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| 1 | Motion trajectory prediction based on a CNN-LSTM sequential model显示文摘Accurate monitoring the surrounding environment is an important research direction in the field of unmanned systems such as bio-robotics,and has attracted much research attention in recent years.The trajectories of surrounding vehicles should be predicted accurately in space and time to realize active defense and running safety of an unmanned system.However,there is uncertainty and uncontrollability in the process of trajectory prediction of surrounding obstacles.In this study,we propose a trajectory prediction method based on a sequential model,that fuses two neural networks of a convolutional neural network(CNN)and a long short-term memory network(LSTM).First,a box plot is used to detect and eliminate abnormal values of vehicle trajectories,and valid trajectory data are obtained.Second,the trajectories of surrounding vehicles are predicted by merging the characteristics of CNN space expansion and LSTM time expansion;the hyper-parameters of the model are optimized according to a grid search algorithm,which satisfies the double-precision prediction requirement in space and time.Finally,data from next generation simulation(NGSIM)and Creteil roundabout in France are taken as test cases;the correctness and rationality of the method are verified by prediction error indicators.Experimental results demonstrate that the proposed CNNLSTM method is more accurate and features a shorter time cost,which meets the prediction requirements and provides an effective method for the safe operation of unmanned systems. | Guo XIE Anqi SHANGGUAN Rong FEI Wenjiang JI Weigang MA Xinhong HEI | 2020 | Science China(Information Sciences)2020，63，11： | 24 |
| 2 | Numerical Prediction and Performance Experiment in a Deep-well Centrifugal Pump with Different Impeller Outlet Width显示文摘The existing research of the deep-well centrifugal pump mainly focuses on reduce the manufacturing cost and improve the pump performance,and how to combine above two aspects together is the most difficult and important topic.In this study,the performances of the deep-well centrifugal pump with four different impeller outlet widths are studied by the numerical,theoretical and experimental methods in this paper.Two stages deep-well centrifugal pump equipped with different impellers are simulated employing the commercial CFD software to solve the Navier-Stokes equations for three-dimensional incompressible steady flow.The sensitivity analyses of the grid size and turbulence model have been performed to improve numerical accuracy.The flow field distributions are acquired and compared under the design operating conditions,including the static pressure,turbulence kinetic energy and velocity.The prototype is manufactured and tested to certify the numerical predicted performance.The numerical results of pump performance are higher than the test results,but their change trends have an acceptable agreement with each other.The performance results indicted that the oversize impeller outlet width leads to poor pump performances and increasing shaft power.Changing the performance of deep-well centrifugal pump by alter impeller outlet width is practicable and convenient,which is worth popularizing in the engineering application.The proposed research enhances the theoretical basis of pump design to improve the performance and reduce the manufacturing cost of deep-well centrifugal pump. | SHI Weidong ZHOU Ling LU Weigang PEI Bing LANG Tao | 2013 | Chinese Journal of Mechanical Engineering2013，26，1： | 20 |
| 3 | Dry Friction and Wear Characteristics of Impregnated Graphite in a Corrosive Environment显示文摘Tribological properties of impregnated graphite are greatly influenced by preparation technology and working conditions and it’s highly susceptible to corrosion environmental impacts,but the experimental research about it are few.In this paper,three kinds of impregnated graphite samples are prepared with different degree of graphitization,the tribological properties of these samples in the dry friction environment and in a corrosive environment are analyzed and contrasted.The tribo-test results show that the friction coefficient of samples is reduced and the amount of wear of samples increase when the graphitization degree of samples increases in dry friction condition.While in a corrosive environment(samples are soaked N2O4),the friction coefficient and amount of wear are changed little if the graphitization degree of samples are low.If the degree of graphitization increase,the friction coefficient and amount of wear of samples increase too,the amount of wear is 2 to 3 times as the samples tested in the non-corrosive environment under pv value of 30MPa?m/s.The impregnated graphite,which friction coefficient is stable and graphitization degree is in mid level,such#2,is more appropriate to have a work in the corrosion conditions.In this paper,preparation and tribological properties especially in corrosive environment of the impregnated graphite is studied,the research conclusion can provide an experimental and theoretical basis for the selection and process improvement of graphite materials,and also provide some important design parameters for contact seal works in a corrosive environment. | JIA Qian YUAN Xiaoyang ZHANG Guoyuan DONG Guangneng ZHAO Weigang | 2014 | Chinese Journal of Mechanical Engineering2014，27，5： | 15 |
| 4 | Progress and Prospects of Salt Lake Research in China显示文摘China has unique salt lake resources, and they are distributed in the east of Eurasian salt lake subzone of the Northern Hemisphere Salt Lake Zone, mainly concentrated in the regions with modern mean annual precipitation lower than 500 mm. This paper preliminarily reviews the progress made in salt lake research in China for the past 60 years. In the research of Paleoclimate and paleoenvironment from salt lake sediments, a series of salts have been proposed to be indicators of paleoclimate, and have been well accepted by scholars. The chloride-sulfate depositional regions of the west Qaidam and the east Tarim have been revealed to be the drought center of China since the Quaternary, and more than 6 spreading stages of arid climate(salt forming) have been identified. Five pan-lake periods with highstands have been proved to exist during the late Quaternary on the Tibetan Plateau. In mineral resource prospecting and theories of the forming of salt deposits: the atlas(1:2500000) of hydrochemical zoning of salt lakes on the Tibetan Plateau has been compiled for the first time, revealing the zonal distribution and transition from carbonate type to chloride type from south to north and presenting corresponding mineral assemblages for different type of salt lakes; several large continental salt deposits have been discovered and the theory of continental potash deposition has been developed, including the salt deposition in deep basins surrounded by high mountains, the mineral deposition from multistage evolution through chains of moderate or shallow lakes with multilevels, the origin of potassium rich brines in gravel layers, and the forming of potassium deposits through the inheriting from ancient salt deposits, thus establishing the framework of 'Continental Potash Deposition Theory'; several new types of Mg-borate deposits have been discovered, including the ulexite and pinnoite bed in Da Qaidam Lake, Qinghai, the pinnoite and kurnakovite bed in Chagcam Caka, Tibet, the kurnakovite bed in Lake Nyer, and the corresponding model of borate deposition from the cooling and dissolution of boron rich brines was proposed based on principles of geology, physics and chemistry. The anti-floatation-cold crystallization method developed independently has improved the capacity of KCl production to 3 million tons per year for the Qarham, serving the famous brand of potash fertilizer products. One 1.2 million ton K-sulfate production line, the biggest in the world, has been built in Lop Nor, and K-sulfate of about 1.6 million tons was produced in 2015. Supported by the new technology, i.e. brine preparation in winter-cooling-solarization-isolation-lithium deposition from salt gradient solar pond' the highest lithium production base at Zabuye Lake(4421 m), Tibet, has been established, which is the first lithium production base in China that reaches the year production of 5000 tons of lithium carbonate. The concept of Salt lake agriculture(Salt land agriculture) has been established based on the mass growth of Dunaliella and other bacillus-algae and the occurrence of various halophytes in saltmarsh and salt saline-alkali lands, finding a new way to increase arable lands and develop related green industry in salt rich environments. Finally this paper presents some new thoughts for the further research and development on salt science, and the further progress in salt science and technology will facilitate the maturing of the interdisciplinary science 'Salinology'. | ZHENG Mianping ZHANG Yongsheng LIU Xifang NIE Zhen KONG Fanjing QI Wen Jia Qingxian PU Linzhong HOU Xianhua WANG Hailei ZHANG Zhen KONG Weigang LIN Yongjie | 2016 | Acta Geologica Sinica(English Edition)2016，90，4： | 15 |
| 5 | TOA-Based NLOS Error Mitigation Algorithm for 3D Indoor Localization显示文摘In the process of indoor localization,the existence of the non-line of sight(NLOS)error will greatly reduce the localization accuracy.To reduce the impact of this error,a 3 dimensional(3D)indoor localization algorithm named LMR(LLS-Minimum-Residual)is proposed in this paper.We first estimate the NLOS error and use it to correct the measurement distances,and then calculate the target location with linear least squares(LLS)solution.The final nodes location can be obtained accurately by NLOS error mitigation.Our algorithm can work efficiently in both indoor 2D and 3D environments.The simulation results show that the proposed algorithm has better performance than traditional algorithms and it can significantly improve the localization accuracy. | Weigang Wang Yunwei Zhang Longbin Tian | 2020 | China Communications2020，17，1： | 13 |
| 6 | Ultrasound-Guided Transmuscular Quadratus Lumbar Block Reduces Opioid Consumption after Laparoscopic Partial Nephrectomy显示文摘Objectives Transmuscular quadratus lumborum block(TQLB)may provide postoperative analgesia in patients undergoing intraperitoneal surgeries.The purpose of this study was to examine the potential efficacy of TQLB among patients undergoing retroperitoneal procedures,such as the laparoscopic partial nephrectomy(LPN).Methods This prospective,randomized,controlled study was conducted from August 2017 to November 2018 at Peking Union Medical College Hospital(Beijing,China).Patients who were scheduled for a LPN,aged 18・70 years old with an ASA physical status score of I-II were randomly assigned to receive either TQLB with 0.6 ml/kg of 0.5%ropivacaine plus general anesthesia(TQLB group)or general anesthesia alone(control group).Patient-controlled intravenous analgesia with morphine was initiated immediately upon surgery completion.The primary outcome was the cumulative consumption of morphine within 8 h after surgery.The secondary outcome included postoperative consump廿ons of morphine at other time points,pain score at rest and during activity,postoperative nausa and vomitting(PONV),and recovery related parameters.Results Totally 30 patients per group were recruited in the study.The 8 h consumption of morphine was lower in theTQLB group than in the control group(median,0.023 mg/kg vs.0.068 mg/kg,U=207.5,P<0.001).No significant differences were observed in postoperative pain scores between the two groups.Patients in the TQLB group had fewer episodes of PONV(20%vs.47%,χ2=4.&P=0.028)in the first 24 h after surgery and higher scores for quality of recovery(mean,13&6 vs.131.9,t=-2.164,P=0.035)120 h after surgery than the controls.Conclusions TQLB resulted in an opioid-sparing effect during the early postoperative period following LPN,as well as a lower incidence of PONV and improved quality of recovery. | Xulei Cui Xu Li Minna Li Yuelun Zhang Yi Xie Weigang Yan Yushi Zhang Zhigang Ji Yuguang Huang | 2020 | Chinese Medical Sciences Journal2020，35，4： | 10 |
| 7 | Security information factor based airborne radar RF stealth显示文摘Radar radio frequency(RF) stealth is very important in electronic war(EW), and waveform design and selection. Existing evaluation rules of radar RF stealth include too many parameters of radar and interceptors, such as Schleher interception factor,which makes it difficult to evaluate radar RF stealth technologies if interceptor parameters are unknown. In communication, security capacity has been presented to describe the possible ability to communicate in complete security. Since the essential of the security capacity is to have the interceptor get none valued information from the emitter, this paper is proposed to study security information factors taking advantage of mutual information to evaluate radar RF stealth under some conditions. Through analyzing mutual information obtained by the radar and the interceptor, this paper defines the security information factor with and without cooperative jamming. Furthermore, this paper deduces the ratio of the match filter to the match incoherent filter and discuss mutual information received by the interceptor. Numerical simulations illustrate radar RF stealth effects based on the security information factor concept under different conditions. | Fei Wang Mathini Sellathurai Weigang Liu Jiangjiang Zhou | 2015 | Journal of Systems Engineering and Electronics2015，26，2： | 9 |
| 8 | Improvement on On-line Ferrograph Image Identification显示文摘A newly developed on-line visual ferrograph(OLVF) gives a new way for engine wear state monitoring. However, the reliability of on-line wear debris image processing is challenged in both monitoring ship engines and the Caterpillar bench test, which weren’t reported in previous studies. Two problems were encountered in monitoring engines and processing images. First, small wear debris becomes hard to be identified from the image background after monitoring for a period of time. Second, the identification accuracy for wear debris is greatly reduced by background noise because of oil getting dark after running a period of time. Therefore, the methods adopted in image processing are examined. Two main reasons for the problems in wear debris identification are generalized as follows. Generally, the binary threshold was determined by global image pixels, and was easily affected by the non-objective zone in the image. The boundary of the objective zone in the binary image was misrecognized because of oil color becoming lighter during monitoring. Accordingly, improvements were made as follows. The objective zone in a global binary image was identified by scanning a column of pixels, and then a secondary binary process confined in the objective zone was carried out to identify small wear debris. Linear filtering with a specific template was used to depress noise in a binary image, and then a low-pass filtering was performed to eliminate the residual noise. Furthermore,the morphology parameters of single wear debris were extracted by separating each wear debris by a gray stack, and two indexes, WRWR (relative wear rate) and WRWS (relative wear severity), were proposed for wear description. New indexes were provided for on-line monitoring of engines. | WU Tonghai WANG Weigang WU Jiaoyi MAO Junhong XIE Youbai | 2010 | Chinese Journal of Mechanical Engineering2010，23，1： | 8 |
| 9 | Experimental study on the effect of H2S and SO2 on high temperature corrosion of 12Cr1MoV显示文摘Aiming at the high temperature corrosion in a coal-fired boiler,the effect of H2S and SO2 on the corrosion of 12 CrlMoV under the water wall condition has been investigated by experiments.The results indicate that H2 S can promote the corrosion significantly,and the coarse porous oxide film formed cannot stop the progress of corrosion.While SO2 presents little effect on the corrosion.The main composition of the surface of 12 CrlMoV corrosion products is Fe2 O3.With H2S in the atmosphere,the corrosion gradually develops into deeper layers by forming FeS,FeO and Fe2 O3 alternately.The corrosion rate is doubled for every 50℃ inerease in temperature at 400-500℃. | Hong Xu Shangkun Zhou Yiming Zhu Weigang Xu Xiaohe Xiong Houzhang Tan | 2019 | Chinese Journal of Chemical Engineering2019，27，8： | 8 |
| 10 | A Comparative Analysis of Evaporate Sediments on Earth and Mars: Implications for the Climate Change on Mars显示文摘The knowledge of Martian salts has gone through substantial changes during the past decades. In the 70th of last century, Viking landers have noticed the existence of salts on Mars. Several salt species have been suggested from then on, such as sulfates and chlorides. However, their origin was a mystery due to the lack of observations. The recent explorations and related studies at the beginning of this century revealed that the crustal composition of Mars is similar to that of Earth, and it was hypothesized that almost one third of Martian surface was covered by oceans and lakes in the early stage of Mars. The huge water bodies may have dissolved a large quantity of ions from Martian primary rocks during the whole Noachian and Hesperian epoch. After the enormous drought event happened during the late Hesperian and the early Amazonian, these dissolved ions have formed huge salts deposits and most of them were preserved on Mars until today. To date, carbonates, sulfates, chlorides have all been detected by orbital remote sensing and by landers and rovers. However, the salt mineral assemblages on Mars seems to have some differences from those on Earth, e.g., rich in sulfates and lack of massive carbonates. To explain this difference, we propose that most of the surface carbonates precipitated from the ancient oceans may have been dissolved by the later ubiquitous acidic fluids originated from the global volcanism in the Hesperian era, and formed the enormous sulfate deposits as detected, and this hypothesis seems to be supported by the evidence that most of the sulfate deposits distribute around the Tharsis volcanic province while the survived carbonates located far from it. This process can release most of the carbon on Mars to the atmosphere in the form of CO2 and then be erased by the late heavy bombardments, which might have profound influence on the climate change happened in the Hesperian age. The positive correlation between the GRS results of the potassium distributions and the distribution of chlorides on Mars, together with the high Br concentration measured from the evaporate sediments at two Mars exploration rover landing sites, indicate that the brines in the regions where the chlorides deposited may have reached the stage for potassium salts deposition, thus we propose for the first time that potassium salts deposits might be prevalent in these regions. | ZHENG Mianping KONG Weigang ZHANG Xuefei CHEN Wenxi KONG Fanjing | 2013 | Acta Geologica Sinica(English Edition)2013，87，3： | 7 |
| 11 | Newly discovered Palaeolithic artefacts from loess deposits and their ages in Lantian,central China显示文摘Eight new Palaeolithic open-air sites were identified and 770 stone artefacts were collected from 2009 to 2011 in the Lantian area of the Bahe River valley, central China. Because the famous Homo erectus fossils were unearthed at the Gongwangling and Chenjiawo localities, and more than 30 Palaeolithic open-air sites were investigated in the 1960s in this region, the catchment of Bahe River is regarded as one of the most important hominin sites from the late early Pleistocene to the middle Pleistocene. These eight newly discovered open-air sites are located at the second(n = 6), third(n = 1) or higher terraces(n = 1) of the Bahe River. The Diaozhai section on the second terrace was sampled in detail. Two samples were collected for optically stimulated luminescence dating(OSL). The OSL results suggest that a buried lithic artefact layer at the Diaozhai site spans approximately 70–30 ka. The lithic assemblage analysis suggests that the stone artefacts were made of local pebbles/cobbles such as greywacke, quartz, sandstone and igneous rocks. The main percussion techniques that were used were direct hard hammer percussion and bi-polar techniques. The lithic artefacts comprise hammer stones, cores, flakes, retouched tools and flaking debris. Acheulian-type large cutting tools(LCTs) such as hand-axes, picks and cleavers were indentified in the Lantian region as well. This is the first time Acheulian-type LCTs from the late Pleistocene have been identified in this region. This study distinguishes age gaps between Western world and East Asian Acheulian-type tools. | Shejiang Wang Huayu Lu Hongyan Zhang Xuefeng Sun Shuangwen Yi Yingyong Chen Gaike Zhang Luda Xing Weigang Sun | 2014 | Chinese Science Bulletin2014，59，7： | 7 |
| 12 | Non-limit passive soil pressure on rigid retaining walls显示文摘This paper aims to reveal the depth distribution law of non-limit passive soil pressure on rigid retaining wall that rotates about the top of the wall(rotation around the top(RT) model). Based on Coulomb theory, the disturbance degree theory, as well as the spring-element model, by setting the rotation angle of the wall as the disturbance parameter, we establish both a depth distribution function for sand and a nonlinear depth distribution calculation method for the non-limit passive soil pressure on a rigid retaining wall under the RT model, which is then compared with experiment. The results suggest that under the RT model: the non-limit soil pressure has a nonlinear distribution; the backfill disturbance degree and the lateral soil pressure increase with an increase in the wall rotation angle; and, the points where the resultant lateral soil pressure acts on the retaining wall are less than 2/3 of the height of the wall. The soil pressure predicted by the theoretical calculation put forward in this paper are quite similar to those obtained by the model experiment, which verifies the theoretical value, and the engineering guidance provided by the calculations are of significance. | Dou Guotao Xia Junwu YU Wenjie Yuan Fang Bai Weigang | 2017 | International Journal of Mining Science and Technology2017，27，3： | 7 |
| 13 | New Developments in Maritime Communications: a Comprehensive Survey显示文摘This paper summarizes the requirements for modern maritime wireless communication networks in the marine environments including the sea-to-sea and sea-to-shore communication scenarios.The existing maritime wireless communication systems are presented and the development of the state-of-the-art maritime communication systems is surveyed.Furthermore,a hierarchical and integrated maritime network architecture is proposed to satisfy the increasing various classes of services which demand different Quality of Service(QoS).Finally,the open issues for further development of maritime communications are identified. | Chen Weigang Yang Jinsheng Ma Jianguo Li Si | 2012 | China Communications2012，9，2： | 7 |
| 14 | Systematic characterization of transport and thermoelectric properties of a macroscopic graphene fiber显示文摘Graphene,有非凡的电、热、有弹性的性能的二维的材料,是未来技术的一个潜在的候选人。然而, graphene 的优异性质还没为 graphenederived 被认识到宏观的结构象 graphene 纤维那样。在这研究,我们系统地调查了温度(T) 依赖者运输和 graphene 纤维的热电的性质,包括热传导性() ,电的电导率() ,并且 Seebeck 系数(S) 。从 45.8 ~ 149.7 Wd | Weigang Ma Yingjun Liu Shen Yan Tingting Miao Shaoyi Shi Mincheng Yang Xing Zhang Chao Gao | 2016 | Nano Research2016，9，11： | 6 |
| 15 | Chemically doped macroscopic graphene fibers with significantly enhanced thermoelectric properties显示文摘当与突出的热电的性质结合了时,灵活便携电子学为收获系统的未来精力正在答应候选人。Graphene 和它的宏观的集会(例如,基于 graphene 的纤维和电影) 因为他们的非凡的电、机械的性质,因此是众多的研究的题目。然而,这些集会没由于他们的高内在的热传导性为热电的应用程序被认为合适。在这研究,溴做被表明是为显著地提高 graphene 纤维的热电的性质的一个有效方法。做提高声子由于增加的缺点散布并且因此减少热传导性,当电的传导性和 Seebeck 系数被费密增加时,铺平换至较低排挡。作为结果,优点的最大的数字是 2. | Weigang Ma Yingjun Liu Shen Yan Tingting Miao Shaoyi Shi Zhen Xu Xing Zhang Chao Gao | 2018 | Nano Research2018，11，2： | 6 |
| 16 | Heterogeneous uptake of nitrogen dioxide on Chinese mineral dust显示文摘Mineral dust is one of the major aerosols in the atmosphere.To assess its impact on trace atmospheric gases,in this work we present a laboratory study of the effect of temperature on the heterogeneous reaction of NO_2 on the surface of ambient Chinese dust over the temperature range from 258 to 313 K.The results suggest that nitrogen dioxide could mainly be adsorbed on these types of Chinese mineral dust reversibly with little temperature dependence.Similar to a previous study on NO_2 uptake on mineral aerosols,the uptake coefficients are mainly on the order of 10^(-6) for the Chinese dust,when BET areas are taken into account.HONO was observed as a product,and its formation and decomposition on Chinese mineral dust during the uptake processes were also studied.The complete dataset from this study was compiled with previous literature determinations.Atmospheric implications of the heterogeneous reaction between NO_2 and mineral dust are also discussed,in an effort to understand this important heterogeneous process. | Li Zhou Weigang Wang Siqi Hou Shengrui Tong Maofa Ge | 2015 | Journal of Environmental Sciences2015，27，12： | 6 |
| 17 | Virtual 5G Network Embedding in a Heterogeneous and Multi-Domain Network Infrastructure显示文摘The pursuit of the higher performance mobile communications forces the emergence of the fifth generation mobile communication(5G). 5G network, integrating wireless and wired domain, can be qualified for the complex virtual network work oriented to the cross-domain requirement. In this paper, we focus on the multi-domain virtual network embedding in a heterogeneous 5G network infrastructure, which facilitates the resource sharing for diverse-function demands from fixed/mobile end users. We proposed the mathematical ILP model for this problem.And based on the layered-substrate-resource auxiliary graph and an effective six-quadrant service-type-judgment method, 5G embedding demands can be classified accurately to match different user access densities. A collection of novel heuristic algorithms of virtual 5G network embedding are proposed. A great deal of numerical simulation results testified that our algorithm performed better in terms of average blocking rate, routing latency and wireless/wired resource utilization, compared with the benchmark. | Cunqian Yu Weigang Hou Yingying Guan Yue Zong Pengxing Guo | 2016 | China Communications2016，13，10： | 6 |
| 18 | Motion Error Compensation of Multi-legged Walking Robots显示文摘Existing errors in the structure and kinematic parameters of multi-legged walking robots,the motion trajectory of robot will diverge from the ideal sports requirements in movement.Since the existing error compensation is usually used for control compensation of manipulator arm,the error compensation of multi-legged robots has seldom been explored.In order to reduce the kinematic error of robots,a motion error compensation method based on the feedforward for multi-legged mobile robots is proposed to improve motion precision of a mobile robot.The locus error of a robot body is measured,when robot moves along a given track.Error of driven joint variables is obtained by error calculation model in terms of the locus error of robot body.Error value is used to compensate driven joint variables and modify control model of robot,which can drive the robots following control model modified.The model of the relation between robot's locus errors and kinematic variables errors is set up to achieve the kinematic error compensation.On the basis of the inverse kinematics of a multi-legged walking robot,the relation between error of the motion trajectory and driven joint variables of robots is discussed.Moreover,the equation set is obtained,which expresses relation among error of driven joint variables,structure parameters and error of robot's locus.Take MiniQuad as an example,when the robot MiniQuad moves following beeline tread,motion error compensation is studied.The actual locus errors of the robot body are measured before and after compensation in the test.According to the test,variations of the actual coordinate value of the robot centroid in x-direction and z-direction are reduced more than one time.The kinematic errors of robot body are reduced effectively by the use of the motion error compensation method based on the feedforward. | WANG Liangwen CHEN Xuedong WANG Xinjie TANG Weigang SUN Yi PAN Chunmei | 2012 | Chinese Journal of Mechanical Engineering2012，25，4： | 6 |
| 19 | Light absorption properties and potential sources of brown carbon in Fenwei Plain during winter 2018–2019显示文摘A distinctive kind of organic carbon aerosol that could absorb ultraviolet-visible radiation is called brown carbon(Br C),which has an important positive influence on radiative budget and climate change.In this work,we reported the absorption properties and potential source of Br C based on a seven-wavelength aethalometer in the winter of 2018–2019 at an urban site of Sanmenxia in Fenwei Plain in central China.Specifically,the mean value of Br C absorption coefficient was 59.6±36.0 Mm^(-1) at 370 nm and contributed 37.7%to total absorption,which made a significant impact on visibility and regional environment.Absorption coefficients of Br C showed double-peak pattern,and Br C had shown small fluctuations under haze days compared with clean days.As for the sources of Br C,Br C absorption coefficients expressed strong correlations with element carbon aerosols and primary organic carbon aerosols,indicating that most of Br C originated from primary emissions.The linear correlations between trace metal elements(K,As,Fe,Mn,Zn,and Pb)and Br C absorption coefficients further referred that the major sources of Br C were primary emissions,like coal burning,biomass burning,and vehicle emissions.The moderate relationship between Br C absorption coefficients and secondary organic aerosols suggested that secondary production of Br C also played an important role.The 120 hr backward air mass trajectories analysis and concentration-weighted trajectories analysis were also used to investigate potential sources of Br C in and around this area,which inferred most parts of Br C were derived from local emissions. | Wenyu Zhang Weigang Wang Jie Li Shuangliang Ma Chaofan Lian Kun Li Bo Shi Mingyuan Liu Yanyu Li QingQing Wang Yele Sun Shengrui Tong Maofa Ge | 2021 | Journal of Environmental Sciences2021，33，4： | 6 |
| 20 | A single-level composite structure optimization method based on a blending tapered model显示文摘In order to decrease the number of design variables and improve the efficiency of com- posite structure optimal design, a single-level composite structure optimization method based on a tapered model is presented. Compared with the conventional multi-level composite structure opti- mization method, this single-level method has many advantages. First, by using a distance variable and a ply group variable, the number of design variables is decreased evidently and independent with the density of sub-regions, which makes the single-level method very suitable for large-scale composite structures. Second, it is very convenient to optimize laminate thickness and stacking sequence in the same level, which probably improves the quality of optimal result. Third, ply con-tinuity can be guaranteed between sub-regions in the single-level method, which could reduce stress concentration and manufacturing difficulty. An example of a composite wing is used to demonstrate the advantages and competence of the single-level method proposed. | An Weigang Chen Dianyu Jin Peng | 2013 | Chinese Journal of Aeronautics2013，26，4： | 5 |
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