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Spatial and Temporal Distribution of PM

Xiao-hong Chen,Xiang-bo Tang

《工程管理前沿(英文)》 2016年 第3卷 第2期   页码 171-181 doi: 10.15302/J-FEM-2016017

摘要: Utilizing the initial hourly monitoring data of PM concentrations at 23 monitoring sites across the Chang-Zhu-Tan city cluster between January 2013 and February 2014 that released in Real-time Air Quality Reporting System in Hunan Province, this paper draws diagrams and analyzes the change rule of the pollutants concentration over time. In addition, this paper studies the regional distribution of PM seasonal pollution in the vicinity of the monitoring sites using ArcGIS geographic information system with the Kriging interpolation method. On this basis, this paper puts forward some effective control strategies to cope with regional PM pollution combined with the information of industry distribution and development status in the Chang-Zhu-Tan city cluster.

关键词: PM2.5     spatial and temporal distribution     ArcGIS     the chang-Zhu-Tan city cluster    

System and prospects of China’s intercity rail transit technology

Ming GONG

《机械工程前沿(英文)》 2018年 第13卷 第2期   页码 323-328 doi: 10.1007/s11465-018-0463-4

摘要:

City clusters and metropolitan areas in China are flourishing in the midst of the deepening urbanization in the country, thereby resulting in the emergence of intercity rail transit. Intercity railways connect mainline and urban railways for an integrated regional transportation system that underpins and leads the development of city clusters and metropolitan areas. This study explores the development mode and service characteristics of intercity rail transit, as well as proposes overviews on this system and prospects of its future technology in China.

关键词: intercity rail transit     city cluster     technical demand     technology system    

位移测量光栅干涉仪综述 Special Feature on Precision Measurement and Inst

Peng-cheng HU, Di CHANG, Jiu-bin TAN, Rui-tao YANG, Hong-xing YANG, Hai-jin FU

《信息与电子工程前沿(英文)》 2019年 第20卷 第5期   页码 631-654 doi: 10.1631/FITEE.1800708

摘要: 光栅干涉仪是测量精密位移的常用方法。和激光干涉仪相比,光栅干涉仪对空气折射率不敏感且易于实现多自由度测量结构,因此被广泛研究、应用。从光学测量原理角度看,光栅干涉仪历经零差干涉、外差干涉和空间分离式外差干涉3个阶段。与前两者相比,空间分离式外差光栅干涉仪具有能消除光学混叠引起纳米级周期非线性误差的特性,可以获得更高位移测量精度。与此同时,各式各样光栅干涉仪结构被提出,以提高光学细分数、增加量程、提升适用性或实现多自由度位置姿态测量。本文详细总结了近年来增量式位移测量光栅干涉仪的发展,并简述其测量误差相关的研究。

关键词: 光栅干涉仪;光学编码器;位移测量;精密测量    

现代城市低碳路径与技术分析——沈阳市的案例研究

刘竹,耿涌 , 薛冰,董会娟

《中国工程科学》 2011年 第13卷 第4期   页码 101-105

摘要:

从城市的经济发展、CO2和工业污染物排放、资源消耗的多维视角出发,以沈阳市为研究案例,运用定量化评价指标体系,分析了城市在经济发展与低碳转型过程中的资源消耗和环境影响变化,并评价了城市尺度下各种技术的节能减排潜力和运用愿景;指出城市在全球低碳经济建设中的关键作用,城市尺度的减排技术能够在相当程度上降低碳排放总量。从未来的发展来看,要实现经济增长与污染物排放总量降低,仍须进一步在技术和经济增长方式上大力投入。

关键词: 现代城市     低碳     减排技术    

Concentrations and classification of HCHs and DDTs in soil from the lower reaches of the Jiulong River, China

Jiaquan ZHANG, Shihua QI, Xinli XING, Lingzhi TAN, Wei CHEN, Ying HU, Dan YANG, Chenxi WU

《环境科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 177-183 doi: 10.1007/s11783-011-0354-y

摘要: Soil is an important source to other environmental media and organisms for organochlorine pesticides (OCPs) bioaccumulation. Twenty-four representative surface soil samples were collected from the lower reaches of the Jiulong River, China, in 2009. The concentrations of hexachlorocyclohexane isomers (HCHs) ranged from 0.38 to 39.52 ng·g , with a mean value of 9.51 ng·g . The concentrations of dichlorodiphenyltrichloroethanes (DDTs) and their metabolites were within the ranges of 0.94–700.99 ng·g , with a mean value of 71.17 ng·g . The concentrations of HCHs and DDTs in the soil were lower than the first grade level (50 ng·g ) of the Chinese Environmental Quality Standard (GB15618-1995). Hierarchical Cluster Analysis (HCA) and Pearson’s bivariate Correlations Analysis (PCA) were used to analyse the distribution and contamination levels of OCPs in this region. The results showed that DDTs were the major contaminants and there were no significant correlations between various OCPs concentrations and the total organic carbon (TOC) contents. A significant positive correlation was observed between HCHs and DDTs ( <0.01), which indicates that HCHs and DDTs may have similar sources and fate in the study area.

关键词: Jiulong River     hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethan (DDT)     classification     Hierarchical Cluster Analysis (HCA)     Pearson’s bivariate Correlations Analysis (PCA)    

Source apportionment of ambient PM

Bo HAN, Xiaohui BI, Yonghua XUE, Jianhui WU, Tan ZHU, Baogui ZHANG, Jianqing DING, Yuanxin DU

《环境科学与工程前沿(英文)》 2011年 第5卷 第4期   页码 552-563 doi: 10.1007/s11783-010-0263-5

摘要: A total of 168 PM samples were collected during the year of 2005 at eight sites in the city of Wuxi in China. Fifteen chemical elements, three water-soluble ions, total carbon and organic carbon were analyzed. Six source categories were identified and their contributions to ambient PM in Wuxi were estimated using a nested chemical mass balance method that reduces the effects of colinearity on the chemical mass balance model. In addition, the concentrations of secondary aerosols, such as secondary organic carbon, sulfate and nitrate, were quantified. The spatially averaged PM was high in the spring and winter (123 μg·m and low in the summer–fall (90 μg·m ). According to the result of source apportionment, resuspended dust was the largest contributor to ambient PM , accounting for more than 50% of the PM mass. Coal combustion (14.6%) and vehicle exhaust (9.4%) were also significant source categories of ambient PM . Construction and cement dust, sulfates, secondary organic carbon, and nitrates made contributions ranging between 4.1% and 4.9%. Other source categories such as steel manufacturing dust and soil dust made low contributions to ambient PM .

关键词: source apportionment     inhalable particulate matter     nested chemical mass balance method    

Design of tandem genes cluster for isoflavone engineering

Xunli XIA PhD , Guangxiao YANG PhD , Guangyuan HE PhD ,

《医学前沿(英文)》 2009年 第3卷 第3期   页码 292-296 doi: 10.1007/s11684-009-0057-y

摘要: In this paper, a universal effective novel method of constructing tandem genes cluster for isoflavone engineering was reported. A tandem genes cluster () of secondary metabolites of plant isoflavones was constructed by using the chalcone synthase (CHS), chalcone isomerase (CHI), and isoflavone synthase (IFS) (GenBank accession numbers EU526827, EU526829, EU526830) in only one recombination with the pET22b vector. The resulting expression vector pET- was heterogeneously expressed and co-incubated with barrenwort extractions, and the genistein-like component was detected.

关键词: isoflavones engineering     secondary metabolism     tandem genes cluster    

Understanding high-emitting households in the UK through a cluster analysis

Xinfang WANG, Ming MENG

《能源前沿(英文)》 2019年 第13卷 第4期   页码 612-625 doi: 10.1007/s11708-019-0647-6

摘要: Anthropogenic climate change is a global problem that affects every country and each individual. It is largely caused by human beings emitting greenhouse gases into the atmosphere. In general, a small percentage of the population is responsible for a large amount of emissions. This paper focuses on high emitters and their CO emissions from energy use in UK homes. It applies a cluster approach, aiming to identify whether the high emitters comprise clusters where households in each cluster share similar characteristics but are different from the others. The data are mainly based on the Living Cost and Food survey in the UK. The results show that after equivalising both household emissions and income, the high emitters can be clustered into six groups which share similar characteristics within each group, but are different from the others in terms of income, age, household composition, category and size of the dwelling, and tenure type. The clustering results indicate that various combinations of socioeconomic factors, such as low-income single female living in an at least six-room property, or high-income retired couple owning a large detached house, could all lead to high CO emissions from energy use at home. Policymakers should target each high-emitter cluster differently to reduce CO emissions from energy consumption at home more effectively.

关键词: cluster analysis     emissions reduction     energy use     high emitters     household energy consumption     socioeconomic factors    

Pt-Ni nanourchins as electrocatalysts for oxygen reduction reaction

Qiaowan CHANG, Yuan XU, Shangqian ZHU, Fei XIAO, Minhua SHAO

《能源前沿(英文)》 2017年 第11卷 第3期   页码 254-259 doi: 10.1007/s11708-017-0493-3

摘要: Pt-Ni bimetallic alloys with various nanostructures have shown excellent activity toward oxygen reduction reaction (ORR). The ORR activity is highly dependent on the structure of the catalyst. In this paper, Pt-Ni nanourchins were synthesized with an average size of 50 nm consisting of 10–20 nanorods and nanooctahedra by adjusting the synthesis condition. The formation of Pt-Ni nanourchins is mainly dependent on the adding order of solvents (benzyl ether, oleylamine and oleic acid). Pt-Ni nanourchins present a reasonable high ORR activity (0.81 A/mg at 0.9 V).

关键词: Pt-Ni alloys     nanourchins     oxygen reduction reaction     shape control     fuel cells    

Scaling up of cluster beam deposition technology for catalysis application

《化学科学与工程前沿(英文)》 2021年 第15卷 第6期   页码 1360-1379 doi: 10.1007/s11705-021-2101-7

摘要: Many research works have demonstrated that the combination of atomically precise cluster deposition and theoretical calculations is able to address fundamental aspects of size-effects, cluster-support interactions, and reaction mechanisms of cluster materials. Although the wet chemistry method has been widely used to synthesize nanoparticles, the gas-phase synthesis and size-selected strategy was the only method to prepare supported metal clusters with precise numbers of atoms for a long time. However, the low throughput of the physical synthesis method has severely constrained its wider adoption for catalysis applications. In this review, we introduce the latest progress on three types of cluster source which have the most promising potential for scale-up, including sputtering gas aggregation source, pulsed microplasma cluster source, and matrix assembly cluster source. While the sputtering gas aggregation source is leading ahead with a production rate of ~20 mg·h–1, the pulsed microplasma source has the smallest physical dimensions which makes it possible to compact multiple such devices into a small volume for multiplied production rate. The matrix assembly source has the shortest development history, but already show an impressive deposition rate of ~10 mg·h–1. At the end of the review, the possible routes for further throughput scale-up are envisaged.

关键词: nanoparticle     cluster     cluster beam deposition     magnetron sputtering     heterogeneous catalysis    

A driving pulse edge modulation technique and its complex programming logic devices implementation

Xiao CHEN,Dong-chang QU,Yong GUO,Guo-zhu CHEN

《信息与电子工程前沿(英文)》 2015年 第16卷 第12期   页码 1088-1098 doi: 10.1631/FITEE.1500111

摘要: With the continual increase in switching speed and rating of power semiconductors, the switching voltage spike becomes a serious problem. This paper describes a new technique of driving pulse edge modulation for insulated gate bipolar transistors (IGBTs). By modulating the density and width of the pulse trains, without regulating the hardware circuit, the slope of the gate driving voltage is controlled to change the switching speed. This technique is used in the driving circuit based on complex programmable logic devices (CPLDs), and the switching voltage spike of IGBTs can be restrained through software, which is easier and more flexible to adjust. Experimental results demonstrate the effectiveness and practicability of the proposed method.

关键词: Driving pulse edge modulation     Switching voltage spike     Complex programmable logic device (CPLD)     Active gate drive    

含有任意边界的m×n阶RLC网络的等效复阻抗特性 Article

Zhi-zhong TAN, Hong ZHU, Jihad H. ASAD, Chen XU, Hua TANG

《信息与电子工程前沿(英文)》 2017年 第18卷 第12期   页码 2070-2081 doi: 10.1631/FITEE.1700037

摘要: 现阶段,精确地计算拓扑网络中任意两节点间等效电阻的技术已经取得较大进展,特别是利用递推-变换(recursion-transform, RT)方法确定含有任意边界的非规则m×n电阻网络的一般等效电阻公式。然而,等效阻抗具有不同于等效电阻的性质,复杂阻抗网络的研究比电阻网络研究困难得多。基于电阻公式,本文研究了含有任意阻抗边界的非规则m×n阶RLC网络的等效复阻抗问题,并发现等效复阻抗的振荡特性和谐振特性。在RLC网络中,当边界阻抗取得一系列特殊值时,复阻抗公式与外部交流电产生共振。结果表明,该公式可以应用到谐振电路中。

关键词: RLC网络;谐振性质;振荡特性;幅频特性    

A cytoprotective graphene oxide-polyelectrolytes nanoshell for single-cell encapsulation

Luanying He, Yulin Chang, Junhao Zhu, Ying Bi, Wenlin An, Yiyang Dong, Jia-Hui Liu, Shihui Wang

《化学科学与工程前沿(英文)》 2021年 第15卷 第2期   页码 410-420 doi: 10.1007/s11705-020-1950-9

摘要: Graphene oxide (GO) has been increasingly utilized in the fields of food, biomedicine, environment and other fields because of its benign biocompatible. We encapsulated two kinds of GO with different sizes on yeast cells with the assistance of polyelectrolytes poly (styrene sulfonic acid) sodium salt (PSS) and polyglutamic acid (PGA) (termed as Y@GO). The result does not show a significant difference between the properties of the two types of Y@GO (namely Y@GO1 and Y@GO2). The encapsulation layers are optimized as Yeast/PGA/PSS/PGA/GO/PGA/PSS based on the morphology, dispersity, colony-forming unit, and zeta potential. The encapsulation of GO increases the roughness of the yeast. It is proved that the Y@GO increases the survival time and enhance the activity of yeast cells. The GO shell improves the resistance of yeast cells against pH and salt stresses and extends the storage time of yeast cells.

关键词: GO     yeast     polyelectrolyte     cytoprotection     nanomaterials    

Effective degradation of tetracycline by mesoporous Bi

Xiaolong CHU,Guoqiang SHAN,Chun CHANG,Yu FU,Longfei YUE,Lingyan ZHU

《环境科学与工程前沿(英文)》 2016年 第10卷 第2期   页码 211-218 doi: 10.1007/s11783-014-0753-y

摘要: Bi WO was synthesized with a hydrothermal method at different pHs and used for the degradation of tetracycline (TC) in water. The mesoporous Bi WO prepared at pH 1 (BWO-1) displayed the highest adsorption and degradation capacity to TC due to its large surface area and more efficient capacity to separate photogenerated electrons and holes. 97% of TC at 20 mg·L was removed by BWO-1 at 0.5 g·L after 120 min irradiation under simulated solar light. Only 31% of the total organic carbon (TOC) was removed after 360 min irradiation although the TC removal reached 100%, suggesting that TC was mainly transformed to intermediate products rather than completely mineralized. The intermediates were identified by high-performance liquid chromatography-time of flight-mass spectrometry (HPLC-TOF-MS) and possible photodegradation pathways were proposed.

关键词: Bi2WO6     hydrothermal synthesis     tetracycline (TC)     photocatalysis    

Theoretical analysis of novel weak current sensor using FeCuNbSiB single nanocrystalline toroidal core and double-winding

BAO Bing-hao, ZHU Da-qi, DING Jian-ning, LI Chang-sheng

《机械工程前沿(英文)》 2006年 第1卷 第4期   页码 439-442 doi: 10.1007/s11465-006-0054-7

摘要: An FeCuNbSiB nanocrystalline toroidal core made by isothermal furnace annealing shows good thermal stability of magnetic properties and excellent soft magnetic properties due to the full release of the internal stresses of the core during the annealing process. Based on the feature of the magnetic core, a novel non-contact type weak current sensor adopting single nanocrystalline core and double-winding excited by multivibrator bridge is proposed. The measuring principles for static current are given in theory by an established mathematical model of the sensor. The theory is in good agreement with the experimental results and it indicated clearly the key factors affecting performance parameters for the sensor. The multivibrator bridge output signal was analyzed by Fourier transform. Furthermore, according to the theoretical results, the method to design the signal conditioning circuit was introduced.

关键词: measuring     mathematical     Furthermore     transform     FeCuNbSiB nanocrystalline    

标题 作者 时间 类型 操作

Spatial and Temporal Distribution of PM

Xiao-hong Chen,Xiang-bo Tang

期刊论文

System and prospects of China’s intercity rail transit technology

Ming GONG

期刊论文

位移测量光栅干涉仪综述

Peng-cheng HU, Di CHANG, Jiu-bin TAN, Rui-tao YANG, Hong-xing YANG, Hai-jin FU

期刊论文

现代城市低碳路径与技术分析——沈阳市的案例研究

刘竹,耿涌 , 薛冰,董会娟

期刊论文

Concentrations and classification of HCHs and DDTs in soil from the lower reaches of the Jiulong River, China

Jiaquan ZHANG, Shihua QI, Xinli XING, Lingzhi TAN, Wei CHEN, Ying HU, Dan YANG, Chenxi WU

期刊论文

Source apportionment of ambient PM

Bo HAN, Xiaohui BI, Yonghua XUE, Jianhui WU, Tan ZHU, Baogui ZHANG, Jianqing DING, Yuanxin DU

期刊论文

Design of tandem genes cluster for isoflavone engineering

Xunli XIA PhD , Guangxiao YANG PhD , Guangyuan HE PhD ,

期刊论文

Understanding high-emitting households in the UK through a cluster analysis

Xinfang WANG, Ming MENG

期刊论文

Pt-Ni nanourchins as electrocatalysts for oxygen reduction reaction

Qiaowan CHANG, Yuan XU, Shangqian ZHU, Fei XIAO, Minhua SHAO

期刊论文

Scaling up of cluster beam deposition technology for catalysis application

期刊论文

A driving pulse edge modulation technique and its complex programming logic devices implementation

Xiao CHEN,Dong-chang QU,Yong GUO,Guo-zhu CHEN

期刊论文

含有任意边界的m×n阶RLC网络的等效复阻抗特性

Zhi-zhong TAN, Hong ZHU, Jihad H. ASAD, Chen XU, Hua TANG

期刊论文

A cytoprotective graphene oxide-polyelectrolytes nanoshell for single-cell encapsulation

Luanying He, Yulin Chang, Junhao Zhu, Ying Bi, Wenlin An, Yiyang Dong, Jia-Hui Liu, Shihui Wang

期刊论文

Effective degradation of tetracycline by mesoporous Bi

Xiaolong CHU,Guoqiang SHAN,Chun CHANG,Yu FU,Longfei YUE,Lingyan ZHU

期刊论文

Theoretical analysis of novel weak current sensor using FeCuNbSiB single nanocrystalline toroidal core and double-winding

BAO Bing-hao, ZHU Da-qi, DING Jian-ning, LI Chang-sheng

期刊论文