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Interdecadal variation of East Asian summer monsoon and drought/flood distribution over eastern China in the last 159 years

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Journal of Geographical Sciences 2011年第4期21卷 579-593页

作者： li Qian WEI Fengying li dongliang Nanjing University of Information Science and Technology Nanjing 210044 China State Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China

Based on the drought/flood grades of 90 meterological stations over eastern China and summer average sea-level pressure （SLP） during 1850-2008 and BPCCA statistical methods, the coupling relationship between the drought/flood grades and the East Asian summer SLP is analyzed. The East Asian summer monsoon index which is closely related with interdecadal variation of drought/flood distribution over eastern China is defined by using the key areas of SLP. The impact of the interdecadal variation of the East Asian summer monsoon on the distribution of drought/flood over eastern China in the last 159 years is researched. The results show that there are four typical drought and flood spatial distribution patterns in eastern China, i.e. the distribution of drought/flood in southern China is contrary to the other regions, the distribution of drought/flood along the Huanghe River–Huaihe River Valley is contrary to the Yangtze River Valley and regions south of it, the distribution of drought/flood along the Yangtze River Valley and Huaihe River Valley is contrary to the other regions, the distribution of drought/flood in eastern China is contrary to the western. The main distribution pattern of SLP in summer is that the strength of SLP is opposite in Asian continent and West Pacific. It has close relationship between the interdecadal variation of drought/flood distribution patterns over eastern China and the interdecadal variation of the East Asian summer monsoon which was defined in this paper, but the correlation is not stable and it has a significant difference in changes of interdecadal phase. When the East Asian summer monsoon was stronger （weaker）, regions north of the Yangtze River Valley was more susceptible to drought （flood）, the Yangtze River Valley and regions south of it were more susceptible to flood （drought） before the 1920s; when the East Asian summer monsoon was stronger （weaker）, the regions north of the Yangtze River Valley was prone to flood （drought）, the

关键词： eastern China drought/flood distribution East Asian summer monsoon interdecadal variation

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Pattern dynamics of a diffusive predator-prey model with delay effect

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International Journal of Biomathematics 2017年第4期10卷 353-370页

作者： Guangping Hu Xiaoling li dongliang li School of Mathematics and Statistics Nanjing University of Information Science and Technology Nanjing Jiangsu 210044 P. R. China College of Atmospheric Science Nanjing University of Information Science and Technology Nanjing Jiangsu 210044 P. R. China

We study the spatiotemporal dynamics in a diffusive predator-prey system with time delay. By investigating the dynamical behavior of the system in the presence of Turing- Hopf bifurcations, we present a classification of the pattern dynamics based on the dispersion relation for the two unstable modes. More specifically, we researched the existence of the Turing pattern when control parameters lie in the Turing space. Particularly, when parameter values are taken in Turing-Hopf domain, we numerically investigate the formation of all the possible patterns, including time-dependent wave pattern, persistent short-term competing dynamics and stationary Turing pattern. Furthermore, the effect of time delay on the formation of spatial pattern has also been analyzed from the aspects of theory and numerical simulation. We speculate that the interaction of spatial and temporal instabilities in the reaction-diffusion system might bring some insight to the finding of patterns in spatial predator-prey models.

关键词： Hopf bifurcation Turing instability spatiotemporal pattern.

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Estimation of ultra-stability of methane hydrate at 1 atm by thermal conductivity measurement

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Journal of Natural Gas Chemistry 2010年第3期19卷 229-233页

作者： dongliang li Deqing liang Shuanshi Fan Hao Peng Guangzhou Institute of Energy Conversion CAS Guangzhou 510640 Guangdong China Key Laboratory of Renewable Energy and Gas Hydrate CAS Guangzhou 510640 Guangdong China Key Laboratory of Enhanced Heat Transfer and Energy Conservation MOE Guangzhou 510640 Guangdong China Graduate School of the Chinese Academy of Sciences Beijing 100049 China

Thermal conductivity of methane hydrate was measured in hydrate dissociation self-preservation zone by means of the transient plane source（TPS） technique developed by *** sample was formed from 99.9%（volume ratio） methane gas with 280 ppm sodium dodecyl sulfate（SDS） solution under 6.6 MPa and 273.15 *** methane hydrate sample was taken out of the cell and moved into a low temperature chamber when the conversion ratio of water was more than 90%.In order to measure the thermal conductivity,the sample was compacted into two columnar parts by compact tool at 268.15 *** measurements are carried out in the temperature ranging from 263.15 K to 271.15 K at atmospheric ***,the relationship between thermal conductivity and time is also investigated at 263.15 K and 268.15 K,*** 24 h,thermal conductivity increases only 5.45% at 268.15 K,but thermal conductivity increases 196.29% at 263.15 *** hydrates exhibit only minimal decomposition at 1 atm and the temperature ranging from 263.15 K to 271.15 *** 1 atm and 268.15 K,the total gas that evolved after 24 h was amounted to less than 0.71% of the originally stored gas,and this ultra-stability was maintained if the test was lasted for more than two hundreds hours before terminating.

关键词： methane hydrate self-preservation dissociation velocity thermal conductivity

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Effect of microwave on formation/decomposition of natural gas hydrate

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Chinese Science Bulletin 2009年第6期54卷 965-971页

作者： liANG DeQing HE Song li dongliang Guangzhou Institute of Energy Conversion Key Laboratory of Renewable Energy and Gas Hydrate CAS Guangzhou 510640 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

Natural gas hydrate (NGH) reservoirs have been considered as a substantial future clean energy re-source and how to recover gas from these reservoirs feasibly and economically is very important. Mi-crowave heating will be taken as a promising method for gas production from gas hydrates for its ad-vantages of fast heat transfer and flexible application. In this work, we investigate the formation /decomposition behavior of natural gas hydrate with different power of microwave (2450MHZ), pre-liminarily analyze the impact of microwave on phase equilibrium of gas hydrate,and make calculation based on van der Waals-Platteeuw model. It is found that microwave of a certain amount of power can reduce the induction time and sub-cooling degree of NGH formation, e.g., 20W microwave power can lead to a decrease of about 3℃ in sub-cooling degree and the shortening of induction time from 4.5 hours to 1.3 hours. Microwave can make rapid NGH decomposition, and water from NGH decomposi-tion accelerates the decomposition of NGH with the decomposition of NGH. Under the same pressure, microwave can increase NGH phase equilibrium temperature. Different dielectric properties of each composition of NGH may cause a distinct difference in temperature in the process of NGH decomposi-tion. Therefore, NGH decomposition by microwave can be affected by many factors.

关键词：天然气水合物分解行为微波加热微波功率诱导时间天然气产量清洁能源快速传热

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Multiple Mobile Sinks Data Dissemination Mechanism for Large Scale Wireless Sensor Network

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China Communications 2014年第A01期11卷 1-8页

作者： XIE dongliang WU Xiaojie li Dan SUN Jia StateKeyLaboratoryofNetworkingandSwitchingTechnology BeijingUniversityofPostsandTelecommunicationsBeijing100876China.

WSN has been developing from traditional environment monitoring applications to the ubiquitous information services such as the Congestion-oriented Intelligent Transportation System （ColTS）. However, the mobility of nodes makes data dissemination a hard nut to crack. In this paper, we propose MSDD, a multiple mobile sinks data dissemination mechanism for solving the dissemination problem. The main ideas of MSDD are constructing a two-tier grid structure by a designated sink, exploiting a hierarchical monitoring mechanism, and employing a global agent to track the sink locations in order to make the emergencies reported to the sinks immediately, In addition, MSDD supports the query-driven data dissemination. Being compared with TTDD, MSDD is theoretically proved to have less communication overhead. We also validate MSDD outperforms TTDD in reliability and the emergency delivery latency bv simulations.

关键词： ubiquitous information services multiple-mobile sink hierarchical monitoring two-tier grid global agent query-driven

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Influence of 3A molecular sieve on tetrahydrofuran (THF) hydrate formation

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Science China Chemistry 2008年第9期51卷 893-900页

作者： ZANG XiaoYa FAN ShuanShi liANG DeQing li dongliang CHEN GuangJin Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China Guangzhou Center for Gas Hydrate Research Chinese Academy of SciencesGuangzhou 510070China Key Laboratory of Renewable Energy and Gas Hydrate Chinese Academy of SciencesGuangzhou 510640China China University of Petroleum Beijing 102249China

Visual observation of the THF hydrate formation process in the presence of a 3A molecular sieve has been made at normal atmosphere and below a temperature of zero by microscopy. The results indicate that a 3A molecular sieve can induce the nucleation of the THF hydrate and promote the THF hydrate growth. With the existence of a 3A molecular sieve, the growth rate of THF hydrate is between 0.01 and 0.05 μm/s. In comparison with the system without any 3A molecular sieve, the growth rate increases about 4 nm/s. After the THF hydrate grows into megacryst, the crystals will recombine and partially change under the same condition.

关键词： molecular sieve tetrahydrofuran (THF) hydrate

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Laboratory measurement of longitudinal wave velocity of artificial gas hydrate under different temperatures and pressures

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Science China(Physics,Mechanics & Astronomy) 2008年第12期51卷 1905-1913页

作者： WANG Dong li dongliang ZHANG HaiLan FAN ShuanShi ZHAO HaiBo Institute of Acoustics Chinese Academy of SciencesBeijing 100190China Guangzhou Center for Gas Hydrate Research and Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China

The longitudinal wave velocity and attenuation measurements of artificial gas hydrate samples at a low temperature are reported. And the temperature and pressure dependence of longitudinal wave velocity is also investigated. In order to understand the acoustic properties of gas hydrate, the pure ice, the pure tetrahydrofuran (THF), the pure gas hydrate samples and sand sediment containing gas hydrate are measured at a low temperature between 0°C and ?15°C. For the pure ice, the pure THF and the pure gas hydrate samples, whose density is 898 kg/m3, 895 kg/m3 and 475 kg/m3, the velocity of longitudinal wave is respectively 3574 m/s, 3428 m/s and 2439 m/s. For synthesized and compacted samples, the velocity of synthesized samples is lower than that of compacted samples. The velocities increase when the densities of the samples increase, while the attenuation decreases. Under the condition of low temperature, the results show that the velocity is slightly affected by the temperature. The results also show that wave velocities increase with the increase of piston pressures. For example, the velocity of one sample increases from 3049 up to 3337 m/s and the other increases from 2315 up to 2995 m/s. But wave velocity decreases from 3800 to 3546 m/s when the temperature increases from ?15°C to 5°C and changes significantly close to the melting point. Formation conditions of the two samples are the same but with different conversion ratios of water. The results of the experiment are important for exploration of the gas hydrate resources and development of acoustic techniques.

关键词： gas hydrate velocity amplitude temperature pressure

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Measurement and modeling of the effective thermal conductivity for porous methane hydrate samples

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Science China Chemistry 2012年第3期55卷 373-379页

作者： li dongliang DU Jian HE Song liANG WeiDeQing ZHAO XiangYong YANG XiangYang Key Laboratory of Renewable Energy and Gas Hydrate Guangzhou Institute of Energy Conversion Chinese Academy of Sciences Guangzhou 510640 China Guangzhou Center for Gas Hydrate Research Chinese Academy of Sciences Guangzhou 510640 China Graduate School of the Chinese Academy of Sciences Beijing 100039. China

The effective thermal conductivities of gas-saturated porous methane hydrates were measured by a single-sided transient plane source (TPS) technique and simulated by a generalized fractal model of porous media that based on *** density of porous hydrate,measured by the volume of the sample in the experimental system,was used to evaluate the porosity of methane hydrate *** fractal model was based on Sierpinski carpet,a thermal-electrical analogy technique and one-dimensional heat flow *** the experimental and computational results show the effective thermal conductivity of methane hydrate decreases with the porosity *** porosity of 0.3 can reduce the thermal conductivity of the methane hydrate by 25%.By analysis of the experimental data and the simulative result,the optimized thermal conductivity of the zero-porosity methane hydrate is about 0.7 W m-1K-1.

关键词： gas hydrate thermal conductivity fractal geometry model porosity

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Identification of niclosamide as a novel antiviral agent against porcine epidemic diarrhea virus infection by targeting viral internalization

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Virologica Sinica 2023年第2期38卷 296-308页

作者： Yue Wang Huimin Huang dongliang li Chenxu Zhao Shuai li Panpan Qin Yaqin li Xia Yang Wenjuan Du Wentao li Yongtao li College of Veterinary Medicine Henan Agricultural UniversityZhengzhou450002China State Key Laboratory of Agricultural Microbiology College of Veterinary MedicineHuazhong Agricultural UniversityWuhan430070China Faculty of Veterinary Medicine Utrecht UniversityUtrecht3584 CLthe Netherlands Hubei Hongshan Laboratory Wuhan430070China

Porcine epidemic diarrhea virus(PEDV),an enteropathogenic coronavirus,has catastrophic impacts on the global pig ***,there remain no effective drugs against PEDV *** this study,we utilized a recombinant PEDV expressing renilla luciferase(PEDV-Rluc)to screen potential anti-PEDV agents from an FDAapproved drug library in Vero *** compounds were identified that significantly decreased luciferase activity of *** them,niclosamide was further characterized because it exhibited the most potent antiviral activity with the highest selectivity *** can efficiently inhibit viral RNA synthesis,protein expression and viral progeny production of classical and variant PEDV strains in a dose-dependent *** of addition assay showed that niclosamide exhibited potent anti-PEDV activity when added simultaneously with or after virus ***,niclosamide significantly inhibited the entry stage of PEDV infection by affecting viral internalization rather than viral attachment to *** addition,a combination with other small molecule inhibitors of endosomal acidification enhanced the anti-PEDV effect of niclosamide in *** together,these findings suggested that niclosamide is a novel antiviral agent that might provide a basis for the development of novel drug therapies against PEDV and other related pathogenic coronavirus infections.

关键词： Coronavirus Porcine epidemic diarrhea virus(PEDV) Niclosamide(NIC) Antiviral Virus entry Endocytosis Host-targeted antivirals

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Sensitivity analysis for leaf area index （LAI） estimation from CHRIS/PROBA data

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Frontiers of Earth Science 2014年第3期8卷 405-413页

作者： Jianjun CAO Zhujun GU Jianhua XU Yushan DUAN Yongmei liU Yongjuan liU dongliang li The Key Laboratory of GIScience of the Education Ministry PRC East China Normal University Shanghai 200062 China School of Bio-chemical and Environmental Engineering Nanjing Xiaozhuang University Nanjing 211171 China

Sensitivity analyses were conducted for the retrieval of vegetation leaf area index （LAI） from multi- angular imageries in this study. Five spectral vegetation indices （VIs） were derived from Compact High Resolution Imaging Spectrometer onboard the Project for On Board Autonomy （CHRIS/PROBA） images, and were related to LAI, acquired from in situ measurement in Jiangxi Province, China, for five vegetation communities. The sensitivity of LAI retrieval to the variation of VIs from different observation angles was evaluated using the ratio of the slope of the best-fit linear VI-LAI model to its root mean squared error. Results show that both the sensitivity and reliability of VI-LAI models are influenced by the heterogeneity of vegetation communities, and that perfor- mance of vegetation indices in LAI estimation varies along observation angles. The VI-LAI models are more reliable for tall trees than for low growing shrub-grasses and also for forests with broad leaf trees than for coniferous forest. The greater the tree height and leaf size, the higher the sensitivity. Forests with broad-leaf trees have higher sensitivities, especially at oblique angles, while relatively simple-structured coniferous forests, shrubs, and grasses show similar sensitivities at all angles. The multi-angular soil and/or atmospheric parameter adjustments will hope- fully improve the performance of VIs in LAI estimation, which will require further investigation.

关键词： CHRIS/PROBA LAI sensitivity vegetationindex vegetation type

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