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Bioleaching of spent Ni-Cd batteries and phylogenetic analysis of an acidophilic strain in acidified sludge

ZHAO Ling, WANG Liang, YANG Dong, ZHU Nanwen

《环境科学与工程前沿（英文）》 2007年第1卷第4期页码 459-465 doi: 10.1007/s11783-007-0073-6

摘要： Biohydrometallurgy is a novel method to recycle discarded batteries, in which sewage sludge is used as microorganisms and culture due to the presence of indigenous . A two-step continuous flow leaching system co

关键词： Biohydrometallurgy discarded indigenous two-step continuous presence

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Two-step hydrothermal conversion of biomass waste to humic acid using hydrochar as intermediate

《环境科学与工程前沿（英文）》 2023年第17卷第10期 doi: 10.1007/s11783-023-1719-8

摘要： Converting biomass materials to humic acid is a sustainable method for humic acid production and achieve biomass valorization. A two-step hydrothermal treatment method was adopted in this study to produce humic acid from corn stalks. In the first step of the process, hydrochar was prepared at different hydrothermal temperatures and pH values. Their chemical properties were then analyzed, and the hydrochar-derived humic acids were produced under alkaline hydrothermal conditions (denoted as HHA_alk). The hydrochar, prepared under high temperature (200 °C) and strong acidic (pH 0) conditions, achieved high HHA_alk yields (i.e., 67.9 wt% and 68.8 wt% calculated based on weight of hydrochar). The sources of HHA_alk formation were as follows: 1) production in the hydrochar preparation stage, and 2) increment under the alkaline hydrothermal treatment of hydrochar. The degree of hydrochar unsaturation was suggested as an indicator for evaluating the hydrochar humification potential under alkaline hydrothermal conditions. This study provides an important reference for the preparation of suitable hydrochar with high hydrothermal humification potential.

关键词： Biowaste Hydrochar Humic acid Hydrothermal parameter Unsaturation

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集中式MIMO雷达基于空频域二步优化的雷达波形设计 Article

Yu-xi WANG, Guo-ce HUANG, Wei LI, Jin-liang LI

《信息与电子工程前沿（英文）》 2017年第18卷第7期页码 1021-1032 doi: 10.1631/FITEE.1601726

摘要：提出一种基于空频域二步优化的集中式MIMO雷达波形设计方法。首先，利用最小积分旁瓣策略，形成带有零陷的期望发射方向图。针对所形成的非凸优化问题，利用隐藏的凸优化性能，通过半正定松弛和谱分解，可以在多项式时间内有效取得全局最优解。其次，针对空域优化得到的发射波形，引入相位变换对角矩阵并通过类幂方法迭代优化，在不影响雷达空域发射方向图基础上，雷达发射波形可在频域上进一步优化，从而避免对其他无线电设备造成干扰。实验仿真和现有方法对比分析证明了所提算法的有效性。

关键词： MIMO雷达；波形设计；谱分解；分式二次约束二次规划

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Microbial community structure and dynamics of starch-fed and glucose-fed chemostats during two yearsof continuous operation

Min GOU,Jing ZENG,Huizhong WANG,Yueqin TANG,Toru SHIGEMATSU,Shigeru MORIMURA,Kenji KIDA

《环境科学与工程前沿（英文）》 2016年第10卷第2期页码 368-380 doi: 10.1007/s11783-015-0815-9

摘要： The microbial community structures of two mesophilic anaerobic chemostats, one fed with glucose, the other with starch as sole carbon sources, were studied at various dilution rates (0.05–0.25 d for glucose and 0.025–0.1 d for starch) during two years continuous operation. In the glucose-fed chemostat, the aceticlastic methanogen spp. and hydrogenotrophic methanogen spp. predominated at low dilution rates, whereas spp. and the hydrogenotrophic spp. predominated together when dilution rates were greater than 0.1 d . Bacteria affiliated with the phyla Bacteroidetes, Spirochaetes, and Actinobacteria predominated at dilution rates of 0.05, 0.1, and 0.15 d , respectively, while Firmicutes predominated at higher dilution rates (0.2 and 0.25 d ). In the starch-fed chemostat, the aceticlastic and hydrogenotrophic methanogens coexisted at all dilution rates. Although bacteria belonging to only two phyla were mainly responsible for starch degradation (Spirochaetes at the dilution rate of 0.08 d and Firmicutes at other dilution rates), different bacterial genera were identified at different dilution rates. With the exception of Archaea in the glucose-fed chemostat, the band patterns revealed by denaturing gradient gel electrophoresis (DGGE) of the microbial communities in the two chemostats displayed marked changes during long-term operation at a constant dilution rate. The bacterial community changed with changes in the dilution rate, and was erratic during long-term operation in both glucose-fed and starch-fed chemostats.

关键词： microbial community glucose degradation starch degradation dilution rate continuous methane fermentation phylogenetic analysis

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Bi-modes alternation stepping ultrasonic motors

JIN Jiamei, ZHAO Chunsheng

《机械工程前沿（英文）》 2008年第3卷第1期页码 101-105 doi: 10.1007/s11465-008-0018-1

摘要： Based on the principle of alternative operation of two bending vibration modes in an annular stator, this paper presents a standing-wave stepping ultrasonic motor characterized by no accumulative errors driven by an open-loop control circuitry. The driving forces are generated from the motions of projections on the stator in two modes. The positioning of the motor is achieved by the cooperation between the stator projections and rotor teeth, and the number of the rotors determines the stepping angle of the motor. Two-phase sinusoidal signals corresponding to the two modal frequencies drive the motor bi-direction stepping rotation via a switch unit. The prototype runs steadily without miss-step on trial. The single-step angle displacement of the motor is 2.5°.

关键词： miss-step bi-direction Two-phase sinusoidal positioning accumulative

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八步连续流全合成维生素B₁工艺研究 Article

姜梅芬, 刘敏杰, 李伟剑, 夏应奇, 陈芬儿

《工程（英文）》 2024年第32卷第1期页码 230-239 doi: 10.1016/j.eng.2023.01.016

摘要：

维生素B₁作为一种抗利尿和抗氧化剂被广泛应用于医疗保健和食品行业，以维持神经传导、心脏和胃肠道的正常功能。本研究报道了由市售2-氰基乙酰胺进行的维生素B₁的八步连续流全合成工艺。本研究提出的连续流工艺基于化学、工程和设备设计的创新基础，与间歇釜式工艺相比，生产的性能和安全性均有所提高。本文使用各种微通道流反应器、微混合器、连续分离设备和连续过滤器等装置，对连续流合成工艺中的问题和挑战进行了精确的研究和控制，包括混合、意外堵塞、溶剂切换、放热反应和避免副反应等。维生素B1全合成的连续流工艺总停留时间约为3.5小时，产品纯度高，分离产率为47.7%。该八步连续流动技术方案至少涉及绿色化学的六个关键准则。因此，连续流技术的应用对于提高生产安全性、减少废物污染，尤其是提高批量操作的生产效率至关重要。

关键词：维生素B1 连续流合成微反应器连续制造

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结合选择性和数字湿法腐蚀的InAlAs/InGaAs InP基HEMTs两步栅槽腐蚀工艺 Article

Ying-hui ZHONG, Shu-xiang SUN, Wen-bin WONG, Hai-li WANG, Xiao-ming LIU, Zhi-yong DUAN, Peng DING, Zhi JIN

《信息与电子工程前沿（英文）》 2017年第18卷第8期页码 1180-1185 doi: 10.1631/FITEE.1601121

摘要：本文针对InAlAs/InGaAs InP基高电子迁移率晶体管（HEMTs）提出了一种结合高选择性湿法腐蚀和非选择性数字湿法腐蚀的两步栅槽腐蚀工艺。通过采用丁二酸和双氧水（H2O2）混合溶液，InGaAs与InAlAs材料的腐蚀选择比可以超过100。该选择性湿法腐蚀工艺在InAlAs/InGaAs InP基HEMTs栅槽工艺中得到了很好的验证，栅槽腐蚀会自动终止在InAlAs势垒层。本文通过分离氧化/去氧化过程开发了非选择性数字湿法腐蚀工艺，每个周期能除去1.2 nm InAlAs材料。最终，两步栅槽腐蚀工艺被成功用于器件制备中，数字湿法腐蚀重复两个周期去掉约3 nm InAlAs势垒层材料。通过该方法制备的InP基HEMTs器件比只依靠选择性湿法腐蚀栅槽工艺制备出的器件具有更短的栅沟间距，表现出更好的有效跨导和射频特性。

关键词：高电子迁移率晶体管（High electron mobility transistors HEMTs）；栅槽；数字湿法腐蚀；选择性湿法腐蚀

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Analysis of flow over backward facing step with transition

Dwarikanath RATHA,Arindam SARKAR

《结构与土木工程前沿（英文）》 2015年第9卷第1期页码 71-81 doi: 10.1007/s11709-014-0270-x

摘要： The present study deals with the study of the velocity distribution and the separation phenomenon of flow of air over a two dimensional backward facing step. The flow of air over a backward facing step has been investigated numerically using FLUENT. Flow simulation has been carried out in a backward facing step having an expansion ratio (ratio of the height before and after the step) of 1:1.94 and the results obtained are compared with the published experimental results. Comparison of flow characteristics between steps with three different transitions is made. The variation of reattachment length for all the three cases are analyzed for wide range of Reynolds number ranging from 100 to 7000 which covers the laminar, transition and turbulent flow of air. Simulation of the flow over steps with expansion ratios of 1:1.24, 1:1.38, 1:1.47, 1:1.53, 1:1.94, 1:2.20 are also carried out to examine the effect of different expansion ratios on the reattachment length. It is found that the primary reattachment length increases with increase in the expansion ratio. The primary reattachment length at the bottom wall downstream of the step is minimum for the step with round edged transition and maximum for the step with a vertical drop transition.

关键词： Reattachment length backward facing step transition flow separation k-? model

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Pretest analysis of shake table response of a two-span steel girder bridge incorporating accelerated

Elmira SHOUSHTARI, M. Saiid SAIIDI, Ahmad ITANI, Mohamed A. MOUSTAFA

《结构与土木工程前沿（英文）》 2020年第14卷第1期页码 169-184 doi: 10.1007/s11709-019-0590-y

摘要： This paper presents pretest analysis of a shake table test model of a 0.35-scale, two-span, steel plate girder bridge. The objective of pretest analysis was to obtain an insight on the seismic response of the bridge model during the shake table tests. The bridge included seat type abutments, full-depth precast deck panels, and a two-column bent in which columns were pinned to the footing and integral with superstructure. Six accelerated bridge construction connections were incorporated in the bridge model. An analytical model was developed in OpenSees and was subjected to ten input bi-directional earthquake motions including near-fault and far-field records. The overall seismic response of the bridge was satisfactory for all the earthquake records at 100%, 150%, and 200% design level. All connections and capacity-protected components remained elastic, and the average ductility capacity surpassed the ductility demand even at 200% design level. Using experimental fragility curves developed for RC bridge columns, it was predicted that there was a probability of 45% that columns would undergo the imminent failure in the last run and a probability of 30% for their failure.

关键词： shake table test accelerated bridge construction steel girder bridge OpenSEES UHPC simple for dead continuous for live

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One-step synthesis of recoverable CuCo

Tongzhou Lu, Yongzheng Zhang, Chun Cheng, Yanbin Wang, Yongming Zhu

《化学科学与工程前沿（英文）》 2020年第14卷第4期页码 595-604 doi: 10.1007/s11705-019-1818-z

摘要： A facile one-step hydrothermal method has been adopted to directly synthesize the CuCo S material on the surface of Ni foam. Due to the relatively large specific surface area and wide pore size distribution, the CuCo S material not only effectively increases the reactive area, but also accommodates more side reaction products to avoid the difficulty of mass transfer. When evaluated as anode for Li-ion batteries, the CuCo S material exhibits excellent electrochemical performance including high discharge capacity, outstanding cyclic stability and good rate performance. At the current density of 200 mA·g , the CuCo S material shows an extremely high initial discharge capacity of 2510 mAh·g , and the cycle numbers of the material even reach 83 times when the discharge capacity is reduced to 500 mAh·g . Furthermore, the discharge capacity can reach 269 mAh·g at a current of 2000 mA·g . More importantly, when the current density comes back to 200 mA·g , the discharge capacity could be recovered to 1436 mAh·g , suggesting an excellent capacity recovery characteristics.

关键词： copper cobalt sulfide recoverability one-step hydrothermal method anode material Li-ion battery

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Strain and process engineering toward continuous industrial fermentation

《化学科学与工程前沿（英文）》 2023年第17卷第10期页码 1336-1353 doi: 10.1007/s11705-022-2284-6

摘要： Most current biotechnology industries are based on batch or fed-batch fermentation processes, which often show low productivity and high production costs compared to chemical processes. To increase the economic competitiveness of biological processes, continuous fermentation technologies are being developed that offer significant advantages in comparison with batch/fed-batch fermentation processes, including: (1) removal of potential substrates and product inhibition, (2) prolonging the microbial exponential growth phase and enhancing productivity, and (3) avoiding repeated fermentation preparation and lowering operation and installation costs. However, several key challenges should be addressed for the industrial application of continuous fermentation processes, including (1) contamination of the fermentation system, (2) degeneration of strains, and (3) relatively low product titer. In this study, we reviewed and discussed metabolic engineering and synthetic biology strategies to address these issues.

关键词： continuous fermentation productivity contamination strain degeneration metabolic engineering

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论航空发动机发展的“渐改法”

温俊峰

《中国工程科学》 2000年第2卷第3期页码 23-26

摘要：

文章简要论述了航空发动机发展的两种途径及其特点，从国内外航空发动机改进发展广泛采用的作法和成功的经验事例，论证了“渐改”发展模式的规律性和重要性，提出了对发动机改进发展应加强组织领导和计划落实的建议。

关键词：航空发动机发动机发展途径渐改法

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Ant colony optimization in continuous problem

YU Ling, LIU Kang, LI Kaishi

《机械工程前沿（英文）》 2007年第2卷第4期页码 459-462 doi: 10.1007/s11465-007-0079-6

摘要： Based on the analysis of the basic ant colony optimization and optimum problem in a continuous space, an ant colony optimization (ACO) for continuous problem is constructed and discussed. The algorithm is efficient and beneficial to the study of the ant colony optimization in a continuous space.

关键词： beneficial algorithm efficient continuous ACO

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一款基于改进的步进式译码算法实现的流水线架构RS码译码器 Article

Xing-ru PENG,Wei ZHANG,Yan-yan LIU

《信息与电子工程前沿（英文）》 2016年第17卷第9期页码 954-961 doi: 10.1631/FITEE.1500303

摘要：概要：基于改进的步进式译码算法，我们为超宽带系统设计了一款流水线架构的Reed-Solomon（RS）码译码器。为了减小复杂度，改进的步进式译码算法将传统步进式译码算法中冗余的两部分进行了结合。此外，采用流水线架构，使得所设计的译码器以最小时延获得最大吞吐率。因此，对于RS（23,17）码，我们所设计的译码器面积比ME（modified Euclidean）架构和pDCME（pipelined degree-computationless modified Euclidean）架构分别减少了42.5%和24.4%。此外，与传统步进式译码器相比，我们设计的译码器能减少11.3%的面积，且关键路径延迟更低。

关键词： Reed-Solomon码；步进式译码算法；超宽带；流水线架构

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连续铸钢前沿技术的工程化

干勇

《中国工程科学》 2002年第4卷第9期页码 12-18

摘要：

论述了具有我国自主知识产权的高效连铸和薄板坯连铸工程化关键技术的特点；介绍了连续铸钢领域轻压下、液压非正弦振动、电磁连铸等前沿技术的开发现状；阐述了传统连铸技术超高效率、高品质化及近终形连铸、电磁连铸开发的研发方向。

关键词：连续铸钢高效连铸薄板坯连铸轻压下电磁连铸