大学图书馆组织结构设计探讨

运用现代组织设计的相关理论,对传统大学图书馆的组织结构进行深入剖析,分析了制约大学图书馆功能发挥的各种因素,提出了现代大学图书馆的组织结构设计方案。该方案能够兼顾图书馆教学、学科建设与科研以及图书馆的基本服务功能。     

河北省农业结构调整中的气象保障服务

发展循环农业,进行农业结构调整,必须考虑本地的气候资源条件,通过各种措施做好气象保障服务。     

内蒙古岩画中的动物群落结构及其生态环境的研究——以阴山和乌兰察布两地岩画对比研究为例

动物岩画是内蒙古地区古代动物的图解,通过岩画中的动物群落结构对比,可以推测相同地域范围内,不同时期的动物分布情况,进而推断当地的自然环境变迁的过程。     

河南省承接产业转移的现状和特点

本文就河南省承接产业转移的需要,把快速调整产业结构、实现跨越式发展的现实,区域间的产业梯次分布转移的前提,河南省承接产业转移的时机条件,承接产业转移的势头,以及面临的差距、面临的竞争形势、区域竞争形势进行了阐述。     

北京山区水源林结构与功能关系研究

为了准确把握北京山区水源林林分特征,掌握其结构与功能的关系,以北京山区的水源林16种森林类型作为研究对象,分析了林分的结构特征;采用因子分析方法对林分结构与水源涵养功能关系进行多因子分析研究,结果表明:在林分层次上,影响水源涵养功能的林分结构因子主要是林分树种组成、年龄、郁闭度、起源、层次、生物量以及土壤结构7个因子。研究结果可为北京山区水源林经营提供科学依据。     

有机无机生物活性肥料施用技术对蔬菜作物生长及产量的影响

田间试验结果表明:施用有机无机生物活性肥料能明显提高蔬菜作物长势,提高甘蓝抗根腐和烂心病能力。在等氮条件下,与常规对照相比产量基本持平,差异并不显著;但每666.7m2可节约成本24元左右,幅度达30,7%。椐统计分析,甘蓝最佳施肥置以100kg/666,7m2为宜,此用量可比常规对照增产9.3%,每666.7m2增加收入295元。在施用总量不变的条件下,减少有机无机生物活性肥料基肥比例,甘蓝则有碱产趋势。     

Species-specific differences of the avian oesophagus: Histological and Ultrastructural study

The oesophagus is a muscular tube comprised of cervical and thoracic regions. Several studies have clarified the histological structure of the oesophagus. However, its histoarchitecture in relation to variable dietary habits of each species is still unclear. In the current study, 21 pigeons, cattle egrets and ducks, n = 7, each was used. Macroscopically, the oesophagus of cattle egrets either the cervical or thoracic parts was the longest among the pigeons and ducks. Histologically, the oesophagus comprised of four distinct tunicae: mucosa, propria submucosa, musculosa and adventitia or serosa. A great structural variation in these layers among the three investigated species was recorded. In the cervical oesophagus of pigeons, the superficial squamous cells showed perinuclear halo zone, the propria submucosa was characteristically lacked any gland. Moreover, its musculosa was very thick. On the other hand, the intraepithelial glands were characteristically distributed along the whole length of the cattle egret’s oesophagus. Interestingly, the cervical esophagus of the ducks showed submucosal associated lymphatic tissue; diffuse and nodular Ultrastructurally, the oesophageal glands showed secretory granules of variable electron densities, electron - lucent in the pigeons and ducks and electron - dense in the cattle egrets.     

我国不同奶业产区规模化牧场饲料结构分析

在奶牛养殖规模化水平不断提高,养殖成本日益增加,且区域间差异明显的背景下,饲料作为奶牛养殖主要投入品,了解其在规模化牧场生产成本中的结构对于优化奶牛日粮结构、降低养殖成本、缩小区域间养殖效益差距等具有重要意义。本文利用2018—2020年规模牧场月度调研数据,分析了我国规模化牧场饲料结构情况。研究发现,大城市周边产区和南方产区的精饲料和粗饲料的比例相对更加科学,华北产区仍有较大提升空间,并且玉米、豆粕、玉米青贮和苜蓿草在日粮中占有较大比重,达到84.62%;不同产区奶牛日粮结构具有明显差距,玉米青贮和苜蓿草在西北产区占比最高,玉米和豆粕在南方产区占比最高。注重发挥区域优势,加大优质粗饲料和可替代饲料的利用,有利于降低养殖成本,提高养殖的科学性和可持续性。     

基于ANSYS的永磁电机转子冲片结构的优化设计

运用ANSYS的优化设计模块对永磁电机转子冲片隔磁桥附近的结构进行优化设计,采用APDL参数化设计通过拓扑形状优化功能确定冲片优化的初始区域,在此基础上运用尺寸优化功能确定最优的形状尺寸参数,最终结合工程化要求确定转子冲片的施工结构尺寸。电机最后通过最高转速试验表明文章运用的结构优化设计方法切实可行,满足工程化生产要求。     

Evaluating and Comparing the Natural Cell Structure and Dimensions of Honey Bee Comb Cells of Chinese Bee,Apis cerana cerana (Hymenoptera: Apidae) and Italian Bee,Apis mellifera ligustica (Hymenoptera: Apidae)

The hexagonal structure of the honey bee comb cell has been the source of many studies attempting to understand its structure and function. In the storage area of the comb, only honey is stored and no brood is reared. We predicted that honey bees may construct different hexagonal cells for brood rearing and honey storage. We used quantitative analyses to evaluate the structure and function of the natural comb cell in the Chinese bee, Apis cerana cerana and the Italian bee, A. mellifera ligustica. We made cell molds using a crystal glue solution and measured the structure and inclination of cells. We found that the comb cells of A. c. cerana had both upward-sloping and downward-sloping cells; while the A. m. ligustica cells all tilted upwards. Interestingly, the cells did not conform to the regular hexagonal prism structure and showed irregular diameter sizes. In both species, comb cells also were differentiated into worker, drone and honey cells, differing in their diameter and depth. This study revealed unique differences in the structure and function of comb cells and showed that honey bees design their cells with precise engineering to increase storage capacity, and to create adequate growing room for their brood.