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Tripotassium citrate monohydrate derived carbon nanosheets as a competent assistant to manganese dioxide with remarkable performance in the supercapacitor

《化学科学与工程前沿（英文）》 2022年 第16卷 第3期   页码 420-432 doi: 10.1007/s11705-021-2065-7

摘要： Production cost, capacitance, and electrode materials safety are the key factors to be concerned about for supercapacitors. In this work, a type of carbon nanosheets was produced through the carbonization of tripotassium citrate monohydrate and nitric acidification. Subsequently, a well-designed manganese dioxide/carbon nanosheets composite was synthesized through hydrothermal treating. The carbon nanosheets served as the substrate for growing the manganese dioxide, regulating its distribution, and preventing it from inhomogeneous dimensions and severe agglomeration. Many manganese dioxide nanosheets grew vertically on the numerous functional groups generated on the surface of the carbon nanosheets during acidification. The synergistic combination of carbon nanosheets and manganese dioxide tailors the electrochemical performance of the composite, which benefits from the excellent conductivity and stability of carbon nanosheets. The carbon nanosheets derived from tripotassium citrate monohydrate are conducive to the remarkable performance of manganese dioxide/carbon nanosheets electrode. Finally, an asymmetric supercapacitor with active carbon as the cathode and manganese dioxide/carbon nanosheets as the anode was assembled, achieving an outstanding energy density of 54.68 Wh·kg–1 and remarkable power density of 6399.2 W·kg–1 superior to conventional lead-acid batteries. After 10000 charge-discharge cycles, the device retained 75.3% of the initial capacitance, showing good cycle stability. Two assembled asymmetric supercapacitors in series charged for 3 min could power a yellow light emitting diode with an operating voltage of 2 V for 2 min. This study may provide valuable insights for applying carbon materials and manganese dioxide in the energy storage field.

关键词： carbon nanosheets     manganese dioxide     asymmetric supercapacitors     energy density     power density    

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Investigation on available wind energy at Tungku beach

M. G. YAZDANI, M. A. SALAM

《能源前沿（英文）》 2012年 第6卷 第3期   页码 275-279 doi: 10.1007/s11708-012-0194-x

摘要： In this paper, wind velocities and directions (sea and land) are recorded in different days and times. The data collected were compared with the weather data from the Brunei Darussalam Meteorological Service (BDMS) and the findings of other researchers and were found to be in good agreement. The potential of wind energy is predicted from the available data collected. The average generated power (forenoon and afternoon) is found to be 25 (mean) and 18 W (median), 101 (mean) and 73 W (median), 912 (mean) and 660 W (median), 10137 (mean) and 7331 W (median) for a rotor with a diameter of 2.5, 5, 15 and 50 m, respectively. The power density for wind farming is found to be 0.26 (mean) and 0.19 (median), 0.31 (mean) and 0.22 (median) for the rotor whose diameter is 2.5 and 50 m, respectively, while the average values are found to be 0.28 (mean) and 0.2 (median) for the rotor whose diameter is 5 and 15 m.

关键词： wind velocity     temperature     tower height     power density     Raleigh distribution     electrical power    

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Assessment of wind energy potential in Gaza Strip

Juma Yousuf ALAYDI

《能源前沿（英文）》 2011年 第5卷 第3期   页码 297-304 doi: 10.1007/s11708-010-0134-6

摘要： The analysis of collected wind data at two sites in the Gaza Strip, namely, Gaza City and Gaza International Airport in Rafah city, is presented. The two sites are candidates for remote area wind energy applications. The purpose of this paper is to present the results of the assessment of wind energy potential in the Gaza Strip in order to evaluate the wind regimes for installing wind energy conversion systems for power generation. The data on wind speed, direction and frequency distribution are used to analyze wind energy characteristics and availability at some stations in the Gaza Strip. The vertical extrapolation was based on the power-law expression, and the wind energy and potential have been estimated at the wind turbine hub height of approximately 50 m. Furthermore, the values of the Weibull parameters and are determined from summary statistics of wind resource. Consequently, the wind power is estimated by adoption of the Weibull distribution expression. Based on the results of this paper, sites are recommended for wind energy exploitation in the Gaza Strip.

关键词： wind data     wind resource assessment     wind power density     wind energy     the Weibull distribution and Weibull parameters    

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Evaluation of the wind energy potential of two south west sites in Nigeria

Olaleye M. AMOO

《能源前沿（英文）》 2012年 第6卷 第3期   页码 237-246 doi: 10.1007/s11708-012-0201-2

摘要： Wind resource assessment is a crucial first step in gauging the potential of a site to produce energy from wind turbines. In this paper, the wind energy potential of Abeokuta (07°03'N, 03°19'E) and Ijebu-Ode (06°47'N, 03°58'E), two south west sites in Nigeria were examined. Twenty years (1990–2010) of monthly mean wind data from a 10 m height were subjected to two-parameter Weibull analysis and other statistical analyses. The results show that the average annual mean wind speed variation for Abeokuta ranges from 2.2 to 5.0 m/s. For Ijebu-Ode, it ranges from 2.0 to 5.0 m/s. The wind power density variation based on the Weibull analysis ranges from 4.26 to 24.51 W/m for Abeokuta and from 8.54 to 76.46 W/m for Ijebu-Ode. Ijebu-Ode was found to be the better of the two sites in terms of annual variation of mean wind speed.

关键词： wind potential     wind speed     wind power density     wind gust     turbulence intensity     Nigeria    

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基于纳米孔渗透获取盐度梯度能量发电的可行性研究 Article

王樟新, Li Wang, Menachem Elimelech

《工程（英文）》 2022年 第9卷 第2期   页码 51-60 doi: 10.1016/j.eng.2021.02.016

摘要：

随着具有离子选择性纳米通道的新型材料的研发，一种获取盐度梯度（蓝色）能量的新技术被提出，即纳米孔发电机（NPG）。在本研究中，我们对膜片尺度和组件尺度的NPG运行的实际性能进行了全面分析。结果表明，虽然NPG 膜片可以在理想条件下产生超高的功率密度，但由于浓度极化效应，实际运行中NPG膜片上产生的功率密度很难达到10 W·m−2。对于组件尺度的NPG运行，我们估算了功率密度和可提取比能（即使用单位总体积工作溶液可产生的能量），并基于浓度极化与高浓度溶液和低浓度溶液的混合程度之间的相互作用，阐明运行条件对这两个指标的影响。此外，我们还开发了一个用来评估NPG 系统可行性的模型框架。结果表明，对于使用海水与河水的NPG 系统，总可提取比能非常低（约0.1 kW·h·m−3），且受到系统运行能耗的影响（特别是海水和河水溶液的汲取与预处理能耗）。总的来说，NPG系统产生的净可提取比能（< 0.025 kW·h·m−3）和净功率密度（< 0.1 W·m−2）非常低。我们的研究重点指出了NPG在现实运行中存在极大的局限性，进而对NPG作为一种蓝色能量收集技术的可行性提出了质疑。

关键词： 纳米孔发电机     盐度梯度（蓝色）能量     功率密度     可提取比能    

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石墨烯基超级电容器的发展现状与战略研究

陈静,郭红霞,毛卫国,刘剑洪,付永胜,欧阳晓平

《中国工程科学》 2018年 第20卷 第6期   页码 75-81 doi: 10.15302/J-SSCAE-2018.06.012

摘要：

超级电容器兼具普通电容器和化学电池的优点，具有功率密度高、可快速充放电、循环寿命长等显著优势。电极材料是发展具有优异性能超级电容器的关键材料。石墨烯凭借其优异的力学、电学、热学等性能成为超级电容器理想的电极材料。本文首先基于对石墨烯基超级电容器相关学术论文、专利的统计分析，讨论了石墨烯基超级电容器的发展现状与方向；其次，简要阐述了石墨烯基超级电容器在国内的产业发展现状，讨论了石墨烯基超级电容器未来发展所面临的难点与挑战，并在此基础上提出了未来发展的方向与建议。

关键词： 石墨烯     超级电容器     电极材料     功率密度     能量密度    

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一类高维随机系统的小波分析

夏学文

《中国工程科学》 2004年 第6卷 第11期   页码 43-46

摘要：

利用小波分析研究了线性随机系统在小波变换下的平均功率、稠度、小波展开及展开系数的相关性等。

关键词： 随机系统     小波分析     平均功率     稠度     相关性    

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Review of recent advances of polymer based dielectrics for high-energy storage in electronic power devices

Wenjie Sun, Jiale Mao, Shuang Wang, Lei Zhang, Yonghong Cheng

《化学科学与工程前沿（英文）》 2021年 第15卷 第1期   页码 18-34 doi: 10.1007/s11705-020-1939-4

摘要： Polymer-based dielectric capacitors are widely-used energy storage devices. However, although the functions of dielectrics in applications like high-voltage direct current transmission projects, distributed energy systems, high-power pulse systems and new energy electric vehicles are similar, their requirements can be quite different. Low electric loss is a critical prerequisite for capacitors for electric grids, while high-temperature stability is an essential pre-requirement for those in electric vehicles. This paper reviews recent advances in this area, and categorizes dielectrics in terms of their foremost properties related to their target applications. Requirements for polymer-based dielectrics in various power electronic equipment are emphasized, including high energy storage density, low dissipation, high working temperature and fast-response time. This paper considers innovations including chemical structure modification, composite fabrication and structure re-design, and the enhancements to material performances achieved. The advantages and limitations of these methods are also discussed.

关键词： dielectric capacitors     polymer-based dielectrics     energy density     dielectric loss     working temperature     frequency response    

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煤炭清洁发电技术进展与前景

岑可法,倪明江,高翔,骆仲泱,王智化,郑成航

《中国工程科学》 2015年 第17卷 第9期   页码 49-55

摘要：

近年来，我国大气复合污染问题日益突出，燃煤是造成大气污染的主要原因之一，我国电力行业耗煤量约占全国耗煤总量的一半，实现燃煤电厂烟气污染物高效控制是重中之重。本文介绍了我国煤炭清洁发电实现超低排放的最新进展及未来发展前景。通过理论研究、技术研发及集成应用，形成了符合我国国情的燃煤烟气污染物超低排放技术路线，建立了超低排放清洁环保岛，实现了污染物排放优于天然气机组排放标准限值，为我国大气污染防治特别是高用能密度区域的污染物减排提供了一条重要出路。研究综述了近年来我国超低排放技术的示范应用情况，通过费效分析表明超低排放可实现污染物大幅度减排，具有良好的环境、经济和社会效益。未来，我国燃煤电厂还将进一步发展烟气污染物深度脱除技术及二氧化碳捕集技术，最终实现燃煤烟气污染物的近零排放，为建设全世界最清洁的燃煤电厂奠定坚实的技术基础。

关键词： 煤炭；高用能密度；大气污染；超低排放；清洁发电    

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Effect of current density on groundwater arsenite removal performance using air cathode electrocoagulation

《环境科学与工程前沿（英文）》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1399-1

摘要：

• With the same charge, current density had little effect on As(III) removal in ACEC.

关键词： Electrocoagulation     Air cathode     Arsenic     Current density     Energy consumption    

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Effects of exercise therapy on bone mineral density in early postmenopausal women: a controlled trial

Shilin DENG MD ,

《医学前沿（英文）》 2009年 第3卷 第3期   页码 323-329 doi: 10.1007/s11684-009-0061-2

摘要： The purpose of this article is to determine the effect of a well-designed combined aerobic, resistance, and extension exercise program on bone mineral density (BMD) in postmenopausal women. The population comprised 45 postmenopausal women, who exercised over 12months (exercise group), and 36 women who served as a non-training control group. BMD of the hip, and lumbar spine was measured at the baseline and 12th month. Repeated measurement analysis of variance and nonparametric test were utilized to compare differences between the exercise group and controls. Thirty-six out of 45 persons in the exercise group and 36 controls completed the study. Average compliance was 82.2% for the whole exercise group at the 12th month. All the subjects had decreased BMD, but the rate of bone loss was lower in the exercise group than in the control group at the L4 and hip. Although the exercise program in this study may probably reduce the rate of bone loss in weight-bearing skeletal sites, we do not suggest the exercise by itself be viewed as prevention or treatment for osteoporosis. Further, the exact dose-response relationship of exercise and bone mass in early postmenopause is not clear.

关键词： early postmenopausal women     bone mineral density     exercise     effects    

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客运专线轨道不平顺功率谱分析

陈秀方,金守华,曾华亮

《中国工程科学》 2008年 第10卷 第4期   页码 56-59

摘要：

轨道不平顺是车辆振动的主要激扰源，也是限制列车最高运行速度的主要因素之一，直接关系到列车运行的平稳性、安全性和舒适性。文章以秦沈客运专线轨检车实测轨道不平顺数据为统计样本，基于样本平稳性检验，采用FFT方法进行样本空间的谱估计，并由MATLAB编程得到轨道不平顺谱密度。基于轨道不平顺样本的总体平均，得出了谱密度频率平滑曲线和谱密度曲线拟合表达式，并与我国重载提速干线的谱密度曲线进行了对比分析。在此基础上，对秦沈客运专线的轨道状态进行了评估。

关键词： 客运专线     轨道不平顺     功率谱密度     平稳性检验    

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density measurement for plastic injection molding via ultrasonic technology

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0714-2

摘要： Density variation during the injection molding process directly reflects the state of plastic melt and contains valuable information for process monitoring and optimization. Therefore, in-situ density measurement is of great interest and has significant application value. The existing methods, such as pressure−volume−temperature (PVT) method, have the shortages of time-delay and high cost of sensors. This study is the first to propose an in-situ density measurement method using ultrasonic technology. The analyses of the time-domain and frequency-domain signals are combined in the proposed method. The ultrasonic velocity is obtained from the time-domain signals, and the acoustic impedance is computed through a full-spectral analysis of the frequency-domain signals. Experiments with different process conditions are conducted, including different melt temperature, injection speed, material, and mold structure. Results show that the proposed method has good agreement with the PVT method. The proposed method has the advantages of in-situ measurement, non-destructive, high accuracy, low cost, and is of great application value for the injection molding industry.

关键词： ultrasonic measurement     melt density     in-situ measurement     injection molding    

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Control efficiency optimization and Sobol’s sensitivity indices of MTMDs design parameters for buffeting and flutter vibrations in a cable stayed bridge

Nazim Abdul NARIMAN

《结构与土木工程前沿（英文）》 2017年 第11卷 第1期   页码 66-89 doi: 10.1007/s11709-016-0356-8

摘要： This paper studies optimization of three design parameters (mass ratio, frequency ratio and damping ratio) of multiple tuned mass dampers MTMDs that are applied in a cable stayed bridge excited by a strong wind using minimax optimization technique. ABAQUS finite element program is utilized to run numerical simulations with the support of MATLAB codes and Fast Fourier Transform FFT technique. The optimum values of these three parameters are validated with two benchmarks from the literature, first with Wang and coauthors and then with Lin and coauthors. The validation procedure detected a good agreement between the results. Box-Behnken experimental method is dedicated to formulate the surrogate models to represent the control efficiency of the vertical and torsional vibrations. Sobol’s sensitivity indices are calculated for the design parameters in addition to their interaction orders. The optimization results revealed better performance of the MTMDs in controlling the vertical and the torsional vibrations for higher mode shapes. Furthermore, the calculated rational effects of each design parameter facilitate to increase the control efficiency of the MTMDs in conjunction with the support of the surrogate models.

关键词： MTMDs     power spectral density     fast Fourier transform     minimax optimization technique     Sobol’s sensitivity indices     Box-Behnken method    

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Relationship of adrenomedullin expression and microvessel density and prognosis in smooth muscle tumor

JIANG Yuan, TIAN Xuehong, YUAN Jie, JIN Yuemei, TAN Yusong

《医学前沿（英文）》 2007年 第1卷 第4期   页码 398-400 doi: 10.1007/s11684-007-0077-4

摘要： The aim of this paper was to investigate the relationship between the expression of adrenomedullin (ADM) and microvessel density (MVD) and prognosis in smooth muscle tumor of uterus. The expression of ADM was detected using immunohistochemical staining in specimens from 15 normal controls, 28 cases of uterine leiomyoma (LE) and 19 cases of uterine leiomyosarcoma (LES). The MVD was assayed by immunostainting with CD. There was a positive correlation between the ADM expression and MVD in LE and LES respectively ( = 0.823, <0.01; = 0.793, <0.01). The expression of ADM in LE was statistically lower than that in LES (<0.05). There was a positive correlation between the ADM expression and mitotic figures in LES (<0.05): the more mitotic figures, the higher levels of the ADM expression and poor prognosis. The ADM is an important angiogenic factor in smooth muscle tumor of uterus. The ADM can be used as an accessory marker in estimating the malignant potency of LE and judging the pro gnosis of LES, and as a novel molecular target of anti-angiogenic and anticarcinogenic strategies.

关键词： anticarcinogenic     microvessel density     malignant potency     muscle     uterine leiomyosarcoma    

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标题 作者 时间 类型 操作

Tripotassium citrate monohydrate derived carbon nanosheets as a competent assistant to manganese dioxide with remarkable performance in the supercapacitor

期刊论文

Investigation on available wind energy at Tungku beach

M. G. YAZDANI, M. A. SALAM

期刊论文

Assessment of wind energy potential in Gaza Strip

Juma Yousuf ALAYDI

期刊论文

Evaluation of the wind energy potential of two south west sites in Nigeria

Olaleye M. AMOO

期刊论文

基于纳米孔渗透获取盐度梯度能量发电的可行性研究

王樟新, Li Wang, Menachem Elimelech

期刊论文

石墨烯基超级电容器的发展现状与战略研究

陈静,郭红霞,毛卫国,刘剑洪,付永胜,欧阳晓平

期刊论文

一类高维随机系统的小波分析

夏学文

期刊论文

Review of recent advances of polymer based dielectrics for high-energy storage in electronic power devices

Wenjie Sun, Jiale Mao, Shuang Wang, Lei Zhang, Yonghong Cheng

期刊论文

煤炭清洁发电技术进展与前景

岑可法,倪明江,高翔,骆仲泱,王智化,郑成航

期刊论文

Effect of current density on groundwater arsenite removal performance using air cathode electrocoagulation

期刊论文

Effects of exercise therapy on bone mineral density in early postmenopausal women: a controlled trial

Shilin DENG MD ,

期刊论文

客运专线轨道不平顺功率谱分析

陈秀方,金守华,曾华亮

期刊论文

density measurement for plastic injection molding via ultrasonic technology

期刊论文

Control efficiency optimization and Sobol’s sensitivity indices of MTMDs design parameters for buffeting and flutter vibrations in a cable stayed bridge

Nazim Abdul NARIMAN

期刊论文

Relationship of adrenomedullin expression and microvessel density and prognosis in smooth muscle tumor

JIANG Yuan, TIAN Xuehong, YUAN Jie, JIN Yuemei, TAN Yusong

期刊论文