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期刊论文 31

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三峡工程 1

中断模型；k-可靠性；对偶；线性规划松弛；互补松弛型 1

农业 1

医院中子照射器 1

升船机 1

半旱地 1

变径毛细管节流器 1

变隙滑阀节流器 1

变隙薄板节流器 1

可见光通信；游程长度受限码；有限状态机；最小汉明距离 1

四旋翼飞行器；无人机；运动规划 1

天线对；第五代移动通信技术（5G）；Sub-6 GHz；极化正交；智能终端；智能手机；零净空；全金属外壳；多输入多输出（MIMO） 1

折减 1

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Parasitic rotation evaluation and avoidance of 3-UPU parallel mechanism

Haibo QU, Yuefa FANG, Sheng GUO

《机械工程前沿（英文）》 2012年 第7卷 第2期   页码 210-218 doi: 10.1007/s11465-012-0317-4

摘要：

Based on the prototype of 3-UPU (universal-prismatic-universal joint) parallel mechanism proposed by Tsai [ ], the parasitic rotation evaluation is performed and calculated the bound of instability of SNU Seoul National University 3-UPU parallel mechanism. Through analysis of the terminal constraint system of the 3-UPU parallel mechanism, the equation about the parasitic rotation and limited clearance is presented. Then the norm of possible parasitic rotation is employed to evaluate the mechanism stability with limited clearance. The higher this number the worst is the pose, the lower it is the best it is. And the contour atlas of parasitic rotation is obtained, which can be used for further analysis and design. With the practice experiment result of SUN 3-UPU parallel mechanism, we find it’s bound of instability, which indicates there will appear the parasitic rotation when the number exceeds the bound. Finally, the method for avoidance of possible parasitic motions is presented by adding redundantly actuated limbs.

关键词： parallel mechanism     3-UPU (universal-prismatic-universal joint)     parasitic motions     limited clearance     redundantly actuated limbs    

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Copper and zinc interaction on water clearance and tissue metal distribution in the freshwater mussel

Tianxiang XIA, Xuehua LIU

《环境科学与工程前沿（英文）》 2011年 第5卷 第2期   页码 236-242 doi: 10.1007/s11783-010-0218-8

摘要： Copper and zinc interaction on clearance from water and distribution in different tissues was investigated for the freshwater mussel, , under laboratory conditions. Clearance rate of Cu or Zn from water was highly dependent on exposure concentration. Interaction effect was most evident at 300 μg·L Cu exposure and depressed the Zn clearance rate significantly ( <0.05). However, the presence of 100 μg·L and 300 μg·L Zn hardly affected the Cu clearance rate. The 300 μg·L Cu presence enhanced Cu accumulation in each tissue most significantly ( <0.01), but caused Zn content to decrease in the gills by 62% ( <0.05), viscera by 49% ( <0.05) and foot by 31% ( <0.05), and increase in the mantle by 97% ( <0.05) and the muscles by 243% ( <0.05) for different Zn exposure treatments. The response of metal accumulation in various tissues of the test mussels indicated that Zn transferred from the gills, viscera and foot to the mantle and muscles might be one of the important characteristics of the Zn regulatory mechanism by leading to a narrow range of Zn concentration in the different tissues.

关键词： interaction     mussel     copper     zinc     clearance     distribution    

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Fluid damping clearance in a control valve of injector

ZHANG Jianming, ZHANG Weigang, YANG Bing, WANG Yawei

《机械工程前沿（英文）》 2007年 第2卷 第4期   页码 439-441 doi: 10.1007/s11465-007-0075-x

摘要： A force model of a control valve of injector is set up, and the changes of the fluid damping clearance are investigated on the basis of the results of the computational fluid dynamics (CFD) and the experiments of control valve of injector. Results indicate that a damping clearance of 0.02–0.03 mm between the poppet and the valve guide is the most sufficient to dampen any excessive control valve poppet bouncing.

关键词： control     computational     bouncing     CFD     excessive control    

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Emergent limited perioperative transesophageal echocardiography: should new guidelines exist for limited

null

《医学前沿（英文）》 2012年 第6卷 第3期   页码 332-337 doi: 10.1007/s11684-012-0212-8

摘要：

Bedside limited echocardiography, or focused cardiac ultrasound, continues to gain popularity in many emergency rooms, intensive care units, and operating rooms as a rapid method of assessing unstable patients. Effective monitoring of cardiovascular function in conditions like cardiac arrest or near-arrest is the crucial step to guide successful resuscitative efforts. Transesophageal echocardiography (TEE) has emerged as one of the preferred cardiac diagnostic and monitoring modalities in the intraoperative setting due to the fact that it is less invasive than many other monitors, is immediately accessible, and allows for continuous real-time monitoring of cardiac function. However, the minimum training requirements needed for the anesthesia provider to obtain the competency, knowledge, and skills for basic certification in perioperative TEE far exceed those developed for other medical specialties. We believe there is an urgent need to develop (1) practical guidelines for emergent perioperative TEE use for anesthesiologists and (2) a requisite educational curriculum to teach the basic skills necessary to aid in the diagnosis and treatment of cardiac arrest or near-arrest scenarios. The measures elucidated in this report summarize the efforts of the Department of Anesthesiology at the University of Florida in establishing the necessary steps to make this process not only practical, but accessible to all trainees. We hope that these collective efforts will provide more trainees the confidence in utilizing TEE to aid in establishing a diagnosis in critical situations.

关键词： transesophageal echocardiography     curriculum     competency training     hemodynamic instability    

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Highlights of special issue on ‘Agriculture in Water-Limited Areas’

Pute WU

《农业科学与工程前沿（英文）》 2017年 第4卷 第2期   页码 123-125 doi: 10.15302/J-FASE-2017147

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Bandwidth-limited active suspension controller for an off-road vehicle based on co-simulation technology

FENG Jinzhi, ZHENG Songlin, YU Fan

《机械工程前沿（英文）》 2008年 第3卷 第1期   页码 111-117 doi: 10.1007/s11465-008-0020-7

摘要： This paper presents the design process of a controller for bandwidth-limited active hydro-pneumatic suspension employed by an off-road vehicle based on co-simulation technology. First, a detailed multi-body dynamic model of the vehicle is established by using the ADAMS/View software package, which is followed by validation using a vehicle field test. Second, a combined PID and fuzzy controller is designed for the bandwidth-limited active suspension system and then programmed by means of S-functions in Matlab/Simulink, to which a data exchange interface with ADAMS/View is also defined. Third, the proposed control algorithm is implemented on the multi-body dynamic vehicle model to enable the co-simulation to run repeatedly until a more practical controller is achieved. In the end, the proposed active suspension system is compared with a conventional passive system. Simulation results show that the proposed active suspension system considerably improves both the ride and handling performance of the vehicle and therefore increases the maximum traveling speeds even on rough roads.

关键词： co-simulation technology     exchange interface     conventional     bandwidth-limited     algorithm    

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Measurement and analysis of tip clearance unsteady flow spectrum in axial-flow fan rotor

LIU Bo, HOU Weimin, MA Changyou, WANG Yangang, ZHOU Qiang

《能源前沿（英文）》 2008年 第2卷 第4期   页码 448-452 doi: 10.1007/s11708-008-0088-0

摘要： The dynamic pressure measurement device and test technology are described in this study. The tip clearance unsteady flow development from the inlet to the outlet of an axial-flow rotor was revealed by analyzing pressure frequency spectrum acquired from measuring the unsteady pressure field of the tip endwall. The experiment provides test basis for thoroughly understanding the tip clearance unsteady flow and building interaction models of tip clearance flow and main flow.

关键词： development     endwall     unsteady pressure     pressure measurement     experiment    

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Two-stage scheduling on batch and single machines with limited waiting time constraint

Zhongshun SHI, Zewen HUANG, Leyuan SHI

《工程管理前沿（英文）》 2017年 第4卷 第3期   页码 368-374 doi: 10.15302/J-FEM-2017034

摘要： This study addresses the problem of two-stage scheduling on batch and single machines with limited waiting time constraint; thus, the makespan is minimized. A mixed-integer linear programming model is proposed for this problem. Three tight lower bounds and a heuristic algorithm are developed. The worst-case performance of the proposed algorithm is discussed. A hybrid differential evolution algorithm is also developed to improve the solution quantity. Numerical results show that the hybrid algorithm is capable of obtaining high-quality solutions and exhibits a competitive performance

关键词： batch machine     flow shop     makespan     limited waiting time    

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Adaptation of Chinese and German maize-based food-feed-energy systems to limited phosphate resources—a

null

《农业科学与工程前沿（英文）》 2019年 第6卷 第4期   页码 313-320 doi: 10.15302/J-FASE-2019282

摘要：

Phosphate is supplied to agriculture by mining and fertilizer production, followed by different steps of phosphate utilization, including primary production, feed and food consumption, and conversion of biomass, with accumulation in soils, but little recycling and severe environmental losses. Phosphate is a limited essential nutrient, however, with very uneven distribution worldwide. Closing the cycle and reducing primary phosphate consumption are fundamental future challenges. Maize has a relatively high phosphate requirement. China and Germany together cover the whole range of maize production systems. The new Sino-German international research training group “Adaptation of Chinese and German maize-based food-feed-energy systems to limited phosphate resources” (AMAIZE-P) was initiated in 2018 as a joint venture of the China Agricultural University (Beijing, China) and the University of Hohenheim (Stuttgart, Germany). The interdisciplinary and complementary research is driven by the hypothesis that under phosphate limited conditions, high productivity and high phosphate use efficiency can be achieved simultaneously by adapting phosphate cycling and availability (sources) to the multipurpose phosphate demands (sinks) in maize-based food-feed-energy systems. The educational program for doctoral researchers in China and Germany includes joint block seminars, thematic field trips, case studies, methodological courses, doctoral researchers’ conferences, intercultural training sessions and personal training.

关键词： international research training group     limited resources     maize     phosphate    

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Non-convex sparse optimization-based impact force identification with limited vibration measurements

《机械工程前沿（英文）》 2023年 第18卷 第3期 doi: 10.1007/s11465-023-0762-2

摘要： Impact force identification is important for structure health monitoring especially in applications involving composite structures. Different from the traditional direct measurement method, the impact force identification technique is more cost effective and feasible because it only requires a few sensors to capture the system response and infer the information about the applied forces. This technique enables the acquisition of impact locations and time histories of forces, aiding in the rapid assessment of potentially damaged areas and the extent of the damage. As a typical inverse problem, impact force reconstruction and localization is a challenging task, which has led to the development of numerous methods aimed at obtaining stable solutions. The classical ℓ2 regularization method often struggles to generate sparse solutions. When solving the under-determined problem, ℓ2 regularization often identifies false forces in non-loaded regions, interfering with the accurate identification of the true impact locations. The popular ℓ1 sparse regularization, while promoting sparsity, underestimates the amplitude of impact forces, resulting in biased estimations. To alleviate such limitations, a novel non-convex sparse regularization method that uses the non-convex ℓ1−2 penalty, which is the difference of the ℓ1 and ℓ2 norms, as a regularizer, is proposed in this paper. The principle of alternating direction method of multipliers (ADMM) is introduced to tackle the non-convex model by facilitating the decomposition of the complex original problem into easily solvable subproblems. The proposed method named ℓ1−2-ADMM is applied to solve the impact force identification problem with unknown force locations, which can realize simultaneous impact localization and time history reconstruction with an under-determined, sparse sensor configuration. Simulations and experiments are performed on a composite plate to verify the identification accuracy and robustness with respect to the noise of the ℓ1−2-ADMM method. Results indicate that compared with other existing regularization methods, the ℓ1−2-ADMM method can simultaneously reconstruct and localize impact forces more accurately, facilitating sparser solutions, and yielding more accurate results.

关键词： impact force identification     inverse problem     sparse regularization     under-determined condition     alternating direction method of multipliers    

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Full-field dynamic strain reconstruction of an aero-engine blade from limited displacement responses

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0731-1

摘要： Blade strain distribution and its change with time are crucial for reliability analysis and residual life evaluation in blade vibration tests. Traditional strain measurements are achieved by strain gauges (SGs) in a contact manner at discrete positions on the blades. This study proposes a method of full-field and real-time strain reconstruction of an aero-engine blade based on limited displacement responses. Limited optical measured displacement responses are utilized to reconstruct the full-field strain. The full-field strain distribution is in-time visualized. A displacement-to-strain transformation matrix is derived on the basis of the blade mode shapes in the modal coordinate. The proposed method is validated on an aero-engine blade in numerical and experimental cases. Three discrete vibrational displacement responses measured by laser triangulation sensors are used to reconstruct the full-field strain over the whole operating time. The reconstructed strain responses are compared with the results measured by SGs and numerical simulation. The high consistency between the reconstructed and measured results demonstrates the accurate strain reconstructed by the method. This paper provides a low-cost, real-time, and visualized measurement of blade full-field dynamic strain using displacement response, where the traditional SGs would fail.

关键词： aero-engine blade     displacement response     dynamic strain reconstruction     mode shape     strain gauge    

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dynamics of polymer solar cells probed by a transient photocurrent nearby the regime of the space charge-limited

Boa Jin, Hyunmin Park, Yang Liu, Leijing Liu, Jongdeok An, Wenjing Tian, Chan Im

《化学科学与工程前沿（英文）》 2021年 第15卷 第1期   页码 164-179 doi: 10.1007/s11705-020-1976-z

摘要： To understand the complex behaviors of photogenerated charge carriers within polymer-based bulk-heterojunction-type solar cells, the charge-carrier photogeneration and extraction dynamics are simultaneously estimated using a transient photocurrent technique under various external-bias voltages, and a wide range of excitation intensities are analyzed. For this purpose, conventional devices with 80 nm thick active layers consisting of a blend of representative P3HT and PTB7 electron-donating polymers and proper electron-accepting fullerene derivatives were used. After the correction for the saturation behavior at a high excitation-intensity range nearby the regime of the space charge-limited current, the incident-photon-density-dependent maximum photocurrent densities at the initial peaks are discussed as the proportional measures of the charge-carrier-photogeneration facility. By comparing the total number of the extracted charge carriers to the total number of the incident photons and the number of the initially photogenerated charge carriers, the external quantum efficiencies as well as the extraction quantum efficiencies of the charge-carrier collection during a laser-pulse-induced transient photocurrent process were obtained. Subsequently, the charge-carrier concentration-dependent mobility values were obtained, and they are discussed in consideration of the additional influences of the charge-carrier losses from the device during the charge-carrier extraction that also affects the photocurrent-trace shape.

关键词： charge-carrier photogeneration     transient photocurrent     polymer solar cells     charge-carrier extraction     space charge-limited current    

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北方缺水地区半旱地农业有限补灌模式探讨

李英能

《中国工程科学》 2012年 第14卷 第3期   页码 41-45

摘要：

以降水利用和灌溉程度为依据，对半旱地农业进行了研究，着重讨论了与半旱地农业涵义有关的问题，论述了在北方缺水地区发展半旱地农业的意义，给出了半旱地农业有限补灌技术模式。针对北方缺水地区的特点，提出了不同类型区半旱地农业有限补灌发展模式，并探讨了北方缺水地区半旱地农业发展有限补灌的策略。

关键词： 半旱地     农业     有限补灌     模式    

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Industrial Structure Adjustment of Shaanxi Province under the Limited Water Resources Condition

Xiao-jun Liu,Zhen-yu Guo,Chao Ding,Han-liang Fu

《工程管理前沿（英文）》 2014年 第1卷 第4期   页码 378-384 doi: 10.15302/J-FEM-2014057

摘要： Shaanxi Province is a region poor of water resources in China, and the lack of water resources is becoming a key factor which restricts the social and economic development of Shaanxi Province. In the perspective of efficient utilization of water resources, Shaanxi Province is committed to the transformation of the economic growth and the industrial structure, and treats these measures as important guarantees for the future development of Shaanxi Province. This paper focuses on building multi-objective programming model of industrial structure optimization under the limited water resources condition, indicates the direction of the industrial transformation and water consumption structural adjustment by solving the model, and furthermore points out the key factors that affect the development of Shaanxi Province in the future. Finally, the authors give some advices of promoting the reasonable and effective utilization of water resources of Shaanxi Province.

关键词： water resources     capacity of water resources     industrial transformation     multi-objective programming    

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手机直连卫星，未来可期

Mitch Leslie

《工程（英文）》 2023年 第28卷 第9期   页码 4-6 doi: 10.1016/j.eng.2023.07.003

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标题 作者 时间 类型 操作

Parasitic rotation evaluation and avoidance of 3-UPU parallel mechanism

Haibo QU, Yuefa FANG, Sheng GUO

期刊论文

Copper and zinc interaction on water clearance and tissue metal distribution in the freshwater mussel

Tianxiang XIA, Xuehua LIU

期刊论文

Fluid damping clearance in a control valve of injector

ZHANG Jianming, ZHANG Weigang, YANG Bing, WANG Yawei

期刊论文

Emergent limited perioperative transesophageal echocardiography: should new guidelines exist for limited

null

期刊论文

Highlights of special issue on ‘Agriculture in Water-Limited Areas’

Pute WU

期刊论文

Bandwidth-limited active suspension controller for an off-road vehicle based on co-simulation technology

FENG Jinzhi, ZHENG Songlin, YU Fan

期刊论文

Measurement and analysis of tip clearance unsteady flow spectrum in axial-flow fan rotor

LIU Bo, HOU Weimin, MA Changyou, WANG Yangang, ZHOU Qiang

期刊论文

Two-stage scheduling on batch and single machines with limited waiting time constraint

Zhongshun SHI, Zewen HUANG, Leyuan SHI

期刊论文

Adaptation of Chinese and German maize-based food-feed-energy systems to limited phosphate resources—a

null

期刊论文

Non-convex sparse optimization-based impact force identification with limited vibration measurements

期刊论文

Full-field dynamic strain reconstruction of an aero-engine blade from limited displacement responses

期刊论文

dynamics of polymer solar cells probed by a transient photocurrent nearby the regime of the space charge-limited

Boa Jin, Hyunmin Park, Yang Liu, Leijing Liu, Jongdeok An, Wenjing Tian, Chan Im

期刊论文

北方缺水地区半旱地农业有限补灌模式探讨

李英能

期刊论文

Industrial Structure Adjustment of Shaanxi Province under the Limited Water Resources Condition

Xiao-jun Liu,Zhen-yu Guo,Chao Ding,Han-liang Fu

期刊论文

手机直连卫星，未来可期

Mitch Leslie

期刊论文