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Dynamics of Two Extensive Classes of Recursive Sequences

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Journal of Mathematical Research and Exposition 2010年第5期30卷 929-935页

作者： Bin ZHAO1,2.1.Department of Mathematics,northwest agriculture & {2. university,Shaanxi 712.00,P.R.China 2.Department of Mathematics,northwest university,Shaanxi 71012.,P.R.China Department of Mathematics Northwest Agriculture & Forestry University Shaanxi 712100

We investigate the dynamics of two extensive classes of recursive sequences：Xn＋1 =c∑j=0^k（i0,i1…,i2.）∈A2. ∑xn-i0xn-i1… xn-i2.＋.f（xn-i0, xn-i1,..., xn-i2.）/c∑j=1^k（i0,i1,…,i2.-1）∈A2.-1∑ xn-i0xn-i1… xn-i2.-1 ＋ c ＋ f（xn-i0, xn-i1,…, xn-i2.）and Xn＋1c∑j=1^k（i0,i1,…,i2.-1）∈A2.-1∑ xn-i0xn-i1… xn-i2.-1 ＋ c ＋ f（xn-i0, xn-i1,…, xn-i2.）/c∑j=0^k（i0,i1…,i2.）∈A2. ∑xn-i0xn-i1… xn-i2.＋.f（xn-i0, xn-i1,..., xn-i2.）We prove that their unique positive equilibrium 5 = 1 is globally asymptotically stable. And a new access is presented to study the theory of recursive sequences.

关键词： recursive sequence equilibrium dynamics.

Quantitative traits correlative analysis and growth comparison among different populations of bay scallop,Argopecten irradians

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Acta Oceanologica Sinica 2004年第3期23卷 533-540页

作者： LIUBaozhong LIANGYubo LIUXiaolin DONGBo XIANGJianhai InstituteofOceanology ChineseAcademyofSciencesQingdao266071China NationalMarineEnvironmentMonitoringCenter Dalian116023China CollegeofAnimalscienceandtechnology NorthwestSci-TechUniversityofAgricultureandForestryYangling712100China

The shell traits and weight traits are measured in cultured populations of bay scallop, Argopecten irradians. The results of regression analysis show that the regression relationships for all the traits are significant (P0.05). The multiple regression equation is obtained to estimate live body weight and tissue weight. The above traits except anterior and posterior auricle length are used for the growth and production comparison among three cultured populations, Duncan's new multiple range procedure analysis shows that all the traits in the Lingshuiqiao (LSQ) population are much more significant than those of the other two populations (P0.05). The results indicate that the LSQ population has a higher growth rate and is expected to be more productive than the other two populations.

关键词： Argopecten irradians quantitative traits correlative analysis growth comparison

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土质心墙与斜心墙堆石坝静动力特性比较分析

水力发电学报 2004年第6期23卷 61-65页

作者：张爱军骆亚生李鹏西北农林科技大学水建学院

本文结合山西某新建水库大坝的静动力特性数值分析成果,从坝体的受力和变形方面分析比较了心墙与斜心墙堆石坝的优缺点,得出了一些有益的结论,可为相关工程建设参考。

关键词：水利水电工程静动力特性数值分析堆石坝比较

Erosion environment in the sediment-rich area on the Loess Plateau

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Journal of Geographical sciences 2002年第1期12卷 49-57页

作者： JIAO Ju-ying, LI Jing, WANG Wan-zhong (Institute of Soil and Water Conservation, CAS and Ministry of Water Resources northwest sci-{2.onology {2. of agriculture and forestry, yangling 712.00, China) Institute of Soil and Water Conservation CAS and Ministry of Water Resources northwest sci-{2.onology {2. of agriculture and forestry Yangling 712100

Based on the investigation and analysis of characteristics of precipitation, natural environment, socio-economic factors and soil erosion, this paper indicates that the precipitation is the main driving force for the soil erosion in the sediment-rich area, its variability determines the characteristics of soil and water loss; the natural conditions such as the drainage systems, geological and topographic features, the composition of soil and land surface materials, vegetation and climate determine the seriousness of soil and water loss; irrational socio-economic activities of human beings usually accelerated soil and water loss; meanwhile, the low preservation rate and inferiority of soil and water conservation measures made it impossible to make rapid progress on soil and water loss control. Furthermore, the characteristics of erosion environment endowed this area with more sediment that is the main reason for the flooding disasters by the Yellow River. Therefore, more emphasis should be placed on the enhancement of soil and water conservation. The soil loss prediction models will provide scientific basis for the planning of soil and water conservation, the designing of soil and water conservation measures and the valuation of effects of soil and water loss control. According to the analysis of the previous studies on soil loss prediction, and the water-sediment variation features, it is thought that study on soil loss prediction under various rainfall conditions and soil-water conservation measures should be carried out.

关键词： Loess Plateau sediment-rich area soil erosion environmental characteristics

戊唑醇对赤霉病菌生长发育影响的细胞学和免疫细胞化学研究

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菌物学报 2004年第4期23卷 580-589页

作者：韩青梅康振生黄丽丽蒋选利西北农林科技大学生物技术中心陕西杨凌712100 西北农林科技大学植物保护学院

本文采用电子显微镜和免疫细胞化学技术研究了三唑类杀菌剂戊唑醇 (Tebuconazole) 对小麦赤霉病菌Fusarium graminearum菌丝的形态结构、细胞壁成份和毒素产生的影响。结果表明,戊唑醇不但强烈抑制了培养基上菌丝的生长,而且可引起菌丝... 详细信息

本文采用电子显微镜和免疫细胞化学技术研究了三唑类杀菌剂戊唑醇 (Tebuconazole) 对小麦赤霉病菌Fusarium graminearum菌丝的形态结构、细胞壁成份和毒素产生的影响。结果表明,戊唑醇不但强烈抑制了培养基上菌丝的生长,而且可引起菌丝形态和结构的明显畸形。电镜观察发现,药剂处理后菌丝呈现不规则的肿胀、过度分枝;菌丝细胞壁不规则加厚,尤其是菌丝顶端部位加厚明显;菌丝形成的不完整隔膜增多,且隔膜壁不规则增厚;菌丝细胞内液泡增加、脂肪粒累积,细胞器排列紊乱,原生质最终坏死。有时在坏死菌丝内可发现新的子菌丝,但子菌丝细胞壁不规则加厚、细胞质坏死、也呈不正常状态,并可再度形成新的菌丝。免疫细胞化学标记表明,药剂处理后菌丝细胞中毒素的标记密度明显低于对照菌丝,表明毒素的产生受到了抑制;而菌丝细胞壁的主要成份几丁质和-1,3-葡聚糖的标记密度明显高于对照处理,表明药剂处理可引起菌丝细胞壁中几丁质和-1,3-葡聚糖的过度累积。

关键词：超微结构免疫标记脱氧雪腐镰刀菌烯醇(DON) 几丁质 β-1,3-葡聚糖

渭北黄土高原主要造林树种根系分布特征及抗旱性研究

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水土保持学报 2002年第A1期16卷 96-99,107页

作者：赵忠李鹏西北农林科技大学林学院陕西杨陵712100

采用土钻法和盆栽试验研究了渭北地区主要造林树种的垂直根系分布特征及其抗旱性。结果表明立地条件对刺槐根系分布特征有明显的影响 ,林地土壤水分状况的差异是造成这种影响的关键所在 ;土壤种类、结构等对刺槐根系的分布特征也有很大... 详细信息

采用土钻法和盆栽试验研究了渭北地区主要造林树种的垂直根系分布特征及其抗旱性。结果表明立地条件对刺槐根系分布特征有明显的影响 ,林地土壤水分状况的差异是造成这种影响的关键所在 ;土壤种类、结构等对刺槐根系的分布特征也有很大的影响 ;不同树种在根系垂直分布特征方面存在着很大的差异 ,其中刺槐的根系分布最深 ;在一定的土壤干旱范围内 ,苗木可以通过提高根系活力来适应逆境 ,当土壤干旱超过一定的阈值后 ,树木根系将逐步丧失其活力和功能 ,最终导致地上部分的枯死 ;在供试的 4个树种中 ,山杏根系的抗旱性最强 ,其次是侧柏、刺槐和油松。苗木根系活力除了受土壤干旱协迫程度的影响之外 ,还受到干旱持续时间的影响。当土壤含水量降至 4 0 %的田间持水量时 ,土壤干旱已经对油松的生长构成了威胁 ,但对山杏。

关键词：渭北黄土高原造林树种根系分布特征土壤干旱苗木根系活力

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黄土结构性的研究成果及其新发展

水力发电学报 2004年第6期23卷 66-69页

作者：骆亚生张爱军西北农林科技大学水建学院

黄土是一种典型的结构性土,黄土结构性研究在土结构性研究中占有重要地位。本文简要回顾了土结构性的研究历史,评述了在我国黄土结构性研究的主要成果和发展现状,并提出了作者对今后研究工作的展望。

关键词：岩土工程结构性综述黄土成果

Histology and Ultrastructure of Incompatible Combination Between Puccinia striiformis and Wheat Cultivars with Low Reaction Type Resistance

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Agricultural sciences in China 2003年第10期2卷 1102-1113页

作者： KANG Zhen-sheng, WANG Yao, HUANG Li-li, WEI Guo-rong and ZHAO Jie (Shaanxi Provincial Key Lab of Molecular Biology for agriculture/Plant Protection College, northwest {2.-{2. university of agriculture and forestry, yangling 712.00, P.R.China) Shaanxi Provincial Key Lab of Molecular Biology for agriculture/Plant Protection College Northwest Sci-Tech University of Agriculture and Forestry Yangling 712100 P. R. China

The incompatible combinations between races of Puccinia striiformis and wheat cultivars with low reaction type resistance were examined by means of fluorescent microscopy, differential interference contrast microscopy and electron microscopy. The incompatible combinations consisted of wheat cultivar Niuzhute plus CY2., Hybrid46 plus CY2. and Tianxuan882.plus CY2., while the compatible combination was wheat cultivar Huixianhong plus CY2.. The observation revealed a striking difference in the fungal development and the host responses between susceptible and resistant wheat cultivars following infection by the pathogen. The main histological manifestation of the pathogen development in the resistant wheat cultivars include inhibition of hyphal growth, delay of hyphal branching and colony formation, decrease of formation of haustorial mother cells and haustoria, and occurrence of host cell necrosis. The observation by electron microscopy demonstrated that a series of abnormal changes occurred in intercellular hyphae, haustorial mother cells and haustoria during pathogen development in the resistant wheat cultivars. The cytoplasm became more electron-dense and vacuoles in the cytoplasm increased in number and size. The cell walls of hyphae, haustorial mother cells were thickened irregularly. The organelles were disorderly distributed in the cytoplasm and the haustorial mother cells and haustoria lost their physiological function. In the final stage of the pathogen development, the intercellular hyphae, haustorial mother cells and haustoria became necrotic and collapsed. The structural defense reactions such as formation of cell wall apposition, collar and encasement of haustorium were essentially more pronounced in the infected wheat leaves of the resistant cultivars than in the susceptible one. In addition, the relationship between the host resistance expression and the histological and cytological features occurred in the incompatible combination was discussed in this

关键词： Triticum aestivum Puccinia striiformis Resistance Histology Cytology

Crop Yield and Soil Responses to Long-Term Fertilization on a Red Soil in Southern China

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Pedosphere 2009年第2期19卷 199-207页

作者： ZHANG Hui-Min WANG Bo-Ren XU Ming-Gang FAN Ting-Lu Key Laboratory of Plant Nutrition and Nutrient Cycling Ministry of Agriculture of China and Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing 100081 China Department of Resource and Environment Northwest Sci-Tech University of Agriculture and Forestry Yangling 712100 China Department of Agronomy Henan University of Science and Technology Luoyang 471003 China

A 15-year fertilization experiment with different applications of inorganic N,P and K fertilizers and farmyard manure (M)was conducted to study the yield and soil responses to long-term fertilization at Qiyang,Hunan Province,China. Average grain yields of wheat and corn(1 672.and 5 111 kg ha-1,respectively)for the treatment NPKM were significantly higher than those(405 and 310 kg ha-1)of the unfertilized control and single inorganic fertilizer *** with the corresponding initial values of the experiment,all treatments showed a yield decline of 9 to 111 kg ha-1 year-1 in wheat and 35 to 2.0 kg ha-1 year-1 in corn,respectively,and a significant pH decline of 0.07 to 0.12.pH year?1,except for the treatments PK and *** long-term fertilization,the soil organic C,soil available P,exchangeable Ca2. and Mg2.and available Cu2.and Zn2.contents were higher in the treatment NPKM than in the treatments applied with inorganic fertilizer *** to the treatment NPK,the treatment NPKM,where manure partially replaced inorganic N,had a positive impact on arresting the decline of soil *** improved grain yields of wheat and corn, suggesting that application of NPK fertilizer in combination with farmyard manure is important to maintain soil fertility and buffering capacity in red soil.

关键词： corn long-term fertilization red soil wheat yield