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Impact of anthropogenic activities on vegetation dynamics in a reservoir area: model establishment and a case study of Longkaikou Reservoir in China

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Journal of Mountain Science 2021年第7期18卷 1823-1836页

作者： YANG Wei PEI jun CAI Yan-peng yi yu-jun State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing 100875China Binjiang Branch Agency of Ecology and Environment of HangzhouHangzhou 310053China

Vegetation in hot and arid valleys is a crucial indicator of ecosystem health,but is vulnerable to human activities and environmental *** the Longkaikou Reservoir in the Jinsha River in southwestern China as a case study,we developed a spatially explicit model that combined the plant growth,fruiting,seed dispersal,and seed germination stages to reveal the potential impact of multiple human activities(reservoir construction,logging,grazing,and aerial seeding) on the vegetation dynamics of Dodonaea viscosa and Pinus *** reservoir construction,the grassland area of 68 km^(2) in 2003 decreased to 24 km^(2) in 2018,replaced by forest,shrubland,and bodies of water,and the precipitation increased during the dry season,which indicated the improvement of the local plant and soil *** model predicted that when soil moisture decreased by more than 20% compared to current levels,the area of *** increased greatly at low elevations;however,when at higher soil moisture,*** would occupy more of the study *** and grazing would slightly change the spatial pattern of vegetation and delay *** communities from achieving stability by directly reducing plant *** such as aerial seeding would increase the total area by 13.13 km^(2) and 8.09 km^(2) of two plants,respectively,and accelerate the stabilization of plant *** effects of multiple human activities on vegetation may counteract each other;for example,logging decreased the *** area whereas aerial seeding increased it,and plant biomass changed in response to this *** the complex relationships between vegetation and human impacts,our study provides a scientific basis for vegetation restoration and ecological security in this hot and arid valley.

关键词： Spatially explicit model Vegetation dynamics Human activities Longkaikou Reservoir

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Effect of geomorphologic features and climate change on vegetation distribution in the arid hot valleys of Jinsha River,Southwest China

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Journal of Mountain Science 2022年第10期19卷 2874-2885页

作者： ZHOU Yang yi yu-jun LIU Hong-xi TANG Cai-hong ZHU yu-long ZHANG Shang-hong School of Water Resources and Hydropower Engineering North China Electric Power UniversityBeijing 102206China State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBejing 100875China Advanced Institute of Natural Sciences Beijing Normal UniversityZhuhai 519087China

Rapid change of climate in vertical and considerable geomorphologic features form a typical diversity and distribution of biota in mountain ecosystems,i.e.,the subalpine forest zone(SFZ),the valley savanna zone(VSZ),and the transition zone between *** arid hot valley in the middle and lower reaches of Jinsha River,China represents a well target area to study distribution and the driving factors in these typical mountain ***,this study selects four sub-sample areas in the arid-hot valley to explore the distinctive changes of vegetation during 1990 to 2020,and their driving factors in the three different vegetation zones on spatiotemporal *** the spatial scale,the Moran’s index was applied to identify the transition zone between the SFZ and the *** show that the VSZ at low altitudes(less than 600-1000 m from the valley bottom)is mainly affected by geomorphologic features,especially the slope *** increase in altitude,the climate factors(e.g.,humidity,temperature,etc.)play a more significant role in the development of the SFZ,while the effect of geomorphologic features gradually *** the time scale,The SFZ at higher altitudes experienced more rapid changes in temperature(temperature increase of 1.41°C over the last 60 years)than the VSZ at lower altitudes(temperature increase of 0.172°C over the past 60 years).It caused the forest cover increase faster than that of savanna *** and heat conditions are altered by topography and climate conditions,which shapes the development and physiology of plants as they adapt to the different climatic ***,according to the driving factors(geomorphologic and climate factors)of vegetation distribution found in this study,it suggests that suitable tree species should be planted in the transition zone to evolve into the forest zone and making the forest zone to recover from high to low altitudes gradually.

关键词： Mountain vegetation distribution Subalpine forest zone Valley savanna zone Geomorphologic features Climate change

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Studies on the Synthesis of Morphinan Alkaloid:Preparation of the Key Allylic Silyl Ether Precursor

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Chinese Chemical Letters 2005年第11期16卷 1445-1447页

作者： Zhen Lei SONG Yong Qiang TU Shuan Hu GAO yi jun JIANG Shu yu ZHANG State Key Laboratory of Applied Organic Chemistry ＆ Department of Chemistry Lanzhou University Lanzhou 730000

A convergent strategy to the key allylic silyl ether precursor 4 in our synthetic efforts toward morphinan alkaloid is presented. The vital step is the selective 1,2-addition of the organocerium agent of 6 to ketene 5.

关键词： Morphinan alkaloid Weinreb amide cerium chloride synthesis.

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单柱失效下结构连续倒塌的动力响应分析

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工程力学 2017年第4期34卷 72-77页

作者：郭义庆喻君河海大学土木与交通学院南京210098

该文提出了一种基于三折线结构抗力形式和升压平台形荷载函数的非线性单自由度模型,并推导了该模型的解析解,用于分析由单柱移除引起的连续倒塌过程中的结构瞬态动力响应。该模型可以涵盖各类抗力形式,包括抗力软化及大变形条件下的悬... 详细信息

该文提出了一种基于三折线结构抗力形式和升压平台形荷载函数的非线性单自由度模型,并推导了该模型的解析解,用于分析由单柱移除引起的连续倒塌过程中的结构瞬态动力响应。该模型可以涵盖各类抗力形式,包括抗力软化及大变形条件下的悬链作用,并考虑了柱子移除时间对动力响应的影响。钢筋混凝土和钢结构的梁柱子结构的动力试验结果与非线性单自由度模型计算所得到的动力响应结果(例如跨中位移)的对比表明:此模型可以准确地预测结构倒塌过程中结构的动力响应,计算速度快,准确性高,便于应用。

关键词：关键柱失效结构倒塌动力响应单自由度模型悬链作用

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Gene Mapping of Brachytic Stem and Its Effect on Main Agronomic Traits in Soybean

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Agricultural Sciences in China 2005年第10期4卷 728-732页

作者： CUI Shi-you MENG Qing-chang HUANG Fang ZHAO Tuan-jie GAI jun-yi yu De-yue National Center for Soybean Improvement National Key Laboratory of Crop Genetics and Germplasm Enhancement Nanjing Agricultural University Nanjing 210095 P.R.China

Brachytic stem is a major trait in plant type .of soybean and its yield potential may be higher under high population when compared with normal stem. In the present investigation, 152 recombinant inbred line （RIL） families derived from the cross of Bogao （normal stem） and Nannong 94-156 （brachytic stem） were used to map genes and QTLs of three plant type traits and to identify the effects of brachytic stem on agronomic traits such as yield. The primary results indicated that brachytic stem （sb） and determinate growth habit （drl） were mapped on linkage groups B2 and L, three major QTLs related to plant height were detected and mapped on linkage group L near drl, another minor QTL was mapped near sb on linkage group B2-1. Lines with brachytic stem had shorter plant height, lower biomass, yield, harvest index and pods per plant, and essentially no differences in days to maturity and 100-seed weight when compared with normal stem lines. It was obvious that the effect of brachytic stem on yield was due to the decreased height, biomass and harvest index.

关键词： Brachytic stem Gene mapping Quantitative trait loci (QTL) Agronomic trait Soybean

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长江中华鲟栖息地适合度模型研究

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水科学进展 2007年第4期18卷 538-543页

作者：易雨君王兆印陆永军清华大学水沙科学与水利水电工程国家重点实验室北京100084 南京水利科学研究院江苏南京210029

对与水生生物生存栖息相关的河流底质、水深、水温、流速、水质等生态因子进行研究。提出水生生物的栖息地适合度模型,从生物生存栖息地影响角度对河流治理工程进行科学的评价。以长江珍稀动物中华鲟为研究对象,通过对影响中华鲟的各种... 详细信息

对与水生生物生存栖息相关的河流底质、水深、水温、流速、水质等生态因子进行研究。提出水生生物的栖息地适合度模型,从生物生存栖息地影响角度对河流治理工程进行科学的评价。以长江珍稀动物中华鲟为研究对象,通过对影响中华鲟的各种生态因子的统计研究,分析整理出适宜其生存繁殖的河流水温、水深、底质、流速、含沙量及食卵鱼10个因子的临界指标,得出了这些因素的适合度曲线。发展了适合评价长江中华鲟栖息地的适合度方程,并用12组实测数据对模型进行了修改验证,提出了适合评价长江中华鲟栖息地适合度模型。

关键词：长江中华鲟栖息地适合度模型

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Preventive effect of gelatinizedly-modified chitosan film on peritoneal adhesion of different types

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World Journal of Gastroenterology 2007年第8期13卷 1262-1267页

作者： Xie-Lai Zhou Shan-Wen Chen Guo-Dong Liao Zhou-jun Shen Zhi-Liang Zhang Li Sun yi-jun yu Qiao-Ling Hu Xiao-Dong Jin Department of Urology The First Affiliated Hospital College of Medicine Zhejiang University Hangzhou 310003 Zhejiang Province China Department of Urology Ruijin Hospital School of Medicine Shanghai Jiaotong University Shanghai 200025 China Surgical Department Clinical Medical College of Hangzhou Teachers College Hangzhou 310036 Zhejiang Province China Experimental Center of Medical Science Hangzhou Teachers College Hangzhou 310036 Zhejiang Province China Institute of Polymer Composites Zhejiang University Hangzhou 310027 Zhejiang Province China

AIM： To comparatively study the preventive effect of gelatinizedly-modified chitosan film on peritoneal adhesions induced by four different factors in rats. METHODS： Chitosan was chemically modified by gelatinization, and made into films of 60 μm in thickness, and sterilized. Two hundred Sprague-Dawley rats were randomly divided into five groups, Sham-operation group （group A）, wound-induced adhesion group （group B）, purified talc-induced adhesion group （group C）, vascular ligation-induced adhesion group （group D）, and infection-induced adhesion group （group E）, respectively. In each group, the rats were treated with different adhesion-inducing methods at the cecum of vermiform processes and then were divided into control and experimental subgroups. Serous membrane surface of vermiform processes were covered with the films in the experimental subgroups, and no films were used in the control subgroups. After 2 and 4 wk of treatments, the abdominal cavities were reopened and the adhesive severity was graded blindly according to Bhatia＇s method. The cecum of vermiform processes were resected for hydroxyproline （OHP） measurement and pathological examination. RESULTS： Adhesion severity and OHP level： After 2 and 4 wk of the treatments, in the experimental subgroups, the adhesions were significantly lighter and the OHP levels were significantly lower than those of the control subgroups in group B （2 wk： 0.199 ± 0.026 vs 0.285 ± 0.041 μg/mg pr, P 〈 0.001; 4 wk： 0.183 ± 0.034 vs 0.276 ± 0.03 μg/mg pr, P 〈 0.001）, D （2 wk： 0.216 ± 0.036 vs 0.274 ± 0.040 μg/mg pr, P = 0.004; 4 wk： 0.211 ± 0.044 vs 0.281 ± 0.047 μg/mg pr, P = 0.003） and E （2 wk： 0.259 ± 0.039 vs 0.371 ± 0.040 μg/mg pr, P 〈 0.001; 4 wk： 0.242 ± 0.045 vs 0.355 ± 0.029 μg/mg pr, P 〈 0.001）, but there were no significant differences in groups A （2wk： 0.141 ± 0.028 vs 0.137 =k 0.026 μg/mg pr, P = 0.737; 4 wk： 0.132 ± 0.031 vs 0.150 ± 0.035 μg/mg pr, P = 0.225） and C （2 wk： 0.395 ± 0.044 vs 0.378 ± 0.043 μg/mg p

关键词： Chitosan Gelatinization Chemical modification Peritoneum Adhesion

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World Wind在汶川地震应急系统中的应用研究

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系统仿真学报 2010年第5期22卷 1296-1300页

作者：张尚弘易雨君华北电力大学可再生能源学院北京102206 北京师范大学环境学院北京100875

采用三维地理信息系统World Wind对汶川地震灾区应急系统建设进行了研究。通过对World Wind中地形影像资料调度模式、实时渲染流程、地名标注和救灾路径添加等方法的研究,显示了地震灾区三维地理状况,为救援进展提供了直观的环境展示。... 详细信息

采用三维地理信息系统World Wind对汶川地震灾区应急系统建设进行了研究。通过对World Wind中地形影像资料调度模式、实时渲染流程、地名标注和救灾路径添加等方法的研究,显示了地震灾区三维地理状况,为救援进展提供了直观的环境展示。通过对唐家山DEM数据的测算,得出堰塞湖的水位库容曲线和淹没面曲线,在World Wind中对淹没情况进行了模拟显示。研究成果在地震应急救援上得到了一定的应用。

关键词：三维可视化 World Wind 汶川地震唐家山堰塞湖

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温度、氨氮和亚硝氮对西伯利亚鲟胚胎孵化的联合影响效应

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水生态学杂志 2023年第6期44卷 72-78页

作者：贾文飞易雨君北京师范大学环境学院水环境模拟与污染控制国家重点实验室北京 100875 北京师范大学环境学院水沙科学教育部重点实验室北京 100875

鲟作为具有重要生态和经济价值的水生生物,在气候变暖和人类活动的影响下其自然繁育面临巨大威胁.为了探究环境因子对鲟早期胚胎发育的影响,采用3因子3水平的Box-Behnken设计和响应曲面分析法,开展了温度(14～22℃)、氨氮(0.05～0.15 mg... 详细信息

鲟作为具有重要生态和经济价值的水生生物,在气候变暖和人类活动的影响下其自然繁育面临巨大威胁.为了探究环境因子对鲟早期胚胎发育的影响,采用3因子3水平的Box-Behnken设计和响应曲面分析法,开展了温度(14～22℃)、氨氮(0.05～0.15 mg/L)和亚硝氮(0.05～0.25 mg/L)对西伯利亚鲟(Acipenser baerii)早期胚胎发育的联合影响效应研究,旨在建立温度、氨氮和亚硝氮与西伯利亚鲟胚胎孵化率的定量关系,并通过多元回归得出温度、氨氮和亚硝氮的最佳组合.结果表明,随着温度的升高,西伯利亚鲟胚胎孵化率呈现先升高后降低的趋势,随着氨氮和亚硝氮浓度的降低,西伯利亚鲟胚胎孵化率逐渐升高.水温与氨氮的联合效应对鲟胚胎孵化率的影响呈显著水平(P＜0.05),而水温与亚硝氮的联合效应以及氨氮与亚硝氮的联合效应对鲟胚胎孵化率的影响不显著(P＞0.05).建立的西伯利亚鲟胚胎孵化率模型方程的相关系数为0.9832,校正相关系数为0.9616.通过模型优化得出西伯利亚鲟胚胎在温度18℃,氨氮浓度低于0.08 mg/L和亚硝氮浓度低于0.13 mg/L条件下西伯利亚鲟胚胎的孵化率最高,达到90%以上.研究结果为西伯利亚鲟的人工繁殖和自然资源保护提供了理论依据.

关键词：西伯利亚鲟胚胎温度氨氮亚硝氮孵化率

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图像多次无降质编解码的研究

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上海交通大学学报 2004年第4期38卷 616-619页

作者：易彦孙军余松煜上海交通大学图像通信与信息处理研究所上海200030

利用向量矩阵的完全可逆性和量化过程的幂等特性,在编解码过程中引入可逆整数DCT实现了图像的多次无降质编解码.在此基础上,借鉴量化DCT的思想,进一步将可分的量化矩阵分解为多个向量矩阵的组合与乘积,提高了图像第1次编解码后的图像质... 详细信息

利用向量矩阵的完全可逆性和量化过程的幂等特性,在编解码过程中引入可逆整数DCT实现了图像的多次无降质编解码.在此基础上,借鉴量化DCT的思想,进一步将可分的量化矩阵分解为多个向量矩阵的组合与乘积,提高了图像第1次编解码后的图像质量.该方法与AT-LANTIC计划中提出的"鼹鼠"计划相结合,可实现高质量的视频多次无降质编解码.

关键词：编码解码数字电视向量矩阵量化离散余弦变换

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