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Detecting spatio-temporal changes of arable land and construction land in the Beijing-tianjin corridor during 2000–2015

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Journal of Geographical Sciences 2019年第5期29卷 702-718页

作者：郭丽英 DI Liping tian qing Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Center for Spatial Information Science and Systems George Mason University Department of Computational and Data Sciences George Mason University

Rapid peri-urbanization has become a new challenge for sustainable urban-rural development worldwide. To clarify how unprecedented urban sprawl at the metropolitan fringe impacts urban-rural landscape, this study took the Beijing-tianjin corridor of Beijing-tianjin-Hebei metropolitan area, one of the largest urban clusters in China, as a typical example. By using Landsat-based landscape metrics and a practical methodology, we investigated the landscape changes and discussed the potential reasons in the context of rapid peri-urbanization of China. Specifically, multi-temporal land use maps derived from Landsat images were used to calculate landscape metrics and analyze their characteristics along the urban-rural gradients. The practical methodology was used to monitor spatio-temporal characteristics of landscape change in large metropolitan areas. The results showed that landscape patterns in the area had changed greatly from 2000 to 2015 with characteristics of construction land sprawl and arable land shrinkage. The intensity and scale of landscape changes varied along the urban-rural gradients. Sampled plots in urbanized areas and rural areas demonstrated distinguishable landscape patterns and significant differences. Urban areas had more heterogeneous and fragmented landscapes than rural areas. Peri-urban areas in general experienced higher levels of land diversification than rural areas. Rural residential land appeared to be more aggregated near Beijing and tianjin cities. Besides, our findings also indicated that urban expansion was largely responsible for landscape *** findings of this study potentially provide strategical insights into landscape planning around mega cities and sustainable coordinated urban-rural development.

关键词： spatio-temporal characteristics arable land construction land peri-urbanization Beijing-tianjin corridor(BTC) metropolitan area China

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Performance analysis of broadband satellite communication system based on OFDM/TDM

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The Journal of China Universities of Posts and Telecommunications 2013年第3期20卷 37-42,77页

作者： tian qing-hua ZHANG Qi TAO Ying LIU Nai-jin XIN Xiang-jun ZHANG Li-jia XU Da-xiong Institute of Optical Communication and Optoelectronics Beijing University of Posts and Telecommunications School of Electronic Engineering Beijing University of Posts and Telecommunications Institute of Telecommunication Satellite China Academy of Space Technology

Orthogonal frequency division multiplexing （OFDM） is attracting more attention for its capability of high speed transmission. However, the OFDM possesses an obvious shortage in its high ratio of the peak power to the average power （PAPR）, which has become the main issue holding it back to be applied to the broadband satellite communication system. OFDM combined with time division multiplexing （TDM）, dividing the subcarriers of OFDM into some blocks in time tune, can decrease the high PAPR of OFDM. Meanwhile, the advantages of OFDM can be preserved. In this paper, OFDM/TDM is applied to the broadband satellite communication system. This paper theoretically analyses OFDM/TDM system model as well as its restraining effect on PAPR, and proposes frequency domain multiplexing-pilot （FDM-Pilot） channel estimation algorithm. Simulation results show OFDM/TDM in broadband satellite communication system has approving performance and decreased the PAPR.

关键词： OFDM/TDM broadband satellite communication system PAPR channel estimation

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天广直流双侧频差调制异常分析

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电力系统保护与控制 2011年第14期39卷 94-98页

作者：田庆南方电网超高压输电公司检修试验中心广东广州510663

分析了天广直流控制保护系统改造完成后发生的一次功率振荡事件,根据天生桥换流站的实际录波和实际过程,对双侧频差控制增加带通滤波环节后,直流控制的幅频和相频特性进行了分析,并对带通滤波环节所带来的高频幅值的衰减和相位滞后,进... 详细信息

分析了天广直流控制保护系统改造完成后发生的一次功率振荡事件,根据天生桥换流站的实际录波和实际过程,对双侧频差控制增加带通滤波环节后,直流控制的幅频和相频特性进行了分析,并对带通滤波环节所带来的高频幅值的衰减和相位滞后,进行了利弊分析,发现功率振荡的起因和持续振荡的原因为:双侧频差控制器开放逻辑的抗干扰能力不强、传递函数中缺少了带通滤波环节。给出了三个办法解决该高频振荡问题,完善双侧频差控制器输出值的开放逻辑、在传递函数中增加了带通滤波环节、完善隔直环节和滤波环节的参数。

关键词：天广直流功率振荡带通滤波器双侧频差相频特性

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State-to-state dynamics of reactions H+DH'(v=0,j=0)→HH'(v',j')+D/HD(v',j')+H'with time-dependent quantum wave packet method

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Chinese Physics B 2021年第7期30卷 192-199页

作者： Juan Zhao Da-Guang Yue Lu-Lu Zhang Shang Gao Zhong-Bo Liu qing-tian Meng School of Science Shandong Jiaotong UniversityJinan 250357China School of Physics and Electronics Shandong Normal UniversityJinan 250358China

State-to-state time-dependent quantum dynamics calculations have been carried out to study H+DH'→HH'+D/HD+H'reactions on BKMP2 *** total integral cross sections of both reactions are in good agreement with earlier theoretical and experimental results,moreover the rotational state-resolved reaction cross sections of H+DH'→HH‘+D at collision energy Ec=0.5 eV are closer to the experimental values than the ones calculated by Chao et al[***.1178341(2002)],which proves the higher precision of the quantum calculation in this *** addition,the state-to-state dynamics of H+DH'→HD'+H reaction channel have been discussed in detail,and the differences of the micro-mechanism of the two reaction channels have been revealed and analyzed clearly.

关键词： state-to-state time-dependent quantum wave-packet method differential cross sections

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Indica rice restorer lines with large sink potential exhibit improved nutrient transportation to the panicle,which enhances both yield and nitrogen-use efficiency

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Journal of Integrative Agriculture 2021年第6期20卷 1438-1456页

作者： tian qing-lan HE Lian-hua LIAO Shuang LI Wu DENG Fei ZHOU Wei ZHONG Xiao-yuan REN Wan-jun Key Laboratory of Crop Ecophysiology and Farming System in Southwest China/Crop Ecophysiology and Cultivation Key Laboratory of Sichuan Province/College of Agronomy Sichuan Agricultural UniversityChengdu 611130P.R.China Biotechnology Research Institute Guangxi Academy of Agricultural SciencesNanning 530007P.R.China

The yield and nitrogen use efficiency(NUE)of hybrid rice combinations are closely related to restorer ***,it is essential to evaluate the agronomic characteristics of restorer lines with high yield and high NUE(HYHN).However,it is unclear which restorer lines are HYHN,and neither have the common agronomic traits of the HYHN restorer lines been *** to address this issue,we conducted two filed experiments using three nitrogen applications,which screened five HYHN restorer lines from 15 indica restorer ***,NUE and nutrient transportation of restorer lines with different yields and NUE types were *** and total nitrogen absorption in aboveground biomass(TNA)increased,whereas NUE for grain production decreased with increasing nitrogen application *** HYHN restorer lines had large spikelets and high weight per panicle that were significantly positively correlated with yield and ***,large sink potential may be beneficial for both yield and *** further studied the differences in nutrient transportation to panicles between the HYHN and low yield and low NUE(LYLN)restorer lines and found that the former had a higher nitrogen absorption level and dry matter weight ratios of panicle in ***,the HYHN lines also had a higher root and neck-panicle node bleeding intensity per stem after heading and more developed vascular bundles of neck-panicle nodes and leaves than the LYLN lines,which could contribute to the transportation of nutrients from root to ground and from stem and leaf to ***,the advantages of large sink potential of the HYHN restorer lines include large nutrient accumulation in and distribution to the panicles and smooth flow of nutrients along the transportation channels.

关键词： indica hybrid rice restorer lines grain yield nitrogen-use efficiency sink potential nutrient transportation

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Dynamics of molecular alignment steered by a few-cycle terahertz laser pulse

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Chinese Physics B 2022年第10期31卷 377-383页

作者： Qi-Yuan Cheng Yu-Zhi Song Deng-Wang Li Zhi-Ping Liu qing-tian Meng Medical Engineering Department Shandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinan 250021China School of Physics and Electronics Shandong Normal UniversityJinan 250358China Shandong Laibo Biotechnology Co. Ltd.Jinan 250101China School of Control Science and Engineering Shandong UniversityJinan 250061China

The field-free alignment of molecule Cl CN is investigated by using a terahertz few-cycle pulse(THz FCP)based on the time-dependent density matrix *** is shown that a high degree of molecular alignment can be obtained by changing the matching number of the THz FCPs in the adiabatic regime and the non-adiabatic *** matching number can affect both the maximum value of the alignment and the time at which it is *** is also found that a higher degree of alignment can be achieved by using the THz FCP at lower intensity and there exists an optimal threshold of molecular alignment with the increase of the field *** found is the frequency sensitive region in which the degree of maximum alignment can be enhanced greatly by modulating the center frequencies of different THz *** investigation demonstrates that comparing with a THz single-cycle pulse,a better result of the field-free alignment can be created by a THz FCP at a constant rotational temperature of molecule.

关键词： molecular alignment few-cycle terahertz pulse density matrix theory

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Anthostomella is polyphyletic comprising several genera in Xylariaceae

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Fungal Diversity 2015年第4期73卷 203-238页

作者： Dinushani A.Daranagama Erio Camporesi qing tian Xingzhong Liu Sunita Chamyuang Marc Stadler Kevin D.Hyde State Key Laboratory of Mycology Institute of MicrobiologyChinese Academy of SciencesNo 31st West Beichen RoadChaoyang District Beijing 100101People’s Republic of China Institute of Excellence in Fungal Research and School of ScienceMae Fah Luang UniversityChiang Rai 57100Thailand College of Science Botany and Microbiology DepartmentKing Saud UniversityRiyadh 1145Saudi Arabia Helmholtz-Zentrum für Infektionsforschung GmbH Department of Microbial DrugsInhoffenstrasse 738124 BraunschweigGermany A.M.B.Gruppo Micologico Forlivese "Antonio Cicognani" Via Roma 18ForlìItaly A.M.B.Circolo Micologico "Giovanni Carini" C.P.314 BresciaItaly Societàper gli Studi Naturalistici della Romagna C.P.144 BagnacavalloRAItaly

Anthostomella has long been regarded as a large,but polyphyletic genus in the family Xylariaceae,but species in this group generally lack phylogenetic *** this study,14 anthostomella-like taxa collected from Italy,were studied using both morphology and molecular *** ascospore isolates were obtained and the asexual morphs of five taxa *** phylogenetic relationships of the xylariaceous taxa were inferred using combined ITS,RPB2,βtubulin and LSU gene *** introduce new sequence data for 24 with included the 14 new anthostomella-like *** subfamilies Hypoxyloideae and Xylarioideae within Xylariaceae were recognized as the two major clades with high bootstrap *** the two clades 21 subclades were resolved and the anthostomella-like taxa clustered in five of these subclades indicating that the genus is *** sensu stricto comprised ***,***,***,*** and *** *** and *** collections morphologically closely resemble the type specimens and therefore we designate reference *** new species Anthostomella helicofissa,*** and *** are also *** distinct lineages of anthostomella-like taxa correspondent to four new genera,Anthocanalis,Brunneiperidium,Lunatiannulus and Pyriformiascoma,which are also introduced,while one clustered in Astrocystis and is introduced as a new *** to the new anthostomella-like genera and species examined in this study are provided.

关键词： Asexual morph Multigene phylogeny Taxonomy Xylariaceous taxa Xylariales

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The resource-based project cooperation model in the strategic alliance with neural network

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Chinese Business Review 2008年第1期7卷 1-5页

作者： tian qing-feng School of Management Northwestern Polytechnical University Xi＇an 710072 China

This study proposed a neural network model of resource-based project cooperation in the strategic alliance. From the angel of project, it is assumed that alliance members work together to process a project with equipment, labor force and capital. The greatest output of project could be forecasted. Afterwards, on the basis of constructing utility function of profit, resources constraint, resources input risk, synthetically utility function is obtained. With above work, the neural network model is established under the condition of many cooperative members. Finally, using one kind of new neural net means, we have carded on the imitation resolution as to the variable value of the latter model.

关键词： strategic management project cooperation neural network

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Liquidus Temperatures of System Na_3AlF_6-K_3AlF_6-AlF_3 for Aluminum Electrolysis at Lower Temperature

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Chemical Research in Chinese Universities 2011年第6期27卷 1019-1022页

作者： WEI Chen-juan LAI Yan-qing LI Jie tian Zhong-liang WANG Jia-wei ZOU Zhong LIU Ye-xiang School of Metallurgical Science and Engineering Central South University Changsha 410083 P. R. China

Liquidus temperatures in the molten salt system Na3AlF6-K3AlF6-AlF3 of interest for aluminum electrolysis were determined by thermal analysis method. The results were presented and an empirical equation describing liquidus temperatures for primary crystallization was derived t=1003.5–0.081×A2.3159–5.87×B0.657–0.024×A2.22×B1.14＋ 0.035×A2.17×B1.084, where t is the liquidus temperature in degree Celsius, A denotes the mass fraction of AlF3 in system Na3AlF6-K3AlF6- AlF3, and B denotes K3AlF6/（Na3AlF6＋K3AlF6 ） in mass（%, the value was defined as KR in this paper）. The composition limitations are 0w（AlF3）30%, and 0KR50%. The isothermal diagram of molten salt system Na3AlF6-K3AlF6-AlF3 was obtained in this composition limitation.

关键词： Liquidus temperature Na3AlF6-K3AlF6-AlF3 system Empirical equation

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Celastrol regulates the oligomeric state and chaperone activity of αB-crystallin linked with protein homeostasis in the lens

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Fundamental Research 2024年第2期4卷 394-400页

作者： Huaxia Wang qing tian Ying Zhang Yibo Xi Lidan Hu Ke Yao Jingyuan Li Xiangjun Chen Eye Center of the Second Affiliated Hospital Zhejiang University School of Medicine88 Jiefang RoadHangzhou 310009China Institute of Translational Medicine Zhejiang University School of Medicine268 Kaixuan RoadHangzhou 310020China. State Key Laboratory of Membrane Biology School of Life SciencesTsinghua UniversityBeijing 100084China The Children’s Hospital Zhejiang University School of MedicineNational Clinical Research Center for Child HealthHangzhou 310052China Zhejiang Province Key Laboratory of Quantum Technology and Device Department of PhysicsZhejiang UniversityZheda Road 38Hangzhou 310027China

Protein misfolding and aggregation are crucial pathogenic factors for cataracts,which are the leading cause of visual impairment worldwide.α-crystallin,as a small molecular chaperone,is involved in preventing protein misfolding and maintaining lens *** chaperone activity of α-crystallin depends on its oligomeric *** previous work identified a natural compound,celastrol,which could regulate the oligomeric state of α*** this work,based on the UNcle and SEC analysis,we found that celastrol induced𝛼αB-crystallin to form large *** oligomer formation enhanced the chaperone activity of αB-crystallin and prevented aggregation of the cataract-causing mutant α*** interactions between𝛼αB-crystallin and celastrol were detected by the FRET(Fluorescence Resonance Energy Transfer)technique,and verified by molecular *** least 9 binding patterns were recognized,and some binding sites covered the groove structure of α***,αB-R120G,a cataract-causing mutation located at the groove structure,and celastrol can decrease the aggregates of α***,our results suggested celastrol not only promoted the formation of large αB-crystallin oligomers,which enhanced its chaperone activity,but also bound to the groove structure of its α-crystallin domain to maintain its structural *** might serve as a chemical and pharmacological chaperone for cataract treatment.

关键词： αB-crystallin Celastrol Interactions Oligomeric state Chaperone activity Structural stability

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