排序方式： 共有29条查询结果，搜索用时 15 毫秒
11.
Pan XL Wen ZS Zou XT Zhou EK Kou HQ Xu ZR Zhang WJ 《Research in veterinary science》2011,91(3):405-411
The chemical composition and microstructure of five urolith samples (4 bladder stones and one kidney stone) associated with the feeding of high level of cottonseed meal (CSM) diet to Chinese merino fine wool sheep (Junken breed, Xinjiang) were examined by optical microscope, X-ray diffraction, X-ray energy dispersive spectrometry (EDS), scanning electron microscopy (SEM), and infrared spectroscopy analysis. The bladder stone samples appeared yellow or white, small powder and loose mass, and as finely granular under the optical microscope. However, the kidney stone samples from a experimental sheep were found as small brown mass, higher hardness, and as a cracklike structure. Oxygen, phosphorus, potassium and magnesium were found as four major elements in these uroliths by X-ray energy dispersive spectrometry (EDS). Potassium magnesium phosphate (MgKPO4) and potassium magnesium phosphate hexahydrate (MgKPO4·6H2O) were major components in the bladder stones, while less magnesium ammonium phosphate hexahydrate (MgNH4PO4·6H2O) examined by X-ray diffraction and infrared spectroscopy analysis. However, the newly found prismatic crystals, which were rich in magnesium and pyrophosphate, were identified as magnesium pyrophosphate (Mg2P2O7) in the kidney stone. The bladder stone samples appeared irregular mass and balls, cracked under SEM with low magnification, while appeared cracked, irregular layer-like, honeycomb-like or tiny balls under high magnification. The kidney stone samples were observed as cone, irregular block or layered crystal structures. 相似文献
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为了提高B.t.MP-342菌株对甜菜夜蛾的毒力,以B.t.MP-342菌株作亲株,根据MP-342菌株基因和毒蛋白的组成,采用重组DNA技术将对甜菜菜夜蛾高毒的CrylCa基因引入MP-342菌株,构建了工程菌B.t.MP-342IC-15工程菌.对该菌检测结果表明:MP-342IC-15工程菌表达两种Cry1类晶体蛋白,其分子量分别为135kD(CrylCa)和133kD(CrylAc),其CrylCa基因蛋白表达量占Cryl类晶体蛋白的35%和总晶体蛋白的29%.工程菌能良好表达CrylCa基因蛋白,且比例合适.据工程菌B.t.MP-342IC-15对甜菜夜蛾的生测表明.其毒力较亲株MP-342提高近1倍.对工程菌和亲株发酵上清液增效因子的增效活性进行了测定:工程菌上清液增效因子对小菜蛾具有一定增效作用;亲株上清液未显示对小菜蛾的增效作用. 相似文献
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P. Heilman R.W. MaloneL. Ma J.L. HatfieldL.R. Ahuja K.P. BoyleR.S. Kanwar 《Agricultural Systems》2012,106(1):59-71
A 45% reduction in riverine total nitrogen flux from the 1980-1996 time period is needed to meet water quality goals in the Mississippi Basin and Gulf of Mexico. This paper addresses the goal of reducing nitrogen in the Mississippi River through three objectives. First, the paper outlines an approach to the site-specific quantification of management effects on nitrogen loading from tile drained agriculture using a simulation model and expert review. Second, information about the net returns to farmers is integrated with the nitrogen loading information to assess the incentives to adopt alternative management systems. Third, the results are presented in a decision support framework that compares the rankings of management systems based on observed and simulated values for net returns and nitrogen loading. The specific question addressed is how information about the physical and biological processes at Iowa State University’s Northeast Research Farm near Nashua, Iowa, could be applied over a large area to help farmers select management systems to reduce nitrogen loading in tile drained areas. Previous research has documented the parameterization and calibration of the RZWQM model at Nashua to simulate 35 management system effects on corn and soybean yields and N loading in tileflow from 1990 to 2003. As most management systems were studied for a 6 year period and in some cases weather had substantial impacts, a set of 30 alternative management systems were also simulated using a common 1974-2003 input climate dataset. To integrate an understanding of the economics of N management, we calculated net returns for all management systems using the DevTreks social budgeting tool. We ranked the 35 observed systems in the Facilitator decision support tool using N loading and net returns and found that rankings from simulated results were very similar to those from the observed results from both an onsite and offsite perspective. We analyzed the effects of tillage, crop rotation, cover crops, and N application method, timing, and amount for the 30 long term simulations on net returns and N loading. The primary contribution of this paper is an approach to creating a quality assured database of management effects on nitrogen loading and net returns for tile drained agriculture in the Mississippi Basin. Such a database would systematically extend data from intensively monitored agricultural fields to the larger area those fields represent. 相似文献
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黄瓜花叶病毒病防治策略研究进展 总被引：2，自引：0，他引：2
针对黄瓜花叶病毒病防治现状,分析不同防治策略的优缺点,指出药剂防治、生物制剂、疫苗等由于污染环境、防效不明显等原因,在防治CMV上的应用受到越来越多的限制;常规育种由于缺少抗源及育种周期长,在抗CMV育种上成效较低.转基因技术由于基因资源丰富、育种周期短、抗性稳定、不污染环境等优点,在抗CMV研究上有较广泛的应用价值,获得了一批对CMV有较好抗性的转基因植株.运用植物细胞工程技术结合理化诱变因子诱变筛选抗CMV突变体,为创造抗CMV突变系提供了有益的尝试. 相似文献
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田春美 《农产品加工．学刊》2008,(11)
MP果蔬是一种新型的果蔬加工方法,具有新鲜、营养、方便等特点,市场前景广阔。介绍了国内外MP果蔬的生产现状、加工技术及保鲜技术。 相似文献
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甘蔗黄叶病毒(Sugarcane yellow leaf virus,ScYLV)属于黄症病毒科(Luteoviridae)、马铃薯卷叶病毒属(Polerovirus),主要由蚜虫传播,能够侵染甘蔗、玉米等多种作物,引发严重的植物病害。本研究将编码ScYLV运动蛋白(Movement protein,MP)的基因连接到pDB-His-MBP原核表达载体上,转化到大肠杆菌菌株Rosetta中,经IPTG诱导,表达分子量大小约为70 kDa的融合蛋白,将纯化后的融合蛋白制备多克隆抗血清。利用western blot检测抗血清的效价为1:128 000,灵敏度为1:256,抗血清不与马铃薯卷叶病毒属(Polerovirus)的其它病毒以及黄症病毒属(Luteovirus)病毒发生交叉反应,具有很好的特异性。本文制备的ScYLV MP抗血清可以用于ScYLV的检测,并为深入研究ScYLV与寄主的相互作用等问题提供材料基础。 相似文献
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苏芸金杆MP-342菌株发酵工艺技术 总被引：1，自引：1，他引：1
为了探索Ｂ．ｔ．ＭＰ—３４２菌株的发酵工艺技术以便进行大规模批量生产．于１９９５～１９９７年间在湖北省农科院 Ｂ． ｔ．研究开发中心对 ＢｔＭＰ— ３４２菌株的发酵工艺技术进行了研究。结果表明：采用 ＭＰ— ３４２菌株和ＹＭ—２Ｓ配方发酵生产液剂、原粉和高含量粉剂具有显著经济效益．ＭＰ－３４２菌株的发酵效价通常可达４ ０００ＩＵ／μＬ以上。采用离心－喷雾干燥工艺制备的ＭＰ３４２原粉．其粉平均效价和晶体含量分别为５５７４４ ＩＵ／μＬ和 １０． ４０％。原粉的物料收率平均为 ３． ５％．效价和晶体平均总收率分别为 ４２． ３０％和 ８３． ３０％。喷雾干燥过程的效价和晶体损失率很小．分别为９．２％和６．１％。ＭＰ－３４２原料贮存过程中稳定性较好。采用发酵液未经浓缩直接喷雾干燥．可获得 ６６ ８００ＩＵ／ｍｇ的原粉．晶体含量为 ７． ６％．原粉收率达 ６．５％，含水量为 ９． ４％，其效价收率和晶体收率分别为９５．７％和９９．８％。发酵液加６．８％ＣaＣＯ_（３）喷雾干燥、菌粉含水量４．５%.菌粉效价为３６ １５３ＩU／ｍｇ，效价收率为 １００．６％、晶体含量３．９％。晶体收率为 １０１．７％。两种工艺的效价和晶体收率均达９５％以上．较离心工 相似文献
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李路 《农业图书情报学刊》2007,19(11):144-145
多媒体视频MP4与光学视频的光学成像分不开的。光学的几何光学成像是光学的一个分支学科。几何光学的基本原理是光学成像的关键。纠正像差是检验光学设备好坏的关键。 相似文献