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382篇 您的检索式:作者名="LI Yanfeng"
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1Contrasting 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 2020National Science Review2020,7,8:51
2Influence of Atmospheric Particulate Matter on Ozone in Nanjing,China:Observational Study and Mechanistic Analysis显示文摘Particulate matter with diameters of 2.5 μm or smaller(PM_(2.5)) and ozone(O_3) are major pollutants in the urban atmosphere. PM_(2.5) can affect O_3 by altering the photolysis rate and heterogeneous reactions. However, these two processes and their relative importance remain uncertain. In this paper, with Nanjing in China as the target city, we investigate the characteristics and mechanism of interactions between particles and O_3 based on ground observations and numerical modeling.In 2008, the average concentrations of PM_(2.5) and O_3 at Caochangmen station are 64.6 ± 47.4 μg m^(-3) and 24.6 ± 22.8 ppb,respectively, while at Pukou station they are 94.1 ± 63.4 μg m^(-3) and 16.9 ± 14.9 ppb. The correlation coefficient between PM_(2.5) and O_3 is -0.46. In order to understand the reaction between PM_(2.5) and O_3, we construct a box model, in which an aerosol optical property model, ultraviolet radiation model, gas phase chemistry model, and heterogeneous chemistry model,are coupled. The model is employed to investigate the relative contribution of the aforementioned two processes, which vary under different particle concentrations, scattering capability and VOCs/NOxratios(VOCs: volatile organic compounds;NOx: nitric oxide and nitrogen dioxide). Generally, photolysis rate effect can cause a greater O_3 reduction when the particle concentrations are higher, while heterogeneous reactions dominate O_3 reduction with low-level particle concentrations.Moreover, in typical VOC-sensitive regions, O_3 can even be increased by heterogeneous reactions. In Nanjing, both processes lead to O_3 reduction, and photolysis rate effect is dominant. Our study underscores the importance of photolysis rate effect and heterogeneous reactions for O_3, and such interaction processes should be fully considered in future atmospheric chemistry modeling.Yawei QU Tijian WANG Yanfeng CAI Shekou WANG Pulong CHEN Shu LI Mengmeng LI Cheng YUAN Jing WANG Shaocai XU 2018Advances in Atmospheric Sciences2018,35,11:33
3Effect of nitrification inhibitor DMPP on nitrogen leaching, nitrifying organisms, and enzyme activities in a rice-oilseed rape cropping system显示文摘DMPP (3,4-dimethylpyrazole 磷酸盐) 被用来从沥滤或脱氮减少氮(N) 损失并且在农业土地改进 N 供应。然而,它使涉及 N 的有机体和酶活动硝化骑车的土壤上的影响大部分是未知的。因此,为二年,一个在农场上实验被进行了,到阐明矿物质 N 上的 DMPP 的效果(NH4+- N 和 NO3 ? 在 rice-oilseed 的沥滤的 -N) ,使硝化的有机体,和从的酶强奸收割系统。独自包括脲的三个处理(UA ) ,脲 +1% DMPP (DP ) ,和没有化肥(CK ) ,被执行了。结果证明那 DP 提高了吝啬的 NH4+-N 集中由 19.1%24.3% ,但是减少了吝啬的 NO3 ?-N 集中由 44.9%56.6% 在 leach 吃了在二年的大米强奸旋转下面,与 UA 处理相比。氧化的氨的人口细菌,硝酸盐还原酶的活动,和在 DP 处理的亚硝酸根 reductase 减少了大约 24.5%30.9% , 14.9%43.5% ,和 14.7%31.6% ,分别地作为与 UA 处理相比。然而,亚硝酸根氧化细菌和氢氧根胺 reductase 由 DMPP 仍然保持几乎未受影响。DMPP 有潜力也减少 NO3,这被建议 ?-N 由从脱氮禁止氨氧化或 N 损失沥滤,它赞成在 rice-oilseed 的 N 谈话强奸收割系统。LI Hua LIANG Xinqiang CHEN Yingxu LIAN Yanfeng TIAN Guangming NI Wuzhong 2008Journal of Environmental Sciences2008,20,2:27
4Ginkgo biloba extract improved cognitive and neurological functions of acute ischaemic stroke:a randomised controlled trial显示文摘Purpose To evaluate the efficacy and safety of Ginkgo biloba extract(GBE)in acute ischaemic stroke and its impact on the recurrence of vascular events.Methods We conducted a multicentre,prospective,randomised,open label,blinded,controlled clinical trial enrollingpatients with an onset of acute stroke within 7 days from five hospitals in China Jiangsu Province.Participants were assigned to the GBE group(450 mg GBE with 100 mg aspirin daily)or the control group(100 mg aspirin daily)for 6 months.The primary outcome was the decline in the Montreal Cognitive Assessment score at 6 months.Secondary outcomes were other neuropsychological tests of cognitive and neurological function,the the incidence of adverse events and vascular events.results 348 patients were enrolled:179 in the GBE group and 169 in the control group.With 18 patients lost to follow-up,the dropout rate was 5.17%.Admission data between two groups were similar,but in the GBE group there was a marked slow down in the decline in the Montreal Cognitive Assessment scores(−2.77±0.21 vs−1.99±0.23,P=0.0116(30 days);−3.34±0.24 vs−2.48±0.26,P=0.0165(90 days);−4.00±0.26 vs−2.71±0.26,P=0.0004(180 days))compared with controls.The National Institutes of Health Stroke Scale scores at 12 and 30 days,the modified Rankin Scale scores for independent rate at 30,90 and 180 days,and the Barthel Index scores at 30,90 and 180 days in the GBE group were significantly improved compared with controls.Improvements were also observedin GBE groups for Mini-Metal State Examination scores of 30,90 and 180 days,Webster's digit symbol test scores at 30 days and Executive Dysfunction Index scores at 30 and 180 days.No significant differences were seen in the incidence of adverse events or vascular events.conclusions We conclude that GBE in combination with aspirin treatment alleviated cognitive and neurological deficits after acute ischaemic stroke without increasing the incidence of vascular events.Shanshan Li Xinjiang Zhang Qi Fang Junshan Zhou Meijuan Zhang Hui Wang Yan Chen Biyun Xu Yanfeng Wu Lai Qian Yun Xu 2017Stroke & Vascular Neurology2017,2,4:25
5Age-related rhesus macaque models of COVID-19显示文摘Background:Since December 2019,an outbreak of the Corona Virus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus(SARS-CoV-2)in Wuhan,China,has become a public health emergency of international concern.The high fatality of aged cases caused by SARS-CoV-2 was a need to explore the possible age-related phenomena with non-human primate models.Methods:Three 3-5 years old and two 15 years old rhesus macaques were intratracheally infected with SARS-CoV-2,and then analyzed by clinical signs,viral replication,chest X-ray,histopathological changes and immune response.Results:Viral replication of nasopharyngeal swabs,anal swabs and lung in old monkeys was more active than that in young monkeys for 14 days after SARS-CoV-2 challenge.Monkeys developed typical interstitial pneumonia characterized by thickened alveolar septum accompanied with inflammation and edema,notably,old monkeys exhibited diffuse severe interstitial pneumonia.Viral antigens were detected mainly in alveolar epithelial cells and macrophages.Conclusion:SARS-CoV-2 caused more severe interstitial pneumonia in old monkeys than that in young monkeys.Rhesus macaque models infected with SARS-CoV-2 provided insight into the pathogenic mechanism and facilitated the development of vaccines and therapeutics against SARS-CoV-2 infection.Pin Yu Feifei Qi Yanfeng Xu Fengdi Li Peipei Liu Jiayi Liu Linlin Bao Wei Deng Hong Gao Zhiguang Xiang Chong Xiao Qi Lv Shuran Gong Jiangning Liu Zhiqi Song Yajin Qu Jing Xue Qiang Wei Mingya Liu Guanpeng Wang Shunyi Wang Haisheng Yu Xing Liu Baoying Huang Wenling Wang Li Zhao Huijuan Wang Fei Ye Weimin Zhou Wei Zhen Jun Han Guizhen Wu Qi Jin Jianwei Wang Wenjie Tan Chuan Qin 2020Animal Models and Experimental Medicine2020,3,1:22
6Whole-genome sequencing of 508 patients identifies key molecular features associated with poor prognosis in esophageal squamous cell carcinoma显示文摘Esophageal squamous cell carcinoma(ESCC)is a poor-prognosis cancer type with limited understanding of its molecular etiology.Using 508 ESCC genomes,we identified five novel significantly mutated genes and uncovered mutational signature clusters associated with metastasis and patients’outcomes.Several functional assays implicated that NFE2L2 may act as a tumor suppressor in ESCC and that mutations in NFE2L2 probably impaired its tumor-suppressive function,or even conferred oncogenic activities.Additionally,we found that the NFE2L2 mutations were significantly associated with worse prognosis of ESCC.We also identified potential noncoding driver mutations including hotspot mutations in the promoter region of SLC35E2 that were correlated with worse survival.Approximately 5.9%and 15.2%of patients had high tumor mutation burden or actionable mutations,respectively,and may benefit from immunotherapy or targeted therapies.We found clinically relevant coding and noncoding genomic alterations and revealed three major subtypes that robustly predicted patients’outcomes.Collectively,we report the largest dataset of genomic profiling of ESCC useful for developing ESCC-specific biomarkers for diagnosis and treatment.Yongping Cui Hongyan Chen Ruibin Xi Heyang Cui Yahui Zhao Enwei Xu Ting Yan Xiaomei Lu Furong Huang Pengzhou Kong Yang Li Xiaolin Zhu Jiawei Wang Wenjie Zhu Jie Wang Yanchun Ma Yong Zhou Shiping Guo Ling Zhang Yiqian Liu Bin Wang Yanfeng Xi Ruifang Sun Xiao Yu Yuanfang Zhai Fang Wang Jian Yang Bin Yang Caixia Cheng Jing Liu Bin Song Hongyi Li Yi Wang Yingchun Zhang Xiaolong Cheng Qimin Zhan Yanhong Li Zhihua Liu-Show 2020Cell Research2020,30,10:19
7Mesozoic-Cenozoic Multi-Stage Intraplate Deformation Events in the Langshan Region and their Tectonic Implications显示文摘In the Langshan region, northwestern China, marked multi-stage intraplate deformation events have occurred since the Mesozoic, including(1) northeast-striking ductile left-lateral strike slip during the Middle-Late Triassic, which is closely related to the collision between the North China and the Yangtze plates;(2) top-to-the-southeast thrust with northwest-southeast trending maximum compression during the Late Jurassic;(3) nearly eastward detachment during the Early Cretaceous;(4) top-to-the-northwest thrust with northwest-southeast trending maximum compression during the Late Cretaceous and Early Cenozoic;(5) northeast-striking brittle left-lateral strike slip with nearly north-south trending maximum compression; and(6) northwest-southeast extension during the Middle-Late Cenozoic. All these deformation events belong to the intraplate deformation across the entire Central Asian region and respond to the tectonic events along the plate boundaries or deep tectonics. The structures developed in early events in the crust were the most important factors controlling the later deformation styles, and few new structures have later developed. Based on previous research and our results, the paleostress inversion in the Langshan region shows that the Mesozoic intraplate deformations in the study region mainly resulted from the tectonic events from the Paleo-Pacific region and have no or a weak relation to the Tethys region. During the Late Jurassic, the maximum compression from the Mongolia-Okhotsk region cannot be excluded. The Langshan region is the bridge between southern Mongolia and the western Ordos tectonic belt and is thus important to understand the nature and relationship between both regions.ZHANG Jin LI Jinyi LI Yanfeng QI Wenhua ZHANG Yiping 2014Acta Geologica Sinica(English Edition)2014,88,1:18
8Effect of thermomechanical treatment on microstructure and properties of Cu-Cr-Zr-Ag alloy显示文摘The effects of thermomechanical treatment on the properties and microstructure of Cu-Cr-Zr alloy and Cu-Cr-Zr-Ag alloy were investigated. Ag addition improves the mechanical properties of the alloy through solid solution strengthening and brings a little effect on the electrical conductivity of the alloy. A new Cu-Cr-Zr-Ag alloy was developed, which has an excellent combination of the tensile strength, elongation, and electrical conductivity reaching 476.09 MPa, 15.43% and 88.68% IACS respectively when subjected to the optimum thermomechanical treatment, i.e., solution-treating at 920°C for 1 h, cold drawing to 96% deformation, followed by aging at 400°C for 3 h. TEM analysis re-vealed two kinds of finely dispersed precipitates of Cr and Cu4Zr. It is very important to use the mechanisms of solid solution strengthening, work hardening effect as well as precipitate pinning effect of dislocations to improve tensile strength of the alloy without adversely affecting its electrical conductivity.XIE Haofeng MI Xujun HUANG Guojie GAO Baodong YIN Xiangqian LI Yanfeng 2011Rare Metals2011,30,6:17
9Effects of culm carbohydrate partitioning on basal stem strength in a high-yielding rice population显示文摘Rice culm carbohydrate transport can simultaneously affect grain filling and stem lodging resistance by regulating non-structural carbohydrate(NSC) and structural carbohydrate(SC) contents. However, the relationship between carbohydrate transposition and culm strength is not well documented. Accordingly, a high-yielding hybrid rice cultivar(Y Liangyou 2) was tested under different N fertilization regimes at two locations, Taoyuan(a special high-yield eco-site), Yunnan province and Danyang(a representative eco-site of the middle and lower Yangtze), Jiangsu province, China. Significantly higher grain yield and basal stem strength were found at Taoyuan than Danyang under all N rates throughout the two-year experiment. At heading stage, soluble sugars, starch, cellulose and lignin contents of the basal culm at Taoyuan were significantly 132.0%, 73.7%, 1.2%, and 62.7% higher than those at Danyang, respectively. At 20 days after heading, soluble sugars and starch content at Taoyuan decreased significantly compared to Danyang, but lignin content remained higher. Culm carbohydrate transport to kernels at Taoyuan was significantly greater than that at Danyang, and the proportion of soluble sugars and starch was correspondingly 62.9%lower. However, the proportion of lignin and cellulose was 22.7% higher at Taoyuan than that at Danyang. Soluble sugars and starch partitioning were significantly reduced under an increased nitrogen application rate, but SC partitioning was little affected. There were significant positive correlations between basal culm bending stress and dry weight and cellulose and lignin proportions at both locations under all N rates, suggesting that the higher SC proportion at 20 days after heading was primarily responsible for culm strength.These results suggest that high-yielding rice populations with greater culm strength require both moderate NSC transport and greater SC accumulation.Jun Zhang Ganghua Li Qingyu Huang Zhenghui Liu Chengqiang Ding She Tang Lin Chen Shaohua Wang Yanfeng Ding Weijian Zhang 2017The Crop Journal2017,5,6:13
10Glial cell-derived neurotrophic factor mRNA expression in a rat model of spinal cord injury following bone marrow stromal cell transplantation显示文摘BACKGROUND: Several animal experiments utilizing bone marrow stromal cell (BMSC) transplantation for the treatment of spinal cord injury have proposed a hypothesis that BMSC transplantation effects are associated with increased glial cell-derived neurotrophic factor (GDNF) expression. OBJECTIVE: To confirm the effects of BMSC transplantation on GDNF mRNA expression in rats with spinal cord injury by reverse transcription-polymerase chain reaction (RT-PCR). DESIGN, TIME AND SETTING: The present molecular, cell biology experiment was performed at the Key Laboratory of Children's Congenital Malformation, Ministry of Health of China & Department of Developmental Biology, Basic Medical College, China Medical University between March 2006 and May 2007. MATERIALS: Sixty healthy Wistar rats aged 2-4-months and of either gender were included in this study. Spinal cord injury was induced in all rats by hemisection of T9 on the left side. RT-PCR kits were purchased from TaKaRa Company, China. Type 9600 RCR amplifier was provided by PerkinElmer Company, USA. METHODS: Three rats were selected for BMSC culture and subsequent transplantation (after three passages). Of the remaining 57 rats, nine were selected for sham-operation (sham-operated group), where only the T9 spinal cord was exposed without hemisection. A total of 48 rats were randomly and evenly divided into BMSC transplantation and model groups. In the BMSC transplantation group, following spinal cord injury induction, each rat was administered a BMSC suspension through two injection sites selected on the gray and white matter boundary caudally and cephalically, seperately and near to injury site in the spinal cord. The model group received an equal volume of PBS through the identical injection sites. MAIN OUTCOME MEASURES: At 24 and 72 hours, as well as at 7 days, following spinal cord injury, the spinal cord at the T 9 segment was removed. Eight rats were allocated to each time point in the BMSC transplantation and model groups, with three rats allocated to the sham-operated group. GDNF mRNA expression was semiquantitatively analyzed by RT-PCR. RESULTS: The sham-operated group exhibited extremely low GDNF mRNA expression. GDNF mRNA expression significantly increased at 24 hours after spinal cord injury, reached a peak level at 72 hours, and slowly decreased thereafter. However, it remained higher than normal levels at 7 days (P < 0.05). At all time points following spinal cord injury, GDNF mRNA expression was significantly greater in the BMSC transplantation group than in the model group (P < 0.05). CONCLUSION: Transplantation of BMSCs into the injured spinal cord up-regulated GDNF mRNA expression, thereby promoting repair of the injured spinal cord.Lei Li Gang Lu Yanfeng Wang Hong Gao XinXu Lunhao Bai Lunhao Bai Huan Wang 2008Neural Regeneration Research2008,3,10:13
11Chemical vapor deposition growth of large-scale hexagonal boron nitride with controllable orientation显示文摘有一致厚度的大域的六角形的硼氮化物(h-BN ) 的化学蒸汽免职(CVD ) 合成是很挑战性的,主要由于这材料的极其高的成核密度。此处,我们报导晶片规模的成功的生长,有大单人赛水晶的领域尺寸的高质量的 h-BN 单层电影,吗直到~ 72 ??????????????????????????慮潮档湡敮獬???????慮潮畴敢??洠獥灯牯????  ??Xiuju Song Junfeng Gao Yufeng Nie Teng Gao Jingyu Sun Donglin Ma Qiucheng Li Yubin Chen Chuanhong Jin Alicja Bachmatiuk Mark H. Rummeli Feng Ding Yanfeng Zhang Zhongfan Liu 2015Nano Research2015,8,10:12
12Microstructural investigation of Nd-rich phase in sintered Nd-Fe-B magnets through electron microscopy显示文摘intergranular 的分发,形态学和结构在 sintered Nd-Fe-B 磁铁的 Nd 富有的阶段通过电子显微镜学被学习。Backscattered 电子(BSE ) 成像表明有各种各样的形态学和尺寸的 Nd 富有的粒子在谷物边界和四角形的 Nd2Fe14B 矩阵的三倍的连接是随机分布式的。通过选择区域电子衍射(SAED ) 在一个系统的倾斜条件下面的分析,大多数 intergranular 与从几百 nanometres 到几 micrometres 的尺寸, Nd 富有的阶段粒子作为集中脸被识别立方(FCC ) 结构。如此的粒子与他们的邻近的 Nd2Fe14B 矩阵谷物拥有了几种近似取向关系,例如(002 )Nd2Fe14B//(200 )FCC_Nd 富有[120 ]Nd2Fe14B//[001 ]FCC_Nd 富有,(002 )Nd2Fe14B//(22 ? 湯洠条敮楴慺楴湯爠癥牥慳? 敢慨楶牯映牯愠湮慥敬 ? 摎 ???? 敆渠湡潣灭獯瑩 ?FU Xin HAN Xiaolei DU Zhiwei FENG Haibo LI Yanfeng 2013Journal of Rare Earths2013,31,8:11
13TLR4 is essential for dendritic cell activation and anti-tumor T-cell response enhancement by DAMPs released from chemically stressed cancer cells显示文摘免疫疗法和化疗的联合为癌症的某些类型的治疗被认为是一条有希望的途径。然而,内在的机制需要充分被调查为癌症 chemoimmunotherapy 指导更有效的协议的设计。联系危险的分子的模式(阻尼) 能激活有免疫力的房间,是众所周知的,包括树枝状的房间(DC ) ,经由像使用费的受体(TLR ) ;然而,在有免疫力的反应的激活免除化学对待药的肿瘤房间的阻尼的角色需要进一步被阐明。这里,我们发现那 colorectal 与 oxaliplatin (OXA ) 对待的癌症(CRC ) 房间或 5 氟尿嘧啶(5-Fu ) 释放了高活动性的组盒子 1 的高水平(HMGB1 ) 和热吃惊蛋白质 70 (HSP70 ) 。在 OXA/5-Fu 治疗以后,也展出的 CRC 病人的 sera 增加了 HMGB1 和 HSP70 的层次,哪个是著名阻尼。与 OXA/5-Fu 对待的垂死的 CRC 房间的上层清液支持了老鼠和人的 DC 成熟,与 HLA 医生, CD80 和 CD86 表示和 IL-1β 的改进的 upregulation;, TNF-α, MIP-1α, MIP-1β, RANTES 和 IP-10 生产。由 DC 组成的疫苗与导致的化学上强调的 CRC 房间的上层清液搏动了更重要的 IFN-γ在 vitro 并且在 vivo 生产 Th1 反应。然而,化学上强调的 CRC 房间的上层清液没能在 TLR4 缺乏的 DC 导致 phenotypic 成熟和 cytokine 生产,显示在导致阻尼的 DC 成熟和激活的 TLR4 的一个必要角色。而且,有化学上强调的 CRC 房间的上层清液的 pulsing 高效地没导致 IFN-γ在 TLR4 缺乏的 DC 生产 Th1 反应。一起,这些结果证明免除化学上强调的癌症房间的阻尼能经由 TLR4 激活 DC 并且提高反肿瘤 T 房间有免疫力的回答的正式就职,描出一条临床上相关的免疫助手小径由阻尼被触发。Hongliang Fang Bing Ang Xinyun Xu Xiaohui Huang Yanfeng Wu Yanping Sun Wenying Wang Nan Li Xuetao Cao Tao Wan 2014Cellular & Molecular Immunology2014,11,2:11
14Late Mesozoic-Cenozoic Exhumation of the Northern Hexi Corridor:Constrained by Apatite Fission Track Ages of the Longshoushan显示文摘The apatite fission track(AFT) ages and thermal modeling of the Longshoushan and deformation along the northern Hexi Corridor on the northern side of the Qinghai-Tibetan Plateau show that the Longshoushan along the northern corridor had experienced important multi-stage exhumations during the Late Mesozoic and Cenozoic. The AFT ages of 7 samples range from 31.9 Ma to 111.8 Ma.Thermal modeling of the AFT ages of the samples shows that the Longshoushan experienced significant exhumation during the Late Cretaceous to the Early Cenozoic(-130-25 Ma). The Late Cretaceous exhumation of the Longshoushan may have resulted from the continuous compression between the Lhasa and Qiangtang blocks and the flat slab subduction of the Neo-Tethys oceanic plate, which affected wide regions across the Qinghai-Tibetan Plateau. During the Early Cenozoic, the Longshoushan still experienced exhumation, but this process was caused by the Indian-Eurasian collision. Since this time,the Longshoushan was in a stable stage for approximately 20 Ma and experienced erosion. Since ~5 Ma,obvious tectonic deformation occurred along the entire northern Hexi Corridor, which has also been reported from the peripheral regions of the Qinghai-Tibetan Plateau, especially in the Qilianshan and northeastern margin of the plateau. The AFT ages and the Late Cenozoic deformation of the northern Hexi Corridor all indicate that the present northern boundary of the Qinghai-Tibetan Plateau is situated along the northern Hexi Corridor.ZHANG Beihang ZHANG Jin WANG Yannan ZHAO Heng LI Yanfeng 2017Acta Geologica Sinica(English Edition)2017,91,5:11
15Methane emissions from rice fields under continuous straw return in the middle-lower reaches of the Yangtze River显示文摘A three-year experiment was conducted in the middle-lower reaches of the Yangtze River in China to study the influence of continuous wheat straw return during the rice season and continuous rice straw return in wheat on methane (CH 4 ) emissions from rice fields in which, the rice-wheat rotation system is the most dominant planting pattern. The field experiment was initiated in October 2009 and has continued since the wheat-growing season of that year. The analyses for the present study were conducted in the second (2011) and third (2012) rice growing seasons. Four treatments, namely, the continuous return of wheat straw and rice straw in every season (WR), of rice straw but no wheat straw return (R), of wheat straw but no rice straw return (W) and a control with no straw return (CK), were laid out in a randomized split-plot design. The total seasonal CH 4 emissions ranged from 107.4 to 491.7 kg/ha (2011) and 160.3 to 909.6 kg/ha (2012). The increase in CH 4 emissions for treatments WR and W were 289% and 230% in the second year and 185% and 225% in the third year, respectively, in relation to CK. We observed less methane emissions in the treatment R than in CK by 14%-43%, but not statistically significant. Treatment R could increase rice productivity while no more CH 4 emission occurs. The difference in the total CH 4 emissions mainly related to a difference in the methane flux rate during the first 30-35 days after transplant in the rice growing season, which was caused by the amount of dissolved oxygen in paddy water and the amount of reducible soil materials.Pengfu Hou Ganghua Li Shaohua Wang Xin Jin Yiming Yang Xiaoting Chen Chengqiang Ding Zhenghui Liu Yanfeng Ding 2013Journal of Environmental Sciences2013,25,9:10
16Tillage Pedogenesis of Purple Soils in Southwestern China显示文摘Land cultivation and tillage process, and their consequent impacts on soil erosion, have been criticized as the main cause of degradation of land or soil quality. However, purple soils, classified as Regosols in FAO Taxonomy or Entisols in USDA Taxonomy, are formed from purple rocks of the Trias-Cretaceous system, have been developed or at least accelerated the development due to continual tillage operation, especially digging and ridging. The present study took micromorphological investigation on the sedimentary rocks and the soils under different operations of tillage. Results show that the purple rock of Feixiangguan Formation of the Trias system (T1f) is the easiest to physical weathering and the most fertile soil material enriched in nutrients, and it has been, therefore, mostly cultivated and intensively tilled around the year. It has the fastest soil formation rate. Soil formation rate in the cropland with conventional tillage is higher than that in the forestland and the grassland. It implies that the artificial brokenness and tillage disturbance play a great role in physical weathering and initiating soil formation processes.HE Xiubin BAO Yuhai NAN Hongwei XIONG Donghong WANG Li LIU Yanfeng ZHAO Jingbo 2009Journal of Mountain Science2009,6,2:10
17Fate of Basal N Under Split Fertilization in Rice with ^(15)N Isotope Tracer显示文摘Split fertilization strategy is popularly adopted in rice to synchronize soil nitrogen(N) supply and crop N demand. Attention has been paid more on mid-season topdressing N, but limited on basal N. A clearer understanding of the basal N fate under split fertilization is crucial for determining rational basal N split ratio to improve the yield and reduce the loss to environment. A two-year field experiment with two N rates of 150 and 300 kg Nha^(-1), two split ratios of basal N, 40% and 25%, and two rice varieties,Wuyunjing 23(japonica) and Y-liangyou 2(super hybrid indica), was conducted. Labelled ^(15) N urea was supplied in micro-plots as basal fertilizer to determine the plant uptake, translocation, soil residual, and loss of basal N fertilizer. The results showed that basal N absorbed by rice was only 1.6%–11.5% before tillering fertilization(8–10 d after transplanting), 6.5%–21.4% from tillering fertilization to panicle fertilization, and little(0.1%–4.4%) after panicle fertilization. The recovery efficiency of basal N for the entire rice growth stage was low and ranged from 18.7% to 24.8%, not significantly affected by cultivars or N treatments. Soil residual basal N accounted for 10.3%–36.4% and decreased with increasing total N rate and basal N ratio, regardless of variety and year. 43.8%–70.4% of basal N was lost into the environment based on the N balance. Basal N loss was significantly linearly positive related with the basal N rate and obviously enhanced by the increasing basal N ratio for both varieties in both 2012 and 2013. The N use efficiency and yield was significantly improved when decreasing the basal N ratio from 40% to 25%. The results indicated that the basal N ratio should be reduced, especially with limited N inputs, to improve the yield and reduce the N loss to the environment.LI Ganghua LIN Jingjing XUE Lihong DING Yanfeng WANG Shaohua YANG Linzhang 2018Pedosphere2018,28,1:9
18Terahertz spoof surface-plasmon-polariton subwavelength waveguide显示文摘Surface plasmon polaritons(SPPs) with the features of subwavelength confinement and strong enhancements have sparked enormous interest. However, in the terahertz regime, due to the perfect conductivities of most metals, it is hard to realize the strong confinement of SPPs, even though the propagation loss could be sufficiently low. One main approach to circumvent this problem is to exploit spoof SPPs, which are expected to exhibit useful subwavelength confinement and relative low propagation loss at terahertz frequencies. Here we report the design,fabrication, and characterization of terahertz spoof SPP waveguides based on corrugated metal surfaces. The various waveguide components, including a straight waveguide, an S-bend waveguide, a Y-splitter, and a directional coupler, were experimentally demonstrated using scanning near-field terahertz microscopy. The proposed waveguide indeed enables propagation, bending, splitting, and coupling of terahertz SPPs and thus paves a new way for the development of flexible and compact plasmonic circuits operating at terahertz frequencies.YING ZHANG YUEHONG XU CHUNXIU TIAN QUAN XU XUEQIAN ZHANG YANFENG LI XIXIANG ZHANG JIAGUANG HAN WEILI ZHANG 2018Photonics Research2018,9,1:9
19Efficient and Large-Scale Synthesis of Few-Layered Graphene Using an Arc-Discharge Method and Conductivity Studies of the Resulting Films显示文摘An arc-discharge method using a buffer gas containing carbon dioxide has been developed for the efficient and large-scale synthesis of few-layered graphene.The resulting samples of few-layered graphene,well-dispersed in organic solvents such as N,N-dimethylformamide(DMF)and 1,2-dichlorobenzene(o-DCB),were examined by transmission electron microscopy(TEM),X-ray diffraction(XRD),Raman spectroscopy,atomic force microscopy(AFM),and thermal gravimetric analysis(TGA).The electrical conductivity and transparency of flexible films prepared using a direct solution process have also been studied.Yingpeng Wu Bin Wang Yanfeng Ma Yi Huang Na Li Fan Zhang Yongsheng Chen 2010Nano Research2010,3,9:8
20Hydroisomerization performance of platinum supported on ZSM-22/ZSM-23 intergrowth zeolite catalyst显示文摘Hydroisomerization catalysts Pt/ZSM-22,Pt/ZSM-23,and Pt/ZSM-22/ZSM-23 were prepared by supporting Pt on ZSM-22,ZSM-23,and intergrowth zeolite ZSM-22/ZSM-23,respectively.The typical physicochemical properties of these catalysts were characterized by X-Ray Diffraction(XRD),N2 absorption-desorption,Pyridine-Fourier Transform Infrared(Py-FTIR),Transmission Electron Microscopy(TEM),X-Ray Fluorescence(XRF),Scanning Electron Microscopy(SEM) and NH3-Temperature Programmed Desorption(NH3-TPD),and the performance of these catalysts in n-dodecane hydroisomerization was evaluated in a continuous down-flow fixed bed with a stainless steel tubular reactor.The characterization results indicated that the intergrowth zeolite ZSM-22/ZSM-23 possessed the dual structure of ZSM-22 and ZSM-23,and the catalyst Pt/ZSM-22/ZSM-23 had similar pores and weak acidity to Pt/ZSM-22 and Pt/ZSM-23 catalysts.Moreover,Pt/ZSM-22/ZSM-23 catalyst showed a high selectivity in hydroisomerization of long chain n-alkanes to mono-branched isomers.The evaluation results for n-dodecane hydroisomerization indicated that the activity of Pt/ZSM-22/ZSM-23 was the lowest,while the hydroisomerization selectivity was the highest among the three catalysts.The maximum yield of i-dodecane product was 68.3% over Pt/ZSM-22/ZSM-23 at 320 oC.Chi Kebin Zhao Zhen Tian Zhijian Hu Sheng Yan Lijun Li Tianshu Wang Bingchun Meng Xiangbin Gao Shanbin Tan Mingwei Liu Yanfeng 2013Petroleum Science2013,10,2:8
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