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Perfluoroalkane acids in human milk under the global monitoring plan of the Stockholm Convention on Persistent Organic Pollutants (2008–2019)

《环境科学与工程前沿（英文）》 2022年 第16卷 第10期 doi: 10.1007/s11783-022-1541-8

摘要：

● Perfluorooctanesulfonic acid and perfluorooctanoic acid highest in human milk.

关键词： Human biomonitoring     Human breast milk     LC-MS/MS analysis     Lifestyle parameters    

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Effectiveness of lifestyle intervention for hypertension in Shanghai communities: Results from the Shanghai

Xin-Jian LI MD, Min-Na CHENG MPH, Yu-Heng WANG MD, Sun MIAO MPH, Zong-Qi ZHANG PhD, Yi-Sheng CHEN MD, Wei LU PhD,

《医学前沿（英文）》 2010年 第4卷 第1期   页码 67-70 doi: 10.1007/s11684-010-0023-8

摘要： A community-based multi-center randomized controlled trial was conducted to evaluate the effectiveness of blood pressure control for hypertension patients in communities in urban Shanghai by integrated intervention. At present, patients (=1395) from four communities have completed follow-up for one year, including the intervention group (=921) and usual care group (=474). The intervention programs included disease management by a care manager. Blood pressure of each patient was measured regularly. Compared with the control group, the net change of mean systolic blood pressure (SBP) was −6.75 (95% CI: −7.79 to −5.71, <0.001) mmHg, mean diastolic blood pressure (DBP) was −4.29 (95% CI: −5.08 to −3.49, <0.001) mmHg, and mean pulse pressure (PP) was −2.46 (95% CI: −3.50 to −1.43, <0.001) mmHg in the intervention group. The net change extent was larger in patients with regular pharmacological treatment than in those with irregular pharmacological treatment or non-pharmacological treatment. The measures of integrated intervention for hypertension patients in communities can lower significantly not only SBP and DBP, but also PP. It is suggested that measures of integrated intervention can decrease the risk of cardiovascular diseases in hypertension patients.

关键词： hypertension     community     pharmacological adherence     control of blood pressure    

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Inverse identification of the mechanical parameters of a pipeline hoop and analysis of the effect of

Ye GAO, Wei SUN

《机械工程前沿（英文）》 2019年 第14卷 第3期   页码 358-368 doi: 10.1007/s11465-019-0539-9

摘要： To create a dynamic model of a pipeline system effectively and analyze its vibration characteristics, the mechanical characteristic parameters of the pipeline hoop, such as support stiffness and damping under dynamic load, must be obtained. In this study, an inverse method was developed by utilizing measured vibration data to identify the support stiffness and damping of a hoop. The procedure of identifying such parameters was described based on the measured natural frequencies and amplitudes of the frequency response functions (FRFs) of a pipeline system supported by two hoops. A dynamic model of the pipe-hoop system was built with the finite element method, and the formulas for solving the FRF of the pipeline system were provided. On the premise of selecting initial values reasonably, an inverse identification algorithm based on sensitivity analysis was proposed. A case study was performed, and the mechanical parameters of the hoop were identified using the proposed method. After introducing the identified values into the analysis model, the reliability of the identification results was validated by comparing the predicted and measured FRFs of the pipeline. Then, the developed method was used to identify the support stiffness and damping of the pipeline hoop under different preloads of the bolts. The influence of preload was also discussed. Results indicated that the support stiffness and damping of the hoop exhibited frequency-dependent characteristics. When the preloads of the bolts increased, the support stiffness increased, whereas the support damping decreased.

关键词： inverse identification     pipeline hoop     frequency response function     mechanical parameters     preload    

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Impact of anthropogenic heat emissions on meteorological parameters and air quality in Beijing using

《环境科学与工程前沿（英文）》 2022年 第16卷 第4期 doi: 10.1007/s11783-021-1478-3

摘要：

The Large scale Urban Consumption of energ Y model was updated and coupled with WRF.

关键词： Anthropogenic heat emissions     LUCY     High-resolution     Meteorological parameters     Air quality    

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Effect of thermodynamic parameters on the performance of refrigerator-ejector

Lihong CAO, Yicai LIU, Chao WAN, Tianlong XIN, Qian HUANG, Mingyan ZHANG

《能源前沿（英文）》 2010年 第4卷 第4期   页码 517-521 doi: 10.1007/s11708-010-0004-2

摘要： A 3D calculation model of a refrigerator-ejector was built and simulated in a compression/injection hybrid refrigeration cycle system by using the FLUENT software of CFD. The effect of thermodynamic parameters (the pressure of primary fluid and secondary fluid) on the performance of the refrigerator-ejector was studied. The boundary conditions were set according to the actual operating condition and the parameters of refrigerator experimental sample. The numerical calculation results show that there is one optimal pressure of primary fluid, i.e., = 0.06612 MPa, corresponding to the maximum entrainment ratio, i.e., = 0.568; and there is one optimal pressure of secondary fluid, i.e., = 0.04837 MPa, corresponding to the maximum entrainment ratio, i.e., = 0.564.

关键词： refrigerator-ejector     FLUENT     thermodynamic parameters     entrainment ratio performance    

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Attitude toward preventive counseling and healthy practices among medical students at a Colombian university

null

《医学前沿（英文）》 2015年 第9卷 第2期   页码 251-259 doi: 10.1007/s11684-015-0393-z

摘要：

Unhealthy behaviors of medical students influence their attitudes toward preventive counseling. The burden of chronic diseases is continually growing in developing countries, emphasizing the need for the increased role of general practitioners in preventive counseling. The objective of this study was to describe the effect of medical training on the risk profiles and attitudes of medical students toward preventive counseling in a Colombian university. Students in their first and fifth years of training were surveyed using the “Healthy Doctor= Healthy Patient” questionnaire to assess counseling attitudes; personal practices, such as risky drinking, smoking, inadequate nutrition, and non-compliance with physical activity recommendations; and the university environment. The association among these components was estimated, as well as the effect of the university environment. Risky drinking and smoking decreased from first to fifth year (59.3% vs. 37.1%, P = 0.021 and 31.5% vs. 25.9%, P = 0.51, respectively), whereas inadequate nutrition and non-compliance with physical activity recommendations increased. Physical activity (PA) was associated with positive counseling attitude (ORs: nutrition 7.6; alcohol 5.2; PA 10.6). Areas governed by institutional policies that are emphasized in the curriculum positively affected student practices. PA promoted preventive counseling and healthy lifestyles most effectively. Universities should therefore strengthen their preventive medicine curricula and modify social determinants.

关键词： lifestyle     medical students     preventive medicine     counseling     universities     schools     medical    

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Effects of critical geometric parameters on the optical performance of a conical cavity receiver

Hu XIAO, Yanping ZHANG, Cong YOU, Chongzhe ZOU, Quentin FALCOZ

《能源前沿（英文）》 2019年 第13卷 第4期   页码 673-683 doi: 10.1007/s11708-019-0630-2

摘要： The optical performance of a receiver has a great influence on the efficiency and stability of a solar thermal power system. Most of the literature focuses on the optical performance of receivers with different geometric shapes, but less research is conducted on the effects of critical geometric parameters. In this paper, the commercial software TracePro was used to investigate the effects of some factors on a conical cavity receiver, such as the conical angle, the number of loops of the helical tube, and the distance between the focal point of the collector and the aperture. These factors affect the optical efficiency, the maximum heat flux density, and the light distribution in the conical cavity. The optical performance of the conical receiver was studied and analyzed using the Monte Carlo ray tracing method. To make a reliable simulation, the helical tube was attached to the inner wall of the cavity in the proposed model. The results showed that the amount of light rays reaching the helical tube increases with the increasing of the conical angle, while the optical efficiency decreases and the maximum heat flux density increases. The increase in the number of loops contributed to an increase in the optical efficiency and a uniform light distribution. The conical cavity receiver had an optimal optical performance when the focal point of the collector was near the aperture.

关键词： parabolic collector     conical cavity receiver     critical geometric parameters     optical performance    

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Effect of preparation parameters on catalytic properties of Pt/graphite

LIU Zhengqian, MA Jun, ZHAO Lei

《环境科学与工程前沿（英文）》 2007年 第1卷 第4期   页码 482-487 doi: 10.1007/s11783-007-0077-2

摘要： Catalytic ozonation of aqueous solutions of oxalic acid was examined in the presence of graphite-supported platinum catalysts. The catalytic activity of graphite was significantly enhanced by loading platinum. The removal efficiency of oxalic acid was 3.0%, 47.6% and 99.3% for ozonation alone, graphite catalytic ozonation and Pt/graphite catalytic ozonation in 30 min under the experimental condition, respectively. The influence of support pretreatment, solvent, impregnation time, platinum loading amount and reduction temperature on the activity of Pt/graphite catalyst was investigated. The pretreatment of graphite support had no effect on activity improvement of Pt/graphite catalyst. Solvent and impregnation time also had no great effect on the activity. Platinum loading amount and reduction temperature influenced the catalyst activity significantly. The optimal catalytic performance of Pt/graphite was obtained when 1.0% platinum loading and 623 K of reduction temperature was adopted. The Pt/graphite catalyst was used for five times with no significant decrease in its activity and more than 90% oxalic acid removal was obtained.
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An energy consumption prediction approach of die casting machines driven by product parameters

《机械工程前沿（英文）》 2021年 第16卷 第4期   页码 868-886 doi: 10.1007/s11465-021-0656-0

摘要： Die casting machines, which are the core equipment of the machinery manufacturing industry, consume great amounts of energy. The energy consumption prediction of die casting machines can support energy consumption quota, process parameter energy-saving optimization, energy-saving design, and energy efficiency evaluation; thus, it is of great significance for Industry 4.0 and green manufacturing. Nevertheless, due to the uncertainty and complexity of the energy consumption in die casting machines, there is still a lack of an approach for energy consumption prediction that can provide support for process parameter optimization and product design taking energy efficiency into consideration. To fill this gap, this paper proposes an energy consumption prediction approach for die casting machines driven by product parameters. Firstly, the system boundary of energy consumption prediction is defined, and subsequently, based on the energy consumption characteristics analysis, a theoretical energy consumption model is established. Consequently, a systematic energy consumption prediction approach for die casting machines, involving product, die, equipment, and process parameters, is proposed. Finally, the feasibility and reliability of the proposed energy consumption prediction approach are verified with the help of three die casting machines and six types of products. The results show that the prediction accuracy of production time and energy consumption reached 91.64% and 85.55%, respectively. Overall, the proposed approach can be used for the energy consumption prediction of different die casting machines with different products.

关键词： die casting machine     energy consumption prediction     product parameters    

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The influence of manufacturing parameters and adding support layer on the properties of Zirfon

Li XU,Yue YU,Wei LI,Yan YOU,Wei XU,Shaoxing ZHANG

《化学科学与工程前沿（英文）》 2014年 第8卷 第3期   页码 295-305 doi: 10.1007/s11705-014-1433-y

摘要： The composite separator comprising of polysulfone and zirconia was prepared by phase inversion precipitation technique. The influence of manufacturing parameters on its properties was investigated, and the results show that the manufacturing parameters affect the ionic resistance and maximum pore size significantly. A modified composite separator with a support layer was prepared to enhance the tensile strength of separator. By adding support layer, the tensile strength of the separator increases from 1.85 MPa to 13.66 MPa. In order to evaluate the practical applicability of the composite separator, a small-scale industrial electrolytic experiment was conducted to investigate the changes of cell voltage, gas purity and separator stability. The results show that the modified composite separator has a smaller cell voltage and a higher H purity than the asbestos separator, and are promising material for industrial hydrogen production.

关键词： separator     alkaline water electrolysis     manufacturing parameters     support layer    

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Steam turbine governor modeling and parameters testing for power system simulation

Ying LI, Chufeng PENG, Zenghui YANG

《能源前沿（英文）》 2009年 第3卷 第2期   页码 198-203 doi: 10.1007/s11708-009-0004-2

摘要： The theoretical modeling, parameters test and model correction for a steam turbine (ST) governor are discussed. A set of ST Governor system model for power system simulation is created based on this research. A power system simulation for an actual power grid accident is conducted using this new model and the comparison between the simulation and actual data show that the results are satisfactory.

关键词： power system simulation     ST governor system     modeling     parameters testing    

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Analysis and experiment on structure parameters for an energy reclaiming suspension

CHEN Shi‘an, HE Ren, LU Senlin

《机械工程前沿（英文）》 2008年 第3卷 第2期   页码 200-204 doi: 10.1007/s11465-008-0024-3

摘要： An energy reclaiming suspension is proposed to reclaim vibration energy in the suspension. To study its riding performance and reclaiming energy performance, a hydraulic energy reclaiming device prototype is produced and its mechanical behavior is analyzed and tested according to the hydraulic theory. Theoretical analysis shows that mechanical behavior of the energy reclaiming device is embodied by a viscidity damping parameter and an analogous coulomb damping parameter determined by its structure; their expressions are obtained. Experimental investigation shows that theoretical predictions agree with test results.

关键词： Experimental investigation     analogous coulomb     hydraulic     performance     suspension    

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Determination of the feasible setup parameters of a workpiece to maximize the utilization of a five-axis

Aqeel AHMED, Muhammad WASIF, Anis FATIMA, Liming WANG, Syed Amir IQBAL

《机械工程前沿（英文）》 2021年 第16卷 第2期   页码 298-314 doi: 10.1007/s11465-020-0621-3

摘要： The machining industry must maximize the machine tool utilization for its efficient and effective usage. Determining a feasible workpiece location is one of the significant tasks performed in an iterative way via machining simulations. The maximum utilization of five-axis machine tools depends upon the cutting system’s geometry, the configuration of the machine tool, and the workpiece’s location. In this research, a mathematical model has been developed to determine the workpiece’s feasible location in the five-axis machine tool for avoiding the number of iterations, which are usually performed to eliminate the global collision and axis limit errors. In this research, a generic arrangement of the five-axis machine tool has been selected. The mathematical model of post-processor has been developed by using kinematic modeling methods. The machine tool envelopes have been determined using the post-processor and axial limit. The tooltip reachable workspace is determined by incorporating the post-processor, optimal cutting system length, and machining envelope, thereby further developing an algorithm to determine the feasible workpiece setup parameters accurately. The algorithm’s application has been demonstrated using an example. Finally, the algorithm is validated for feasible workpiece setup parameters in a virtual environment. This research is highly applicable in the industry to eliminate the number of iterations performed for the suitable workpiece setup parameters.

关键词： workpiece setup parameter     five-axis     space utilization     setup parameters     machine tool    

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Multi-objective optimization of cutting parameters in high-speed milling based on grey relational analysis

Tao FU, Jibin ZHAO, Weijun LIU

《机械工程前沿（英文）》 2012年 第7卷 第4期   页码 445-452 doi: 10.1007/s11465-012-0338-z

摘要：

This paper investigates optimization problem of the cutting parameters in high-speed milling on NAK80 mold steel. An experiment based on the technology of Taguchi is performed. The objective is to establish a correlation among spindle speed, feed per tooth and depth of cut to the three directions of cutting force in the milling process. In this study, the optimum cutting parameters are obtained by the grey relational analysis. Moreover, the principal component analysis is applied to evaluate the weights so that their relative significance can be described properly and objectively. The results of experiments show that grey relational analysis coupled with principal component analysis can effectively acquire the optimal combination of cutting parameters and the proposed approach can be a useful tool to reduce the cutting force.

关键词： high-speed milling     grey relational analysis     principal component analysis     parameters optimization    

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Application of micro-genetic algorithm for calibration of kinetic parameters in HCCI engine combustion

HUANG Haozhong, SU Wanhua

《能源前沿（英文）》 2008年 第2卷 第1期   页码 86-92 doi: 10.1007/s11708-008-0003-8

摘要： The micro-genetic algorithm (?GA) as a highly effective optimization method, is applied to calibrate to a newly developed reduced chemical kinetic model (40 species and 62 reactions) for the homogeneous charge compression ignition (HCCI) combustion of -heptane to improve its autoignition predictions for different engine operating conditions. The seven kinetic parameters of the calibrated model are determined using a combination of the Micro-Genetic Algorithm and the SENKIN program of CHEMKIN chemical kinetics software package. Simulation results show that the autoignition predictions of the calibrated model agree better with those of the detailed chemical kinetic model (544 species and 2 446 reactions) than the original model over the range of equivalence ratios from 0.1–1.3 and temperature from 300–3 000 K. The results of this study have demonstrated that the mGA is an effective tool to facilitate the calibration of a large number of kinetic parameters in a reduced kinetic model.

关键词： homogeneous     different     combustion     autoignition     compression    

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标题 作者 时间 类型 操作

Perfluoroalkane acids in human milk under the global monitoring plan of the Stockholm Convention on Persistent Organic Pollutants (2008–2019)

期刊论文

Effectiveness of lifestyle intervention for hypertension in Shanghai communities: Results from the Shanghai

Xin-Jian LI MD, Min-Na CHENG MPH, Yu-Heng WANG MD, Sun MIAO MPH, Zong-Qi ZHANG PhD, Yi-Sheng CHEN MD, Wei LU PhD,

期刊论文

Inverse identification of the mechanical parameters of a pipeline hoop and analysis of the effect of

Ye GAO, Wei SUN

期刊论文

Impact of anthropogenic heat emissions on meteorological parameters and air quality in Beijing using

期刊论文

Effect of thermodynamic parameters on the performance of refrigerator-ejector

Lihong CAO, Yicai LIU, Chao WAN, Tianlong XIN, Qian HUANG, Mingyan ZHANG

期刊论文

Attitude toward preventive counseling and healthy practices among medical students at a Colombian university

null

期刊论文

Effects of critical geometric parameters on the optical performance of a conical cavity receiver

Hu XIAO, Yanping ZHANG, Cong YOU, Chongzhe ZOU, Quentin FALCOZ

期刊论文

Effect of preparation parameters on catalytic properties of Pt/graphite

LIU Zhengqian, MA Jun, ZHAO Lei

期刊论文

An energy consumption prediction approach of die casting machines driven by product parameters

期刊论文

The influence of manufacturing parameters and adding support layer on the properties of Zirfon

Li XU,Yue YU,Wei LI,Yan YOU,Wei XU,Shaoxing ZHANG

期刊论文

Steam turbine governor modeling and parameters testing for power system simulation

Ying LI, Chufeng PENG, Zenghui YANG

期刊论文

Analysis and experiment on structure parameters for an energy reclaiming suspension

CHEN Shi‘an, HE Ren, LU Senlin

期刊论文

Determination of the feasible setup parameters of a workpiece to maximize the utilization of a five-axis

Aqeel AHMED, Muhammad WASIF, Anis FATIMA, Liming WANG, Syed Amir IQBAL

期刊论文

Multi-objective optimization of cutting parameters in high-speed milling based on grey relational analysis

Tao FU, Jibin ZHAO, Weijun LIU

期刊论文

Application of micro-genetic algorithm for calibration of kinetic parameters in HCCI engine combustion

HUANG Haozhong, SU Wanhua

期刊论文