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    题名 作者 年代 出处 被引量
1Detection of nighttime sea fog/stratus over the Huang-hai Sea using MTSAT-1R IR data显示文摘A dual channel difference (DCD) method is applied to detect nighttime sea fog/stratus over the Huanghai Sea using the infrared (IR) data of shortwave (3.5–4.0 μm) and longwave (10.3–11.3 μm) channels from the Multi-functional Transport Satellite (MTSAT)-1R, i.e., shortwave minus longwave brightness temperature difference (SLTD). Twenty-four sea fog events over the Huanghai Sea during March to July of 2006 and 2007 are chosen to determine a suitable value of SLTD for nighttime sea fog/stratus detection, and it is found that the value of –5.5––2.5°C can be taken as a criterion. Two case examples of sea fog events are especially demonstrated in detail utilizing the criterion, and the results show that the derived sea fog/stratus coverage is quite reasonable. This coverage information is very helpful to analyze the formation and evolution of sea fog/stratus during night and can provide sea fog researchers with observational evidences for model results verification. However, more efforts are needed to further obtain vertical extent information of sea fog/stratus and attempt to discriminate between sea fog and stratus.GAO Shanhong WU Wei ZHU Leilei FU Gang HUANG Bin 2009Acta Oceanologica Sinica2009,28,2:36
2Enhancement of human ACAT1 gene expression to promote the macrophage-derived foam cell formation by dexamethasone显示文摘In macrophages, the accumulation of cholesteryl esters synthesized by the activated acyl-coenzyme A:cholesterol acyltransferase-1 (ACAT1) results in the foam cell formation, a hallmark of early atherosclerotic lesions. In this study,with the treatment of a glucocorticoid hormone dexamethasone (Dex), lipid staining results clearly showed the large accumulation of lipid droplets containing cholesteryl esters in THP- 1-derived macrophages exposed to lower concentration of the oxidized low-density lipoprotein (ox-LDL). More notably, when treated together with specific anti-ACAT inhibitors, the abundant cholesteryl ester accumulation was markedly diminished in THP-l-derived macrophages, confirming that ACAT is the key enzyme responsible for intracellular cholesteryl ester synthesis. RT-PCR and Western blot results indicated that Dex caused up-regulation of human ACAT1 expression at both the mRNA and protein levels in THP-1 and THP- 1-derived macrophages. The luciferase activity assay demonstrated that Dex could enhance the activity of human ACAT1 gene P1 promoter, a major factor leading to the ACAT1 activation, in a cell-specific manner.Further experimental evidences showed that a glucocorticoid response element (GRE) located within human ACAT1gene P1 promoter to response to the elevation of human ACAT1 gene expression by Dex could be functionally bound with glucocorticoid receptor (GR) proteins. These data supported the hypothesis that the clinical treatment with Dex,which increased the incidence of atherosclerosis, may in part due to enhancing the ACAT1 expression to promote the accumulation of cholesteryl esters during the macrophage-derived foam cell formation, an early stage of atherosclerosis.LiYANG JinBoYANG JiaCHEN GuangYaoYU PeiZHOU LeiLEI ZhenZhenWANG CatherineCYCHANG XinYingYANG TaYuanCHANG BoLiangLI 2004Cell Research2004,14,4:24
3ABO sequence analysis in an AB type with anti-B patient显示文摘ABO blood group system is the first to be discovered and the most clinically important in transfusion medicine.1The ABO gene encodes a glycosyltransferase which synthesize the oligosaccharide epitopes.The difference between the consensus A gene (A101 allele) usually used as the reference and the consensus B gene (B101 allele) are 7 in-frame single nucleotide polymorphisms (SNPs),among which only 4 alleles cause amino acid mutations in the enzyme.When A allele was inherited from one parent and B allele was inherited from the other which produced the AB blood group,this is known as trans-AB.Cis-AB is characterized as mutant ABO alleles encoding a glycosyltransferase capable of synthesizing both A and B antigens which is very rare.Chen Qing Xiao Jianyu Wang Shuya Li Jiahuang Du Leilei Lu Le Huang Chengyin Li Min Li Ping 2014Chinese Medical Journal2014,,5:17
4The Clinical Outcomes of Three Surgical Managements on Primary Angle-closure Glaucoma显示文摘Purpose: To investigate the efficacy of trabeculectomy, phacotrabeculectomy and phaco-emulsification in the management of primary angle closure glaucoma (PACG). Methods: A prospective observational study was performed in 88 chronic PACG patients (97 eyes) who were divided into three groups following defined indications to receive different surgical interventions. The indications and clinical outcomes were evaluated. The mean follow-up was (17.7±4.9) months. Results: Success rate in trabeculectomy, phacotrabeculectomy and phacoemulsification group was 81.08%, 78.57‰ and 81.25‰, respectively. The anterior chamber depth was deeper and the angle was wider postoperatively vs. preoperatively both in phaco-trabeculectomy and phacoemulsification group. No obvious changes were seen in trabeculectomy group. The coefficient of outflow facility of aqueous humor (C values) significantly increased in three groups postoperatively (P < 0.01). No severe intra-operative complications were found and the incidence of postoperative complications was low. Five eyes sustained hypotony 3±1.87 months in trabeculectomy group and 1 eye happened malignant glaucoma in phacotrabeculectomy group. The visual acuity in patients with phacotrabeculectomy plus intraocular lens implantation and those only with phacoemulsification plus intraocular lens implantation were improved 78.57% and 93.74%, respectively. No significant improvement was found in trabeculectomy group (χ2 = 47.10, P < 0.001). Conclusion: Three surgical interventions were beneficial to manage PACG and with co-existing cataract. The indication choosing was suggested according to visual acuity, angle closure circumference, cataract, medication requirements and optic nerve damage. Phacotrabeculectomy was recommended for angle closed ≥180° circumference while phacoemulsification for angle closed < 180°.Xiulan Zhang Leilei Teng Ang Li Shaolin Du Yunyun Zhu Jian Ge 2007眼科学报2007,23,2:16
5Lightweight Design of Automobile Drive Shaft Based on the Characteristics of Low Amplitude Load Strengthening显示文摘There are two kinds of internationally recognized approaches in terms of lightweight design.One is based on fatigue accumulated damage theory to achieve better reliability by optimal structural design;another is to use high performance lightweight materials.The former method takes very few considerations on the structural strengthening effects caused by the massive small loads in service.In order to ensure safety,the design is usually conservative,but the strength potential of the component is not fully exerted.In the latter method,cost is the biggest obstacle to lightweight materials in automotive applications.For the purpose of light weighting design on a fuel cell vehicle,the new design method is applied on drive shafts.The method is based on the low amplitude load strengthening characteristics of the material,and allows the stress,corresponding to test load,to enter into the strengthened range of the material.Under this condition,the light weighting design should assure that the reliability of the shaft is not impaired,even maximizes the strength potential of machine part in order to achieve the weight reduction and eventually to reduce the cost.At last,the feasibility of the design is verified by means of strength analysis and modal analysis based on the CAD model of light weighted shaft.The design applies to the load case of half shaft in independent axle,also provides technological reference for the structural lightweight design of vehicles and other machineries.ZHENG Songlin XU Honghui FENG Jinzhi ZHENG Zuanxi WANG Youtao LU Leilei 2011Chinese Journal of Mechanical Engineering2011,24,6:16
6Single-atom catalyst: a rising star for green synthesis of fine chemicals显示文摘The green synthesis of fine chemicals calls for a new generation of efficient and robust catalysts. Single-atom catalysts(SACs), in which all metal species are atomically dispersed on a solid support, and which often consist of well-defined mononuclear active sites, are expected to bridge homogeneous and heterogeneous catalysts for liquid-phase organic transformations. This review summarizes major advances in the SAC-catalysed green synthesis of fine chemicals in the past several years, with a focus on the catalytic activity, selectivity and reusability of SACs in various organic reactions. The relationship between catalytic performance and the active site structure is discussed in terms of the valence state, coordination environment and anchoring chemistry of single atoms to the support, in an effort to guide the rational design of SACs in this special area, which has traditionally been dominated by homogeneous catalysis.Finally, the challenges remaining in this research area are discussed and possible future research directions are proposed.Leilei Zhang Yujing Ren Wengang Liu Aiqin Wang Tao Zhang 2018National Science Review2018,5,5:15
7Experimental study of an anti-icing method over an airfoil based on pulsed dielectric barrier discharge plasma显示文摘Aircraft icing has long been a plague to aviation for its serious threat to flight safety. Even though lots of methods for anti-icing have been in use or studied for quite a long time, new methods are still in great demand for both civil and military aircraft. The current study in this paper uses widely used Dielectric Barrier Discharge(DBD) plasma actuation to anti-ice on a NACA0012 airfoil model with a chord length of 53.5 cm in a closed-circuit icing wind tunnel. An actuator was installed at the leading edge of the airfoil model, and actuated by a pulsed low-temperature plasma power source. The actuator has two types of layout, a striped electrode layout and a meshy electrode layout.The ice accretion process or anti-icing process was recorded by a CCD camera and an infrared camera. Instantaneous pictures and infrared contours show that both types of DBD plasma actuators have the ability for anti-ice under a freestream velocity of 90 m/s, a static temperature of -7℃,an Median Volume droplet Diameter(MVD) of 20 lm, and an Liquid Water Content(LWC) of 0.5 g/m^3. The detected variations of temperatures with time at specific locations reveal that the temperatures oscillate for some time after spraying at first, and then tend to be nearly constant values.This shows that the key point of the anti-icing mechanism with DBD plasma actuation is to achieve a thermal equilibrium on the model surface. Besides, the power consumption in the anti-icing process was estimated in this paper by Lissajous figures measured by an oscilloscope, and it is lower than those of existing anti-icing methods. The experimental results presented in this paper indicate that the DBD plasma anti-icing method is a promising technique in the future.Yongqiang TIAN Zhengke ZHANG Jinsheng CAI Leilei YANG Lei KANG 2018Chinese Journal of Aeronautics2018,31,7:15
81990—2017年中国伤害负担:2017年全球疾病负担研究结果(摘译)显示文摘伤害是全球性的公共卫生挑战,涉及各年龄组和不同性别的人群。过去三十年来,中国经济快速发展,人口老龄化趋势加重,社会呈现出城镇化、机动化和老龄化等特征。随着人们生活环境和生活方式的改变,伤害已跃居人群致死原因第五位,仅排在恶性肿瘤、心脑血管疾病、呼吸系统疾病和心肌梗死之后。据估计,中国每年在伤害方面消耗的直接医疗费用约为650亿元人民币.林泽婷(译) 吕来文(译) 黄晓晴(译) 李丽萍(审校) Duan Leilei Ye Pengpeng Juanita A Haagsma Jin Ye Wang Yuan Er Yuliang Deng Xiao Gao Xin Ji Cuirong Wang Linhong Marlena S Bannick W Cli Mountjoy-Venning Caitlin N Hawley Zichen Liu Mari Smith Spencer L James Theo Vos Christopher J L Murray 2020伤害医学(电子版)2020,9,2:15
9Characteristics 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 2021Journal of Environmental Sciences2021,33,2:14
10Study on the antiulcer effects of Veronicastrum axillare on gastric ulcer in rats induced by ethanol based on tumor necrosis factor-α(TNF-α)and endothelin-1(ET-1)显示文摘Objective:To assess whether Veronicastrum axillare(V.axillare)can ameliorate ethanol-induced gastric mucosal lesions in rats,reduce the production of pro-inflammatory cytokines,suppress apoptosis and improve local microcirculation disturbances.Methods:Totally 48 male Sprague-Dawley rats were randomly divided into six groups,eight rats in each group.Rats in the normal group and the model group were administered with 0.9%normal saline respectively.Rats in the positive group and ranitidine group were administered with 0.18%ranitidine suspension by intragastric administration respectively.Those in the high dose V.axillare group,the medium dose V.axillare group and the low dose V.axillare group were administrated with V.axillare at the daily dose of 2.8 g/kg,1.4 g/kg and 0.7 g/kg by intragastric administration.Gastric mucosal lesions were produced by intragastric administration of absolute ethanol.Water extract of V.axillare was successively injected for 14 d and last day was injected 1 h before ethanol administration.Gastric mucosal ulcer index and ulcer inhibitory rate were counted by improved Guth methods.The tissue sections were made for pathological histology analysis.Also,we measured the concentrations of tumor necrosis factor-α(TNF-α)and endothelin-1(ET-1)in gastric mucosal,as an index of the pro-inflammatory cytokines,apoptosis and local microcirculation.Besides,the mRNA contents of TNF-αand ET-1 were measured to verify effects on gene expression by real-time fluorescent quantitative PCR.Results:Water extract of V.axillare significantly ameliorated the gastric mucosal lesions induced by ethanol administration(P<0.01).Pro-inflammatory cytokines,TNF-a and ET-1 were increased after ethanol administration and significantly reduced by water extract of V.axillare.The expressions of TNF-αand ET-1 mRNA were also be inhibited by water extract of V.axillare.Conclusion:Current evidences show water extract of V.axillare is effective for defending against ethanol-induced gastric mucosal lesions,significantly inhibiting the production of proinflammatory cytokines and the expressions of TNF-αand ET-1 mRNA,which may be useful for inhibiting apoptosis and improving local microcirculation.Yong Du Weichun Zhao Leilei Lu Jiayan Zheng Xishi Hu Zhehan Yu Lixin Zhu 2013Asian Pacific Journal of Tropical Biomedicine2013,3,12:13
11The Change of the Inlet Geometry of a Centrifugal Compressor Stage and its Influence on the Compressor Performance显示文摘The impact on the compressor performance is important for designing the inlet pipe of the centrifugal compressor of a vehicle turbocharger with different inlet pipes. First, an experiment was performed to determine the compressor performance from three cases: a straight inlet pipe, a long bent inlet pipe and a short bent inlet pipe. Next, dynamic sensors were installed in key positions to collect the sign of the unsteady pressure of the centrifugal compressor. Combined with the results of numerical simulations, the total pressure distortion in the pipes, the pressure distributions on the blades and the pressure variability in the diffuser are studied in detail. The results can be summarized as follows: a bent pipe results in an inlet distortion to the compressor, which leads to performance degradation, and the effect is more apparent as the mass flow rate increases. The distortion induced by the bent inlet is not only influenced by the distance between the outlet of the bent section and the leading edge of the impeller but also by the impeller rotation. The flow fields in the centrifugal impeller and the diffuser are influenced by a coupling effect produced by the upstream inlet distortion and the downstream blocking effect from the volute tongue. If the inlet geometry is changed, the distributions and the fluctuation intensities of the static pressure on the main blade surface of the centrifugal impeller and in the diffuser are changed accordingly.WANG Leilei YANG Ce ZHAO Ben LAO Dazhong MA Chaochen LI Du 2013Journal of Thermal Science2013,22,3:13
12nterferon alpha (IFNα)-induced TRIM22 interrupts HCV 'eplication by ubiquitinating NS5A显示文摘Chen Yang Xinhao Zhao Dakang Sun Leilei Yang Chang Chong Yu Pan Xiumei Chi Yanhang Gao Moli Wang Xiaodong Shi Haibo Sun Juan Lv Yuanda Gao Jin Zhong Junqi Niu Bing Sun 2016Cellular & Molecular Immunology2016,13,1:13
13Effects of subchronic oral toxic metal exposure on the intestinal microbiota of mice显示文摘Oral exposure to toxic metals such as cadmium(Cd), lead(Pb), copper(Cu) and aluminum(Al) can induce various adverse health effects in humans and animals. However, the effects of these metals on the gut microbiota have received limited attention. The present study demonstrated that long-term toxic metal exposure altered the intestinal microbiota of mice in a metal-specific and time-dependent manner.Subchronic oral Cu exposure for eight weeks caused a profound decline in gut microbial diversity in mice,whereas no significant changes were observed in groups treated with other metals. Cd exposure significantly increased the relative abundances of organisms from the genera Alistipes and Odoribacter and caused marked decreases in Mollicutes and unclassified Ruminococcaceae. Pb exposure significantly decreased the abundances of eight genera: unclassified and uncultured Ruminococcaceae, unclassified Lachnospiraceae, Ruminiclostridium_9, Rikenellaceae_RC9_gut_group, Oscillibacter, Anaerotruncus and Lachnoclostridium. Cu exposure affected abundances of the genera Alistipes, Bacteroides,Ruminococcaceae_UCG-014, Allobaculum, Mollicutes_RF9_norank, Rikenellaceae_RC9_gut_group,Ruminococcaceae_unclassified and Turicibacter. Al exposure increased the abundance of Odoribacter and decreased that of Anaerotruncus. Exposure to any metal for eight weeks significantly decreased the abundance of Akkermansia. These results provide a new understanding regarding the role of toxic metals in the pathogenesis of intestinal and systemic disorders in the host within the gut microbiota framework.Qixiao Zhai Tianqi Li Leilei Yu Yue Xiao Saisai Feng Jiangping Wu Jianxin Zhao Hao Zhang Wei Chen 2017Science Bulletin2017,62,12:12
14Mechanism of intercalation and deintercalation of lithium ions in graphene nanosheets显示文摘Graphene nanosheets (GNSs) were synthesized by reducing exfoliated graphite oxides. Their structure, surface morphology and lithium storage mechanism were characterized and investigated systematically using X-ray diffraction, atomic force microscopy, scanning electron microscopy, charge-discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. It was found that the GNSs, which were obtained via chemical synthesis, were primarily less than 10 graphene layers. The GNS electrodes, which were fabricated from the reduced GNSs, exhibited an enhanced reversible lithium storage capacity and good cyclic stability when serving as anodes in lithium-ion batteries. Also, the first-cycle irreversible capacities of the system were relatively high, because of the formation of a solid electrolyte interphase film on the surface of the GNS electrode and the spontaneous stacking of GNSs during the first lithiation. The electrochemical impedance spectroscopy results suggest that the solid electrolyte interphase film on the GNS electrode during first lithiation were primarily formed at potentials between 0.95 and 0.7 V. Also, the symmetry factor of the charge transfer was measured to be 0.446.TIAN LeiLei ZHUANG QuanChao LI Jia SHI YueLi CHEN JianPeng LU Feng SUN ShiGang 2011Chinese Science Bulletin2011,56,30:11
15Quantifying the effects of short-term heat stress at booting stage on nonstructural carbohydrates remobilization in rice显示文摘Extreme heat stress events are becoming more frequent under anticipated climate change,which can have devastating impacts on rice growth and yield.To quantify the effects of short-term heat stress at booting stage on nonstructural carbohydrates(NSC)remobilization in rice,two varieties(Nanjing 41 and Wuyunjing 24)were subjected to 32/22/27°C(maximum/minimum/mean),36/26/31°C,40/30/35°C,and 44/34/39°C for 2,4 and 6 days in phytotrons at booting stage during 2014 and 2015.Yield and yield components,dry matter partitioning index(DMPI),NSC accumulation and translocation were measured and calculated.The results showed that the increase of high-temperature level and duration significantly reduced grain yield by suppressing spikelet number per panicle,seed-setting rate,and grain weight.Heat stress at booting decreased DMPI in panicles,increased DMPI in stems,but had no significant effect on photosynthetic rate.Stem NSC concentration increased whereas panicles NSC concentration,stem NSC translocation efficiency,and contribution of stem NSC to grain yield decreased.Severe heat stress even transformed the stem into a carbohydrate sink during grain filling.The heat-tolerant Wuyunjing 24 showed a higher NSC transport capacity under heat stress than the heat-sensitive Nanjing 41.Heat degree-days(HDD),which combines the effects of the intensity and duration of heat stress,used for quantifying the impacts of heat stress indicates the threshold HDD for the termination of NSC translocation is 9.82°C day.Grain yield was negatively correlated with stem NSC concentration and accumulation at maturity,and yield reduction was tightly related to NSC translocation reduction.The results suggest that heat stress at booting inhibits NSC translocation due to sink size reduction.Therefore,genotypes with higher NSC transport capacity under heat stress could be beneficial for rice yield formation.Fengxian Zhen Junjie Zhou Aqib Mahmood Wei Wang Xini Chang Bing Liu Leilei Liu Weixing Cao Yan Zhu Liang Tang 2020The Crop Journal2020,8,2:9
16FUNDAMENTAL SOLUTION BASED GRADED ELEMENT MODEL FOR STEADY-STATE HEAT TRANSFER IN FGM显示文摘A novel hybrid graded element model is developed in this paper for investigating thermal behavior of functionally graded materials (FGMs). The model can handle a spatially varying material property field of FGMs. In the proposed approach, a new variational functional is first constructed for generating corresponding finite element model. Then, a graded element is formulated based on two sets of independent temperature fields. One is known as intra-element temperature field defined within the element domain; the other is the so-called frame field defined on the element boundary only. The intra-element temperature field is constructed using the linear combination of fundamental solutions, while the independent frame field is separately used as the boundary interpolation functions of the element to ensure the field continuity over the interelement boundary. Due to the properties of fundamental solutions, the domain integrals appearing in the variational functional can be converted into boundary integrals which can significantly simplify the calculation of generalized element stiffness matrix. The proposed model can simulate the graded material properties naturally due to the use of the graded element in the finite element (FE) model. Moreover, it inherits all the advantages of the hybrid Trefftz finite element method (HT-FEM) over the conventional FEM and boundary element method (BEM). Finally, several examples are presented to assess the performance of the proposed method, and the obtained numerical results show a good numerical accuracy.Leilei Cao Hui Wang Qing-Hua Qi 2012Acta Mechanica Solida Sinica2012,25,4:9
17Reliability analysis of slopes considering spatial variability of soil properties based on efficiently identified representative slip surfaces显示文摘Slope reliability analysis considering inherent spatial variability(ISV)of soil properties is timeconsuming when response surface method(RSM)is used,because of the'curse of dimensionality'.This paper proposes an effective method for identification of representative slip surfaces(RSSs)of slopes with spatially varied soils within the framework of limit equilibrium method(LEM),which utilizes an adaptive K-means clustering approach.Then,an improved slope reliability analysis based on the RSSs and RSM considering soil spatial variability,in perspective of computation efficiency,is established.The detailed implementation procedure of the proposed method is well documented,and the ability of the method in identifying RSSs and estimating reliability is investigated via three slope examples.Results show that the proposed method can automatically identify the RSSs of slope with only one evaluation of the conventional deterministic slope stability model.The RSSs are invariant with the statistics of soil properties,which allows parametric studies that are often required in slope reliability analysis to be efficiently achieved with ease.It is also found that the proposed method provides comparable values of factor of safety(FS)and probability of failure(Pf)of slopes with those obtained from direct analysis and lite rature.Bin Wang Leilei Liu Yuehua Li Quan Jiang 2020Journal of Rock Mechanics and Geotechnical Engineering2020,12,3:9
18An Equivalent Fundamental and Odd Harmonic Resonators Controller for a Single-phase Dynamic Voltage Restorer显示文摘为提高单相动态电压恢复器(dynamic voltage restorer,DVR)的补偿性能,提出一种基于等效基波及奇次谐波谐振器组的数字控制方法。采用可等效为一组谐振器的延时模块,能够有效抑制电网基波和谐波扰动。给出一种包含两个控制参数和一组零相移陷波滤波器的结构及其设计方法,使系统在保证稳定性的同时,获得较大的谐振增益。其中,延时环节衰减系数可增加谐振器组鲁棒性;控制器比例增益可解决零相移陷波器中使用延时带来的问题;零相移陷波器组既能对消LC谐振峰,也能解决等效谐振器组高增益在高频处的稳定性问题。同时,引入电源电压和负载电流双前馈来保证响应速度,增加了对扰动的抑制能力。所提控制策略结构简单,谐波补偿能力强,动态响应快,易于实现。在2kW单相DVR实验装置上的实验结果验证了该控制方法的正确性。HU Leilei XIAO Guochun TENG Guofei LU Yong 2012中国电机工程学报2012,32,22:9
19Effects of two polybrominated diphenyl ethers(BDE-47,BDE-209) on the swimming behavior, population growth and reproduction of the rotifer Brachionus plicatilis显示文摘Polybrominated diphenyl ethers(PBDEs) are new kinds of persistent organic pollutants(POPs) and their potential threats to the equilibrium and sustainability of marine ecosystems have raised worldwide concerns. Here, two kinds of PBDEs, tetra-BDE(BDE-47)and deca-BDE(BDE-209) were applied, and their toxic effects on the swimming behavior,population growth and reproduction of Brachionus plicatilis were investigated. The results showed that:(1) The actual concentrations of BDE-47 and-209 in the seawater phase measured by GC–MS(Gas Chromatography-Mass Spectrometer) were much lower than their nominal concentrations.(2) In accordance with the 24-hr acute tests, BDE-209 did not show any obvious swimming inhibition to rotifers, but a good correlation did exist between the swimming inhibition rate and BDE-47 concentration suggesting that BDE-47 is more toxic than BDE-209.(3) Both BDE-47 and-209 had a significant influence on the population growth and reproduction parameters of B. plicatilis including the population growth rate, the ratio of ovigerous females/non-ovigerous females(OF/NOF), the ratio of mictic females/amictic females(MF/AF), resting egg production and the mictic rate, which indicate that these parameters in B. plicatilis population were suitable for monitoring and assessing PBDEs. Our results suggest that BDE-47 and-209 are not acute lethal toxicants and may pose a low risk to marine rotifers at environmental concentrations for short-term exposure. They also accumulate differently into rotifers. Further research data are needed to understand the mechanisms responsible for the effects caused by PBDEs and to assess their risks accurately.Jingjing Sha You Wang Jianxia Lv Hong Wang Hongmei Chen Leilei Qi Xuexi Tang 2015Journal of Environmental Sciences2015,27,2:9
20Particle properties in granular activated carbon filter during drinking water treatment显示文摘The elemental composition and bacteria attached in particles were investigated during granular activated carbon (GAC) filtration.The experimental results showed that trapped influent particles could form new,larger particles on GAC surface.The sloughing of individuals off GAC surface caused an increase in effluent particles in the size range from 5 to 25 μm.The selectivity for element removal in GAC filters caused an increasing proportion of metallic elements in the effluent particles.The distribution of molar ratio indicated a complicated composition for large particles,involving organic and inorganic substances.The organic proportion accounted for 40% of total carbon attached to the particles.Compared with dissolved carbon,there was potential for the formation of trihalomethanes by organic carbon attached to particles,especially for those with size larger than 10 μm.The pure carbon energy spectrum was found only in the GAC effluent and the size distribution of carbon fines was mainly above 10 μm.The larger carbon fines provided more space for bacterial colonization and stronger protection for attached bacteria against disinfection.The residual attached bacteria after chorine disinfection was increased to 10 2-10 3 CFU/mL within 24 hours at 25°C.Tao Lin Wei Chen Leilei Wang 2010Journal of Environmental Sciences2010,22,5:9
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