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| 1 | Contrasting trends of PM2.5 and surface-ozone concentrations in China from 2013 to 2017显示文摘Although much attention has been paid to investigating and controlling air pollution in China,the trends of air-pollutant concentrations on a national scale have remained unclear.Here,we quantitatively investigated the variation of air pollutants in China using long-term comprehensive data sets from 2013 to 2017,during which Chinese government made major efforts to reduce anthropogenic emission in polluted regions.Our results show a significant decreasing trend in the PM2.5 concentration in heavily polluted regions of eastern China,with an annual decrease of〜7%compared with measurements in 2013.The measured decreased concentrations of SO2>NO2 and CO(a proxy for anthropogenic volatile organic compounds)could explain a large fraction of the decreased PM2.5 concentrations in different regions.As a consequence;the heavily polluted days decreased significantly in corresponding regions.Concentrations of organic aerosol;nitrate;sulfate,ammonium and chloride measured in urban Beijing revealed a remarkable reduction from 2013 to 2017;connecting the decreases in aerosol precursors with corresponding chemical components closely.However;surface-ozone concentrations showed increasing trends in most urban stations from 2013 to 2017;which indicates stronger photochemical pollution.The boundary-layer height in capital c让ies of eastern China showed no significant trends over the Beijing-Tianjin-Hebei,Yangtze River Delta and Pearl River Delta regions from 2013 to 2017;which confirmed the reduction in anthropogenic emissions.Our results demonstrated that the Chinese government was successful in the reduction of particulate matter in urban areas from 2013 to 2017,although the ozone concentration has increased significantly;suggesting a more complex mechanism of improving Chinese air quality in the future. | Yonghong Wang Wenkang Gao Shuai Wang Tao Song Zhengyu Gong Dongsheng Ji Lili Wang Zirui Liu Guiqian Tang Yanfeng Huo Shili Tian Jiayun Li Mingge Li Yuan Yang Biwu Chu Tuukka Petaja Veli-Matti Kerminen Hong He Jiming Hao Markku Kulmala Yuesi Wang Yuanhang Zhang | 2020 | National Science Review2020，7，8： | 51 |
| 2 | Trends in particulate matter and its chemical compositions in China from 2013–2017显示文摘Accurate determination of the atmospheric particulate matter mass concentration and chemical composition is helpful in exploring the causes and sources of atmospheric enthalpy pollution and in evaluating the rationality of environmental air quality control strategies.Based on the sampling and chemical composition data of PM2.5 in different key regions of China in the CARE-China observation network,this research analyzes the environmental air quality data released by the China National Environmental Monitoring Centre during the studied period to determine the changes in the particulate matter mass concentration in key regions and the evolution of the corresponding chemical compositions during the implementation of the Action Plan for Prevention and Control of Air Pollution from 2013-2017.The results show the following.(1)The particulate matter mass concentration in China showed a significant downward trend;however,the PM2.5 annual mass concentration in 64%of cities exceeds the New Chinese Ambient Air Quality Standard(CAAQS)GradeⅡ(GB3095-2012).The region to the east of the Taihang Mountains,the Fenhe and Weihe River Plain and the Urumqi-Changji regions in Xinjiang,all have PM2.5 concentration loading that is still high,and heavy haze pollution occurred frequently in the autumn and winter.(2)During the heavy pollution in the autumn and winter,the concentrations of sulfate and organic components decreased significantly.The mean SO42-concentration in PM2.5 decreased by 76%,12%,81%and 38%in Beijing-Tianjin-Hebei(BTH),the Pearl River Delta(PRD),the Sichuan-Chongqing region(SC)and the Fenhe and Weihe River Plain,respectively.The mean organic matter(OM)concentration decreased by 70%,44%,48%and 31%,respectively,and the mean concentration of NH4+decreased by 68%,1.6%,38%and 25%,respectively.The mean elemental carbon(EC)concentration decreased by 84%and 20%in BTH and SC,respectively,and it increased by 61%and 11%in the PRD and Fenhe and Weihe River Plain,respectively.The mean concentration of mineral and unresolved chemical components(MI)dropped by 70%,24%and 13%in BTH,the PRD and the Fenhe and Weihe River Plain,respectively.The change in the PM2.5 chemical composition is consistent with the decrease of the PM2.5mass concentration.(3)In 2015,the mean OM concentration contributions to fine particles and coarse particles were 13-46%and 46-57%,respectively,and the mean MI concentration contributions to fine particles and coarse and particles were 31-60%and 39-73%,respectively;these values are lower than the 2013 values from the key regions,which is the most important factor behind the decrease of the particulate matter mass concentration.From 2013 to 2015,among the chemical components of different particle size fractions,the peak value of the coarse particle size fraction decreased significantly,and the fine particle size fractions of SO42-,NO3-,and NH4+decreased with the decrease of the particulate matter mass concentration in different particle size fractions.The fine-particle size peaks of SO42-,NO3-and NH4+shifted from 0.65-1.1μm to the finer size range of0.43-0.65μm during the same time frame. | Yuesi WANG Wenjie LI Wenkang GAO Zirui LIU Shili TIAN Rongrong SHEN Dongsheng JI Shuai WANG Lili WANG Guiqian TANG Tao SONG Mengtian CHENG Gehui WANG Zhengyu GONG Jiming HAO Yuanhang ZHANG | 2019 | Science China Earth Sciences2019，62，12： | 23 |
| 3 | From concept to reality-A review to the primary test stand and its preliminary application in high energy density physics显示文摘Pulsed power technology,whereas the electrical energy stored in a relative long period is released in much shorter timescale,is an efficient method to create high energy density physics(HEDP)conditions in laboratory.Around the beginning of this century,China Academy of Engineering Physics(CAEP)began to build some experimental facilities for HEDP investigations,among which the Primary Test Stand(PTS),a multi-module pulsed power facility with a nominal current of 10 MA and a current rising time~90 ns,is an important achievement on the roadmap of the electro-magnetically driven inertial confinement fusion(ICF)researches.PTS is the first pulsed power facility beyond 10 TW in China.Therefore,all the technologies have to be demonstrated,and all the engineering issues have to be overcome.In this article,the research outline,key technologies and the preliminary HEDP experiments are reviewed.Prospects on HEDP research on PTS and pulsed power development for the next step are also discussed. | Jianjun Deng Weiping Xie Shuping Feng Meng Wang Hongtao Li Shengyi Song Minghe Xia Ji Ce An He Qing Tian Yuanchao Gu Yongchao Guan Bin Wei Xianbin Huang Xiaodong Ren Jiakun Dan Jing Li Shaotong Zhou Hongchun Cai Siqun Zhang Kunlun Wang Qiang Xu Yujuan Wang Zhaohui Zhang Guilin Wang Shuai Guo Yi He Yiwei Zhou Zhanji Zhang Libing Yang Wenkang Zou | 2016 | Matter and Radiation at Extremes2016，1，1： | 19 |
| 4 | Evolution of boundary layer ozone in Shijiazhuang,a suburban site on the North China Plain显示文摘The structure of the boundary layer affects the evolution of ozone(O3), and research into this structure will provide important insights for understanding photochemical pollution.In this study, we conducted a one-month observation(from June 15 to July 14, 2016) of the boundary layer meteorological factors as well as O3 and its precursors in Luancheng County,Shijiazhuang(37°53′N, 114°38′E). Our research showed that photochemical pollution in Shijiazhuang is serious, and the mean hourly maximum and mean 8-hr maximum O3 concentrations are 97.9 ± 26.1 and 84.4 ± 22.4 ppbV, respectively. Meteorological factors play a significant role in the formation of O3. High temperatures and southeasterly winds lead to elevated O3 values, and at moderate relative humidity(40%–50%) and medium boundary layer heights(1200–1500 m), O3 production sensitivity occurred in the transitional region between volatile organic compounds(VOC) and nitrogen oxides(NOx) limitations,and the O3 concentration was the highest. The vertical profiles of O3 were also measured by a tethered balloon. The results showed that a large amount of O3 was stored in the residual layer, and the concentration was positively correlated with the O3 concentration measured the previous day. During the daytime of the following day, the contribution of O3 stored in the residual layer to the boundary layer reached 27%± 7% on average. | Wei Zhao Guiqian Tang Huan Yu Yang Yang Yinghong Wang Lili Wang Junlin An Wenkang Gao Bo Hu Mengtian Cheng Xingqin An Xin Li Yuesi Wang | 2019 | Journal of Environmental Sciences2019，31，9： | 15 |
| 5 | Characteristics of PM_(2.5) pollution in Beijing after the improvement of air quality显示文摘Following the implementation of the strictest clean air policies to date in Beijing,the physicochemical characteristics and sources of PM_(2.5) have changed over the past few years.To improve pollution reduction policies and subsequent air quality further,it is necessary to explore the changes in PM_(2.5) over time.In this study,over one year(2017-2018)field study based on filter sampling(TH-150C;Wuhan Tianhong,China)was conducted in Fengtai District,Beijing,revealed that the annual average PM_(2.5) concentration(64.8±43.1μg/m^3)was significantly lower than in previous years and the highest PM_(2.5) concentration occurred in spring(84.4±59.9μg/m^3).Secondary nitrate was the largest source and accounted for 25.7%of the measured PM_(2.5).Vehicular emission,the second largest source(17.6%),deserves more attention when considering the increase in the number of motor vehicles and its contribution to gaseous pollutants.In addition,the contribution from coal combustion to PM_(2.5) decreased significantly.During weekends,the contribution from EC and NO3−increased whereas the contributions from SO4^2−,OM,and trace elements decreased,compared with weekdays.During the period of residential heating,PM_(2.5) mass decreased by 23.1%,compared with non-heating period,while the contributions from coal combustion and vehicular emission,and related species increased.With the aggravation of pollution,the contribution of vehicular emission and secondary sulfate increased and then decreased,while the contribution of NO3−and secondary nitrate continued to increase,and accounted for 34.0%and 57.5%of the PM_(2.5) during the heavily polluted days,respectively. | Xiaojuan Huang Guiqian Tang Junke Zhang Baoxian Liu Chao Liu Jin Zhang Leilei Cong Mengtian Cheng Guangxuan Yan Wenkang Gao Yinghong Wang Yuesi Wang | 2021 | Journal of Environmental Sciences2021，33，2： | 14 |
| 6 | Transparently curved metamaterial with broadband millimeter wave absorption显示文摘We present a conformal metamaterial with simultaneous optical transparency and broadband millimeter-wave absorption for a curved surface. By tailoring the reflection response of meta-atoms at oblique angles, it is possible to achieve excellent absorption performance from 26.5 to 40.0 GHz within a wide angular range from 0° to 60°for transverse-electric and transverse-magnetic waves. In the meantime, by employing transparent substrates,including polyvinyl chloride and polyethylene terephthalate, good optical transmittance(80.1%) and flexibility are obtained simultaneously. The reflectivity of a curved metallic surface coated with the proposed curved metamaterial is simulated and measured experimentally. Both results demonstrate excellent absorption performance of the metamaterial, which is highly favored for practical applications. | CHENG ZHANG JIN YANG WENKANG CAO WEI YUAN JUNCHEN KE LIUXI YANG QIANG CHENG TIEJUN CUI | 2019 | Photonics Research2019，7，4： | 7 |
| 7 | Applications of Acrylate-based Polymer and Silicone Resin on LPFG-based Devices显示文摘Both acrylate based polymer and silicone resin are proposed as recoating materials surrounding LPFGs for purposes of different applications. For the LPFG recoated with a thin layer of acrylate based polymer, the range of wavelength shift as much as 60nm is expected when temperature changes from 0~100℃. As for that with surrounding material of silicone resin, the temperature stability is greatly improved depicted as the maximum wavelength shift of about 0.6nm with the same temperature variation. The former is potentially a broadband tunable band rejection filter or temperature sensor with enhanced sensitivity. And the latter could be applied as temperature insensitive filter, demultiplexer or strain sensor. | 何万迅 Shi Wenkang Gong Xiangyang Ye Ailun GAO Kan Fang Zujie | 2002 | High Technology Letters2002，8，2： | 4 |
| 8 | Sequential changes of serum ferritin levels and their clinical significance in lamivudine-treated patients with chronic viral hepatitis B显示文摘AIM: To study the sequential changes of serum ferritin levels in lamivudine-treated patients with chronic viral hepatitis B and the clinical implications. METHODS: Thirty-eight patients with chronic viral hepatitis B were prospectively studied during their treatment with lamivudine. Each patient received 100 mg oral lamivudine daily for 12 mo, and was observed and tested for blood biochemistry and hepatitis B virus (HBV) DNA levels and serum ferritin levels at baseline and at 3, 6 and 12 mo during the treatment. Serum HBV DNA levels were quantitatively determined using fluorescent quantitative polymerase chain reaction (FQ-PCR), and serum ferritin levels were measured by radioimmunoassay. The sequential changes of serum ferdtin levels and their relationships with virological, serological and biochemical responses in the patients were analyzed. RESULTS: All the patients had a baseline HBV DNA level higher than 1×10^7 copies/L as determined by FQ-PCR and positive HBsAg and HBeAg and abnormal ALT levels. At the end of the 12-mo treatment, 19 of the 38(50.00%) patients had undetectable serum HBV DNA levels by FQ-PCR, and 12(31.58%) became negative for serum HSeAg and 10(26.32%) had seroconversion from HBeAg to HBeAb. Nineteen out of the 38(50.00%) patients had biochemically normal ALT levels after 12-mo lamivudine treatment. Sequential determination showed bhat lamivudine treatment significantly reduced ferritin levels in chronic hepatitis B patients. When the patients were divided into different groups according to their posttreatment virological, serological and biochemical responses for analysis of the sequential changes of ferritin levels, it was found bhat the decrease of ferritin levels in HBV DNA-negative group was significantly more obvious than that in HBV DNApositive group at 6 mo during the treatment (P=-0.013). Consecutive comparisons showed that ferritin levels at 3 mo of treatment were obviously decreased as compared with the baseline levels (P<0.05) in HBeAg-negative group, and the decrease of serum ferritin levels in patients with normalized ALT was more significant than that in patients with abnormal ALT at the end of the 12-mo treatment (P=0.048). CONCLUSION: Lamivudine treatment can reduce the serum ferritin levels in chronic viral hepatitis B patients and decreases of ferdtin levels can be more significant in patients exhibiting virological, serological and biochemical responses, indicating that dynamic observation of serum ferritin levels in patients with chronic viral hepatitis B during lamivudine treatment might be helpful for monitoring and predicting patients' responses to the therapy. | Zheng-WenLiu Qun-YingHan NiZhang WenKang | 2004 | World Journal of Gastroenterology2004，10，7： | 4 |
| 9 | Electric Load Clustering in Smart Grid:Methodologies,Applications,and Future Trends显示文摘With the increasingly widespread of advanced metering infrastructure,electric load clustering is becoming more essential for its great potential in analytics of consumers’energy consumption patterns and preference through data mining.Moreover,a variety of electric load clustering techniques have been put into practice to obtain the distribution of load data,observe the characteristics of load clusters,and classify the components of the total load.This can give rise to the development of related techniques and research in the smart grid,such as demand-side response.This paper summarizes the basic concepts and the general process in electric load clustering.Several similarity measurements and five major categories in electric load clustering are then comprehensively summarized along with their advantages and disadvantages.Afterwards,eight indices widely used to evaluate the validity of electric load clustering are described.Finally,vital applications are discussed thoroughly along with future trends including the tariff design,anomaly detection,load forecasting,data security and big data,etc. | Caomingzhe Si Shenglan Xu Can Wan Dawei Chen Wenkang Cui Junhua Zhao | 2021 | Journal of Modern Power Systems and Clean Energy2021，9，2： | 4 |
| 10 | Experts' Knowledge Fusion in Model-Based Diagnosis Based on Bayes Networks显示文摘In previous researches on a model-based diagnostic system, the components are assumed mutually independent. Howerver , the assumption is not always the case because the information about whether a component is faulty or not usually influences our knowledge about other components. Some experts may draw such a conclusion that 'if component m 1 is faulty, then component m 2 may be faulty too'. How can we use this experts’ knowledge to aid the diagnosis? Based on Kohlas’s probabilistic assumption-based reasoning method, we use Bayes networks to solve this problem. We calculate the posterior fault probability of the components in the observation state. The result is reasonable and reflects the effectiveness of the experts’ knowledge. | Deng Yong & Shi Wenkang School of Electronics & Information Technology, Shanghai Jiaotong University, Shanghai 200030, P. R. China | 2003 | Journal of Systems Engineering and Electronics2003，14，2： | 4 |
| 11 | Lamb wave sensors array for nonviscous liquid sensing显示文摘The interdigital transducer (IDT) can excite Lamb wave in a piezoelectric plate loading with a liquid layer, and the phase velocity of Lamb wave is associated with the properties of the liquid layer. In this paper, the concept of effective permittivity is introduced to study the Lamb wave's potential application in liquid sensing. Considering the measuring of ideal nonviscous liquid, the sensors array is designed to sense the density and the dielectric constant of the liquid layer simultaneously. Using LiNbO3 as piezoelectric material, in order to improve the sensors array sensitivity and the electro-mechanical coupling coefficient, the optimized results including plate thicknesses and cut orientations are presented by numerical simulation. These studies show that the Lamb wave sensors array can be potential in liquid sensing. | CHEN Zhijun HAN Tao JI Xiaojun GUO Huawei SHI Wenkang | 2006 | Science China(Physics,Mechanics & Astronomy)2006，49，4： | 3 |
| 12 | A vector inserting TPG for BIST design with low peak power consumption显示文摘 | 谈恩民 Song Shengdong Shi Wenkang | 2007 | High Technology Letters2007，13，4： | 2 |
| 13 | PD-based trajectory tracking control in automatic cell injection system显示文摘Trajectory tracking technology has been the focus of industrial manipulatory applications for many years, and its research has been found in micromanipulation in bioengineering recently. In this paper, a hybrid vision and force control method is applied to the automatic cell injection. The three-dimensional cell injection process involves the trajectory tracking in free space and the force control in contact space. A PD plus feedforward compensation control method is applied to the trajectory tracking in 3D space. Further, a PD-based robust controller is introduced into trajectory tracking while the systemic uncertainty of the cell injection is additionally considered. Both of the two control methods are theoretically proved to be exponential convergent. Finally, the effectiveness of the proposed method is verified as compared with other control methods by its application to trajectory tracking problem. | Wenkang XU Chenxiao CAI Yun ZOU | 2013 | 控制理论与应用(英文版)2013，11，2： | 2 |
| 14 | Temperature Characteristics of Surface Acoustic Waves Propagating on La_3Ga_5SiO_4 Substrates显示文摘Langasite (LGS) is a novel piezoelectric crystal. The authors numerically analyses the temperature stability of surface acoustic waves (SAW) and the relation of SAW propagation with temperature on certain optimal cuts on LGS in this paper. The results show that LGS has better temperature stability than traditional piezo crystals. The results alsodemonstrate that the velocity of SAW decrease with temperature, the electro-mechanical coupling constant (k2) and temperature coefficient of frequency increases parabolically and the power flow angle increases linearly on certain optimal cuts of LGS. The calculation result compared with the experimental and show good agreement. | Guowei ZHANG, Wenkang SHI, Xiaojun JI, Tao HAN, Feng DU and Lianger LISchool of Electronics & Information, Shanghai Jiao Tong University, Shanghai 200030, China | 2004 | Journal of Materials Science & Technology2004，20，1： | 2 |
| 15 | Optimal pressure-sensitive cuts for surface acoustic waves on langasite显示文摘The crystal langasite manifests its unique advantages and potentials for high temperature applications due to a high electromechanical coupling coefficient, temperature compensated orientations for surface acoustic wave (SAW), and temperature stability. In order to analyze the pressure-induced frequency shift in SAW resonator type sensors at high temperature, this paper presents the electroelastic wave equations employing the effective material constants for small vibrations superimposed on biases originated from homogeneous temperature and external pressure fields in the Lagrangian description. Incorporated with the first-order perturbation integration, a model including both the mechanical and electrical perturbation items originating from thermal biases and small pressure fields is proposed. This universal model is suitable for substrate with high piezoelectricity and can be applied at either room temperature or high temperature circumstance. The criteria of optimal cuts for SAW pressure sensitivity, i.e., high electromechanical coupling coefficient and low temperature coefficient of delay, are proposed. A thorough investigation in trebly rotated cuts has shown that optimal pressure sensitive crystallographic areas can be obtained. The areas suitable for pressure sensors at room temperature are defined with Euler angles?1: φ = 0°―0.6°, θ = 144.4°―145.8°, ψ = 23.2°―24.1°, ?2: φ =59.4°―61°, θ = 34.2°―36.2°, ψ = 24.1°―22.3°, ?3: φ =119°―120°, θ = 143.8°―145.5°, ψ = 22.3°―23.5°.The areas suitable for pressure sensors at high temperature are defined with Euler anglesI: φ = 8°―30°, θ = 24°―36°, ψ = 4°―25°, II: φ = 30°―55°, θ = 144°―158°, ψ = 4°―28°.A set of experiments employing LGS (0, 150°, 22°) and (0, 90°, 0) has been performed to check the validity of the proposed calculation. The experimental relative sensitivity is in excellent agreement with the theoretical results. | HAN Tao JI Xiaojun SHI Wenkang | 2006 | Science in China(Series F)2006，49，2： | 2 |
| 16 | Combining belief functions based on distance of evidence 显示文摘 | Deng Yong Shi Wenkang Zhu Zenfu | 2004 | Decision Support Systems2004，38，3： | 1 |
| 17 | Effects of electron flow current density on flow impedance of magnetically insulated transmission lines显示文摘 | He Yong Zou Wenkang Song Shengyi | | 0，，： | 1 |
| 18 | A NORMAL YIELD TABLE FOR LARIX GMELINII INDAXIN GANLING BASED ON THE MAXIMUM GROWTH RATE METHOD显示文摘Normal yield tables for Larix gmelimii(Rupr) Rupr were constructed from 228 tem-porary sample plois.A normal stand was defined as having the maximum growh rate parameter,based on the theory of forest growth.Basal area growth curves were described with Richard’s equa-tion according to Von-Bertalanfy’s growth theory and allometric law.The growth rate parameterwas found to be K,so a normal stand had maximum K.Thus the basal area growth curve of a nor-mal stand was obtaied simply by increasing K.A normal yield table for L.gmelinii of Daxinganlingnatural forest was then constructed. | Weng Guoqing Hao Wenkang Lee LongchangNortheast Forestry University, Harbin 150040 P. R. China | 1990 | Journal of Northeast Forestry University1990，1，1： | 1 |
| 19 | The designand the first test results of a fast LTD stage显示文摘 | CHEN Lin ZHOU Liangji ZOU Wenkang | 2009 | ACTA Physi-ca Polonica2009，115，6： | 1 |
| 20 | Combining belief function based on distance function显示文摘 | Deng Yong Shi Wenkang Liu Qi | 2004 | Decision Support Systems2004，38，3： | 1 |
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