基质栽培中不同配比的有机固态肥对番茄生长及产量品质的影响

研究了有机基质栽培中有机固态肥、羊粪、猪粪、牛粪不同配比对番茄生长及产量品质的影响。结果表明:中水平施肥组合对番茄生长有促进作用;对番茄产量品质的影响主要表现为产量、品质与均衡施肥呈正相关,得出最优化施肥配比:羊粪996 kg/667 m2,牛粪1 125kg/667 m2,猪粪1 125 kg/667 m2。     

基质型容器育苗营养块的研制与应用

基质型容器育苗营养块是在继承传统穴盘育苗技术的基础上及不断创新过程中得到快速发展的一种新型育苗方式。文章详述了该育苗方式的技术要点,并得出了该产品集基质、养分、容器为一体,带基定植、所以移栽时不伤根,直接与土壤相结合,无需缓苗,是一项既经济又环保的实用育苗技术,有很好的应用前景。     

一类连续区间系统的鲁棒圆盘极点配置

针对一类连续线性区间系统,基于线性矩阵不等式,介绍一类能够将给出的连续区间系统的闭环系统的极点配置到指定圆盘中的状态反馈和输出反馈增益矩阵的设计方法.这类设计方法也包括分别基于执行器故障和传感器故障的可靠控制器的设计方法,基于矩阵的谱半径不大于自身的最大奇异值的理论以及矩阵的Schur补引理,将矩阵的最大奇异值限定后就能将矩阵的特征值限制在某个圆盘内,再将这种结果以线性矩阵不等式的形式表达出来.最后,给出的数值例子说明这类方法的可行性和有效性。     

论我国社会转型与国有林管理体制创新的关联

社会转型对我国国有林和国有林管理提出了新要求、赋予了新任务、提出了新课题,必须把国有林管理体制改革纳入到我国社会转型的大环境中去进行认真谋划和统筹研究。国有林管理体制改革的核心问题是根据我国社会转型的形势和需要,对国有林的功能作用进行重新定位,以此为基础,解决好＂谁来管理国有林＂和＂怎样管理国有林＂两个命题,同时,在国有林管理体制改革中,要妥善处理国有林与国有林区经济社会发展的关系。     

沙漠腹地-荒漠戈壁-绿洲的气候过渡性研究

利用塔里木盆地塔中气象站、肖塘气象站和轮台气象站1999-2003年的资料,通过对比分析,研究沙漠腹地-荒漠戈壁-绿洲的气候过渡性规律。结果表明,由于地理位置和下垫面的不同,从沙漠腹地-荒漠戈壁-绿洲,气候存在过渡性差异。     

太湖流域土地利用碳排放变化及其预测

太湖流域地处长三角中心区域,人类活动剧烈导致生态环境退化和碳排放量上升.为探究土地利用变化对碳排放量的影响,利用ArcGIS软件,结合土地利用转移概率矩阵,依据2000年、2005年、2010年和2020年4期太湖流域遥感影像数据,对太湖流域各历史时期(2000—2020年)不同土地利用类型下碳排放进行了分析.同时,为...     

基质金属蛋白酶-2在胃癌中的表达及其对癌微血管生成和转移的影响

目的：观察胃癌组织中基质金属蛋白酶2(MMP-2)的表达及其对癌微血管生成和转移的影响。方法：应用免疫组化S-P法检测87例胃癌组织中MMP-2的表达和微血管密度(MVD)。结果：胃癌组织MMP-2阳性表达率为59．8％(52／87)。MMP-2的阳性表达与胃腺癌患者的淋巴结转移与临床病理分期关系密切。结论：MMP-2与胃腺癌新生血管的形成及转移密切相关,是判断胃癌转移有价值的指标。     

输电塔-螺旋锚基础-土体系相互作用的侧向分析

提出了侧向风荷载作用下输电塔—螺旋锚基础—土体系相互作用分析的简化计算模型,推导出刚度矩阵方程,编制了计算程序,并对某一具体输电塔进行了计算,按考虑与不考虑相互作用两种情况进行了对比分析。     

盐池县荒漠草原人工植被重建对区域生态系统蒸散的影响

[目的]研究荒漠草原人工植被重建对区域蒸散的潜在影响,旨在为区域生态恢复重建提供理论依据。[方法]基于2001—2018年MODIS ET和NDVI产品,利用趋势分析、相关分析和分区统计等方法,以宁夏回族自治区盐池县为例,研究了荒漠草原人工植被重建对区域生态系统蒸散的影响。[结果]①2001—2018年盐池县NDVI整体呈上升趋势,增长幅度为0.006 0/a,98.55%的区域显著上升。②2001—2018年均蒸散量(ET)为266.73 mm,空间上表现为西南高于西北的特征,近18 a盐池县蒸散量显著上升(p0.01),增长幅度为6.27 mm/a,全县区域内ET均达到了显著上升趋势。③盐池县大面积人工植被重建后,ET显著升高,ET与NDVI呈显著正相关。ET与NDVI的变化趋势相关性为0.76(p0.01)。④在盐池荒漠草原地区,人工植被重建造成的植被结构变化导致生态系统蒸散量更大,消耗更多的水分,同时也使ET增长速率加快。[结论]盐池荒漠草原人工植被重建提高了区域NDVI值,也增强了生态系统的ET,水分消耗的加剧将影响生态系统的稳定性。     

Technical Review of Fast Detection of Heavy Metals in Soil

Recently, with the high-speed development of industry and agriculture in China, the contamination of heavy metal has become a severe environmental problem caused by immoderate mining operation, "three wastes" emissions, vehicle exhaust, and misuse of agricultural chemical inputs. So, it is very important to monitor the contamination of heavy metals in soil. However, the national and industrial standards of detecting heavy metals in soil mainly focus on the traditional analytical approaches employed in laboratory at present. So, it is still difficult to achieve the on-site and fast detection of heavy metals in soil, which gives rise to such difficulty of monitoring and preventing the source contamination effectively and timely. In view of the matrix of soil sample, solid sampling analysis should be feasible to the fast detection of heavy metals, including electrothermal vaporization (ETV), X-ray fluorescence spectrometry (XRF), laser ablation (LA), laser induced breakthrough spectrometry (LIBS), X-ray photoelectron spectroscopy (XPS), and instrumental neutron activation analysis (INAA). The solid sampling techniques do not require digestion treatment and is thereby fast and efficient. However, among them, the detection limit and stability of XRF, LA, and LIBS cannot satisfy the all demands in standards of soil quality; on the other hand, it is too difficult to reach the miniaturization and on-site testing for LA, XAS, and INAA. By comparison, ETV is a kind of solid sampling tool with excellent advantages such as high analytical sensitivity, favorable stability, and being easy to be miniaturized, using electric heating to introduce analyses via aerosol from the sample into the atomizer or exciter for measurement. ETV is able to introduce heavy metals fast and efficiently, which is versatile to atomic absorption spectrometry (AAS), atomic fluorescence spectrometry (AFS), atomic emission spectrometry (AES), and induced coupled plasma mass spectrometry (ICP-MS). As usual, many materials such as carbon, metals, and quartz can be utilized for ETV, which are frequently processed into graphite furnace, porous carbon tube, tungsten coil, rhenium coil, quartz tube and so on. Among various ETV approaches, electromagnetic induction ETV is characterized with no cold zone, fast heating or cooling and miniaturization. Considering the complicated soil matrices, however, ETV has been always confronted with the bottleneck problem, namely matrix interference. Through integrating these advanced techniques including gas phase enrichment (GPE), dielectric barrier discharge, matrix modifier, background correction and so on, the matrix interference will be eliminated completely for the detection of heavy metals in soil when solid sampling by using ETV atomic spectrometers. Especially for GPE, it can realize both two aims at one time: eliminating matrix interference and improving analytical sensitivity. This review is about to bring some valuable suggestions for innovating the fast detection of heavy metals in soil, to play parts in the environmental monitoring and protection in the future.