inner product operation of a signal with basis functions containing scale function and wavelet function,signal decomposition and reconstruction are obtained.Acoustic emission signals generated in the milling processes of a CNC machine were analyzed by using the basis functions of SGW which are oscillation,decay and compact support.The features of end milling cutter breakage have been extracted,and the influences on machining surface quality have been identified effectively,which provide scientific bases for fault diagnosis,error tracing and quality control.HE ZhengJia CAO HongRui LI Zhen ZI YanYang CHEN XueFeng 2009Science China(Technological Sciences)2009,52,5:5
10Type I CRISPR-Cas targets endogenous genes and regulates virulence to evade mammalian host immunity显示文摘定期聚类短 palindromic 重复的 interspaced (CRISPR ) 在细菌和 archaea 的 -CRISPR-associated (Cas ) 系统对入侵外国 nucleic 酸提供适应免疫。以前的研究建议某些细菌采用他们的类型 II CRISPR-Cas 系统指向他们的自己的基因,因此躲避主人免疫。然而,另外的 CRISPR-Cas 系统是否在主机房间的细菌的侵略期间有类似的函数,仍然保持未知。这里,我们为类型识别一个新奇角色我在在 Pseudomonas aeruginosa 躲避主人防卫的 CRISPR-Cas 系统拉紧 UCBPP-PA14。类型我 PA14 的 CRISPR-Cas 系统指向细菌的察觉到治安法官的管理者 LasR 的 mRNA 阻抑由像使用费的受体的识别 4,因此减少在房间和鼠标模型的主机的支持 inflammatory 回答。机械学地,这调停核酸酶的 RNA 降级在类型的 Cas3 在目标 mRNA,和 HD 和 DExD/H 领域要求一个 5-GGN-3 识别主题我 CRISPR-Cas 系统。作为 LasR 和类型我 CRISPR-Cas 系统在细菌是无所不在地在场的,我们的调查结果阐明重要普通机制内在的细菌的毒力。Rongpeng Li Lizhu Fang Shirui Tan Min Yu Xuefeng Li Sisi He Yuquan Wei Guoping Li Jianxin Jiang Min Wu 2016Cell Research2016,26,12:4
11Rumen-protected glucose supplementation in transition dairy cows shifts fermentation patterns and enhances mucosal immunity显示文摘Manipulation of perinatal diets,such as supplementing feed with rumen-protected glucose(RPG),has been positively regarded as a strategy to improve milking performance.This study was conducted to assess the effects of RPG on the fermentation profiles,resident microbiota and mucosal immunity in the cecum.Ten Holstein dairy cows were randomly assigned to either a 25 g/kg RPG diet(DM basis)or a 11 g/kg coating fat diet(control,CON).Compared with the CON group,the acetate-to-propionate ratio was lower in the RPG group.Gene expression analysis indicated that RPG supplementation tended to upregulate the expression of Na^(+)/H^(+)hydrogen exchanger 3(NHE3)(P=0.076).RPG supplementation downregulated the expression of genes involved in self-rehabilitation such as matrix metalloproteinase 1(MMP1),MMP3,MMP9 and MMP13.Additionally,the mRNA expression of genes involved in immunity including Toll-like receptors(TLR4,TLR6 and TLR7)and proinflammatory cytokines(immune interferon gamma[IFNG]and interleukins interleukin 17 A[IL7 F],IL17 A,IL22),was downregulated by RPG supplementation.Nonetheless,no differences existed in the bacterial copy number and beta diversity between the 2 groups.Overall,supplementation with RPG would probably cause a shift towards propionate production in the cecal digesta,and promote the immune homeostasis of the cecal mucosa in transition dairy cows.Our results extended the basic understanding of RPG supplementation and utilization in transition dairy cows in terms of host microbe interplay in the cecum.Xiaoli Zhang Xiaopeng Li Jian Wu Jinzhen Jiao Zhixiong He Zhiliang Tan Xuefeng Han 2021Animal Nutrition2021,,4:4
12SARS-CoV-2 ORF10 suppresses the antiviral innate immune response by degrading MAVS through mitophagy显示文摘The global coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has caused severe morbidity and mortality in humans.It is urgent to understand the function of viral genes.However,the function of open reading frame 10(ORF10),which is uniquely expressed by SARS-CoV-2,remains unclear.In this study,we showed that overexpression of ORF10 markedly suppressed the expression of type I interferon(IFN-I)genes and IFN-stimulated genes.Then,mitochondrial antiviral signaling protein(MAVS)was identified as the target via which ORF10 suppresses the IFN-I signaling pathway,and MAVS was found to be degraded through the ORF10-induced autophagy pathway.Furthermore,overexpression of ORF10 promoted the accumulation of LC3 in mitochondria and induced mitophagy.Mechanistically,ORF10 was translocated to mitochondria by interacting with the mitophagy receptor Nip3-like protein X(NIX)and induced mitophagy through its interaction with both NIX and LC3B.Moreover,knockdown of NIX expression blocked mitophagy activation,MAVS degradation,and IFN-I signaling pathway inhibition by ORF10.Consistent with our observations,in the context of SARS-CoV-2 infection,ORF10 inhibited MAVS expression and facilitated viral replication.In brief,our results reveal a novel mechanism by which SARS-CoV-2 inhibits the innate immune response;that is,ORF10 induces mitophagy-mediated MAVS degradation by binding to NIX.Xingyu Li Peili Hou Wenqing Ma Xuefeng Wang Hongmei Wang Zhangping Yu Huasong Chang Tiecheng Wang Song Jin Xue Wang Wenqi Wang Yudong Zhao Yong Zhao Chunqing Xu Xiaomei Ma Yuwei Gao Hongbin He 2022Cellular & Molecular Immunology2022,19,1:4
13Second Generation Wavelet Finite Element and Rotor Cracks Quantitative Identification Method显示文摘The presence of cracks in the rotor is one of the most dangerous and critical defects for rotating machinery.Defect of fatigue cracks may lead to long out-of-service periods,heavy damages of machines and severe economic consequences.With the method of finite element,vibration behavior of cracked rotors and crack detection was received considerable attention in the academic and engineering field.Various researchers studied the response of a cracked rotor and most of them are focused on the crack detection based on vibration behavior of cracked rotors.But it is often difficult to identify the crack parameters quantitatively.Second generation wavelets (SGW) finite element has good ability in modal analysis for singularity problems like a cracked rotor.Based on the fact that the feature of SGW could be designed depending on applications,a multiresolution finite element method is presented.The new model of SGW beam element is constructed.The first three natural frequencies of the rotor with different crack location and size were solved with SGW beam elements,and the database for crack diagnosis is obtained.The first three metrical natural frequencies are employed as inputs of the database and the intersection of the three frequencies contour lines predicted the normalized crack location and size.With the Bently RK4 rotor test rig,rotors with different crack location and size are tested and diagnosed.The experimental results denote the cracks quantitative identification method has higher identification precision.With SGW finite element method,a novel method is presented that has higher precision and faster computing speed to identify the crack location and size.CHEN Xuefeng LI Bing HE Yuming HE Zhengjia 2010Chinese Journal of Mechanical Engineering2010,23,2:3
14Cross-Scale Synthesis of Organic High-k Semiconductors Based on Spiro-Gridized Nanopolymers显示文摘High dielectric constants in organic semiconductors have been identified as a central challenge for the improvement in not only piexoelectric,preolecric,and freeltric efcts but also photoclecric conversion eficiency in OPVs,carrier mobility in OFETS,and charge density in charge-trapping memories.Herein,we report an ultralong persistence length(≈41 nm)efet of spiro-fused organic nanopolymers on dielectric properties,together with excitonic and charge carrier behaviors.The state-of-the-art nanopolymers,namely,nanopolyspirogrids(NPSGs),are synthesized via the simple crossscale Friedel-Crafts polygridlization of AjB-type nanomonomers.The high dielectric constant(k=8.43)of NPSG is firstly achieved by locking spiro-polygridization efect that results in the enhancement of dipole polarization.When doping into a polystyrene-based dielectric layer,such a high-k feature of NPSG increases the feld-ffct carrier mobility from 0.20 to 0.90cm^(2)Vl s'in pentacene OFET devices.Meanwhile,amorphous NPSG film exhibits an ultralow energy disorder(<50 meV)for an exellent zero-field hole mobility of 3.94×10^(-1)cm^(2)V^(-1)s^(-1).surpassing most of the amorphousπconjugated polymers Onganic nanopolymers with high dielectric constants open a new way to break through the bottleneck of eficiency and multifunctionality in the blueprint of the fourth generation semiconductors.Dongqing Lin Wenhua Zhang Hang Yin Haixia Hu Yang Li He Zhang Le Wang Xinmiao Xie Hongkai Hu Yongxia Yan Haifeng Ling Jin'an Liu Yue Qian Lei Tang Yongxia Wang Chaoyang Dong Linghai Xie Hao Zhang Shasha Wang Ying Wei Xuefeng Guo Dan Lu Wei Huang 2022Research2022,,2:3
15I-beam Crack Identification Based on Study of Local Flexibility due to Crack显示文摘Local flexibility of crack plays an important role in crack identification of structures.Analytical methods on local flexibility in a cracked beam with simple geometric crossing sections,such as rectangle,circle,have been made,but there are some difficulties in calculating local flexibility in a cracked beam with complex crossing section,such as pipe and I-beam.In this paper,an analytical method to calculate the local flexibility and rotational spring stiffness due to crack in I-beam is proposed.The local flexibility with respect to various crack depths can be calculated by dividing a cracked I-beam into a series of thin rectangles.The forward and inverse problems in crack detection of I-beam are studied.The forward problem comprises the construction of crack model exclusively for crack section and the construction of a numerically I-beam model to gain crack detection database.The inverse problem consists of the measurement of modal parameters and the detection of crack parameters.Two experiments including measurement of rotational spring stiffness and prediction of cracks in I-beam are conducted.Experimental results based on the current methods indicate that relative error of crack location is less than 3%,while the error of crack depth identification is less than 6%.Crack identification of I-beam is expected to contribute to the development of automated crack detection techniques for railway lines and building skeletons.LI Bing CHEN Xuefeng HE Zhengjia 2011Chinese Journal of Mechanical Engineering2011,24,6:3
16Study of frequency-shifted and re-scaling stochastic resonance and its application to fault diagnosis显示文摘Jiyong Tan Xuefeng Chen Junying Wang Huaxin Chen Hongrui Cao Yanyang Zi Zhengjia He 2008Mechanical Systems and Signal Processing2008,,3:3
17Three-Steps-Meshing Based Multiple Crack Identification for Structures and Its Experimental Studies显示文摘Multiple crack identification plays an important role in vibration-based crack identification of structures. Traditional crack detection method of single crack is difficult to be used in multiple crack diagnosis. A three-step-meshing method for the multiple cracks identification in structures is presented. Firstly, the changes in natural frequency of a structure with various crack locations and depth are accurately obtained by means of wavelet finite element method, and then the damage coefficient method is used to determine the number and the region of cracks. Secondly, different regions in the cracked structure are divided into meshes with different scales, and then the small unit containing cracks in the damaged area is gradually located by iterative computation. Lastly, by finding the points of intersection of three frequency contour lines in the small unit, the crack location and depth are identified. In order to verify the effectiveness of the presented method, a multiple cracks identification experiment is carried out. The diagnostic tests on a cantilever beam under two working conditions show the accuracy of the proposed method: with a maximum error of crack location identification 2.7% and of depth identification 5.2%. The method is able to detect multiple crack of beam with less subdivision and higher precision, and can be developed as a multiple crack detection approach for complicated structures.LI Bing CHEN Xuefeng HE Zhengjia 2013Chinese Journal of Mechanical Engineering2013,26,2:3
18Numerical investigation of the moving liquid column coalescing with a droplet in triangular microchannels using CLSVOF method显示文摘The dynamic behavior of the moving liquid column coalescing with a sessile droplet in triangular microchannels is numerically investigated by using coupled volume of fluid with level set interface tracking method implemented in ANSYS Fluent 14.5 in conjunction with the continuum surface force model. It is found that for both hydrophobic and hydrophilic microchannels, the coalescence between the moving liquid column and droplet can accelerate the original liquid column movement as a result of the induced curvature that lowers the liquid pressure at the interface. As compared to the rectangular microchannel with the same hydraulic diameter, the triangular microchannel exhibits smaller velocity increment ratio because of stronger viscous effect. Simulation results also reveal that the velocity increment ratio increases with the contact angle in hydrophobic microchannels, but it is reverse in the hydrophilic microchannels. The effects of the droplet size, lengthways and transverse positions are also investigated in this work. It is shown that larger droplet and smaller distance between the droplet and inlet or the substrate center can result in larger velocity increment ratio as a result of higher surface energy and lower viscous dissipation energy, respectively. The results obtained in this study create a solid theoretical foundation for designingand optimizing microfluidic devices encountering such a typical phenomenon.Shuzhe Li Rong Chen Hong Wang Qiang Liao Xun Zhu Zhibin Wang Xuefeng He 2015Science Bulletin2015,60,22:3
19Design and Characterization of a Low-Cost Piezoelectric Vibration Energy Harvester with Bulk PZT Film显示文摘To improve the efficiency of MEMS piezoelectric vibration energy harvesters(PVEHs), the bulk lead zirconate titanate(PZT) has been used to substitute the thin film PZT for the higher mechanical-electrical coupling coefficients. The expensive equipment of micromachining set a high entry barrier on the research of PVEHs with high efficiency. To solve this issue, this paper developed an efficient PVEH with bulk PZT using common precision machining, whose dimensions and electrical outputs are comparable to the MEMS devices. After numerically analyzing the effects of the length ratio of the proof mass to the harvester on the output power, a compact PVEH consisting of a cantilevered uni-morph and a tungsten proof mass was designed. Simulations show that the mechanical damping ratio and the thickness have little effects on the optimized length ratio. By using a uni-morph with the copper structural layer of about 80-90μm and the bulk PZT-5 H layer of 139μm, a low-cost harvester prototype was assembled. The key parameters of the prototype were experimentally identified and compared with the theoretical predictions. Under the harmonic base excitation of 0.4 g(where g = 9.8 m/s^2) at 160 Hz, the maximum output power of the prototype is about 76.7μW, with the normalized power density of about 3.35 mW/cm^3/g^2. Under base excitation of 0.4 g at 159 Hz, the prototype charged a 680μF capacitor from 0 to 4.84 V in about 154 seconds.TIAN Xingyao HE Xuefeng 2018Instrumentation2018,5,4:2
20A Study on Rural Social Network and Village Planning Paradigm in China显示文摘Current village planning in China, which mostly draws on the experience from urban planning, is a rational planning model based on elite decision-making, resulting in many problems. Essentially, planning is a kind of institutional arrangement according to the demands of multiple actors under certain social context. Since actors and their behaviors in villages are far different from those in cities, leading to the reorganization of planning assumptions and prerequisites, village planning paradigms are prominently distinct from urban planning paradigms. This paper figures out the significance of social networks and argues that village planning is a kind of communicative planning based on endogenous order, referring to the paradigm development course of Western urban planning theories and the features of Chinese villages. In conclusion, it stresses that village planning should focus on social network and promote communication, coordination, and consensus-building, and accordingly planners should adjust their role.Wang Xu Huang Yaping Roger C.K.Chan He Xuefeng Li Min 2018China City Planning Review2018,27,1:2
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