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Exergy analysis of R1234ze(Z) as high temperature heat pump working fluid with multi-stage compression

WANG, R.Z. WANG

《能源前沿（英文）》 2017年 第11卷 第4期   页码 493-502 doi: 10.1007/s11708-017-0510-6

摘要： In this paper, the simulation approach and exergy analysis of multi-stage compression high temperature heat pump (HTHP) systems with R1234ze(Z) working fluid are conducted. Both the single-stage and multi-stage compression cycles are analyzed to compare the system performance with 120°C pressurized hot water supply based upon waste heat recovery. The exergy destruction ratios of each component for different stage compression systems are compared. The results show that the exergy loss ratios of the compressor are bigger than that of the evaporator and the condenser for the single-stage compression system. The multi-stage compression system has better energy and exergy efficiencies with the increase of compression stage number. Compared with the single-stage compression system, the coefficient of performance (COP) improvements of the two-stage and three-stage compression system are 9.1% and 14.6%, respectively. When the waste heat source temperature is 60°C, the exergy efficiencies increase about 6.9% and 11.8% for the two-stage and three-stage compression system respectively.

关键词： multi-stage compression     high temperature heat pump     heat recovery     exergy destruction     R1234ze(Z) working fluid    

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Predicting the response of continuous RC deep beams under varying levels of differential settlement

Z. NASER, R. A. HAWILEH

《结构与土木工程前沿（英文）》 2019年 第13卷 第3期   页码 686-700 doi: 10.1007/s11709-018-0506-2

摘要： This paper investigates the effect of differential support settlement on shear strength and behavior of continuous reinforced concrete (RC) deep beams. A total of twenty three-dimensional nonlinear finite element models were developed taking into account various constitutive laws for concrete material in compression (crushing) and tension (cracking), steel plasticity (i.e., yielding and strain hardening), bond-slip at the concrete and steel reinforcement interface as well as unique behavior of spring-like support elements. These models are first validated by comparing numerical predictions in terms of load-deflection response, crack propagation, reaction distribution, and failure mode against that of measured experimental data reported in literature. Once the developed models were successfully validated, a parametric study was designed and performed. This parametric study examined number of critical parameters such as ratio and spacing of the longitudinal and vertical reinforcement, compressive and tensile strength of concrete, as well as degree (stiffness) and location of support stiffness to induce varying levels of differential settlement. This study also aims at presenting a numerical approach using finite element simulation, supplemented with coherent assumptions, such that engineers, practitioners, and researchers can carry out simple, but yet effective and realistic analysis of RC structural members undergoing differential settlements due to variety of load actions.

关键词： concrete     continuous beams     deep beams     finite element modeling     support settlement    

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Performance design of a cryogenic air separation unit for variable working conditions using the lumped

Jinghua XU, Tiantian WANG, Qianyong CHEN, Shuyou ZHANG, Jianrong TAN

《机械工程前沿（英文）》 2020年 第15卷 第1期   页码 24-42 doi: 10.1007/s11465-019-0558-6

摘要： Large-scale cryogenic air separation units (ASUs), which are widely used in global petrochemical and semiconductor industries, are being developed with high operating elasticity under variable working conditions. Different from discrete processes in traditional machinery manufacturing, the ASU process is continuous and involves the compression, adsorption, cooling, condensation, liquefaction, evaporation, and distillation of multiple streams. This feature indicates that thousands of technical parameters in adsorption, heat transfer, and distillation processes are correlated and merged into a large-scale complex system. A lumped parameter model (LPM) of ASU is proposed by lumping the main factors together and simplifying the secondary ones to achieve accurate and fast performance design. On the basis of material and energy conservation laws, the piecewise-lumped parameters are extracted under variable working conditions by using LPM. Takagi–Sugeno (T–S) fuzzy interval detection is recursively utilized to determine whether the critical point is detected or not by using different thresholds. Compared with the traditional method, LPM is particularly suitable for “rough first then precise” modeling by expanding the feasible domain using fuzzy intervals. With LPM, the performance of the air compressor, molecular sieve adsorber, turbo expander, main plate-fin heat exchangers, and packing column of a 100000 Nm O /h large-scale ASU is enhanced to adapt to variable working conditions. The designed value of net power consumption per unit of oxygen production (kW/(Nm O )) is reduced by 6.45%.

关键词： performance design     air separation unit (ASU)     lumped parameter model (LPM)     variable working conditions     T–S fuzzy interval detection    

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Z源逆变器在异步电动机中的应用

朱红,祝龙记,夏若飞

《中国工程科学》 2014年 第16卷 第3期   页码 86-91

摘要： 本文采用IFOC技术来控制异步电机的速度大小，并使用Z源逆变器，即在逆变器主电路前加上一对阻抗（LC）网络，通过控制直通占空比，可以实现升/降压功能、提高异步电机的效率。

关键词： IFOC     异步电机     Z源逆变器    

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Two-level uncapacitated lot-sizing problem considering the financing cost of working capital requirement

Yuan BIAN, David LEMOINE, Thomas G. YEUNG, Nathalie BOSTEL

《工程管理前沿（英文）》 2020年 第7卷 第2期   页码 248-258 doi: 10.1007/s42524-019-0069-5

摘要： During financial crisis, companies constantly need free cash flows to efficiently react to any uncertainty, thus ensuring solvency. Working capital requirement (WCR) has been recognized as a key factor for releasing tied up cash in companies. However, in literatures related to lot-sizing problem, WCR has only been studied in the single-level supply chain context. In this paper, we initially adopt WCR model for a multi-level case. A two-level (supplier–customer) model is established on the basis of the classic multi-level lot-sizing model integrated with WCR financing cost. To tackle this problem, we propose sequential and centralized approaches to solve the two-level case with a serial chain structure. The ZIO (Zero Inventory Ordering) property is further confirmed valid in both cases. This property allows us to establish a dynamic programming-based algorithm, which solves the problem in O(T ). Finally, numerical tests show differences in optimal plans obtained by both approaches and the influence of varying delays in payment on the WCR of both actors.

关键词： two-level ULS problem     lot-sizing     working capital requirement     ZIO property     infinite production capacity    

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A method to calculate working capacity space of multi-DOF manipulator and the application in excavating

Baochen WEI, Feng GAO

《机械工程前沿（英文）》 2012年 第7卷 第2期   页码 109-119 doi: 10.1007/s11465-012-0323-6

摘要：

Working capacity refers to the velocity output and force output of a manipulator. It is usually be represented by output capacity space. In this paper, the method of Linear Programming and a geometric method are proposed to calculate working capacity spaces in different situations. With the consideration of gravity effect of every component, the output force capacity space of heavy duty manipulators is calculated. The results show that the effect of the gravity is a translation of the capacity space. This paper gives a method for the output capacity express especially for heavy duty manipulators. The output capacity space can be helpful to the driving parameters selection. With the consideration of the gravity effect of every component and the friction at the joints, the excavating force capacity space of the heavy-load excavating mechanism is calculated and is represented as a multi-dimensional polytope. The results show that the effect of the gravity and friction is to translational act on the capacity space.

关键词： working capacity     multi-DOF manipulator     capacity polytope     excavating mechanism    

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Effect of different gas releasing methods on anaerobic fermentative hydrogen production in batch cultures

Sheng CHANG, Jianzheng LI, Feng LIU, Ze YU

《环境科学与工程前沿（英文）》 2012年 第6卷 第6期   页码 901-906 doi: 10.1007/s11783-012-0403-1

摘要： Decreasing hydrogen partial pressure can not only increase the activity of the hydrogen enzyme but also decrease the products inhibition, so it is an appropriate method to enhance the fermentative hydrogen production from anaerobic mixed culture. The effect of biogas release method on anaerobic fermentative hydrogen production in batch culture system was compared, i.e., Owen method with intermediately release, continuous releasing method, and continuous releasing+ CO absorbing. The experimental results showed that, at 35°C, initial pH 7.0 and glucose concentration of 10 g·L , the hydrogen production was only 28 mL when releasing gas by Owen method, while it increased two times when releasing the biogas continuously. The cumulative hydrogen production could reach 155 mL when carbon dioxide in the gas stream was continuously absorbed by 1 mol·L NaOH. The results showed that acetate was dominated, accounting for 43% in the dissolved fermentation products in Owen method, whereas the butyrate predominated and reached 47%–53% of the total liquid end products when releasing gas continuously. It is concluded that the homoacetogenesis could be suppressed when absorbing CO in the gas phase in fermentative hydrogen production system.

关键词： batch fermentation     hydrogen production     biogas releasing     hydrogen pressure     homoacetogenesis    

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基于Z数的TODIM与TOPSIS方法 None

Renato A. KROHLING, André G. C. PACHECO, Guilherme A. dos SANTOS

《信息与电子工程前沿（英文）》 2019年 第20卷 第2期   页码 283-291 doi: 10.1631/FITEE.1700434

摘要： 提出一种针对多标准决策问题处理Z数的方法。使用模糊数A和B的有序对Z=(A, B)定义Z数，其中A是兴趣变量的语言值，B是A的概率测度语言值。将Z数转化为模糊数，Z-TODIM和Z-TOPSIS分别是模糊TODIM和模糊TOPSIS的直接扩展。将提出的方法应用于两个案例并与使用精确数的标准方法比较，结果证明其可行。

关键词： 多标准决策；TODIM；TOPSIS；模糊数；Z数    

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快Z-箍缩——有前景的聚变能源新途径

彭先觉,华欣生

《中国工程科学》 2008年 第10卷 第1期   页码 47-53

摘要：

简要介绍了快Z-箍缩的基本概念；综述了快Z-箍缩等离子体研究及其作为高能密度物理与惯性约束聚变（ICF），尤其作为低成本聚变能源研究的最新进展；探讨了快Z-箍缩驱动ICF作为聚变能源可能遇到的技术问题及应用前景。

关键词： 快Z-箍缩内爆     高能密度物理     惯性约束聚变     聚变能源    

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workingmethodology for an indoor mobile robot Project supported by the National High-Tech R&D Program (863) of China (No. 2009AA04Z220), the National Natural Science Foundation of China (No. 61375084

Feng-yu ZHOU,Xian-feng YUAN,Yang YANG,Zhi-fei JIANG,Chen-lei ZHOU

《信息与电子工程前沿（英文）》 2016年 第17卷 第4期   页码 365-374 doi: 10.1631/FITEE.1500272

摘要： To overcome the shortcomings of existing robot localization sensors, such as low accuracy and poor robustness, a high precision visual localization system based on infrared-reflective artificial markers is designed and illustrated in detail in this paper. First, the hardware system of the localization sensor is developed. Secondly, we design a novel kind of infrared-reflective artificial marker whose characteristics can be extracted by the acquisition and processing of the infrared image. In addition, a confidence calculation method for marker identification is proposed to obtain the probabilistic localization results. Finally, the autonomous localization of the robot is achieved by calculating the relative pose relation between the robot and the artificial marker based on the perspective-3-point (P3P) visual localization algorithm. Numerous experiments and practical applications show that the designed localization sensor system is immune to the interferences of the illumination and observation angle changes. The precision of the sensor is ±1.94 cm for position localization and ±1.64? for angle localization. Therefore, it satisfies perfectly the requirements of localization precision for an indoor mobile robot.

关键词： Mobile robot     Localization sensor     Visual localization     Infrared-reflective marker     Embedded system    

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河口三角洲系统海平面上升行为甄别研究——以上海海岸为例 Article

程和琴, 陈吉余, 陈祖军, 阮仁良, 徐贵泉, 曾 刚, 朱建荣, 戴志军, 陈小勇, 顾圣华, 张先林, 王寒梅

《工程（英文）》 2018年 第4卷 第1期   页码 156-163 doi: 10.1016/j.eng.2018.02.002

摘要：
气候变化导致海平面上升是河口三角洲城市发展面临的主要威胁，位处长江河口三角洲的特大型城市上海面临同样的问题。就气候变化适应性决策者而言，其困难在于海平面上升的原因、幅度和出现时间的不确定性。本文在年代际尺度上就海平面上升原因、幅度的甄别做了尝试。即在分析上海沿岸11 个潮位站1921 年以来潮位记录及其相邻水域水下地形基础上，发现该地区海平面上升除了众所周知的理论海平面上升、构造沉降和城市地面沉降外，还有三种新的、人为地形改变所致的海平面上升行为。其一为围垦和深水航道整治导致的局域海平面上升；其二是流域沉积物源减少引起河槽冲刷导致的局域海平面下降；其三为局域深度基准面抬升。上海沿岸2011—2030年间海平面上升幅度预测值为10~16 cm。这一海平面上升行为的甄别结果为当地决策者制定河口三角洲系统适应气候变化和海平面上升的工程和非工程措施提供科学依据，以期减少日益加剧的洪灾损失。此项工作未来充满挑战。

关键词： 海平面上升行为     人为地形变化     局域潮汐基准面     洪水管理     适应性    

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Z干扰信道下非正则信号的最佳设计策略 Article

Dan LI, Shan WANG, Fang-lin GU

《信息与电子工程前沿（英文）》 2017年 第18卷 第11期   页码 1900-1912 doi: 10.1631/FITEE.1700030

摘要： 本文提出一种用于在干扰被视为加性高斯噪声的假设下在Z干扰信道（z-interference channel, Z-IC）上实现非正则高斯信号（IGS）的Pareto边界（可实现速率区域的边界）。

关键词： 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    

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Unit commitment using dynamic programming–an exhaustive working of both classical and stochastic approach

Balasubramaniyan SARAVANAN, Surbhi SIKRI, K. S. SWARUP, D. P. KOTHARI

《能源前沿（英文）》 2013年 第7卷 第3期   页码 333-341 doi: 10.1007/s11708-013-0259-5

摘要： In the present electricity market, where renewable energy power plants have been included in the power systems, there is a lot of unpredictability in the demand and generation. There are many conventional and evolutionary programming techniques used for solving the unit commitment (UC) problem. Dynamic programming (DP) is a conventional algorithm used to solve the deterministic problem. In this paper DP is used to solve the stochastic model of UC problem. The stochastic modeling for load and generation side has been formulated using an approximate state decision approach. The programs were developed in a MATLAB environment and were extensively tested for a four-unit eight-hour system. The results obtained from these techniques were validated with the available literature and outcome was good. The commitment is in such a way that the total cost is minimal. The novelty of this paper lies in the fact that DP is used for solving the stochastic UC problem.

关键词： unit commitment (UC)     deterministic     stochastic     dynamic programming (DP)     optimization     state diagram    

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Functional tolerance theory in incremental growth design

YANG Bo, ZE Xiangbo, YANG Tao

《机械工程前沿（英文）》 2007年 第2卷 第3期   页码 336-343 doi: 10.1007/s11465-007-0059-x

摘要： The evolutionary tolerance design strategy and its characteristics are studied on the basis of automation technology in the product structure design. To guarantee a successful transformation from the functional requirement to geometry constraints between parts, and finally to dimension constraints, a functional tolerance design theory in the process of product growth design is put forward. A mathematical model with a correlated sensitivity function between cost and the tolerance is created, in which the design cost, the manufacturing cost, the usage cost, and the depreciation cost of the product are regarded as control constraints of the tolerance allocation. Considering these costs, a multifactor-cost function to express quality loss of the product is applied into the model. In the mathematical model, the minimum cost is used as the objective function; a reasonable process capability index, the assembly function, and assembly quality are taken as the constraints; and depreciation cost in the objective function is expressed as the discount rate terminology in economics. Thus, allocation of the dimension tolerance as the function and cost over the whole lifetime of the product is realized. Finally, a design example is used to demonstrate the successful application of the proposed functional tolerance theory in the incremental growth design of the product.

关键词： successful transformation     mathematical     automation technology     tolerance allocation     minimum    

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Value Engineering/Value Management Model and Application of Aerospace Projects

Wan-hua Qiu,Han-peng Zhang,Ze-Shui Xu,De-Sheng Wu

《工程管理前沿（英文）》 2015年 第2卷 第4期   页码 373-377 doi: 10.15302/J-FEM-2015056

摘要： This paper presents a new space model developed by general value engineering/value management model. The authors take the function analysis, function optimization and function realization of the development object as the basic point, to get the final optimization structure by value evaluation, so as to improve the project quality and reduce the project cost. The final case shows that the application of this model can save about 18% of the time and considerable cost of the usually planned projects under the condition of quality assurance.

关键词： aerospace project     value engineering     value optimization     value stream     design structure matrix    

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标题 作者 时间 类型 操作

Exergy analysis of R1234ze(Z) as high temperature heat pump working fluid with multi-stage compression

WANG, R.Z. WANG

期刊论文

Predicting the response of continuous RC deep beams under varying levels of differential settlement

Z. NASER, R. A. HAWILEH

期刊论文

Performance design of a cryogenic air separation unit for variable working conditions using the lumped

Jinghua XU, Tiantian WANG, Qianyong CHEN, Shuyou ZHANG, Jianrong TAN

期刊论文

Z源逆变器在异步电动机中的应用

朱红,祝龙记,夏若飞

期刊论文

Two-level uncapacitated lot-sizing problem considering the financing cost of working capital requirement

Yuan BIAN, David LEMOINE, Thomas G. YEUNG, Nathalie BOSTEL

期刊论文

A method to calculate working capacity space of multi-DOF manipulator and the application in excavating

Baochen WEI, Feng GAO

期刊论文

Effect of different gas releasing methods on anaerobic fermentative hydrogen production in batch cultures

Sheng CHANG, Jianzheng LI, Feng LIU, Ze YU

期刊论文

基于Z数的TODIM与TOPSIS方法

Renato A. KROHLING, André G. C. PACHECO, Guilherme A. dos SANTOS

期刊论文

快Z-箍缩——有前景的聚变能源新途径

彭先觉,华欣生

期刊论文

workingmethodology for an indoor mobile robot Project supported by the National High-Tech R&D Program (863) of China (No. 2009AA04Z220), the National Natural Science Foundation of China (No. 61375084

Feng-yu ZHOU,Xian-feng YUAN,Yang YANG,Zhi-fei JIANG,Chen-lei ZHOU

期刊论文

河口三角洲系统海平面上升行为甄别研究——以上海海岸为例

程和琴, 陈吉余, 陈祖军, 阮仁良, 徐贵泉, 曾 刚, 朱建荣, 戴志军, 陈小勇, 顾圣华, 张先林, 王寒梅

期刊论文

Z干扰信道下非正则信号的最佳设计策略

Dan LI, Shan WANG, Fang-lin GU

期刊论文

Unit commitment using dynamic programming–an exhaustive working of both classical and stochastic approach

Balasubramaniyan SARAVANAN, Surbhi SIKRI, K. S. SWARUP, D. P. KOTHARI

期刊论文

Functional tolerance theory in incremental growth design

YANG Bo, ZE Xiangbo, YANG Tao

期刊论文

Value Engineering/Value Management Model and Application of Aerospace Projects

Wan-hua Qiu,Han-peng Zhang,Ze-Shui Xu,De-Sheng Wu

期刊论文