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三峡工程 2

微反应器 2

微合金化 2

显微硬度 2

膨化硝酸铵 2

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Z干扰信道；非正则信号；和速率；帕累托边界；协方差；伪协方差 1

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Effect of Joule heating on electro-osmotic flow in a closed-end micro-channel with isothermal and convective

Liang ZHAO, Linhua LIU,

《能源前沿（英文）》 2009年第3卷第4期页码 381-388 doi: 10.1007/s11708-009-0057-2

摘要： The effect of Joule heating on the steady state electro-osmotic flow in a closed-end micro-channel is studied through numerical simulation with the finite volume method. The velocity field and the temperature field are described by a rigorous mathematical model. Thermophysical properties including viscosity and thermal conductivity are considered to be temperature-dependent. The simulations show that the presence of Joule heating causes an increase in temperature and a decrease in viscosity in the whole micro-channel, which, thereafter, induce a large velocity near the wall and an increase in fluid velocity at the central region in order to maintain a zero flow rate at the cross section of the micro-channel. The effect of Joule heating on the induced pressure gradient is also studied, which is very important for the application of the closed-end micro-channel as a micro-actuator. The results reveal that the induced pressure gradient, taking into consideration Joule heating, is significantly smaller than that without considering Joule heating when the wall temperature of the micro-channel is constant. The induced pressure gradient difference between considering Joule heating and without considering Joule heating is small under the convective boundary condition.

关键词： closed-end micro-channel electrical double layer electro-osmotic flow induced pressure gradient Joule heating

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Numerical simulation of micro scale flowing and boiling

Wen WANG, Rui ZHUAN,

《能源前沿（英文）》 2009年第3卷第4期页码 396-401 doi: 10.1007/s11708-009-0049-2

摘要： Numerical simulations of flowing and boiling in micro channels are presented, including the modeling of bubble dynamics of nucleate boiling, and a description of the interface of two phases with the volume-of-fluid (VOF). The two calculated cases are compared with related experimental data in literature. Some simulated results are found corresponding well to the experimental data. The simulated results also show the details of 3-dimensional heat transfer and the flow in micro channels, which are helpful to the investigation of the mechanism of two-phase heat transfer and flow in micro channels.

关键词： volume-of-fluid (VOF) micro channel nucleate boiling bubble dynamics simulation

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28 GHz城市微蜂窝场景中上行与下行信道空间特性

姜涛,张建华,唐盼,田磊

《信息与电子工程前沿（英文）》 2021年第22卷第4期页码 488-502 doi: 10.1631/FITEE.2000443

摘要：介绍了28 GHz城市微蜂窝（UMi）场景中上行和下行链路的水平到达角（AoA）实验研究。目前，大多数毫米波频段的角度测量都在下行链路中进行，然后利用信道互易性来推断上行链路情况。尽管上行链路和下行链路的信道相关系数可以高达0.8，但这并不意味着它们完全相同。只有对真实的上行链路进行测量才能准确描述其信道状况，这也是本文的研究目的。在模拟上行链路和下行链路时，将配备有可旋转喇叭天线的接收机分别置于基站和用户终端。为提高角度分辨率，使用空间替代广义期望最大化（SAGE）算法提取多径分量（MPC），然后使用空间波瓣方法对MPC在功率角谱中分簇。通过将MPC与环境中的对象匹配，发现直射传播和一阶反射传播分别在视距（LoS）和非视距（NLoS）情况下占主导地位。通过将测量结果与标准信道模型比较，可以验证AoA的簇心角在上行链路和下行链路中均遵循高斯分布。最后，为簇内多径的AoA和功率建立二维高斯模型，以反映它们的相关性。

关键词：信道测量；毫米波；上行链路；下行链路；水平到达角

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低高宽比矩形微通道中流动沸腾的压降特性

张炳雷,徐进良,肖泽军

《中国工程科学》 2007年第9卷第12期页码 86-93

摘要：以甲醇为工质，在不同进口温度、质量流率、热流密度和倾角下，对低高宽比矩形微通道中流动沸腾压降特性进行了研究，并分别采用均相模型和分相模型对通道压降进行了计算。通过对比实验结果与计算结果发现，均相模型中两相平均粘度的计算应当采用Dukler公式，用其他计算式时误差较大；利用LockhartMartinelli关系式进行的分相模型计算发现，现有C值计算公式，如Chisholm,Lee and Lee，Mishima及Qu and Mudawar等，都不能用于预测该实验中低高宽比微通道的两相压降。实验发现当通

关键词：压降特性；均相模型；分相模型；微通道；流动沸腾

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A cellphone-based colorimetric multi-channel sensor for water environmental monitoring

《环境科学与工程前沿（英文）》 2022年第16卷第12期 doi: 10.1007/s11783-022-1590-z

摘要：

● A cellphone-based colorimetric multi-channel sensor for in-field detection.

关键词： Colorimetric analysis Multi-channel sensor Cellphone Water quality indexes Environmental monitoring

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Analysis of nonlinear channel friction inverse problem

CHENG Weiping, LIU Guohua

《结构与土木工程前沿（英文）》 2007年第1卷第2期页码 205-210 doi: 10.1007/s11709-007-0024-0

摘要： Based on the Backus-Gilbert inverse theory, the singular value decomposition (SVD) for general inverse matrices and the optimization algorithm are used to solve the channel friction inverse problem. The resolution and covariance friction inverse model in matrix form is developed to examine the reliability of solutions. Theoretical analyses demonstrate that the convergence rate of the general Newton optimization algorithm is in the second-order. The Wiggins method is also incorporated into the algorithm. Using the method, noise can be suppressed effectively, and the results are close to accurate solutions with proper control parameters. Also, the numerical stability can be improved.

关键词： singular SVD second-order covariance Theoretical

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Flexible micro flow sensor for micro aerial vehicles

Rong ZHU, Ruiyi QUE, Peng LIU

《机械工程前沿（英文）》 2017年第12卷第4期页码 539-545 doi: 10.1007/s11465-017-0427-0

摘要：

This article summarizes our studies on micro flow sensors fabricated on a flexible polyimide circuit board by a low-cost hybrid process of thin-film deposition and circuit printing. The micro flow sensor has merits of flexibility, structural simplicity, easy integrability with circuits, and good sensing performance. The sensor, which adheres to an object surface, can detect the surface flow around the object. In our study, we install the fabricated micro flow sensors on micro aerial vehicles (MAVs) to detect the surface flow variation around the aircraft wing and deduce the aerodynamic parameters of the MAVs in flight. Wind tunnel experiments using the sensors integrated with the MAVs are also conducted.

关键词： micro flow sensor flexible sensor surface flow sensing aerodynamic parameter micro aerial vehicle (MAV)

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Improvement of solidification model and analysis of 3D channel blockage with MPS method

《能源前沿（英文）》 2021年第15卷第4期页码 946-958 doi: 10.1007/s11708-021-0754-z

摘要： In a severe accident of a nuclear power reactor, coolant channel blockage by solidified molten core debris may significantly influence the core degradations that follow. The moving particle semi-implicit (MPS) method is one of the Lagrangian-based particle methods for analyzing incompressible flows. In the study described in this paper, a novel solidification model for analyzing melt flowing channel blockage with the MPS method has been developed, which is suitable to attain a sufficient numerical accuracy with a reasonable calculation cost. The prompt velocity diffusion by viscosity is prioritized over the prompt velocity correction by the pressure term (for assuring incompressibility) within each time step over the “mushy zone” (between the solidus and liquidus temperature) for accurate modeling of solidification before fixing the coordinates of the completely solidified particles. To sustain the numerical accuracy and stability, the corrective matrix and particle shifting techniques have been applied to correct the discretization errors from irregular particle arrangements and to recover the regular particle arrangements, respectively. To validate the newly developed algorithm, 2-D benchmark analyses are conducted for steady-state freezing of the water in a laminar flow between two parallel plates. Furthermore, 3-D channel blockage analyses of a boiling water reactor (BWR) fuel support piece have been performed. The results show that a partial channel blockage develops from the vicinity of the speed limiter, which does not fully develop into a complete channel blockage, but still diverts the incoming melt flow that follows to the orifice region.

关键词： boiling water reactor (BWR) severe accident channel blockage moving particle semi-implicit (MPS) method solidification

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Experimental investigation of liquid metal alloy based mini-channel heat exchanger for high power electronic

Manli LUO, Jing LIU

《能源前沿（英文）》 2013年第7卷第4期页码 479-486 doi: 10.1007/s11708-013-0277-3

摘要： There is currently a growing demand for developing efficient techniques for cooling integrated electronic devices with ever increasing heat generation power. To better tackle the high-density heat dissipation difficulty within the limited space, this paper is dedicated to clarify the heat transfer behaviors of the liquid metal flowing in mini-channel exchangers with different geometric configurations. A series of comparative experiments using liquid metal alloy Ga68%In20%Sn12% as coolant were conducted under prescribed mass flow rates in three kinds of heat exchangers with varied geometric sizes. Meanwhile, numerical simulations for the heat exchangers under the same working conditions were also performed which well interpreted the experimental measurements. The simulated heat sources were all cooled down by these three heat dissipation apparatuses and the exchanger with the smallest channel width was found to have the largest mean heat transfer coefficient at all conditions due to its much larger heat transfer area. Further, the present work has also developed a correlation equation for characterizing the Nusselt number depending on Peclet number, which is applicable to the low Peclet number case with constant heat flux in the hydrodynamically developed and thermally developing region in the rectangular channel. This study is expected to provide valuable reference for designing future liquid metal based mini-channel heat exchanger.

关键词： heat exchanger liquid metal mini-channel heat dissipation heat transfer coefficient

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Dependence of error sensitivity of frequency on bias voltage in force-balanced micro accelerometer

Lili CHEN, Wu ZHOU

《机械工程前沿（英文）》 2013年第8卷第2期页码 146-149 doi: 10.1007/s11465-013-0260-z

摘要：

To predict more precisely the frequency of force-balanced micro accelerometer with different bias voltages, the effects of bias voltages on error sensitivity of frequency is studied. The resonance frequency of accelerometer under closed loop control is derived according to its operation principle, and its error sensitivity is derived and analyzed under over etching structure according to the characteristics of Deep Reaction Ion Etching (DRIE). Based on the theoretical results, micro accelerometer is fabricated and tested to study the influences of AC bias voltage and DC bias voltage on sensitivity, respectively. Experimental results indicate that the relative errors between test data and theory data are less than 7%, and the fluctuating value of error sensitivity under the range of voltage adjustment is less than 0.01 μm . It is concluded that the error sensitivity with designed parameters of structure, circuit and process error can be used to predict the frequency of accelerometer with no need to consider the influence of bias voltage.

关键词： Micro-Electro-Mechanical Systems (MEMS) micro accelerometer force-balanced micro accelerometer frequency error sensitivity

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Dynamical research on spherical micro actuator with piezoelectric ceramic stacks drivers

ZHANG Ruihua, CHEN Haichu

《机械工程前沿（英文）》 2007年第2卷第4期页码 433-438 doi: 10.1007/s11465-007-0074-y

摘要： This paper develops a 30 mm × 30 mm × 50 mm spherical micro actuator driven by piezoelectric ceramic stacks (PZT), and analyzes its dynamic performances. First, the space coordinate relationship of the spherical micro actuator and a dynamic model are set up. Second, The Runge-Kutta arithmetic is used to calculate the dynamical parameters of the micro actuator; the SIMULINK module of MATLAB is used to build the dynamical simulating model and then simulate it. Third, an experimental sample of the spherical micro actuator is developed, a micromanipulator is integrated with a micro-gripper based on the sample spherical micro actuator, and the experimental research on the micro assembly is conducted between a micro shaft of 180 μm and a micro spindle sleeve of 200 μm. Finally, the characteristics of the spherical micro actuator influenced by the mass of the metal sphere of the micro actuator, driving signal frequency, friction coefficient of the contact surface between the metal sphere and the friction block of the micro driving unit are analyzed. The experimental results indicate that the rotation resolution of the micro actuator reaches 0.000 1°, the rotation positioning precision reaches 0.000 5°, and the maximum working frequency is about 1200 Hz. The experimental results validate the back rotation vibration model of the spherical micro actuator. The micromanipulator integrated by the spherical micro actuator can meet the requirements of precise micro operation and assembly for micro electro mechanical systems (MEMS) or other microelements in micro degree fields.

关键词： spherical micro-gripper friction coefficient dynamic frequency

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Understanding channel tropism in traditional Chinese medicine in the context of systems biology

null

《医学前沿（英文）》 2013年第7卷第3期页码 277-279 doi: 10.1007/s11684-013-0273-3

摘要：

Channel tropism is investigated and developed through long-term clinical practice. In recent years, the development of channel tropism theory has attracted increasing attention. This study analyzed channel tropism theory and the problems associated with it. Results showed that this theory and systems biology have a similar holistic viewpoint. Systems biology could provide novel insights and platform in the study of channel tropism. Some problems in channel tropism theory, including pharmacology and action mechanism, were investigated.

关键词： systems biology channel tropism theory traditional Chinese medicine application

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长江口深水航道治理工程的创新

范期锦

《中国工程科学》 2004年第6卷第12期页码 13-26

摘要：

经不断探索，依靠技术创新和严格、科学的管理，史无前例的长江口深水航道治理工程在复杂、恶劣的自然条件下取得了成功。文章论述了这一大型水运工程在设计、施工和管理方面创新的思维、作法和效果。

关键词：长江口深水航道工程管理设计施工

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Laboratory assessment of Alaska aggregates using Micro-Deval test

Jenny LIU,Sheng ZHAO,Anthony MULLIN

《结构与土木工程前沿（英文）》 2017年第11卷第1期页码 27-34 doi: 10.1007/s11709-016-0359-5

摘要： Aggregates suitable for use in asphalt concrete (AC) pavement construction must meet durability criteria. Thus, it is critical to select appropriate tests to properly characterize aggregate durability. In Alaska, durability tests currently being used for aggregates in AC pavement include Los Angeles (LA) abrasion test, sulfate soundness test and Washington degradation test. However, there have long been concerns arising over Washington degradation test used as an acceptance tool, motivating pavement practitioners to seek more suitable alternatives. This paper presents a study to investigate the feasibility of using Micro-Deval test, commonly used in other states, to evaluate the durability of Alaskan aggregates in AC pavement as well as its potential to replace Washington degradation test. Micro-Deval test, Washington degradation test and other tests currently specified in Alaska were conducted on aggregates from 16 batches representing statewide sources. Based on the testing results, it is found that using Micro-Deval test for durability assessment of Alaska aggregates was feasible and reproducible, and a high potential was revealed to use Micro-Deval test to replace Washington degradation test in Alaska. It is recommended that Micro-Deval test be considered as an additional test for a certain period, but in the long run should be used along with current LA abrasion and sulfate soundness tests to provide a more desirable durability assessment of Alaska aggregates used in AC pavement.

关键词： aggregate durability Washington degradation test Micro-Deval test

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Characterization of micro-mixing in a novel impinging streams reactor

Hui HU, Zhiming CHEN, Zhen JIAO

《化学科学与工程前沿（英文）》 2009年第3卷第1期页码 58-64 doi: 10.1007/s11705-009-0106-8

摘要： This paper presents an experimental investigation of a novel impinging stream reactor (ISR) with the aim of high mixing intensity. The integral mixing quality in the reactor was measured with the iodide-iodate reaction and showed excellent mixing performance. The impact of the operating parameters, such as fluxes, circulation and inter-nozzle distances, was investigated in terms of segregation index. The results showed that the increase of flux, the decrease of inter-nozzle distance and a suitable circulation can improve the micro-mixing efficiency. Based on turbulence theory, it was estimated that the characteristic micro-mixing time was 0.002—0.02 s, which was much shorter than that in the stirred tank reactor. The micro-mixing time was related to the segregation index, which was in good agreement with those in the literature.

关键词： micro-mixing impinging streams reactor turbulent mixing mass transfer