浅谈高速公路的生态绿化

随着社会经济的高速发展,人民生活水平的不断提高,人们对精神文化生活及生活环境有了更高层次的要求,人们的出行不再是满足于位置转移的心态,而是要求在出行办事的同时,能尝试到轻松的感觉,也就是要求高速公路的运行空间环境应该是高质量的,在满足安全、快速、便利的同时,又要做到美观漂亮。文章在分析了创建高速公路的必要性和实施高速公路生态绿化的重要性的基础上,提出了高速公路生态绿化的思路、实施原则及具体措施。     

甘肃多儿国家级自然保护区维管植物区系分析

基于野外实地考察、植物标本的采集与鉴定以及结合文献研究的方法,分析了多儿保护区维管植物区系的物种组成和分布区类型。结果表明,该区维管植物共115科469属1323种,包括蕨类植物14科25属61种,裸子植物4科8属25种,被子植物97科436属1237种。多儿保护区维管植物区系优势现象明显,≥20种的优势科共879种,占该区维管植物总种数的66.44%;小属和单种属成分比例较大,占该区维管植物总属数的95.31%,总种数的75.51%。科级水平上,热带科（30.43%）稍多于温带科（26.96%）;属级水平上,温带科（72.49%）明显高于热带科（13.01%）;种级水平上,中国特有种有545种,其中538种与周边省份所共有,体现了该区系明显的过渡性和交汇性。该保护区维管植物区系地理成分复杂多样,属的分布有15个分布型和5个变型,温带地理成分占绝对优势,尤其以北温带分布为主。该区珍稀濒危野生植物较多,被列入保护名录有37种;一些古老、孑遗植物在该保护区具有良好的原始类群分布。本研究进一步完善了多儿保护区维管植物区系特征,为以后了解该保护区生物多样性提供可靠依据。     

种草养畜与草场建设综合配套技术

畜牧业快速发展,对于牧草资源需求量越来越大,为更好地满足畜牧业发展需求,我国提出“种草养畜”技术理念,加快草场建设,能在保障畜牧养殖业稳定发展的同时,达到良好的生态环保效益。该文分析种草养畜技术理念的意义,着重探讨种草养畜和草场建设综合配套技术。     

广东水禽源大肠埃希菌耐药性及氨基糖苷类耐药基因研究

为了调查广东地区水禽源大肠埃希菌对氨基糖苷类药物耐药现状和耐药基因的流行情况,探索大肠埃希菌的氨基糖苷类耐药基因型与耐药表型之间的关系,本研究采用琼脂梯度稀释法测定251株广东地区水禽源大肠埃希菌对氨基糖苷类药物的耐药性和采用PCR方法检测耐药基因。药敏试验结果显示,大肠埃希菌对链霉素耐药较严重,鸭源和鹅源的耐药率分别为81.58%和75.43%,对庆大霉素和卡那霉素较敏感,耐药率分别为25%和54.86%,对阿米卡星最为敏感,其中鸭源的菌株耐药率仅为1.32%。PCR方法检测显示,aadA1和aph(3′)-1检出率较高,为84.6%和91.9%,表明携带aadA1和aph(3′)-1耐药基因的水禽源大肠埃希菌在广东地区呈流行趋势。耐药基因型与耐药表型相关性分析结果显示,耐药基因rmtB的携带与4种药物(庆大霉素、阿米卡星、卡那霉素和壮观霉素)耐药株的产生具有显著相关性,表明耐药基因rmtB对大肠埃希菌耐药株的产生起重要的作用。本试验结果可为指导广东地区水禽大肠埃希菌病的临床用药提供理论基础和研究大肠埃希菌的耐药基因提供相关的数据。     

园林中障碍设置探讨

园林中障碍包括视觉障碍、行为障碍、精神障碍.在园林景观设计时合理设置障碍,不但能增加园林景观的层次性,提高人们的审美情趣,还能减少人在环境中的破坏行为,同时可以形成一道美丽的风景.     

Demonstrating freedom from disease using multiple complex data sources 2: case study--classical swine fever in Denmark

A method for quantitative evaluation of surveillance for disease freedom has been presented in the accompanying paper (Martin et al., 2007). This paper presents an application of the methods, using as an example surveillance for classical swine fever (CSF) in Denmark in 2005. A scenario tree model is presented for the abattoir-based serology component of the Danish CSF surveillance system, in which blood samples are collected in an ad hoc abattoir sampling process, from adult pigs originating in breeding herds in Denmark. The model incorporates effects of targeting (differential risk of seropositivity) associated with age and location (county), and disease clustering within herds. A surveillance time period of one month was used in the analysis. Records for the year 2005 were analysed, representing 25,332 samples from 3528 herds; all were negative for CSF-specific antibodies. Design prevalences of 0.1-1% of herds and 5% of animals within an infected herd were used. The estimated mean surveillance system component (SSC) sensitivities (probability that the SSC would give a positive outcome given the animals processed and that the country is infected at the design prevalences) per month were 0.18, 0.63 and 0.86, for among-herd design prevalences of 0.001, 0.005 and 0.01. The probabilities that the population was free from CSF at each of these design prevalences, after a year of accumulated negative surveillance data, were 0.91, 1.00 and 1.00. Targeting adults and herds from South Jutland was estimated to give approximately 1.9, 1.6 and 1.4 times the surveillance sensitivity of a proportionally representative sampling program for these three among-herd design prevalences.     

基于土地利用/覆盖的甘肃省景观生态风险时空变化特征

甘肃省景观类型丰富多样,在中国西部地区的生态安全中起关键性作用,也为当地发展提供着重要的物质基础和生态服务。由于气候变化和人类不合理活动的影响,甘肃省部分地区生态环境的安全与稳定遭到严峻挑战。本研究基于欧洲航空局全球土地利用/覆盖数据（CCI-LC）,利用动态度、转移矩阵方法分析了2005-2019年甘肃省土地利用/覆盖变化特征;通过构建景观生态风险指数并运用空间自相关分析法分析了景观生态风险的空间分布特征。结果显示：1)2005-2019年间,裸地面积减少最多,变化率1.88%,耕地次之,变化率2.31%;草地面积增加最多,变化率1.83%,建设用地次之,变化率191.08%。2）所有土地利用/覆盖类型中,建设用地的动态度最高且在整个研究时期内变化速率都保持在较高水平,综合动态度最大的时期为2010-2019年。3）土地利用/覆盖转移矩阵主要表现为耕地、林地、草地、裸地之间的转入与转出以及其他土地类型向建设用地的转入。4)2019年整体的生态风险值较2005年明显上升。其中低风险区和较低风险区面积最多,转化最频繁;中等风险区、较高风险区和高风险区面积虽然较少,但都存在不同程度的增长。...     

从土壤中分离棉枯萎病菌(Fusarium oxysporum f.sp.vasinfetum (Atk) Synder & Hansen)选择性培养基研究

本文介绍一种用于分离检测土壤中棉枯萎病菌的选择性培养基—植选2号。其成分为:KH_2PO_41g,MgSO_4·7H_2O 0.5g,K_2S_2O_50.2g,KCl0.6g,NH_4NO_3 0.5g,蛋白胨5g,山梨糖10g,蔗糖5g,琼脂20g,蒸馏水1000ml,PCNB 620mg,Oxgall1g,硫酸链霉素300mg,盐酸金霉素75mg。根据棉枯萎病在此培养基上的形态特征,能较容易地识别和检测该病菌。     

Study on Landscape Planning of Mourtcainous City

:In accordance with the problems, occurred in the mountainous city's construction, especially the crises such as the destruction of ecological and humanistic environment, the loss of traditional culture and characteristics and the disorder of urban structure, this paper discusses the distinctive landscape characteristic of mountainous city thoroughly.     

A Globally Convergent Algorithm for Nonlinear Programming

A new globally convergent algorithm was presented for a continuous differen-tiable nonlinear programming by defining a measure function deviating from the Kuhn-Tucker point. With this algorithm which can be used to get the optimum solution of the problem,the optimal lagrangian multiplier corresponding the optimal solution of the problem was also obtained. A new iterative algorithm for quadratic programming is obtained when applying the general algorithm to quadratic programming. Finally,a numerical example was given.