生态评价在城市规划中的应用

对规划地段的自然生态状况深入而全面研究的普遍缺乏是当前城市规划工作的共同特点和缺点。作者提出面对人口的剧增、环境的恶化、物种的丧失等一系列生态矛盾与困惑,需要把规划方案建立在坚实的生态调查研究的基础上,使建设与地方的自然状况协调适应,符合区域固有的生态环境与运行规律。生态评价是达成这一目的的一条途径。     

杨凌示范区特色工业发展战略及对策研究

杨凌示范区正处在二次创业和全面贯彻落实党的十七届三中全会《关于推进农村改革发展若干重大问题的决定》的关键时期,在新的历史时期如何促进杨凌示范区工业又好又快发展,使杨凌示范区在坚持农业示范的方向上,迈向工业与农业协调发展的新阶段,是需要研究的重大课题。立足于杨凌工业发展的已有基础和优势,分析了当前杨凌示范区工业发展中存在的问题,认为杨凌示范区工业在发展中要处理好四个关系,即工业发展与周边地区(特别是西高新、宝高新)、与农业、与城市以及与农村的关系,提出了在生物产业、食品加工、新型环保农资、机械加工及农业装备制造等四个特色产业领域今后的发展方向和重点,以及相应的对策建议。     

杨凌示范区水源地信息调查及管理对策

水资源是杨凌示范区发展的保障和制约因素,对杨凌示范区水源地综合情况进行了调查和分析。最后,对污染控制、水源地建设等方面提出了建议和对策。     

汉阳陵帝陵外藏坑保护展示厅

汉阳陵帝陵外藏坑保护展示厅,位于西汉第四个皇帝刘启帝陵封土的东北侧,是目前我国第一座近帝陵封土,对遗址实现全封闭保护,并采用多种国际先进配套设施的现代化全地下遗址博物馆。世界古迹遗址理事会主席米歇尔·佩赛特先生赞誉:“这是一项杰出的成就,是国际古迹遗址保护的典范”。     

杨凌示范区地下水动态分析与利用

根据杨凌示范区的水文地质特征,采用地下水动态监测数据,分析了地下水在不同水文地质条件及其不同含水层的补给与排泄的变化规律,分析了影响地下水位动态变化的因素,掌握了该区地下水资源的动态规律,并提出地下水资源开发与利用方案,可为其他地区地下水动态分析、开发利用提供参考。     

杨凌示范区水资源可持续发展研究

水资源是杨凌示范区发展的保障和制约因素.论述了杨凌示范区水资源的可持续发展现状和利用情况,分析了开发利用中存在的问题, 并提出相应的对策, 为今后合理开发利用和保护水资源提供参考.     

生态型住区中心绿地设计初探——以杨凌示范区田园居为例

本文深入分析生态型住区中心绿地的设计,对建设生态型住区提供有益参考。以杨凌示范区为例,说明生态型住区处于不断充实的阶段,将成为未来住区建设的典范。生态型住区绿地景观注重绿色健康理念和人们情感满足,实现了未来住区的可持续发展。     

体细胞胚在结构上也具有类似合子胚的基本结

1Tropical crops genetic resource institution, Tropical Agricultural Institute of China, Danzhou Hainan 571737 2College of horticulture, Nanjing agricultural university, Nanjing 210095)It is studied somatic embryogenesis of garlic on histology in this paper, Histological observations showed that Parenchyma cells first experienced dedifferentiation and followed with callus-forming, and ensued with embr     

Lanthanum chloride improves maize grain yield by promoting photosynthetic characteristics,antioxidants enzymes and endogenous hormone at reproductive stages

Despite an increase in application spectrum of rare earth elements in agriculture, all studies show that the suitable accumulation of rare earth elements can improve the crop seedling growth, but there is little research about REEs on physiological mechanisms of crops at reproductive stages. Therefore, this study was conducted to examine the possible potential benefits of lanthanum chloride(LaCl_3) on the senescence and grain yield responses of maize. In this study, maize seeds were pre-treated by soaking with LaCl_3 at the concentrations of 0(CK), 400(LC1), 800(LC2) and 1200(LC3) μmol/L, to evaluate its effect on the green leaf area, chlorophyll contents, photosynthesis, antioxidants, endogenous hormones in the later crop growth stages. The results show that LC1 and LC2 treatments evidently increase green leaf area, above ground dry biomass, accompanied by a distinct increase in the chlorophyll contents, and photo synthetic capacity, which promote the ear characteristics and grain yield of maize. In addition, LC1 and LC2 treatments simultaneously increase the activities of antioxidants, including superoxide dismutases, catalases, peroxidases, soluble protein, and enhanced levels of auxin, gibberellin and zeatin,following a dose-response tendency. Themalondialdehyde and abscisic acid levels transiently increase with the progression in the growth stage of the crop but are markedly decreased at LC1 and LC2 treatments, while LC3 treatment has no significant effect on malondialdehyde and even accelerates the accumulation of abscisic acid in maize leaves. Our data suggest that seed priming with LaCl_3 at a suitable concentration range(400-800 μmol/L) can prolong the functional periods of leaves, increase photosynthetic capacity, enhance antioxidant activity, and alter endogenous hormone levels at reproductive stages, resulting in delaying leaf senescence rate and increasing yield. However, the moderate concentration of LaCl_3 for maize is LC2(800 μmol/L), and can be effectively used to improve grain yield of maize.     

阶地高度对杨凌区农村饮用水水质影响研究

为了解和掌握杨凌示范区的农村饮用水水质现状,采集杨凌示范区不同海拔高度(包括头道源、二道源和三道源)的终端饮用水水样20份,对水样的17项指标进行检测,得出以下结论:(1)共有3个采样点的四项指标超标:下川口的浊度超标;穆家寨的硝酸盐超标;穆家寨和徐西湾的总硬度均超标。(2)随着海拔高度的降低杨凌示范区的饮用水水质总体呈下降趋势,尤其是硝酸盐和总硬度。(3)下川口的水质有异常现象。