共查询到19条相似文献,搜索用时 140 毫秒
1.
陈雄新 《湖南环境生物职业技术学院学报》2008,14(3):17-19
对数据做统计描述和方差分析的方法很多,通过电子表格Excel软件进行统计描述和方差分析,为研究者提供了方便快捷的分析手段.Excel软件对于非统计专业人员的确是一个易学、易用、高效的好帮手.图7,表1,参5. 相似文献
2.
基于遗传算法的苏云金芽孢杆菌培养基配方优化 总被引:1,自引:0,他引:1
为获取苏云金芽孢杆菌(Bacilus thuringiensis)培养基的最优配方,即玉米淀粉、黄豆饼粉、酵母粉、蛋白胨和鱼粉等的最佳配比,运用二次正交回归旋转组合设计安排试验.基于试验数据、背景知识和遗传算法的原理,进一步设计了搜索Bt培养基最优配方的算法,通过该算法搜索出该菌发酵培养基配方的最优解区间.验证性的试验结果和分析表明,基于陔遗传算法的Bt培养基配方优化的方法是有效且优于传统配方优化方法的. 相似文献
3.
《湖南环境生物职业技术学院学报》2016,(3)
在生态学与医学领域的科研工作中经常需要对实验数据做双因素的方差分析,在已知样本例数、平均数、标准差等样本统计量的前提下,如果利用Excel软件制作方差分析模板,可为研究者提供方差分析结果的方便快捷手段,同时,也为我们在审阅论文数据时,如何判断其结论的真实性提供了新方法. 相似文献
4.
《湖南环境生物职业技术学院学报》2016,(2)
生态学与医学领域的科研工作中经常需要对数据做方差分析,在已知样本例数、平均数、标准差等样本统计量的前提下,如果利用Excel软件制作方差分析模板,既可为数据分析提供方便快捷的方差分析手段,也可为审阅论文数据时,如何判断其结论的真实性提供了新方法.图8,表2,参5. 相似文献
5.
荷兰已认识到需要用于污染预防的新计算机程序。虽然各荷兰公司尚不能得到所需类型的软件,但现有的一些程序可充当综合性更强的程序的基础。目前可得到的软件多数是专为帮助地方政府执行环境法律和帮助各公司遵守这些法律而设计的。这两个领域都正在开发新的程序。 相似文献
6.
7.
中国生态系统研究网络各生态站气象自动采集系统采集的数据不能直接应用,需要经过数据的提取与转置过程才能应用,因为所采集的数据量非常大,如果用常规的EX-ECL软件进行这些处理,不但工作量大,而且容易出错,作者运用SAS软件编写了一套程序,使这一工作变的非常简单,省时,省事,该文详细介绍了用SAS软件处理数据的程序流程及其源程序代码,可用于CERN生态站气象数据的处理。 相似文献
8.
造林区生态环境监测信息系统的研究 总被引:2,自引:0,他引:2
根据林业部与世界银行达成的协议,在我国60个县市设立世行贷款“国家造林项目”环境监测点,并对监测信息进行科学管理。本研究建立了基本情况库、水土流失监测库、监测结果汇总库,土壤肥力监测库,病虫害监测库等数据库,采用foxPro2.6 forWindows程序设计语言编制监测信息管理系统,该系统由站点分布,数据维护,数据浏览、报表生态、统计分析等功能模块构成。在系统软件编制过程中,采用了图文交互支持 相似文献
9.
《生态环境学报》2021,(7)
中国的湿地正和世界上其他国家的湿地一样不断消失和退化,全球的湿地面积在1970—2015年间下降了约35%。而湿地的消失将给所在区域的经济发展带来严重损失。在这个将要威胁人类未来生存的问题面前,社会各界不得不考虑如何进行湿地的恢复和重建。为了了解国内外湿地修复领域的研究现状和特点,采用Web of Science核心合集的SCI论文作为数据样本,运用Excel表格软件和文献计量分析工具,对湿地修复领域的发文量、发文国家、发文机构和发文作者等进行统计分析,同时利用VOSViewer可视化软件绘制机构合作网络和研究热点等知识图谱,对1990—2020年湿地修复研究领域的发展历程、现状及未来的发展趋势进行了分析。结果表明,湿地修复领域的研究论文数量保持稳定增长状态,该研究领域呈现出蓬勃发展的势头。美国是最主要的贡献国家,其发文数量和总被引频次显著高于其他国家。中国在该领域的发文量虽处于第二位,但在该领域的研究处于相对弱势,与欧美国家(尤其是美国)的差距悬殊,未来可与美国的地质调查局、路易斯安那州立大学等机构加强合作,提高发文数量和质量。湿地修复领域的研究热点主要集中在生物多样性保护、生态系统结构和功能改变及植被管理等方面。最后结合中国最新生态修复政策,提出了对未来应加强对小微湿地的关注,并应用中度干扰假说,开展全面性保护湿地。 相似文献
10.
《应用与环境生物学报》2017,(3)
为充分利用蘑菇产地的农业废弃物资源,在工厂化生产模式下探索以稻草、玉米秸、杏鲍菇菇渣代替部分麦草的双孢蘑菇(Agaricus bisporus)培养料配方的可行性.以麦草配方为对照设计配方,分别在堆料期和出菇期取培养料样品,提取总DNA,采用PCR-DGGE技术分析细菌群落结构,同时测定理化性状和产量,利用SPASS软件进行结果分析.结果显示:堆料期回收优势条带59条(KR089383-KR089441),分为5个门22个属;出菇期回收37条(KR089346-KR089382),分为5个门13个属;变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)和放线菌门(Actinobacteria)的多个种属为各配方共有的优势菌;与传统麦草配方相比,添加玉米秸秆的配方在堆肥初期细菌多样性较高,但以后持续下降;各配方堆肥期和出菇期细菌群落明显不同.不同配方堆肥期和出菇期培养料含氮量、灰分、电导率(EC)均呈上升趋势,含碳量、碳氮比、含水量以及p H均呈下降趋势,一潮菇后添加菇渣和玉米秸秆的配方含水量急剧下降.添加稻草、菇渣配方的产量稍低于对照纯麦草,添加玉米秸秆的配方产量最低.因此,双孢蘑菇培养料细菌群落和理化特性因原料配方不同表现出一定的差异;综合分析,用稻草和菇渣代替部分麦草的配方是可行的,而添加玉米秸时还需要进一步改进配方或工艺. 相似文献
11.
转基因作物潜在的健康和环境风险一直以来颇受争议,转基因作物加工成动物饲料后可能会诱导动物产生免疫应激反应,影响动物的生长发育、繁殖等。鱼类是水生脊椎动物的代表,已广泛应用于水环境的监测,但目前转基因作物对鱼类的饲用安全性研究还相对较少。文章基于转基因作物作为鱼饲料原料对鱼类生态毒理学效应的研究现状,综述了转基因作物对鱼的生长表现、生理生化、脏器功能及发育、组织病理以及行为活动等方面的生态毒理学效应,分析了当前研究中存在的问题,并对今后的研究趋势进行了探讨。 相似文献
12.
转基因作物对鱼类的生态毒理效应研究综述 总被引:1,自引:0,他引:1
转基因作物潜在的健康和环境风险一直以来颇受争议,转基因作物加工成动物饲料后可能会诱导动物产生免疫应激反应,影响动物的生长发育、繁殖等。鱼类是水生脊椎动物的代表,已广泛应用于水环境的监测,但目前转基因作物对鱼类的饲用安全性研究还相对较少。文章基于转基因作物作为鱼饲料原料对鱼类生态毒理学效应的研究现状,综述了转基因作物对鱼的生长表现、生理生化、脏器功能及发育、组织病理以及行为活动等方面的生态毒理学效应,分析了当前研究中存在的问题,并对今后的研究趋势进行了探讨。 相似文献
13.
纳米零价铁(nZVI)作为一种高效的环境修复材料,被广泛应用在土壤和地下水的修复等环境领域。但研究发现,大量进入环境中的nZVI可能会对生物体和生态系统产生严重危害,如和nZVI接触后,会造成小鼠器官受到损伤,杨树幼苗生长减缓,大肠杆菌等微生物的细胞膜破裂等不利作用出现。此外,nZVI还会改变环境中的氧化还原电位和溶解氧等指标,而且毒性效应容易受到外界条件的干扰。虽然目前对nZVI的致毒机制还不完全明确,但学者们提出了多种可能的假设,主流的观点是铁离子的释放、氧化损伤和基因损伤等。本文综述了国内外对nZVI毒性的最新研究成果,以期为nZVI的使用和毒性研究提供参考。 相似文献
14.
The compelling need to harness the potentials of the numerous agro-industrial by-products and the so-called “wastes” as part replacement for the more expensive conventional feed ingredients have been seriously expressed. This need has arisen mainly from the increasing demand and supply deficit of conventional feed resources with a concomitant sharp rise in their cost prices. The net effect of increased unit cost of the conventional feed resources is increased cost of the compounded rations, which by extension gives rise to increased cost of meat and animal products. It then becomes highly imperative that other sources for rapid livestock output to meet the growing human demands for animal protein foods are sourced. Such other sources should be cheap and nutritionally adequate for feeding animals with the aim of lowering the cost of producing meat. One of such measure is the recycling of poultry litter as part replacement for soya bean in livestock nutrition. Poultry litter is the by-product of poultry production, which should be managed in an environmentally friendly manner. As observed in this study, poultry litter contains 20% crude protein, 621.41 ME kcal kg?1, and substantial amounts of minerals that could be exploited in feeding livestock. This study has explored the possibility of including poultry litter in diets in view of its contents. 相似文献
15.
Bohra NK Purohit DK 《Journal of environmental biology / Academy of Environmental Biology, India》2003,24(3):213-221
Mycotoxins are fungal secondary metabolites formed by consecutive series of enzyme-catalysed reactions from a few biochemically simple intermediates of primary metabolism. These mycotoxins can enter the human and animal food chain by direct or indirect contamination. Mycotoxins are equally harmful to animal and human beings. Realizing the importance of mycotoxins to the health of man and animals there have been concentrated efforts to develop highly sensitive analytical methods for detection and proper determination of mycotoxins in food, mixed feeds and feed ingredients, animal tissue, blood, urine and milk. Most of the mycotoxins are identified and most current research on it is concentrated on increasing sensitivity accuracy and reproducibility and above all to decrease the time of determination. A detailed review of mycotoxin and their detection is summarised in the paper. 相似文献
16.
Alain Billionnet 《Ecological modelling》2011,222(3):546-554
The Reserve Selection Problem consists in selecting certain sites among a set of potential sites for biodiversity protection. In many models of the literature, the species present and able to survive in each site are supposed to be known. Here, for every potential site and for every species considered, only the probability that the species survives in the site is supposed to be known. The problem to select, under a budgetary constraint, a set of sites which maximizes the expected number of species is known in the literature under the name of probabilistic reserve selection problem. In this article, this problem is studied with species weighting to deal differently with common species and rare species. A spatial constraint is also considered preventing to obtain too fragmented reserve networks. As in Polasky et al. (2000), the problem is formulated by a nonlinear mathematical program in Boolean variables. Camm et al. (2002) developed a mixed-integer linear programming approximation that may be solved with standard integer programming software. The method gives tight approximate solutions but does not allow to tell how far these solutions are from the optimum. In this paper, a slightly different approach is proposed to approximate the problem. The interesting aspect of the approach, which also uses only standard mixed-integer programming software, is that it leads, not only to an approximate solution, but also to an upper limit on the true optimal value. In other words, the method gives an approximate solution with a guarantee on its accuracy. The linear reformulation is based on an upper approximation of the logarithmic function by a piecewise-linear function. The approach is very effective on artificial instances that include up to 400 sites and 300 species. Within an average CPU time of about 12 min, near-optimal solutions are obtained with an average relative error, in comparison to the optimum, of less than 0.2%. 相似文献
17.
Tzay-Rong Jenq Christopher G. Uchrin Marvin L. Granstrom Shing-Fu Hsueh 《Ecological modelling》1983,19(4):249-262
A linear programming model for point-nonpoint pollutant source control decisions has been developed. Total phosphorus was highlighted as the water quality substance of concern, although the methodology presented is general enough to permit its use for other substances.The linear program was formulated to minimize the cost of meeting established constraints. Methods to achieve removal of pollutant sources included point and nonpoint (urban and rural) techniques. Constraints were established on the basis of available removal technologies and water quality considerations. The final model is presented in a form such that use of existing linear and separable program software is possible. 相似文献
18.
V. Krivtsov R. Watling S. J. J. Walker D. Knott J. W. Palfreyman H. J. Staines 《Ecological modelling》2003,170(2-3):393
Since 1994 data on fungal fruiting have been gathered in the Dawyck Botanic Garden outside Edinburgh, including that for eight plots within a 7.5 ha wood, which has been left unmanaged in order to investigate relationships amongst fungal succession, habitat characteristics and local weather patterns. The climatic data are provided by a small meteorological station situated on site. To handle nearly 4000 entries of data so far collected a computer database was constructed. This assists querying of the information so that changes in fungal communities and patterns of succession can be observed, and the relevant data extracted for further analysis. To aid in this analysis, and to give the user full control over editing, updating and querying the database, a special computer program was compiled.Analysis of the database records revealed that the currently known Dawyck fungal community comprises over 620 different taxa, and the species list increases every year. Although some species of mycorrhizal fungi showed high specificity towards their preferred host either at species (e.g. Lactarius blennius with beech, Lactarius quietus with oak, Russula fellea and Russula mairei with beech), or at genus level (e.g. Suillus spp. with Pinaceae), some other common fungi (e.g. of the genus Amanita) were found to have very wide host ranges. In addition, unusual mycorrhizal associations have also been recorded. A lime tree (Tilia), which is supposedly primarily endomycorrhizal, has been found regularly associated with Russula cyanoxantha, Russula parazurea, Russula pectinata and Inocybe fastigiata. Many common Scottish fungi were found to be associated with introduced exotic trees, which is illustrated on the example of Pseudotsuga menziesii (Douglas Fir).The software created utilises the Microsoft Office suite of programs. Microsoft Access was used to construct the database, and Microsoft Excel was used for statistical investigations. The software was programmed using Microsoft Visual Basic, and provided a means of extracting the necessary data stored in Access and controlling the formulae used in Excel for their analysis. The recorded seasonal patterns of fungal fruiting was successfully described by a simulation mathematical model comprising differential and algebraic equations. This model may now be used as a submodel within more complex models describing terrestrial ecosystem processes. Examples of model simulations and sensitivity analysis are given and implications for future research discussed. 相似文献
19.
张景国 《城市环境与城市生态》1993,6(2):11-14
本文针对沿河城市污染排放的情况,分析了污染物排放对河流造成的污染,并根据Streeter—Phelps模型和城市河流对水质的要求,建立了沿河城市多点污染排放优化控制的线性规划模模,并编制了计算程序用来求解该数学模型.文中提供的算例及计算结果表明,本文提出的沿河城市多点污染排放量优化控制方法对城市排水系统的建设有较大的指导意义. 相似文献