陇中旱作区马铃薯品种筛选试验初报

为筛选出适宜陇中旱作区种植的优质马铃薯品种,解决当地马铃薯生产中存在的品种老化、抗病性弱、产量低、品质差等问题。以当地主栽马铃薯品种陇薯6号为对照,对引进的7个马铃薯品种进行了品种筛选试验。结果表明,宁薯19号、 陇薯11号折合产量较高,分别为39 245、37 350 kg/hm2,分别较对照品种陇薯6号增产15.87%、10.27%。综合分析认为,宁薯19号、陇薯11号较对照品种陇薯6号增产幅度大,综合农艺性状好,可在陇中旱作区及类似生态区种植。     

西北高寒民族地区农牧村城镇化发展研究——以甘南藏族自治州为例

甘南州是青藏高原"中华水塔"的重要涵养地。其农牧村城镇化条件、城镇化功能、城镇化动力都具有区域特殊性。实施中心城镇优先发展战略,对化解甘南州城镇化弱质与建设资金短缺的区情,协调甘南州生态环境保育与区域发展,降低进城农牧民的转移成本和分享现代文明生活等方面具有重要的作用;中心城镇的发展,为甘南州招商引资,吸纳、存留人才创造良好条件。最后从确定合理的城镇规模、增强中心城镇基础设施和服务设施的供给能力、壮大城镇产业、注重城镇特色化建设、加强中心城镇生态环境保护等5个方面,提出了中心城镇发展的路径。     

官司河流域7种林分枯落物及土壤层水文效应1）

为定量评估森林水源涵养能力,结合野外采样和浸水试验对官司河流域7种林分枯落物及土壤层水文效应进行比较。结果表明：林分枯落物蓄积量范围为4．49～13．19 t· hm－2,其中马尾松纯林最大,麻栎纯林最小;各林分枯落物最大持水深和有效拦蓄量均表现为未分解层大于半分解层,且纯竹林最大,分别为2．87 mm和9．77 t· hm－2。枯落物层持水量和吸水速率与浸水时间均显著。各林分0～30 cm土壤总孔隙度变化范围为37．1％～54．3％,竹林和松栎混交林的表层土壤有效持水量最大,分别为256．52、44．5 t· hm－2。纯竹林、松栎混交林持水效果较好,可作为水源涵养林得以推广。     

新形势下中国农业农村信息化发展的挑战与前景

结合2014年中央一号文件,分析了中国农业农村信息化建设面临的重要挑战,剖析了可持续发展、粮食安全、农业生产经营模式、城乡一体化、乡村治理等重点问题,指出未来中国农业农村信息化的研究和工作重点,并在此基础上提出未来加快中国农业农村信息化建设的对策。     

黄海中部小黄鱼摄食习性的体长变化与昼夜变化

根据2001年3月至2002年1月在黄海中部海域进行的4个季节的定点底拖网调查,应用聚类分析、单因素方差分析和列联表检验等方法,对小黄鱼(PseudosciaenapolyactisBleeker)摄食的体长和昼夜变化进行研究。结果表明:摄食强度没有明显的体长变化,而食物组成却有明显的体长变化。随着体长的增大,鱼类和虾类的比例有所增加,而磷虾类、桡足类和端足类的比例则减少。饵料生境宽度在体长大于109mm后有明显的增加。经检验,小黄鱼平均每个胃中含有的饵料个数显著减少而饵料重量则增加,这符合"最佳摄食理论"。聚类分析的结果表明,小黄鱼在体长达到109mm时,出现了明显的食物转换现象。小黄鱼的摄食强度在各个季节都有明显的昼夜变化,午夜24:00和早晨08:00是2个摄食高峰期。     

供水系统中远程测控站自动控制系统的集成设计

结合工程实践,对供水系统中远程测控站的自动控制系统进行设计,包括采集信号的设计、系统硬件的配置、PLC软件设计和抗干扰设计等。设计的系统具有较高的自动化水平,运行三年多来安全可靠,应用效果显著,适合在供水、供电、供气、气象、水文水利等行业推广与应用。     

Quantitative Mapping and Assessment of Environmentally Sensitive Areas to Desertification in Central Iran

Desertification is one of the main environmental and also social and economic problems facing Iran. Seventeen out of 31 Iranian provinces, which are home to approximately 70% of the total population, are affected by desertification. This study aimed to use geographic information system (GIS) and fuzzy logic for mapping environmentally sensitive areas to desertification based on Mediterranean Desertification and Land Use approach in Isfahan province, central Iran. Six desertification indicators including climate, soil, vegetation, soil erosion, groundwater, and management and policy quality were used to determine various types of environmentally sensitive areas to desertification. Seventeen desertification indices affecting the quality of each indicator were spatially mapped and assigned a value between 0 and 1 using a fuzzy logic option of ArcSDM3 software in GIS environment. Results showed that a 21·7% of the study area was classified as critical, 70% as fragile and 5·5% as potential, and 2·9% of the area was not affected by desertification. In the town of Borkhar, 64·2% of the area was classified as critical, followed by the towns of Isfahan and Nayin with 40·2% and 31·8%, respectively. Results at provincial scale indicated that the climate indicator and humidity index with a weighting mean of 0·71 and 0·77 were the most affective factors in the desertification of the study area. The developed model in this study can be used for mapping desertification status in other 16 provinces that contain desert areas. These assessments provide a GIS‐based desertification database that Iran as a member of the United Nation Convention to Combat Desertification can use to report the condition of desertification at national scale. Copyright © 2013 John Wiley & Sons, Ltd.     

A Class of Planar 5 - Body Central Configurations

Newtonian n-body problem is an old, complicated problem. It is very significant to study it. Even about three problem, the completed solutions have not obtained so far. It is one hottest point studied in n-body problem. Based on some hypothesis of symmetric conditions, some necessary and sufficient conditions have been obtained with the purely algebra method. The classification of planar 5 - body central configurations is discussed , in which three class planar 5 -body central configurations are obtained.     

改进Hargreaves模型估算川中丘陵区参考作物蒸散量

为提高Hargreaves-Samani(HS)模型参考作物蒸散量(ET0)计算精度,该文基于贝叶斯原理利用川中丘陵区1954-2002年逐日资料对其温度指数、温度系数和温度常数进行改进,并使用2003-2013年资料以Penman-Monteith(PM)模型为标准评价HS改进模型计算精度与适应性。结果表明:HS改进模型参数在川中丘陵区各区均小于联合国粮农组织推荐值,并呈现出随纬度上升而增大的趋势;与PM模型计算结果相比,HS改进模型计算的ET0相对误差在川中丘陵区北部从14.2%~60.9%降至-1.1%~33.4%、中部从40.6%~92.6%降至16.9%~61.1%、南部从31.3%~96.0%降至8.5%~64.4%、整个川中丘陵区从32.1%~82.7%降至9.5%~52.6%;相关性分析表明,HS改进模型和PM模型计算的ET0回归曲线的斜率更接近于1(北部1.16、中部1.02、南部0.99、全区1.13),决定系数均达到0.85(P0.01)以上;趋势分析表明,HS改进模型和PM模型计算的ET0变化一致,年内均呈开口向下的抛物线状,年际均呈微小上升趋势。因此,基于贝叶斯原理改进的HS模型在川中丘陵区不同区域变异性较小,适应性较强,具有较高的计算精度,可作为川中丘陵区参考作物蒸散量简化计算的推荐模型。     

桉木单板层积材生产工艺的优化

采用响应面法(RSM)和中心组合旋转设计(CCRD),研究了桉树单板层积材(LVL)的生产工艺条件,并对优化工艺所得的预测值进行了实验验证。方差分析结果表明:面粉添加量对桉木LVL的静曲强度(MOR)和弹性模量(MOE)有着显著影响,而热压温度和热压时间的影响不显著。通过回归分析,建立了相应的回归模型。回归模型的预测值与实验值的拟合良好,说明回归方程能用来预测和优化桉木LVL的力学强度性能。最佳工艺条件为:热压温度130℃,热压时间1.5 min/mm,面粉添加量5%(质量分数)。在此工艺条件下压制的桉木LVL垂直加载条件下的静曲强度(MOR⊥)和弹性模量(MOE⊥)分别为89 MPa和16 722 MPa,平行加载条件下的静曲强度(MOR∥)和弹性模量(MOE∥)分别为88 MPa和15 067 MPa,MOR和MOE分别达到了结构用单板层积材国家标准的优等品和140E级别。