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1New eolian red clay sequence on the western Chinese Loess Plateau linked to onset of Asian desertification about 25 Ma ago显示文摘The expansion of inland Asia deserts has considerably influenced the environmental, social and economic activities in Asia. Aridification of inland Asia, especially timing of the initiation of Asian desertification, is a contentious topic in paleoclimatology. Late Cenozoic eolian loess-red clay sequences on the Chinese Loess Plateau, which possess abundant paleoclimatic and paleo-environmental information, can be regarded as an indicator of inland Asia desertification. Here we present a detailed magnetostratigraphic investigation of a new red clay sequence about 654 m in Zhuanglang located at the western Chinese Loess Plateau. Sedimentological, geochemical, mineralogical, and quartz morphological lines of evidence show that the red clay is of eolian origin. Magnetostratigraphic correlations indicate that this core sequence spans from 25.6 to 4.8 Ma, and typical eolian red clay appears as early as 25 Ma. This extends the lower limit of the red clay on the Chinese Loess Plateau from the previously thought early Miocene back into the late Oligocene. This new red clay record further implies that the inland Asia desertification was initiated at least by the late Oligocene. This sequence provides a unique high-resolution geological record for understanding the inland Asia desertification process since the late Oligocene.QIANG XiaoKe AN ZhiSheng SONG YouGui CHANG Hong SUN YouBin LIU WeiGuo AO Hong DONG JiBao FU ChaoFeng WU Feng LU FengYan CAI YanJun ZHOU WeiJian CAO JunJi XU XinWen AI Li 2011Science China Earth Sciences2011,54,1:73
2Spatial and temporal trends of climate change in Xinjiang, China显示文摘在 65 个气象学的车站的从 1961 ~ 2005 的系列数据集被用来揭示气候的空间、时间的趋势的温度和降水时间在 Xinjiang 变化,中国。年度、季节的吝啬的空气温度和全部的降水用 Mann-Kendall (MK ) 测试被分析,反的距离加权(IDW ) 插值,和 R/S 方法。结果显示那:(1 ) 在过去的 45 年里增加的温度和降水,而是温度的增加比降水的更明显;(2 ) 为温度增加,更高纬度并且更高举起更快增加,不过,纬度在增加以后有更大的影响。北 Xinjiang 显示出比南部的 Xinjiang 的更快的温暖,特别在夏天;(3 )降水的增加在南部的 Xinjiang 主要在冬季发生在北 Xinjiang 并且在夏天。Ili,在 Xinjiang 有大多数降水,显示出降水的弱增加;(4 ) 尽管温度和降水一般来说增加了,增加在 Xinjiang 内是不同的;(5 ) 林中小丘索引(H) 分析显示那个气候变化将继续当前的趋势。LI Qihu CHEN Yaning SHEN Yanjun LI Xingong XU Jianhua 2011Journal of Geographical Sciences2011,21,6:41
3GIS-based Effect Assessment of Soil Erosion Before and After Gully Land Consolidation: A Case Study of Wangjiagou Project Region, Loess Plateau显示文摘The Loess Plateau is one typical area of serious soil erosion in the world. China has implemented ′Grain for Green′(GFG) project to restore the eco-environment of the Loess Plateau since 1999. With the GFG project subsidy approaching the end, it is concerned that farmers of fewer subsidies may reclaim land again. Thus, ′Gully Land Consolidation Project′(GLCP) was initiated in 2010. The core of the GLCP was to create more land suitable for farming in gullies so as to reduce land reclamation on the slopes which are ecological vulnerable areas. This paper aims to assess the effect of the GLCP on soil erosion problems by studying Wangjiagou project region located in the central part of Anzi valley in the middle of the Loess Plateau, mainly using the revised universal soil loss equation(RUSLE) based on GIS. The findings show that the GLCP can help to reduce soil shipment by 9.87% and it creates more terraces and river-nearby land suitable for farming which account for 27.41% of the whole study area. Thus, it is feasible to implement the GLCP in places below gradient 15°, though the GLCP also intensifies soil erosion in certain places such as field ridge, village land, floodplain, natural grassland, and shrub land. In short, the GLCP develops new generation dam land and balances the short-term and long-term interests to ease the conflicts between economic development and environmental protection. Furthermore, the GLCP and the GFG could also be combined preferably. On the one hand, the GFG improves the ecological environment, which could offer certain safety to the GLCP, on the other hand, the GLCP creates more farmland favorable for farming in gullies instead of land reclamation on the slopes, which could indirectly protect the GFG project.LIU Yansui GUO Yanjun LI Yurui LI Yuheng 2015Chinese Geographical Science2015,25,2:30
4Full-colour nanoprint-hologram synchronous metasurface with arbitrary hue-saturationbrightness control显示文摘The colour gamut,a two-dimensional(2D)colour space primarily comprising hue and saturation(HS),lays the most important foundation for the colour display and printing industries.Recently,the metasurface has been considered a promising paradigm for nanoprinting and holographic imaging,demonstrating a subwavelength image resolution,a flat profile,high durability,and multi-functionalities.Much effort has been devoted to broaden the 2D HS plane,also known as the CIE map.However,the brightness(B),as the carrier of chiaroscuro information,has long been neglected in metasurface-based nanoprinting or holograms due to the challenge in realising arbitrary and simultaneous control of full-colour HSB tuning in a passive device.Here,we report a dielectric metasurface made of crystal silicon nanoblocks,which achieves not only tailorable coverage of the primary colours red,green and blue(RGB)but also intensity control of the individual colours.The colour gamut is hence extruded from the 2D CIE to a complete 3D HSB space.Moreover,thanks to the independent control of the RGB intensity and phase,we further show that a singlelayer silicon metasurface could simultaneously exhibit arbitrary HSB colour nanoprinting and a full-colour hologram image.Our findings open up possibilities for high-resolution and high-fidelity optical security devices as well as advanced cryptographic approaches.Yanjun Bao Ying Yu Haofei Xu Chao Guo Juntao Li Shang Sun Zhang-Kai Zhou Cheng-Wei Qiu Xue-Hua Wang 2019Light(Science & Applications)2019,8,1:25
5Numerical simulation for the coupling effect of local atmospheric circulations over the area of Beijing,Tianjin and Hebei Province显示文摘Using the model system MM5.V3 and multi-layer grid nesting technique, we have done a multi-scale numerical simulation over the area of Beijing, Tianjin and Hebei Province to analyze the temperature and wind field there and study its local circulations. The results show a coupling effect of Urban Heat Island Circulation (UHIC), Mountain Valley Breeze (MVB) and Sea Land Breeze (SLB) occurs in this area when the synoptic system is weak. The SLB can penetrate deep into the mainland for about 200 km when it is blooming. MVB can extend to south and cover almost the whole plain area in Beijing. Both MVB and SLB are diurnal periodical; meanwhile the phase of MVB drops behind that of SLB for about six hours. As a local circulation, the UHIC weakens the two circulations above, and it also has a diurnal period. As a result, the coupling effect of circulations reveals not only different features in spring-summer period and autumn-winter period in a year but also the difference between early morn- ing to noonday and afternoon to night in a day. We noted the diffusion of contamination over the area around Beijing, and found the steady presence of a transport routine of contamination over North-China throughout the year caused by the Coupling Effect mentioned above. This find is important for studying the environment pollution in this area.LIU ShuHua LIU ZhenXin LI Ju WANG YinChun MA YanJun SHENG Li LIU HePing LIANG FuMing XIN GuoJun WANG JianHua 2009Science China Earth Sciences2009,52,3:20
6Lower limits of evaluation parameters for the lower Paleozoic Longmaxi shale gas in southern Sichuan Province显示文摘Here we present six key parameters that have been applied to evaluate the Silurian Longmaxi shale gas accumulations of southern Sichuan Province.These parameters include richness of organic matter,single layer shale thickness,burial depth of the shale,maturity,shale properties,and brittle mineral content.In combination with drilling data,the lower limits of these six parameters for marine shale gas have been evaluated and the following conclusions are drawn:(1)Organic carbon recovery, gas content inversion,and production tests have been applied for the first time to measure the lower limit of TOC,which is determined to be 1.0%.(2)Based on the hydrocarbon generation and expulsion theory for source rocks and the characteristics of Longmaxi shale,the lower limit of the single-layer thickness is estimated to be 30 m,of which a thickness of at least 15 m should contain high-quality shale.(3)Based on the correlation of TOC and porosity,the lower limit of gas-filled porosity is 1.2%.(4)Other parameters,such as maturity,burial depth,and brittle mineral content have also been studied with regard to the geologic conditions of southern Sichuan.Based on the study results,an evaluation index system has been established for highly evolved marine shale gas,and the system has been applied successfully to geologically screened shale gas occurrences in southern Sichuan Province.LI YanJun LIU Huan ZHANG LieHui LU ZongGang LI QiRong HUANG YongBin 2013Science China Earth Sciences2013,56,5:20
7Carbonyl emissions from heavy-duty diesel vehicle exhaust in China and the contribution to ozone formation potential显示文摘Fifteen heavy-duty diesel vehicles were tested on chassis dynamometer by using typical heavy duty driving cycle and fuel economy cycle. The air from the exhaust was sampled by 2,4-dinitrophenyhydrazine cartridge and 23 carbonyl compounds were analyzed by high performance liquid chromatography. The average emission factor of carbonyls was 97.2 mg/km, higher than that of light-duty diesel vehicles and gasoline-powered vehicles. Formaldehyde, acetaldehyde, acetone and propionaldehyde were the species with the highest emission factors. Main influencing factors for carbonyl emissions were vehicle type, average speed and regulated emission standard, and the impact of vehicle loading was not evident in this study. National emission of carbonyls from diesel vehicles exhaust was calculated for China, 2011, based on both vehicle miles traveled and fuel consumption. Carbonyl emission of diesel vehicle was estimated to be 45.8 Gg, and was comparable to gasolinepowered vehicles(58.4 Gg). The emissions of formaldehyde, acetaldehyde and acetone were 12.6, 6.9, 3.8 Gg, respectively. The ozone formation potential of carbonyls from diesel vehicles exhaust was 537 mg O3 /km, higher than 497 mg O3 /km of none-methane hydrocarbons emitted from diesel vehicles.Dong Dong Min Shao Yue Li Sihua Lu Yanjun Wang Zhe Ji Dagang Tang 2014Journal of Environmental Sciences2014,26,1:20
8Air route network optimization in fragmented airspace based on cellular automata显示文摘Air route network optimization,one of the essential parts of the airspace planning,is an effective way to optimize airspace resources,increase airspace capacity,and alleviate air traffic congestion.However,little has been done on the optimization of air route network in the fragmented airspace caused by prohibited,restricted,and dangerous areas(PRDs).In this paper,an air route network optimization model is developed with the total operational cost as the objective function while airspace restriction,air route network capacity,and non-straight-line factors(NSLF) are taken as major constraints.A square grid cellular space,Moore neighbors,a fixed boundary,together with a set of rules for solving the route network optimization model are designed based on cellular automata.The empirical traffic of airports with the largest traffic volume in each of the 9 flight information regions in China's Mainland is collected as the origin-destination(OD) airport pair demands.Based on traffic patterns,the model generates 35 air routes which successfully avoids 144 PRDs.Compared with the current air route network structure,the number of nodes decreases by 41.67%,while the total length of flight segments and air routes drop by 32.03% and 5.82% respectively.The NSLF decreases by 5.82% with changes in the total length of the air route network.More importantly,the total operational cost of the whole network decreases by 6.22%.The computational results show the potential benefits of the model and the advantage of the algorithm.Optimization of air route network can significantly reduce operational cost while ensuring operation safety.Shijin WANG Xi CAO Haiyun LI Qingyun LI Xu HANG Yanjun WANG 2017Chinese Journal of Aeronautics2017,30,3:16
9SEUSS and PIF4 Coordinately Regulate Light and Temperature Signaling Pathways to Control Plant Growth显示文摘Junling Huai Xinyu Zhang dialong Li Tingting Ma Ping Zha Yanjun Jing Rongcheng Lin 2018Molecular Plant2018,11,7:15
10The CAMS Climate System Model and a Basic Evaluation of Its Climatology and Climate Variability Simulation显示文摘A new coupled climate system model(CSM) has been developed at the Chinese Academy of Meteorological Sciences(CAMS) by employing several state-of-the-art component models. The coupled CAMS-CSM consists of the modified atmospheric model [ECmwf-HAMburg(ECHAM5)], ocean model [Modular Ocean Model(MOM4)], sea ice model [Sea Ice Simulator(SIS)], and land surface model [Common Land Model(CoLM)]. A detailed model description is presented and both the pre-industrial and 'historical' simulations are preliminarily evaluated in this study.The model can reproduce the climatological mean states and seasonal cycles of the major climate system quantities,including the sea surface temperature, precipitation, sea ice extent, and the equatorial thermocline. The major climate variability modes are also reasonably captured by the CAMS-CSM, such as the Madden–Julian Oscillation(MJO), El Ni?o–Southern Oscillation(ENSO), East Asian Summer Monsoon(EASM), and Pacific Decadal Oscillation(PDO).The model shows a promising ability to simulate the EASM variability and the ENSO–EASM relationship. Some biases still exist, such as the false double-intertropical convergence zone(ITCZ) in the annual mean precipitation field,the overestimated ENSO amplitude, and the weakened Bjerknes feedback associated with ENSO; and thus the CAMS-CSM needs further improvements.Xinyao RONG Jian LI Haoming CHEN Yufei XIN Jingzhi SU Lijuan HUA Tianjun ZHOU Yanjun QI Zhengqiu ZHANG Guo ZHANG Jianduo LI 2018Journal of Meteorological Research2018,32,6:15
11Antisense MMP-9 RNA inhibits malignant glioma cell growth in vitro and in vivo显示文摘The matrix-degrading metalloproteinases (MMPs), particularly MMP-9, play important roles in the pathogenesis and development of malignant gliomas. In the present study, the oncogenic role of MMP-9 in malignant glioma cells was investigated via antisense RNA blockade in vitro and in vivo. TJ905 malignant glioma cells were transfected with pcDNA3.0 vector expressing antisense MMP-9 RNA (pcDNA-AS-MMP9), which significantly decreased MMP-9 expression, and cell proliferation was assessed. For in vivo studies, U251 cells, a human malignant glioma cell line, were implanted subcutaneously into 4-to 6-week-old BALB/c nude mice. The mice bearing well-established U251 gliomas were treated with intratumoral pcDNA-AS-MMP9-Lipofectamine complex (AS-MMP-9-treated group), subcutaneous injection of endostatin (endostatin-treated group), or both (combined therapy group). Mice treated with pcDNA (empty vector)-Lipofectamine served as the control group. Four or eight weeks later, the volume and weight of tumor, MMP-9 expression, microvessel density and proliferative activity were assayed. We demonstrate that pcDNA-AS-MMP9 significantly decreased MMP-9 expression and inhibited glioma cell proliferation. Volume and weight of tumor, MMP-9 expression, microvessel density and proliferative activity in the antisense-MMP-9-treated and therapeutic alliance groups were significantly lower than those in the control group. The results suggest that MMP-9 not only promotes malignant glioma cell invasiveness, but also affects tumor cell proliferation. Blocking the expression of MMP-9 with antisense RNA substantially suppresses the malignant phenotype of glioma cells, and thus can be used as an effective therapeutic strategy for malignant gliomas.Cuiyun Sun Qian Wang Hongxu Zhou Shizhu Yu Alain R. Simard Chunsheng Kang Yanyan Li Yanling Kong Tongling An Yanjun Wen Fudong Shi Junwei Hao 2013Neuroscience Bulletin2013,29,1:14
12BiVO_(4),Bi_(2)WO_(6) and Bi_(2)MoO_(6) photocatalysis:A brief review显示文摘In recent years,photocatalytic technologies have been extensively studied and diffusely used in water splitting,decomposition of organic pollutants,reduction of carbon dioxide,etc.As a type of eye-catching semiconductors,BiVO_(4),Bi_(2)WO_(6),and Bi_(2)MoO_(6) (denoted as BiaAOb)have become a hotspot in photocatalytic researches due to their crystal structure stability,high light quantum and electronic transmission efficiency,and outstanding energy utilization capacity.However,pristine BiaAOb(A=V,W,and Mo)possesses several drawbacks,such as low separation efficiency of photo-excited electron-hole pairs,low specific surface area,as well as the poor quantum utilization,which restrict their photocatalytic performance.Considerable efforts,such as nanostructure modification,surface engineering,and heterojunction/homojunction fabrication,have been conducted to solve these problems.This integrated review aims to sum up recent advances in current studies on fabrication of high efficiency BiaAOb photocatalysts to accelerate the developments of BiaAOb-based materials in the photocatalysis(PC)field.The current challenges and prospects of BiaAOb are emphasized which stretches the existing fundamental theories of PC as well as provide a promising strategy to fabricate high efficiency BiaAOb catalysts to control environmental pollution and assist the sustainable development of energy.Xintong Liu Shaonan Gu Yanjun Zhao Guowei Zhou Wenjun Li 2020Journal of Materials Science & Technology2020,56,21:13
132018 update of expert consensus statement on antiplatelet therapy in East Asian patients with ACS or undergoing PCI显示文摘East Asians are the most populous race in the world and their health status is an important global issue.Compared with Caucasian populations, East Asian patients have a different benefit/risk ratio when using antithrombotic treatment. Despite this observation, treatment strategies in East Asian patients are mostly based on the American and European guidelines. Despite a lower platelet inhibitory response to clopidogrel, East Asian patients show a similar or even a lower rate of ischemic event occurrence and higher bleeding risk compared with Caucasian patients. For potent P2Y_(12) inhibitors(ticagrelor and prasugrel),East Asian patients have shown less favorable net clinical benefits compared with Caucasian patients,which may be related to differences in pharmacokinetic/pharmacodynamic profiles and therapeutic zone of antiplatelet effect. This updated consensus mainly focuses on state-of-the-art and current controversies in the East Asian population. In addition, when East Asian patients are administered potent P2Y_(12) receptor inhibitors, the strategies and ongoing trials to overcome the related hurdles are discussed.Yong Huo Young-Hoon Jeong Yanjun Gong Daowen Wang Ben He Jiyan Chen Guosheng Fu Yundai Chen Jianping Li Yi Li Shinya Goto Udaya S.Tantry Paul A.Gurbel Jong-Hwa Ahn Hyo-Soo Kim Myung Ho Jeong Yaling Han Sidney C.Smith Jr. Junbo Ge 2019Science Bulletin2019,64,3:12
14A method for the production and expedient screening of CRISPR/Cas9-mediated non-transgenic mutant plants显示文摘Developing CRISPR/Cas9-mediated non-transgenic mutants in asexually propagated perennial crop plants is challenging but highly desirable.Here,we report a highly useful method using an Agrobacterium-mediated transient CRISPR/Cas9 gene expression system to create non-transgenic mutant plants without the need for sexual segregation.We have also developed a rapid,cost-effective,and high-throughput mutant screening protocol based on Illumina sequencing followed by high-resolution melting(HRM)analysis.Using tetraploid tobacco as a model species and the phytoene desaturase(PDS)gene as a target,we successfully created and expediently identified mutant plants,which were verified as tetra-allelic mutants.We produced pds mutant shoots at a rate of 47.5%from tobacco leaf explants,without the use of antibiotic selection.Among these pds plants,17.2%were confirmed to be non-transgenic,for an overall non-transgenic mutation rate of 8.2%.Our method is reliable and effective in creating non-transgenic mutant plants without the need to segregate out transgenes through sexual reproduction.This method should be applicable to many economically important,heterozygous,perennial crop species that are more difficult to regenerate.Longzheng Chen Wei Li Lorenzo Katin-Grazzini Jing Ding Xianbin Gu Yanjun Li Tingting Gu Ren Wang Xinchun Lin Ziniu Deng Richard J.McAvoy Frederick G.Gmitter Jr. Zhanao Deng Yunde Zhao Yi Li 2018Horticulture Research2018,5,1:12
15Onco-miR-24 regulates cell growth and apoptosis by targeting BCL2L11 in gastric cancer显示文摘胃的癌症是世界范围的最普通的恶意之一;然而,在 tumorigenesis 的分子的机制仍然需要探索。BCL2L11 属于 BCL-2 家庭,并且充当内在的 apoptotic 串联的一个中央管理者并且调停房间 apoptosis。尽管 miRNAs 被报导了涉及癌症开发的每个阶段,在 GC 的 miR-24 的角色还没被报导。在现在的学习,当 BCL2L11 的表示在 GC 的肿瘤纸巾被禁止时, miR-24 被发现起来调整。研究从在 vitro 并且在显示出的 vivo,那 miR-24 调整 BCL2L11 表示由与 mRNA 的 3UTR 直接有约束力,因此支持房间生长,移植当禁止房间 apoptosis 时。因此, miR-24 是能是为未来的潜在的药目标的新奇 onco-miRNA 临床的使用。Haiyang Zhang Jingjing Duan Yanjun Qu Ting Deng Rui Liu Le Zhang Ming Bai Jialu Li Tao Ning Shaohua Ge Xia Wang ZhenzhenWang~ Qian Fan Hongli Li Guoguang Ying Dingzhi Huang Yi Ba 2016Protein & Cell2016,7,2:11
16Changes in Extreme Maximum Temperature Events and Population Exposure in China under Global Warming Scenarios of 1.5 and 2.0°C: Analysis Using the Regional Climate Model COSMO-CLM显示文摘We used daily maximum temperature data(1986–2100) from the COSMO-CLM(COnsortium for Small-scale MOdeling in CLimate Mode) regional climate model and the population statistics for China in 2010 to determine the frequency, intensity, coverage, and population exposure of extreme maximum temperature events(EMTEs) with the intensity–area–duration method. Between 1986 and 2005(reference period), the frequency, intensity, and coverage of EMTEs are 1330–1680 times yr^(–1), 31.4–33.3°C, and 1.76–3.88 million km^2, respectively. The center of the most severe EMTEs is located in central China and 179.5–392.8 million people are exposed to EMTEs annually. Relative to 1986–2005, the frequency, intensity, and coverage of EMTEs increase by 1.13–6.84, 0.32–1.50, and15.98%–30.68%, respectively, under 1.5°C warming; under 2.0°C warming, the increases are 1.73–12.48, 0.64–2.76,and 31.96%–50.00%, respectively. It is possible that both the intensity and coverage of future EMTEs could exceed the most severe EMTEs currently observed. Two new centers of EMTEs are projected to develop under 1.5°C warming, one in North China and the other in Southwest China. Under 2.0°C warming, a fourth EMTE center is projected to develop in Northwest China. Under 1.5 and 2.0°C warming, population exposure is projected to increase by23.2%–39.2% and 26.6%–48%, respectively. From a regional perspective, population exposure is expected to increase most rapidly in Southwest China. A greater proportion of the population in North, Northeast, and Northwest China will be exposed to EMTEs under 2.0°C warming. The results show that a warming world will lead to increases in the intensity, frequency, and coverage of EMTEs. Warming of 2.0°C will lead to both more severe EMTEs and the exposure of more people to EMTEs. Given the probability of the increased occurrence of more severe EMTEs than in the past, it is vitally important to China that the global temperature increase is limited within 1.5°C.Mingjin ZHAN Xiucang LI Hemin SUN Jianqing ZHAI Tong JIANG Yanjun WANG 2018Journal of Meteorological Research2018,32,1:11
17Systems metabolic engineering strategies for the production of amino acids显示文摘Systems metabolic engineering is a multidisciplinary area that integrates systems biology,synthetic biology and evolutionary engineering.It is an efficient approach for strain improvement and process optimization,and has been successfully applied in the microbial production of various chemicals including amino acids.In this review,systems metabolic engineering strategies including pathwayfocused approaches,systems biology-based approaches,evolutionary approaches and their applications in two major amino acid producing microorganisms:Corynebacterium glutamicum and Escherichia coli,are summarized.Qian Ma Quanwei Zhang Qingyang Xu Chenglin Zhang Yanjun Li Xiaoguang Fan Xixian Xie Ning Chen 2017Synthetic and Systems Biotechnology2017,2,2:10
18Characteristics of Boundary Layer Structure during a Persistent Haze Event in the Central Liaoning City Cluster, Northeast China显示文摘The characteristics of boundary layer structure during a persistent regional haze event over the central Liaoning city cluster of Northeast China from 16 to 21 December 2016 were investigated based on the measurements of particulate matter(PM) concentration and the meteorological data within the atmospheric boundary layer(ABL). During the observational period, the maximum hourly mean PM_(2.5) and PM10 concentrations in Shenyang, Anshan, Fushun, and Benxi ranged from 276 to 355 μg m–3 and from 378 to 442 μg m–3, respectively, and the lowest hourly mean atmospheric visibility(VIS) in different cities ranged from 0.14 to 0.64 km. The central Liaoning city cluster was located in the front of a slowly moving high pressure and was mainly controlled by southerly winds. Wind speed(WS) within the ABL(< 2 km) decreased significantly and WS at 10-m height mostly remained below 2 m s–1 during the hazy episodes, which was favorable for the accumulation of air pollutants. A potential temperature inversion layer existed throughout the entire ABL during the earlier hazy episode [from 0500 Local Time(LT) 18 December to 1100 LT 19 December], and then a potential temperature inversion layer developed with the bottom gradually decreased from 900 m to 300 m. Such a stable atmospheric stratification further weakened pollutant dispersion. The atmospheric boundary layer height(ABLH) estimated based on potential temperature profiles was mostly lower than 400 m and varied oppositely with PM_(2.5) in Shenyang. In summary, weak winds due to calm synoptic conditions, strong thermal inversion layer, and shallow atmospheric boundary layer contributed to the formation and development of this haze event.The backward trajectory analysis revealed the sources of air masses and explained the different characteristics of the haze episodes in the four cities.Xiaolan LI Yangfeng WANG Lidu SHEN Hongsheng ZHANG Hujia ZHAO Yunhai ZHANG Yanjun MA 2018Journal of Meteorological Research2018,32,2:10
19Application and safety assessment for nano-composite materials in food packaging显示文摘The technical breakthroughs and rapid developments in nanotechnologies enabling goods and products based on nanomaterials (NMs) has come to media and public attention as potentially one of the most significant technological advances of our time. Among these technical applications, nano-composite food packaging, which combines the NMs and conventional packaging, is at the forefront of applications in nanotechnologies, leading the whole industrial chain based on nanotechnologies with high speed development. Taking into account the status of the nano-composites applied in food packaging and present development trends, this review is focused on summarizing the basic applications of the nano-composites in food packaging as well as its risk assessment. The status summaries and the conclusions derived from this review are of benefit to manufacturers which produce the nano-composites used in food packaging, to general consumers and to governmental administration entities.HAN Wei YU YanJun LI NingTao WANG LiBing 2011Chinese Science Bulletin2011,56,12:10
20Study of Co-Simulation Methods Applied in Power Systems (Part I): VPNET显示文摘随着智能化电力电子装置在现代电力系统中的应用,信息交换成为电力系统完成复杂保护及控制功能的重要因素,因此通信系统的影响也应该在设计电力系统的过程中给予充分的考虑。但是,传统的电力系统仿真软件都没有系统仿真通信影响的能力;同时,搭建一种新的仿真软件需较多的时间和投入。联合仿真因此成为解决此类问题的另外一种选择,它能够利用各单个仿真软件已经存在的仿真模型,同时支持跨学科仿真软件之间的联合仿真。提出了一种新的联合仿真的平台VPNET,它综合了电力系统虚拟测试平台(virtualtestbed,VTB)和通信仿真软件OPNET来研究通信在电力系统中的影响。首先回顾了电力系统联合仿真方法的国内外发展概况,然后介绍了仿真方案VPNET以及实现该方案所需的关键技术。接着列举了该方案的2个具体应用:一是仿真网络化控制中延迟的影响;二是仿真基于多智能体通信的船舶电力系统保护。仿真结果符合理论分析,验证了该平台的有效性。LI Weilin ZHANG Xiaobin DONG Yanjun 2012中国电机工程学报2012,32,13:9
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