Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 287

年份

2024 2

2023 29

2022 20

2021 9

2020 19

2019 12

2018 6

2017 17

2016 9

2015 20

2014 9

2013 7

2012 10

2011 12

2010 38

2009 13

2008 12

2007 16

2006 5

2005 2

展开︾

关键词

大直径盾构 4

制造业 3

制造大国 3

制造强国 3

CFD 2

中国近海 2

同步注浆 2

大型化成藏 2

海上风电 2

砂卵石地层 2

2016年熊本地震 1

3D打印 1

4D CAD 1

ALOS-2 PALSAR-2 1

Agent 1

BFT 1

CO₂ 捕集 1

CO₂利用 1

CO₂封存 1

展开︾

检索范围：

排序：展示方式：

Full-band error control and crack-free surface fabrication techniques for ultra-precision fly cutting of large-apertureKDP crystals

F. H. ZHANG, S. F. WANG, C. H. AN, J. WANG, Q. XU

《机械工程前沿（英文）》 2017年第12卷第2期页码 193-202 doi: 10.1007/s11465-017-0448-8

摘要：

Large-aperture potassium dihydrogen phosphate (KDP) crystals are widely used in the laser path of inertial confinement fusion (ICF) systems. The most common method of manufacturing half-meter KDP crystals is ultra-precision fly cutting. When processing KDP crystals by ultra-precision fly cutting, the dynamic characteristics of the fly cutting machine and fluctuations in the fly cutting environment are translated into surface errors at different spatial frequency bands. These machining errors should be suppressed effectively to guarantee that KDP crystals meet the full-band machining accuracy specified in the evaluation index. In this study, the anisotropic machinability of KDP crystals and the causes of typical surface errors in ultra-precision fly cutting of the material are investigated. The structures of the fly cutting machine and existing processing parameters are optimized to improve the machined surface quality. The findings are theoretically and practically important in the development of high-energy laser systems in China.

关键词： ultra-precision fly cutting large-aperture KDP crystals spatial frequency processing error

HTML PDF 收藏

大相对口径大线视场光学系统的设计

潘君骅

《中国工程科学》 2000年第2卷第8期页码 89-90

摘要：

文章论述了用于红外远距离探测的光学应是全反射式的大相对口径、大视场的离轴非球面系统。给出了一个通光口径为Φ600mm，相对口径1:1.67，线视场为±5°的设计结果。

关键词：红外探测相对口径大视场离轴系统非球面

HTML PDF 收藏

中国功能晶体研究进展 Review

王继扬,于浩海,吴以成,Robert Boughton

《工程（英文）》 2015年第1卷第2期页码 192-210 doi: 10.15302/J-ENG-2015053

摘要：

功能晶体是现代科学技术发展的基础材料之一，在当前信息时代发挥着重要和关键的作用。本文总结了若干功能晶体的研究进展，综述了中国功能晶体的现状及重大成就和重要应用，讨论了功能晶体面临的挑战和机遇，提出了可能的发展方向。

关键词：功能材料，激光晶体，非线性光学晶体，闪烁晶体，弛豫型铁电晶体，半导体

HTML PDF 收藏

Experimental study on high-efficiency polishing for potassium dihydrogen phosphate (KDP) crystal by using

Ziyuan LIU, Hang GAO, Dongming GUO

《机械工程前沿（英文）》 2020年第15卷第2期页码 294-302 doi: 10.1007/s11465-019-0576-4

摘要： A high-efficiency polishing approach using two-phase air–water fluid (TAWF) is proposed to avoid surface contamination and solve the inefficiency of previous water-dissolution polishing techniques for potassium dihydrogen phosphate (KDP) crystal. In the proposed method, controllable deliquescence is implemented without any chemical impurity. The product of deliquescence is then removed by a polishing pad to achieve surface planarization. The mechanism underlying TAWF polishing is analyzed, a special device is built to polish the KDP crystal, and the effect of relative humidity (RH) on polishing performance is studied. The relationship between key parameters of polishing and surface planarization is also investigated. Results show that the polishing performance is improved with increasing RH. However, precisely controlling the RH is extremely difficult during TAWF polishing. Controllable deliquescence can easily be disrupted once the RH fluctuates, which therefore needs to be restricted to a low level to avoid its influence on deliquescence rate. The material removal of TAWF polishing is mainly attributed to the synergistic effect of deliquescence and the polishing pad. Excessive polishing pressure and revolution rate remarkably reduce the life of the polishing pad and the surface quality of the KDP crystal. TAWF polishing using IC-1000 and TEC-168S increase the machining efficiency by 150%, and a smooth surface with a root mean square surface roughness of 5.5 nm is obtained.

关键词： potassium dihydrogen phosphate (KDP) crystal controllable deliquescence two-phase air–water fluid high-efficiency polishing material removal

HTML PDF 收藏

Synthesis of crystals and particles by crystallization and polymerization in droplet-based microfluidic

Jingtao WANG, Jin ZHANG, Junjie HAN,

《化学科学与工程前沿（英文）》 2010年第4卷第1期页码 26-36 doi: 10.1007/s11705-009-0292-4

摘要： The recent advances in crystallization and polymerization assisted by droplet-based microfluidics to synthesize micro-particles and micro-crystals are reviewed in this paper. Droplet-based microfluidic devices are powerful tools to execute some precise controls and operations on the flow inside microchannels by adjusting fluid dynamics parameters to produce monodisperse emulsions or multiple-emulsions of various materials. Major features of this technique are producing particles of monodispersity to control the shape of particles in a new level, and to generate droplets of diverse materials including aqueous solutions, gels and polymers. Numerous microfluidic devices have been employed to generate monodisperse droplets of range from nm to μm, such as T junctions, flow-focusing devices and co-flow or cross-flow capillaries. These discrete, independently controllable droplets are ideal microreactors to be manipulated in the channels to synthesize the nanocrystals, protein crystals, polymer particles and microcapsules. The generated monodisperse particles or crystals are to meet different technical demands in many fields, such as crystal engineering, encapsulation and drug delivery systems. Microfluidic devices are promising tools in the synthesis of micron polymer particles that have diverse applications such as the photonic materials, ion-exchange and chromatography columns, and field-responsive rheological fluids. Processes assisted by microfluidic devices are able to produce the polymer particles (including Janus particles) with precise control over their sizes, size distribution, morphology and compositions. The technology of microfluidics has also been employed to generate core-shell microcapsules and solid microgels with precise controlled sizes and inner structures. The chosen “smart” materials are sensitive to an external stimulus such as the change of the pH, electric field and temperature. These complex particles are also able to be functionalized by encapsulating nanoparticles of special functions and by attaching some special groups like targeting ligands. The nucleation kinetics of some crystals like KNO was investigated in different microfluidic devices. Because of the elimination of the interactions among crystallites in bulk systems, using independent droplets may help to measure the nucleation rate more accurately. In structural biology, the droplets produced in microfluidic devices provide ideal platforms for protein crystallization on the nanoliter scale. Therefore, they become one of the promising tools to screen the optimal conditions of protein crystallization.

关键词： core-shell monodisperse nucleation Microfluidic different technical

HTML PDF 收藏

Filtration ability of hollow fiber membrane for production of magnesium ammonium phosphate crystals by

H. Watamura, H. Marukawa, I. Hirasawa

《化学科学与工程前沿（英文）》 2013年第7卷第1期页码 55-59 doi: 10.1007/s11705-013-1312-y

摘要： Relationship between magnesium ammonium phosphate (MAP) crystal properties and the filtration ability of hollow fiber membrane (HFM) were investigated. Phosphorus recovery process by crystallization has a problem that it produces a large amount of fine crystals. So improvement of the crystallization process by combining with filtration was discussed. MAP crystals were obtained by batch reaction crystallization and the filtration characteristics were investigated. The filtration was evaluated by the specific filtration resistance ( ) on HFM. Filtered slurry was prepared with each suspension density and crystal size distribution. The solution was filtered at constant pressure of 0.02 MPa and the filtration time on each filtrated volume was recorded. As a result, decreases exponentially with suspension density increasing from 0.25 g/L to 0.5 g/L and decreases moderately with suspension density increasing from 0.5 g/L to 1.5 g/L. of large crystals decreases exponentially at less suspension density than of small crystals does. Also, increases as the ratio of the fractured crystals increases.

关键词： membrane separation crystallization MAP

HTML PDF 收藏

大而复杂形变区域中的精确三维形变反演——基于偏移的相位解缠和改进的多孔径SAR干涉测量集成技术在2016年熊本地震中的应用 Article

Won-Kyung Baek, Hyung-Sup Jung

《工程（英文）》 2020年第6卷第8期页码 927-935 doi: 10.1016/j.eng.2020.06.012

摘要：

常规合成孔径雷达（synthetic aperture radar, SAR）干涉测量（InSAR）已成功用于精确测量雷达视线（line-of-sight, LOS）方向上的表面形变，而多孔径SAR干涉技术（multiple-aperture SAR interferometry, MAI）可以用于精确测量沿轨迹（along-track, AT）方向的表面形变。形变反演使用了两组升轨对和一组高级陆地观测卫星2（Advanced Land Observing Satellite-2, ALOS-2）相控阵型L波段合成孔径雷达2（Phased Array-type L-band Synthetic Aperture

关键词：合成孔径雷达（SAR）常规SAR干涉测量（InSAR）多孔径SAR干涉技术（MAI） ALOS-2 PALSAR-2 三维形变反演 2016年熊本地震

HTML PDF 收藏

Acoustic fault signal extraction via the line-defect phononic crystals

《机械工程前沿（英文）》 2022年第17卷第1期页码 10-10 doi: 10.1007/s11465-021-0666-y

摘要： Rotating machine fault signal extraction becomes increasingly important in practical engineering applications. However, fault signals with low signal-to-noise ratios (SNRs) are difficult to extract, especially at the early stage of fault diagnosis. In this paper, 2D line-defect phononic crystals (PCs) consisting of periodic acrylic tubes with slit are proposed for weak signal detection. The defect band, namely, the formed resonance band of line-defect PCs enables the incident acoustic wave at the resonance frequency to be trapped and enhanced at the resonance cavity. The noise can be filtered by the band gap. As a result, fault signals with high SNRs can be obtained for fault feature extraction. The effectiveness of weak harmonic and periodic impulse signal detection via line-defect PCs are investigated in numerical and experimental studies. All the numerical and experimental results indicate that line-defect PCs can be well used for extracting weak harmonic and periodic impulse signals. This work will provide potential for extracting weak signals in many practical engineering applications.

关键词： phononic crystals line-defect fault signal extraction acoustic enhancement

HTML PDF 收藏

基于块稀疏的超宽带FMCW雷达ISAR大转角成像 Article

Ke JIN, Tao LAI, Gong-quan LI, Ting WANG, Yong-jun ZHAO

《信息与电子工程前沿（英文）》 2017年第18卷第12期页码 2058-2069 doi: 10.1631/FITEE.1601310

摘要：考虑到高分辨条件下信号的块稀疏特性，本文重点研究了基于块稀疏的自适应匹配追踪大转角ISAR（inverse synthetic aperture radar）成像算法。

关键词：调频连续波；逆合成孔径雷达；匹配滤波；压缩感知；块稀疏

HTML PDF 收藏

用于SAR图像分类的统计分布基元特征 Article

Chu HE, Ya-ping YE, Ling TIAN, Guo-peng YANG, Dong CHEN

《信息与电子工程前沿（英文）》 2017年第18卷第10期页码 1614-1623 doi: 10.1631/FITEE.1601051

摘要： None

关键词： None

HTML PDF 收藏

利用地球同步轨道InSAR每日生成DEM的质量分析 Article

杨泽发, 张庆君, 丁晓利, 陈武

《工程（英文）》 2020年第6卷第8期页码 913-918 doi: 10.1016/j.eng.2020.07.003

摘要：

最新的数字高程模型（DEM）产品在灾害防治、城市管理等诸多领域中扮演着重要角色。利用机载或低地球轨道（LEO）的星载干涉合成孔径雷达（InSAR）生成DEM已被证明是可行且极具价值的方法。然而，受成本和卫星重返周期的限制，该技术难以频繁（如每天）生成或更新大区域范围（如大陆尺度或更大范围）的DEM。由于对地同步合成孔径雷达（GEOSAR）卫星运行于地球静止轨道，因此它们能以相当短的重返时间（每天或更短）观测同一地面区域，这为实现生成每日DEM这一理想但目前难以实现的目标提供了潜在可能。为此，本文系统地分析了利用GEOSAR卫星生成的每日DEM产品质量。结果表明：GEOSAR卫星生成的每日DEM产品精度通常远低于利用传统低轨星载合成孔径雷达（SAR）获得的DEM产品。因此，研究GEOSAR DEM生成过程中的误差削弱方法显得至关重要。

关键词：每日DEM生成 InSAR 地球同步SAR 精度分析

HTML PDF 收藏

Control of the agglomeration of crystals in the reactive crystallization of 5-(difluoromethoxy)-2-mercapto

Yongli WANG, Shuyuan MA, Xiaodong Lü, Chuang XIE

《化学科学与工程前沿（英文）》 2012年第6卷第4期页码 423-431 doi: 10.1007/s11705-012-1211-7

摘要： 5-(Difluoromethoxy)-2-mercapto-1 -benzimidazole (DMB) was precipitated by adding acetic acid to the DMB sodium salt solution. The spherical agglomeration of DMB during the reactive crystallization in a batch crystallizer was monitored by real-time Particle Video Microscope (PVM). We found that the low feeding rate of acetic acid, high crystallization temperature, low agitation rate or adding seed crystal can facilitate the formation of spherical agglomerates. By using a simple model, the mean crystal agglomerate size of DMB thus predicted is generally in agreement with the experimental data. In addition, the crystallization process of DMB was optimized by a new control strategy of supersaturation to avoid disadvantages brought by agglomeration.

关键词： 5-(difluoromethoxy)-2-mercapto-1H-benzimidazole (DMB) reactive crystallization agglomeration feeding rate crystallization temperature agitation rate

HTML PDF 收藏

Effect of cutterhead configuration on tunnel face stability during shield machine maintenance outages

《结构与土木工程前沿（英文）》 2023年第17卷第4期页码 522-532 doi: 10.1007/s11709-023-0930-9

摘要： Owing to long-distance advancement or obstacles, shield tunneling machines are typically shut down for maintenance. Engineering safety during maintenance outages is determined by the stability of the tunnel face. Pressure maintenance openings are typically used under complicated hydrogeological conditions. The tunnel face is supported by a medium at the bottom of the excavation chamber and compressed air at the top. Owing to the high risk of face failure, the necessity of support pressure when cutterhead support is implemented and a method for determining the value of compressed air pressure using different support ratios must to be determined. In this study, a non-fully chamber supported rotational failure model considering cutterhead support is developed based on the upper-bound theorem of limit analysis. Numerical simulation is conducted to verify the accuracy of the proposed model. The results indicate that appropriately increasing the specific gravity of the supporting medium can reduce the risk of collapse. The required compressed air pressure increases significantly as the support ratio decreases. Disregarding the supporting effect of the cutterhead will result in a tunnel face with underestimated stability. To satisfy the requirement of chamber openings at atmospheric pressure, the stratum reinforcement strength and range at the shield end are provided based on different cutterhead aperture ratios.

关键词： tunnel face stability cutterhead configuration aperture ratio pressure gradient support ratio

HTML PDF 收藏

多孔径光学成像系统及其光场采集数学模型 Review Article

祁启明,傅瑞罡,邵铮铮,王平,范红旗

《信息与电子工程前沿（英文）》 2022年第23卷第6期页码 823-844 doi: 10.1631/FITEE.2100058

摘要：

受昆虫复眼启发，为提高光学成像质量，如获得高分辨率图像或大视场图像，研究者提出了许多多孔径光学成像系统。光场采集数学模型是联系多孔径光学成像系统结构设计与应用的纽带，但光场采集数学模型较少被关注。本文系统梳理了典型多孔径光学成像系统（仿生复眼、光场相机、相机阵列），总结了不同结构下多孔径光学成像系统的一般性光场采集数学模型。列出的数学模型既可用于计算特定多孔径光学成像系统的关键指标，如视场大小和子图像重叠比等，也可作为数学工具，便于研究者完成对成像系统的定量设计与评估。

关键词：多孔径光学成像系统；仿生复眼；光场相机；相机阵列；光场采集模型

HTML PDF 收藏

光电子晶体与全固态激光器及其应用——光电子技术发展的一个重大方向

许祖彦

《中国工程科学》 1999年第1卷第2期页码 72-77

摘要：

光电子时代是微电子技术、激光技术、材料科学等高速发展、综合集成的产物。20世纪90年代光电子晶体的长足进步和大功率半导体激光技术的突破，导致全固态激光器的实用化，这将促使光电子技术在21世纪前50年对更多的国家支柱产业作出重大贡献，如先进制造业的材料加工、信息业的光存储、娱乐业的激光显示、能源业的激光核聚变电站和核裂变燃料生产、军工业的激光武器升级换代等。

关键词：光电子晶体全固态激光器材料加工光存储激光显示激光核聚变