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Search Results: 1 - 10 of 290688 matches for " 李锦荣 "
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电火工品射频感度试验

兵工学报 , 1996,
Abstract: ?叙述了电火工品的射频鉴定试验,对其中的阻抗匹配,匹配装置传输效率等问题进行了讨论,并参考美军标进行了试验。
测量大学生的心理问题:ghq-20的结构及其信度和效度
,
心里发展与教育 , 2002,
Abstract: 本研究对ghq-20进行了结构分析并检验其对中国大学生被试的可信性和有效性。被试取自北京市两所高校的一至三年级大学生,共1142人。包括两个分研究,研究一(354名被试)和研究二(788名被试)。研究一的因素分析提取出三个因子,它们被分别命名为三个不同的分量表:ghq-自我肯定,ghq-忧郁和ghq-焦虑。两个研究结果均发现,ghq-20的内部一致性满意,其三个分量表的内部一致性或者满意或者可接受。效度检验结果表明,ghq-20及三个分量表均具有良好效度。基于上述结果,ghq-20可以作为测量中国大学生心理问题的一个较为满意的工具,其分量表亦可作为测量中国大学生不同心理问题的较满意或至少是可用工具。
二参数威布尔分布最小二乘法估计的优化研究
A Refine Study on the Least-Squares Estimation for Two-Parameter Weibull Distribution
 [PDF]

陈玲, 余衍然,, , 杨昌
Dynamical Systems and Control (DSC) , 2015, DOI: 10.12677/DSC.2015.43007
Abstract:
威布尔分布是可靠性科学和工程中常用的随机变量分布之一。将具有威布尔分布的非线性可靠度函数对数线性化,可方便威布尔参数的求解,但却降低了参数估计的精度。针对这个问题,提出了应用泰勒级数展开结合最小二乘法提高威布尔分布的拟合精度。通过数值模拟和实例计算,对比分析了泰勒级数展开–最小二乘法与普通最小二乘法及其加权处理的拟合效果。结果表明,该方法可以有效降低威布尔曲线拟合的误差,为可靠性试验提供参考。
Weibull distribution is one of the common random variable distributions in reliability science and engineering. Despite the fact that log-linearizing the nonlinear reliability function with Weibull distribution contributes to solving the Weibull parameters, the precision of parameter estimation is reduced. Thus, a method by combining Taylor series expansion and least square method is pro-posed to improve fitting precision of the Weibull distribution. Contrastive analyses on Taylor series expansion-least square method, common least square method and weighted least square method are conducted to access the fitting effects via numerical simulation and calculation. The results show that the proposed method can reduce the Weibull curve fitting error effectively and thus can be reference for reliability test.
应用丰度生物量比较法监测海洋污染对底栖生物群落的影响
,
华东政法大学学报 , 1992,
Abstract: 应用生物丰度生物量比较法,分析了厦门西部港水域底栖生物群落结构的变化,且将该方法与种内个体对数正态分布做了比较.结果表明,该水域已受到不同程度的污染,底栖生物群落结构受到一定的扰动.在筼筜湖排污口和宝珠屿一带水域,底栖生物群落的丰度生物量复合K优势度曲线相互交叉、相互重叠,所反应的情形与种内个体对数正态分布极为吻合.该水域底栖生物群落不稳定的根本原因在于人为的污染,即填海筑堤造成的海洋生境的扰动和工业污水废物倾倒排放所产生的有机质压力.
厦门港软体动物多样性及其与沉积物的关系
冠?,祥?
生态学报 , 1989,
Abstract: 厦门港属于亚热带河口港湾,受外海水系和沿岸流及九龙江水的影响,形成了一个底质类型极为复杂的港湾。根据沉积物中砾石、砂、粉砂和粘土含量的百分组成,该港湾沉积物主要为:粉砂质泥(ty)、粉砂-砂质泥(t-sy)、砂-粉砂质泥(s-ty)、泥质砂(ys)、泥-砾质砂(y-gs)和中细砂几种类型。
西昆仑布伦口地区发现铁铜共生矿床成矿带
孙海,纯杰,,吴海
地球学报 , 1996,
Abstract:
黑龙江省玉米产业发展策略
The Development Strategies of Maize Industry in Hei-longjiang Province
 [PDF]

胡洪林, 刘清海, 夏艳龙, 张阔, 纪武鹏, 庭锋,
Hans Journal of Agricultural Sciences (HJAS) , 2013, DOI: 10.12677/HJAS.2013.33011
Abstract: 黑龙江省玉米单产增长缓慢,收获时籽粒水分含量高,粮食流通产业不健全导致玉米种植业效益低,本文对此提出了应对策略:1) 实现玉米生产全程机械化;2) 基于全程机械化确定品种熟期标准化;3) 构建黑龙江省现代粮食流通产业。
In Heilongjiang Province, the slow growth of maize per unit area yield, high moisture content of grain at the harvest and distemperedness of the grain circulation industry contribute to the low efficiency of maize planting industry. And this paper proposed coping strategies: 1) Realizing full mechanization in maize production; 2) Confirming mature period of standardization based on the whole process of mechanization; 3) Constructing the modern grain circulation industry in Heilongjiang Province.



THE RELATION OF MOLLUSCA SPECIES DIVERSITY TO THE SEDIMENTS IN XIAMEN BAY
厦门港软体动物多样性及其与沉积物的关系

Li Rongguan,
,

生态学报 , 1989,
Abstract: 厦门港属于亚热带河口港湾,受外海水系和沿岸流及九龙江水的影响,形成了一个底质类型极为复杂的港湾。根据沉积物中砾石、砂、粉砂和粘土含量的百分组成,该港湾沉积物主要为:粉砂质泥(TY)、粉砂-砂质泥(T-SY)、砂-粉砂质泥(S-TY)、泥质砂(YS)、泥-砾质砂(Y-GS)和中细砂几种类型。
Biodiversity and distribution of mollusc around the Luoyangjiang River mangrove nature reserve
泉州湾洛阳江红树林自然保护区潮间带软体动物多样性及分布

黄雅琴,,
海洋科学 , 2011,
Abstract: In order to understand the biological diversity and the stability of mollusc around the Luoyangjiang River mangrove nature reserve and to assess the environmental quality, we assessed mollusc diversity in April and November 2009. We recorded a total of 23 species of mollusc. The numbers of mollusc species differed between transects and were greater in spring than in autumn. Average biomass and density were 45.76 g/m2 and 161 inds./m2, respectively. Both biomass and density of mollusc invertebrates among tidal zones, ranked from highest to lowest, were as follows: low tidal zone, middle tidal zone, and high tidal zone. Both biomass and density were lowest in the high tidal zone. With the abundance biomass comparison (ABC) curve to analyze the structure of the mollusc community in the Luoyangjiang River mangrove nature reserve, it was found that the optical flat community disturbance was apparent. Other communities were not apparent.
甜玉米新品种‘正甜88’
韩福光,,余良
园艺学报 , 2015, DOI: 10.16420/j.issn.0513-353x.2015-0272
Abstract: ‘正甜88’是鲜食与加工兼用型超甜玉米新品种。丰产性好,单苞质量360g,鲜苞产量18256.5kg?hm-2;优质,可溶性糖含量30.74%,果皮薄(70.08μm),适口性好;一级果穗率88%;中抗纹枯病和小斑病;长势旺,整齐度好,适应性强。
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