四种实验动物脏器质量系数的测定     

韩芬茹 《畜牧兽医杂志》2006,25(4):1-3

对鲤鱼、蟾蜍、家鸡、家兔四种动物主要内脏器官进行称量并对脏器系数进行测定,对同类动物不同性别间脏器系数的差异和各脏器系数之间的大小进行了比较。结果表明,鲤鱼、蟾蜍和家兔各脏器质量,雌雄间无明显差异,但家鸡部分脏器质量雌雄间有明显差异。家鸡的脏器系数(肝脏除外),雄性明显高于雌性(P<0.05),鲤鱼和蟾蜍的肾脏系数性别差异显著(P<0.05)。四种动物的心脏系数:家鸡>蟾蜍>家兔>鲤鱼;肝脏系数:家兔>蟾蜍>家鸡;肺脏系数:蟾蜍>家鸡>家兔;脾脏系数:鲤鱼>家鸡>家兔>蟾蜍;肾脏系数:家鸡>家兔>蟾蜍>鲤鱼。由此可见,动物的脏器系数的大小与其进化水平有一定的相关性。  相似文献   

A nonlinear, dynamic, simulation model for transport, and whole plant allocation of systemic xenobiotics following foliar application. IV: Physicochemical properties requirements for optimum absorption and translocation     

Norbert M. Satchivi  Loyd M. Wax 《Pesticide biochemistry and physiology》2006,84(2):83-97

The relationship between the physicochemical properties (molar volume, partition coefficient, and dissociation constant) of slow-acting systemic postemergence xenobiotics and their uptake and translocation to the sites of action was investigated using the nonlinear, dynamic simulation model ERMESSE. When the pK_a was held constant at 4.0, the model enables the prediction of the uptake of a systemic xenobiotic as a function of its partition coefficient and molar volume. The model also considered the effects of the physicochemical properties of a systemic xenobiotic on its long-distance translocation within the vascular tissues. For instance, when the log K_ow and pK_a were held constant at 1.5 and 6.0, respectively, the model predicted a higher translocation rate (55%) for molecules with a small (e.g., MV = 100 cm³ mol⁻¹) as opposed to a large (e.g., MV = 300 cm³ mol⁻¹, 33%) molar volume. In addition, the theoretical predictions from the ERMESSE model showed that any xenobiotic with a molar volume not exceeding 300 cm³ mol⁻¹ could provide an uptake ?50% and a translocation rate ?25% when its log K_ow is between −0.5 and 2.5 and its pK_a is between 0.0 and 8.0.  相似文献   

用小波系数估计图像边缘方向的相干增强扩散图像降噪算法     

赵佰秋  黄凤岗  唐立群 《植物保护》2007,(12):2096-2100

在分析相干增强扩散方法和小波阈值收缩方法之间关系的基础上,给出了相干增强扩散在小波分析意义下的解释,同时解释了相干增强扩散方法与小波阈值收缩方法在图像性质上的等价性。针对相干增强扩散计算扩散矩阵较慢的缺点,提出了一种用小波系数估计图像边缘方向的相干增强扩散图像降噪算法。仿真试验结果表明,该扩散算子可以很好地定位图像边缘,较好地运用了小波的时频分析功能。  相似文献   

Classification of Morchella species from Yunnan and Zhejiang Provinces Based on rDNA ITS Sequences     

SHEN Hong    CHEN Mingjie  ZHAO Yongchang  PAN Yingjie Key Laboratory of Agricultural Genetics  Breeding of Shanghai 《食用菌学报》2007,(2)

Fourteen Morchella samples (eleven from Yunnan and three from Zhejiang Provinces) were selected on the basis of differences in fruit body morphology. Ribosomal DNA internal transcribed spacers (ITS) were amplified in each case using the universal primer pair, ITS-1 and ITS-4, and the amplification products were purified and sequenced. Comparisons with sequence data in GenBank revealed that the 11 Morchella isolates collected from Yunnan belonged to four species: Morchella elata, Morchella conica, Morchella crassipes and Morchella costata. The three isolates collected from Zhejiang Province (M12, M13 and M14) were designated as unknown Morchella species. When Verpa conica (AJ544206) (from the genus Verpa belonging to the same family as Morchella) was taken as the outgroup, the 14 isolates formed three groups, M. elata, M. costata (Group 1); Morchella esculenta, M. conica (Group 2); and M. crassipes, M12, M13 and M14 (Group 3).  相似文献   

用大肠杆菌K99和F41菌毛抗原检测牛血清抗体的琼脂扩散试验的研究   总被引：4，自引：0，他引：4  

崔玉东  杜学昆 《黑龙江畜牧兽医》1998,(4):3-5

用含２ｍｏｌ／Ｌ尿素的磷酸盐缓冲液以热处理方法提取的Ｋ９９和Ｆ４１菌毛作为抗原,对琼脂扩散试验方法进行研究。结果表明本试验方法简便,特异性强,敏感性高,可用于血清抗体检测;所制备的抗原稳定、重复性好。  相似文献   

微孔草的分布及植物群落特征研究   总被引：5，自引：0，他引：5  

王钦  尚可政 《草业科学》1998,15(1):18-26

采用定量样地法,对孔微草这一特种油料植物的群落结构、群落变异以及群落特征进行了研究。结果表明,微孔草干物质生产量占总量的比率,休闲地为９．１６％、撩荒地为１６．９０％、油草地为１５．３２％、燕麦地为１０．６６％、青稞地为５．９７％;群落系数相应为８７．０９％、８７．９１％、９１．８２％、９５．６５％、９３．６０％;优势度相应为９．６０％、１３．４５％、１１．９９％、１６．６１％、７．１３％。经主分  相似文献   

Assessment of diffusive phosphate supply in soils by microdialysis     

《植物养料与土壤学杂志》2017,180(2):220-230

Standard procedures to assess P availability in soils are based on batch experiments with various extractants. However, in most soils P nutrition is less limited by bulk stocks but by strong adsorption and transport limitation. The basic principle of root‐phosphate uptake is to strip phosphate locally from the solid phase by forming a radial depletion zone in the soil solution, optionally enhanced by release of mobilizing substances. Microdialysis (MD), a well‐established method in pharmacokinetics, is capable to mimic important characteristics of P root uptake. The sampling is by diffusional exchange through a semipermeable membrane covering the probes with their sub‐mm tubular structure. Additionally, the direct environment of the probe can be chemically modified by adding, e.g ., carboxylates to the perfusate. This study is the first approach to test the applicability of MD in assessing plant available phosphate in soils and to develop a framework for its appropriate use.We used MD in stirred solutions to quantify the effect of pumping rate, concomitant ions, and pH value on phosphate recovery. Furthermore, we measured phosphate yield of top‐soil material from a beech forest, a non‐fertilized grassland, and from a fertilized corn field. Three perfusates have been used based on a 1 mM KNO₃ solution: pure (1), with 0.1 mM citric acid (2), and with 1 mM citric acid (3). Additionally, a radial diffusion model has been parametrized for the stirred solutions and the beech forest soil.Results from the tests in stirred solutions were in good agreement with reported observations obtained for other ionic species. This shows the principal suitability of the experimental setup for phosphate tests. We observed a significant dependency of phosphate uptake into the MD probes on dialysate pumping rate and on ionic strength of the outside solution. In the soils, we observed uptake rates of the probes between 1.5 × 10⁻¹⁵ and 6.7 × 10⁻¹⁴ mol s⁻¹ cm⁻¹ in case of no citrate addition. Surprisingly, median uptake rates were mostly independent of the bulk soil stocks, but the P‐fertilized soil revealed a strong tailing towards higher values. This indicates the occurrence of hot P spots in soils. Citrate addition increased P yields only in the higher concentration but not in the forest soil. The order of magnitude of MD uptake rates from the soil samples matched root‐length related uptake rates from other studies. The micro‐radial citrate release in MD reflects the processes controlling phosphate mobilization in the rhizosphere better than measurements based on “flooding” of soil samples with citric acid in batch experiments. Important challenges in MD with phosphate are small volumes of dialysate with extremely low concentrations and a high variability of results due to soil heterogeneity and between‐probe variability. We conclude that MD is a promising tool to complement existing P‐analytical procedures, especially when spatial aspects or the release of mobilizing substances are in focus.  相似文献   

抗战时期陕甘宁边区奶业 技术扩散及其影响因素     

李琦珂  曹幸穗 《草业科学》2013,30(2):306-309

抗日战争时期，陕甘宁边区的奶业方兴未艾。以光华农场为代表的奶业科研及生产机构，大力开展奶畜育种、饲养、管理、防疫等方面的科研工作，试验制作奶酪、奶皮、奶油、酸奶等奶制品，成为了边区奶业的技术扩散源。抗日军民对牛、羊奶的大量需求，客观上促进了边区奶业技术的传播与辐射，但受经济条件、饮食习惯以及市场流通等多重因素的影响和制约，边区奶业技术扩散呈现出比较复杂的情形。  相似文献   

利用髙稳系数法分析夏大豆品种的高产稳产性     

曹金锋  卢思慧  胡铁欢  高广居  吴凤训  孙永媛 《河北农业科学》2013,(2):75-77

利用髙稳系数法（HSC法）,对2011～2012年参加国家大豆品种区域试验的材料进行了高产性和稳产性分析。结果表明：产量最高的中黄41稳定性较差,仅适宜在高产地区如北京、天津和山东等地种植;中作05-15、中黄39和冀06B9高产性和稳定性均较好,可在生产上推广应用;中作017020、汾9877-10和中黄30产量均  相似文献   

试用关联度分析人才结构的合理性     

孙枫林 《湖南农业大学学报(自然科学版)》2000,27(2)

人才，是经济社会活动诸多要素中最主要，最活跃的要求，结构合理的人才队伍才有可能产生高的效率和效益。本文应用灰关联度分析方法，以通信产业人才队伍为例进行分析，为制定合理的人才队伍结构提供了一种评价方法。  相似文献