黑龙江省垦区2OO3年农业机械化水平评价

根据已有的农机化评价体系,调查了黑龙江垦区2003年农机化实际值,计算出了该年垦区的农业机械化水平,并进行分析评价。这对于今后提高黑龙江垦区农业机械化的综合保障能力、农机经营效益以及农业机械化水平的进一步提高有着重要的指导意义。     

Short-Term Response of Sage-Grouse Nesting to Conifer Removal in the Northern Great Basin

Conifer woodlands expanding into sage-steppe (Artemisia spp.) are a threat to sagebrush obligate species including the imperiled greater sage-grouse (Centrocercus urophasianus). Conifer removal is accelerating rapidly despite a lack of empirical evidence to assess outcomes to grouse. Using a before-after-control-impact design, we evaluated short-term effects of conifer removal on nesting habitat use by monitoring 262 sage-grouse nests in the northern Great Basin during 2010–2014. Tree removal made available for nesting an additional 28% of the treatment landscape by expanding habitat an estimated 9603 ha (3201 ha [± 480 SE] annually). Relative probability of nesting in newly restored sites increased by 22% annually, and females were 43% more likely to nest within 1000 m of treatments. From 2011 (pretreatment) to 2014 (3 yr after treatments began), 29% of the marked population (9.5% [± 1.2 SE] annually) had shifted its nesting activities into mountain big sagebrush habitats that were cleared of encroaching conifer. Grouping treatments likely contributed to beneficial outcomes for grouse as individual removal projects averaged just 87 ha in size but cumulatively covered a fifth of the study area. Collaboratively identifying future priority watersheds and implementing treatments across public and private ownerships is vital to effectively restore the sage-steppe ecosystem for nesting sage-grouse.     

Biophysical dynamics of western transition zones: a preliminary synthesis

The nature of the western portions of the biogeographic temperate or transition zones in the North Pacific and North Atlantic is reviewed. The physical transport of nutrients and biomass into them from the Kuroshio and Gulf Stream as well as from the poleward sides are estimated. The conclusion is that the upwelling in the two western boundary currents makes the largest contribution to the nutrient and biomass fluxes into these transition zones. A conservative estimate of the amount of upwelled fluid is derived from absolute velocity sections in the Gulf Stream. The estimate suggests that upwelling into the euphotic zone exceeds 2 × 10⁶ m³ s^–1. This implies that upwelling in these western boundary currents matches or exceeds that in eastern boundary currents such as the California Current. The two western boundary regimes have very different poleward situations. The Oyashio extension flows parallel to the Kuroshio and is a deep current. The North Atlantic Shelf Front flow is to the west where it is ultimately entrained into the edge of the Gulf Stream. There does not seem to be any tendency for this to occur in the Kuroshio. Despite these differences in the northern and western boundaries, the two transition zones are similar with large amplitude meanders, anticyclonic rings and streamers dominating their physical structure. The physical features responsible for the transfer of materials from the boundary current extensions into the transition zones are similar in both systems. Ring formation contributes only ? 10% of the transfer, while ring‐induced streamers contribute 30%. The rest of the transport is contributed by branching of the boundary current front. Both currents have well developed secondary fronts consisting of subtropical surface water pulled into the transition zone. Biologically, the upwelling in both western boundary currents leads to a biomass maximum along the boundary in both secondary producers (copepods) and in small pelagic fish. In the Kuroshio, the latter are the Japanese sardine, Sardinops melanostictus, that spawn in the Kuroshio and then enter the transition zone for the summer and fall months. In the Gulf Stream, the dominate species are menhaden, Brevoortia tyrannus and B. smithi. These species make use of the coastal environments of North America and although the adults spawn in the Gulf Stream, they are not thought to play a major role in the Slope Water, transition zone. The similar differences in the use of the Kuroshio and the Gulf Stream ecosystems occurs in the behaviour of bluefin tuna, squid and other large pelagics. The Gulf Stream system also lacks an equivalent to Pacific saury, Cololabis saira. The biology therefore is at least subtly different, with saury and sardines being replaced by mid‐water fish in the North Atlantic. A fuller comparison of the biology with quantitative methods in both systems should be encouraged.     

山西省乳品质量安全现状及对策

近年来,我国乳品质量安全现状持续好转,消费者的消费信心正在逐步恢复,保障乳品安全的各项治理整顿行动正在持续深入进行,山西省已经成为全国主要奶牛生产基地之一。针对山西省乳品生产质量安全现状,从生鲜乳的生产、贮运、乳制品的加工销售和政府部门的监管等方面剖析了乳制品质量安全影响因素,提出了如何进一步提升山西省乳品质量安全水平的对策:首先加快推进奶牛标准化规模养殖,扩大优质奶源基地,从源头上强化对原料乳的质量安全控制;大力推进奶牛良种工程建设,做好选种和选配工作;加强政府监管力度,全面实施生鲜乳监测计划;提高乳品生产企业管理水平,重视和抓好质量文化建设、道德文化建设,强化诚信体系建设。     

河南省县域投资对农民收入的影响

使用河南省108个县(市)截面数据建立计量模型,定量分析县域投资数量及结构对农民收入的影响程度。结果表明,加大投资力度,对增加农民收入具有显著正面影响;城市倾向经济政策所导致的不合理城乡投资分布结构对农民收入具有显著负面影响。     

从隐私权看中西文化差异

以透析中西方隐私权观念差异为视角,分析中西方文化差异,并探究缩小中西交流中的文化差异的有效途径。     

吉林省肉牛业发展情况及对策的基本分析

通过对吉林省肉牛数量的估算及肉牛业发展状况,增长模式的分析,提出今后吉林省肉牛业的发展应努力提高牛肉质量,积极预防肉牛生产的大幅度波动。     

鸡BLB重组蛋白的原核表达及多抗制备

为分析鸡主要组织相容性复合体(MHC)Ⅱ类抗原β亚基BLB蛋白在鸡脾脏中的表达情况,本研究采用RT-PCR技术从鸡脾细胞中扩增了BLB基因的保守区第3外显子的部分序列,大小约为380 bp.将其克隆于表达载体pET-30a(+)中.在大肠杆菌BL21 (DE3)中,经IPTG诱导表达,获得大小约为19ku以包涵体形式存在的His-BLB重组蛋白.切取含有重组蛋白的SDS-PAGE胶免疫实验兔,获得抗血清.以制备的血清通过westemblot在鸡脾脏中检测到MHCⅡ类分子特异性条带,其大小约为28 ku,与BLB天然蛋白的大小相符合.本研究为进一步分析MHC-Ⅱ类分子在鸡体内的蛋白表达水平提供了依据.     

河北省薯类资源开发与综合利用的探讨

通过推广高干型薯类优良品种和高产栽培技术;开展好薯类的就地加工,把薯类粉丝生产搞上去;发展薯类的深度加工和综合利用;改进落后的技术装备;发展适销对路的薯类食品工业;建立统一管理的协调组织;加强科学研究,推广科技成果等措施、对我省的薯类资源开发与综合利用,提高其经济效益具有现实意义。     

黔北地区主要竹种竹材气干密度与力学性质的关系研究

对黔北地区几种主要竹种的气干密度与力学性质的关系研究表明:各竹种的气千密度与力学性质除部分竹种外均存在一定的曲线或直线关系,其中在气干密度与抗剪强度关系中,除慈竹、花吊丝、毛脚龙竹、金佛山方竹等竹种外,其他竹种均可利用回归方程T12=ap12b,T12=ap12+b进行估测.在气干密度与顺纹抗拉强度关系中除硬头黄、花吊...