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Food-Chain Model of Grassland Degradation and Its Restoration Process in Northern Tibet Plateau:A Case Study in Nierong County

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Wuhan University Journal of Natural Sciences 2006年第4期11卷 963-968页

作者： ZHOU Wei ZENG Yunying liu shuzhen Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 Sichuan China Graduated University of Chinese Academy of Sciences Beijing 100049China College of Civil Engineering and Urban Construction JiujiangUniversity Jiujiang 332005 Jiangxi China

Based on the model of grassland climate ecological productivity, the process of grassland degradation and its restoration mechanism in northern Tibetan Plateau were discussed by the model of food-chain in which the environmental and human factors were corrected. The results of case study in Nierong County showed that： ① the climate trend of becoming warmer, more droughts and gales were conflicted with the restoration of grassland degradation, even under level of perfect management the climate ecological productivity was declined from 89. 3 kg/m^2 of 1983 to 71.8 kg/m^2 of 2003; ② from 1983 to 2003, the population increased fast, while the variation of livestock on hand was little, and the cost of its maintaining is rapid grassland degradation; ③ on the present condition of overgrazing, the livestock on hand can be maintained on the level of theoretical carrying capacity in 2033 by applying the mechanism of food-chain in grassland ecological system controlled with expected coefficients, so that to realize the policy of determining the quantity of livestock according to grass growth.

关键词： grassland degradation food-chain restoration northern Tibetan Plateau Nierong County

Analysis on the Spatio-Temporal Changes of Sustainable Land Use in Tibet

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Wuhan University Journal of Natural Sciences 2006年第4期11卷 937-944页

作者： GU Shixian XU Xia liu shuzhen Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 Sichuan China Graduated University of Chinese Academy of Sciences Beijing 100049 China School of Geography Beijing Normal University Beijing 100875 China

By constructing evaluation indicator system of sustainable land use of Tibet from three aspects of ecological environment, economic development, resources and social advancement, this article studies the following contents respectively in two dimensions of time and space： the changes of sustainable land use of Tibet in recent 20 years and spatial characteristics of sustainable land use of Tibet in 2002. The following conclusions can be drawn from evaluation results .① With regard to com- prehensive evaluation value of sustainable land use, the trend of Tibet sustainable land use evaluation values from 1983 to 2002 are very close to the comprehensive evaluation values of ecological environment, which is up trend; ② sustainable utilization degree of land use in eastern region of Tibet is much higher than that of western region. ③ the sustainable land use evaluation value of Nyingtri County is the highest, and the counties with relatively higher land sustainable use values include Lhasa, Lhoka, Chamdo. While Nakchu, Ngari, Shigatse counties have the relatively lower evaluation values; ④ By analyzing each evaluation indicator＇s weight on sustainable land use, it can be concluded that the key limiting factors of sustainable Tibet land resource utilization are land desertification, grassland degradation and low economic level.

关键词： spatio-temporal changes sustainable land use ecological environment economic development resources and social advancement

Dynamic of Grassland Biomass in Different Degenerative Stages

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Wuhan University Journal of Natural Sciences 2006年第4期11卷 958-962页

作者： YAN Yan liu shuzhen ZHOU Wei Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 Sichuan China Graduate University of Chinese Academy of Sciences Beijing 100049China

The dynamics of plant community and above- and belowground biomass of the different degenerative stages was researched of Kobresia hurnlis meadows of Nakchu prefecture in Tibet Autonomous Region. The results indicated that the aggravation of the degree of deterioration of alpine meadow is, the lower the vegetation coverage, percentage of excellent forage, and biodiversity are. The total aboveground biomass is highest in the lightly degraded stages while it is lowest in the extremely degraded stages. With the aggravation of degradation, the aboveground biomass of forbs increases while that of Cyperaceae decreases. We found that the belowground biomass was mostly distributed in the 0-10 cm soil depth in the alpine meadow with a ＂T＂-shape distribution feature, and with the acceleration of deterioration, the numbers of roots becomes less and less. Meanwhile, the above- and belowground biomass of the different degraded communities was significantly correlated（r= 0. 963）. There is an obvious positive correlation with the above- and belowground biomass in different degenerative stages, and their ratio increased with the aggravation of degradation.

关键词： degenerative grassland biomass dynamics alpine meadow

A Study of Tensile Strength Tests of Arborous Species Root System in Forest Engineering Technique of Shallow Landslide

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Wuhan University Journal of Natural Sciences 2006年第4期11卷 892-896页

作者： YANG Yonghong liu shuzhen WANG Chenghua TANG Chuan National Professional Laboratory of Geogical Hazard Prevention and Geogical Environment Chengdu University of Technology Chengdu 610059 Sichuan China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 Sichuan China

One experiment was conducted, through tensile tests of Albazzia and Eucalypt roots culled from the fields. The other experiment was conducted, by testing anti-drawing strength of these root systems in the Albazzia and Eucalypt lands. These two experiments had an aim to give insights into the maximum tensile strength and anti-drawing strength of the root systems. Results indicated that the maximum tensile strength of root system is in an exponential relation with the diameter of root system while the maximum tensile strength is positively correlative with the diameter of root system. Anti-drawing force of root system together with root diameter, length, and soil bulk density are folded into a regression equation in an attempt to figure out the static friction coefficient between root system and its ambient soil.

关键词： root system tensile strength anti-drawing strength tensile force

Close Relationship between the Frangibility of Mountain Eco-Environment and Mountain Disasters:A Case Study of Dongchuan,Kunming in Yunnan Province

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Wuhan University Journal of Natural Sciences 2007年第4期12卷 721-728页

作者： WANG Yuyi TIAN Bing liu shuzhen Key Laboratory of Mountain Hazards and Surface Process Chinese Academy of Sciences/Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 Sichuan China Graduated University of Chinese Academy of Sciences Beijing 100049 China College of Resources and Environment Science Hebei Normal University Shijiazhuang 050061 Hebei China

Anatomical details are given in this article, which is performed by investigating the relationship between through the frangibility of mountain eco-environment and the status of irrational land-use in typical region of debris flow in Dongchuan district, Kunming city, yunnan Province. This analysis is extended to the relationship between vicissitude of mountain disasters and the frangibility of mountain environment. The relatively coupling action of a vicious circle is a evolving characteristic by debris flow sand-gravel there. The eco-security is being faced with serious challenge. The tactics of eco-security has been constructed since 1980s. Thus, the eco-environrnent can gradually be repaired and optimized to achieve a fine circle.

关键词： eco-environment frangibility mountain disasters eco-security

Association of single nucleotide polymorphism rs2065955 of the filaggrin gene with susceptibility to Epstein-Barr virus-associated gastric carcinoma and EBV-negative gastric carcinoma

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Virologica Sinica 2016年第4期31卷 306-313页

作者： Xiaojing Kuang Lingling Sun shuzhen liu Zhenzhen Zhao Danrui Zhao Song liu Bing Luo Department of Medical Microbiology Qingdao University Medical College Department of Pathology The Affiliated Hospital of Qingdao University Department of Blood Transfusion The Affiliated Hospital of Qingdao University

The relationship between the Filaggrin gene(FLG) rs2065955 polymorphism and susceptibility to Epstein-Barr virus(EBV)-associated gastric carcinoma(EBVa GC) and EBV-negative gastric carcinoma(EBVn GC) was investigated in Shandong Province,*** detected the FLG rs2065955 genotype and allele distribution by using PCR and restriction fragment length polymorphism(RFLP) in 64 EBVa GC,82 EBVn GC,and 111 normal control *** was used to detect the level of FLG protein in 35 EBVa GC and 51 EBVn GC tumor *** with normal controls,the genotype CC and allele C of FLG rs2065955 showed higher frequency in EBVa GC and EBVn *** was no significant difference between EBVa GC and EBVn GC in allele distribution of FLG rs2065955,but the genotype CC was found more frequently in EBVa GC than in EBVn *** risk of developing either EBVa GC or EBVn GC in genotype CC was higher than in other ***,genotype CC of FLG rs2065955 may contribute more to the risk of developing EBVa GC than EBVn *** was no significant difference in the expression level of FLG protein between EBVa GC and EBVn *** conclusion,the FLG rs2065955 polymorphism was significantly related to gastric *** C of FLG rs2065955 could be a risk factor for EBVa GC or EBVn GC,while genotype CC of FLG rs2065955 was especially associated with EBVa GC.

关键词： Filaggrin gene(FLG) rs2065955 gastric carcinoma Epstein-Barr virus(EBV) gene polymorphism immunohistochemistry

Improved Diamond Search Algorithm for H.264/AVC Video Coding Standard

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Wuhan University Journal of Natural Sciences 2008年第1期13卷 62-66页

作者： HU Feng liu Jia CHEN shuzhen School of Electronic Information Wuhan University Wuhan 430072 Hubei China

Diamond search （DS） is an excellent fast block matching motion estimation （BMME） algorithm. In this paper, we propose an improved diamond search （IDS） algorithm, which revises the two search patterns of DS. The proposed algorithm is compared with several mainstream algorithms. The simulation results show that the proposed algorithm over DS can be up to 20% gain on speedup on average, while maintain the similar or even better quality, both objectively and subjectively. The proposed algorithm is also competitive with other fast algorithms.

关键词： diamond search H.264 motion estimation peak signal to noise ratio

Quantitative Assessment on Endangerment Degree of Rare Animal and Plant Species in Tibet,China

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Wuhan University Journal of Natural Sciences 2007年第4期12卷 684-688页

作者： DONG Ke ZHONG Xianghao liu shuzhen Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 Sichuan China Graduate University of Chinese Academy of Sciences Beijing 100049 China

It is of profound theoretical and practical significance to study endangerment status of rare species in Tibet. Index system is firstly set down for quantitative assessment of rare animal and plant species, then endangerment degree of wildlife under special state protection are calculated, which is expressed by value E. The results reveal that Yunnan snub-nosed monkey （Rhinopithecus bieti）, Himalayan tahr （Hemitragus jemlahicus） and Gigantic Cypress （Cupressus gigantea） have the highest E respectively in animals and plants. According to value E, all species are categorized into 4 ranks： critically endangered（0.6-0.8）, endangered （0.4- 0.6）, vulnerable （0.2-0.4） and lower risk （ E ≤ 0.2）. By comparison of the first five animals and plants of the highest E, each sub-ecozone bears a distinct identity.

关键词： endangerment degree endemism specific type endangerment rank

A Two-Layer Real-Time Rate Control Algorithm Based on Lagrange Optimum Algorithm

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Wuhan University Journal of Natural Sciences 2009年第1期14卷 35-38页

作者： HU Feng liu Jia CHEN shuzhen School of Electronic Information Wuhan University Wuhan 430079 Hubei China

Because of the iterative process in the rate control algorithm of the H.264 draft, it is not suitable for real-time transmission. A two-layer real-time rate control algorithm based on the Lagrange optimum algorithm is proposed. This algorithm consists of two layers, namely, the group of pictures （GOP） layer and the frame layer. The simulation results show that the proposed algorithm is competitive in terms of peak signal-to-noise ratio （PSNR）, real bitrates and the Q-value among frames over the original algo- rithm.

关键词： H.264 Lagrange optimum peak signal to noise ratio(PSNR) quantize rate-distortion