设施农业科学与工程专业人才培养模式研究与实践

针对中国设施农业产业的发展现状及存在的问题进行了分析,提出设施农业相关高级人才的缺乏是限制产业进一步发展的关键因素。结合河北农业大学的情况,就设施农业科学与工程本科专业的开设背景、人才培养方案设计的指导思想、教学基本条件、教学实验实习基地、课程体系构建及方案的可行性等方面进行了探讨与总结。     

多相混输泵输送技术在油田的应用

多相混输泵输送技术是近几年发展较快的一项新技术，概述了混输泵应用的意义及试验情况，对混输泵试验的结果及设计安装中的有关问题进行了分析和讨论，，介绍了多相混输泵现场应用效果和经验。     

冷缠胶带在管道防腐层大修中的适用性

结合冷缠胶带在东北输油管道防腐层大修的应用,提出了冷缠带在使用过程中存在的问题。分析讨论了冷缠带在管道防腐层大修中的产品分级、表面处理、绝缘性能及服役寿命。对冷缠带在管道防腐层大修中的适应性问题进行了研究。     

Protective effect of recombinant SCR15-18 domain of human complement receptor type 1 on intestinal ischemia and reperfusion injury

AIM: To investigate the protective effect of recombinant SCR15-18 domain of human complement receptor type 1 (CR1-SCR-15-18) on intestinal ischemia and reperfusion in a rat model. METHODS: Sprague-Dawley rats were randomly divided into 3 groups: sham operation(SO) group, ischemia and reperfusion (I/R) group and CR1-SCR15-18 treatment group. The superior mesenteric artery of the rats was clamped for 30 min followed by 60 min of reperfusion. PBS alone or CR1-SCR15-18 protein (30 mg/kg) in PBS was intravenously administered 5 min before reperfusion. Intestinal vascular permeability, myeloperoxidase (MPO), malondialdehyde (MDA) and superoxide dismutase (SOD) were measured. The histopathological changes of intestinal mucosa were examined by HE staining and complement 3 was detected by immunohistochemical analysis. RESULTS: Compared with SO group, the vascular permeability, the activity of MPO and the content of MDA in I/R group were significantly increased, and the activity of SOD was decreased. HE staining demonstrated that I/R induced severe intestinal histological damages and the increased amount of complement 3 and its derivates were deposited in the necrosis area. Compared with I/R group, the vascular permeability, the activity of MPO and the content of MDA were decreased and the activity of SOD was significantly increased in CR1-SCR15-18 treatment group. CR1-SCR15-18 also significantly attenuated intestinal histological injury, and reduced the deposition of complement 3 and its derivates in the necrosis zone. CONCLUSION: sCR1-SCR15-18 protein exerts a protective effect against intestinal I/R injury in rats, possibly by inhibiting the activation of complement.     

杏杂合位点共显性标记的分离方式及连锁图谱构建

以‘串枝红’ב金太阳’杏的F1代为材料,在分析共显性标记分离方式的基础上利用简单重复序列（SSR）和相关序列扩增多态性（SRAP）标记,构建了两张杏分子连锁图谱。‘串枝红’图谱共14个连锁群,包含37个SSR标记和32个SRAP标记,连锁群总长度为1086.6cM,每连锁群平均长度77.6cM,标记间平均连锁距离为1...     

温敏型核雄性不育系番茄T4育性的研究

以温敏型核雄性不育系番茄T4及对照First为试材,通过调查花粉发芽率、自交结实率、果实种子数以及采用Tricine-SDS-PAGE电泳方法分析叶片及花药蛋白质的变化,研究T4的育性转化,并分析其在可育和不育条件下花粉发芽率、自交结实率、果实种子数、叶片及花药蛋白质的差异。结果表明：28 ℃/18 ℃（昼/夜）处理的T4花粉发芽率、自交结实率最高,果实种子数最多,与对照First差异不显著,表明此时T4恢复部分育性|28 ℃/24 ℃和28 ℃/12 ℃处理的T4花粉发芽率、自交结实率和果实种子数与对照差异均达到极显著水平,表现为不育。不同温度处理的T4花药蛋白质与叶片蛋白质差异均达到显著水平|28 ℃/24 ℃和28 ℃/12 ℃处理的T4叶片蛋白质与对照差异显著,但28 ℃/18 ℃处理的差异不明显。     

Breeding and post-breeding responses of woodland birds to modification of habitat structure by deer

Birds in woodland can be affected by increasing deer populations through changes to vegetation structure and potential impacts on foraging resources; these effects need to be better understood. Effects of deer browsing are reported from a replicated split-plot exclusion experiment in English coppiced woodland. All stages of growth were examined up to eight years after felling. We used standardised mist-netting (totaling 1920 h) to sample birds in breeding and post-breeding periods. Deer browsing strongly altered vegetation structure by reducing canopy cover and shrub layer foliage density. However deer did not affect invertebrate density per unit of foliage, providing no evidence of an ungulate-mediated plant chemical response affecting forage quality for invertebrate herbivores. At avian guild level, significantly more ground and understorey foraging birds were captured where deer were excluded, and negative responses to browsing were more marked for pooled migrants than pooled residents. At the species level, especially pronounced negative effects were evident for dunnock (Prunella modularis) and garden warbler (Sylvia borin); approximately five times more dunnocks were captured in deer exclosures than in browsed vegetation. We also detected negative responses to browsing by nightingale (Luscinia megarhynchos) and long-tailed tit (Aegithalos caudatus). No significant positive responses to browsing were detected. For some species the use of young re-growth increased post breeding relative to the breeding period, including a marked shift by pooled residents that involved a disproportionate number of juveniles. Previous studies in North America have shown that, through vegetation modification, ungulate activity can alter woodland bird assemblages; as far as we are aware this is the first experimental demonstration of effects in Europe, and at low to moderate browsing intensity typical of the wider landscape scale.     

Stable isotope N and C labelling of different functional groups of earthworms and their casts: A tool for studying trophic links

Earthworms (Oligochaeta: Lumbricidae) have substantial effects on the structure and fertility of soils with consequences for the diversity of plant communities and associated ecosystem functions. However, we still lack a clear understanding of the functional role earthworms play in terrestrial ecosystems, partly because easy-to-use methods to quantify their activities are missing. In this study, we tested whether earthworms and their casts can be dual-labelled with ¹⁵N and ¹³C stable isotopes by cultivating them in soil substrate amended with ¹⁵N ammonium nitrate and ¹³C-glucose. Additionally, we also wanted to know whether (i) earthworms from different functional groups (soil-feeders vs. litter-feeders) and their casts would differ in their incorporation of stable isotopes, (ii) if enrichment levels are higher if the same amount of isotopes is applied in one dose or in staggered doses, and (iii) if isotopic enrichment in casts changes when they are stored in a conditioning cabinet or in a pot filled with soil placed in a greenhouse. Our findings show the feasibility of dual-labelling tissues and casts of both litter-feeding (Lumbricus terrestris) and soil-feeding (Aporrectodea caliginosa) earthworms using the same method. The advantage of this method is that earthworms and their casts can be labelled under realistic conditions by cultivating them for only four days in soil that received a one-time addition of commercially available stable isotopes instead of offering labelled plant material. In earthworms, the isotopic enrichment remained at a stable level for at least 21 days; labelled casts could be stored for at least 105 days without significantly decreasing their isotopic signals. This simple and efficient method opens new avenues for studying the role of these important ecosystem engineers in nutrient cycling and their functional relationships with other organisms.     

高压气动比例减压阀设计与仿真

提出一种高压气动比例减压阀,该阀由比例电磁铁控制的二位三通型滑阀式先导阀和活塞提升式主阀组成,通过压力传感器和控制器构成闭环电反馈控制,最高工作压力为31.5 MPa。该阀虽然存在少量先导耗气,但保证了压力调整的快速性和稳定性,克服了先导泄漏对减压阀的影响,避免了先导阀意外结冰的发生。在介绍结构及工作原理的基础上分析了该减压阀的特点,利用AMESim建立了考虑气源压力和负载流量波动的仿真模型。仿真结果表明:该阀在气源压力缓慢下降且负载流量大范围波动的情况下能实现稳定的压力输出,在不改变控制参数的前提下,当气源压力为31.5 MPa时输出压力可在1~30 MPa范围内稳定;先导阀预开口形式对压力精度影响较小,但应避免正开口以减少气体浪费;先导阀环形间隙高度控制在10μm左右较为合适。     

根癌农杆菌Ⅵ型分泌系统关键组分ClpⅤ型ATPase基因表达及活性位点分析

细菌Ⅵ型分泌系统（type Ⅵ secretion system,T6SS）是近年发现的一种分布广泛且与细菌致病性密切相关的新型分泌系统,ClpⅤ型ATPase是不同细菌T6SS中均含有的关键保守组分,据推测可能为底物蛋白的分泌提供动力,但对其生化功能尚未进行深入鉴定。在本研究中,我们克隆了根癌农杆菌（Agrobacterium tumefaciens）C58中的ClpⅤ型ATPase基因atu4344并在大肠杆菌中表达,酶学检测证实了其ATPase活性,定点突变分析发现K232/608和E299/675突变体均丧失ATPase活性,表明Walker A模体和Walker B模体与其活性密切相关。这是首次对植物病原细菌T6SS中的ClpⅤ型ATPase进行生化鉴定和突变分析研究。