新疆小城镇建设与发展研究

中共中央已明确提出了“发展小城镇 ,是带动农村经济和社会发展的一个大战略”,结合新疆“十五”计划 ,文章论述了新疆加快发展小城镇的现实意义 ,通过对小城镇建设与发展的现状评价及对新疆小城镇发展机制的探讨 ,提出了适合新疆实际的小城镇发展模式 ,小城镇建设与发展的总体目标及加快发展小城镇的对策建议     

阿尔山市旅游业发展SWOT分析与对策

在目前旅游业发展蒸蒸日上的形势下,充分发挥旅游资源优势、环境优势,改善目前发展难题对阿尔山市旅游业的发展意义非常重大.文中在对阿尔山市旅游发展现状进行实地考察基础上,采用SWOT分析法,结合相关的文献资料,分析了阿尔山地区旅游业发展的优势、劣势、机会和威胁,总结出阿尔山市旅游业发展优势及制约其旅游业发展的主要因素,进而...     

新疆小城镇空间组团发展的战略思考

本文针对新疆小城镇发展的“大分散 ,小集中”绿洲特性 ,提出了组团式发展的空间组织模式设想 ,认为新疆小城镇空间布局将形成一个天山北坡小城镇密集带和若干小城镇组团。尽管不同组团的发展特点 ,发展优势和发展途径不同 ,但集中发展是其共同主旨思想。文章针对各自组团提出了因地制宜的发展策略和建议     

我国县域农业与乡村经济发展的时空特征研究

工业化城镇化快速发展背景下,侧重于农业的农村区域发展政策是否仍然符合实际并取得成功,值得进行深入的数据验证.文中选取了2000、2005、2010年三个时间段面,对我国县域农业发展及乡村经济发展进行秩相关分析及时空特征分析.结果表明:1)近年来我国县域农业发展与乡村经济发展之间的相关性在下降.2)中国县域农业及乡村经济发展水平和速率都存在明显的地域差异,在发展水平上:2000～2010年,中国县域农业发展水平与乡村经济发展水平分布不对称现象越来越明显,比较突出的区域有东北平原地区、黄淮平原及长江中下游平原地区;在发展速度上:2000～2010年,我国东部县域农业发展速度缓慢,部分县市甚至后退,但是乡村经济却有较大的发展,虽然中西部大部分县市农业都有很大的发展,但是乡村经济发展相对于农业发展来说仍比较缓慢,有的县市乡村经济甚至是呈现负发展.基于以上结论,笔者认为我国应制定全面考虑农村经济部门和农村区域发展差异性的发展政策.     

武汉市江夏区柑橘产业发展现状与升级对策

通过调查了解武汉市江夏区柑橘产业发展基本情况,分析了柑橘产业发展过程中遇到的困难,如种植结构不合理、品牌建设基础薄弱、全产业链发展不够健全等,提出了江夏区柑橘产业发展升级的对策,以促进该产业的健康快速发展。     

绿洲农业发展的可持续性分析——以民勤县为例

可持续发展理论和实践的发展要求更彻底地了解在发展实践中出现不可持续的原因。目前民勤县的荒漠绿洲农业发展是不可持续的 ,分析其社会经济发展中存在的不可持续性 ,有针对性地提出发展对策 ,对我国干旱地区绿洲农业的发展具有借鉴意义。     

宁夏中部生态脆弱区生态城镇化发展模式研究

通过分析宁夏中部地区生态环境问题以及地区城镇化发展的基本趋势,认为这一地区城镇发展不应延续我国许多地区“先发展,后治理”的老路,提出了地区应该在城镇化发展的初期,利用各种城镇发展有利时机和宁夏生态移民的过程中走一条“生态城镇化”的发展道路,并初步探讨了宁夏中部地区生态城镇化的发展模式。     

基于“点-轴”理论的蒙东区域开发路径选择

内蒙古东、西部经济差距逐年增大,蒙东经济振兴迫在眉睫。文中根据"点-轴"发展理论,从资源、产业、城市、对外联系等角度分析蒙东区域经济发展轴形成与发展,认为目前正处在赤锡、通霍、海满三大发展轴形成与发展阶段,也是蒙东地区经济跨越式发展关键阶段,具有承前启后的作用。三大发展轴中,赤锡发展轴、通霍发展轴最有可能率先发展,逐渐演变成"赤锡通"发展轴。针对这些问题提出了对策与建议。     

旅游形象研究与乌鲁木齐城市旅游发展关系探讨

本文在分析旅游形象研究对城市旅游发展的意义基础上 ,以乌鲁木齐市为研究靶区 ,探讨旅游形象研究与乌鲁木齐城市旅游发展关系。认为旅游形象研究与乌鲁木齐市旅游业发展息息相关 ,相辅相成。良好的旅游形象有利于弱化乌鲁木齐市旅游业发展中不利因素 ,带动旅游业的发展 ;同时旅游业的发展更能提升本地旅游形象 ,彼此是互动协调发展的关系。     

新疆工业化和城镇化协调发展研究

工业化和城镇化是推动区域经济社会发展的主要动力,实现工业化和城镇化的协调发展是促进新疆经济社会跨越式发展重要途径之一。文中运用钱纳里发展模型,并通过计算工业化和城镇化协调指数,论述了工业化和城镇化协调发展关系,结合城镇人口与农业劳动力人口指标,分析了新疆工业化进程与城镇化进程的互动关系,并对省域层面工业化和城镇化区域协调发展状况进行了初步探讨。认为新疆工业化和城镇化之间的发展存在显著不协调状况,总体发展水平低、城镇化滞后工业化发展态势明显;在省域85个县市中,协调发展区域尚处于低度协调水平,为提升新疆区域经济社会发展水平,必须打破当前发展模式,实现由"协调发展-交互发展-更高层次协调发展"模式的转变。     

Influence of host resistance and phenology on South American leaf blight of the rubber tree with special consideration of temporal dynamics

South American leaf blight (SALB), the most dangerous disease of the rubber tree, is responsible for the lack of significant natural rubber production in South America and is a major threat to rubber tree plantations in Asia and Africa. Although the selection of resistant clones is the preferred disease control method, greater knowledge is required of the relationship between host and pathogen, in order to construct more durable resistance. Based on small-scale trials, this study set out to compare the dynamics of SALB on two highly susceptible and one moderately susceptible clone and to analyse the effect of host phenology on disease severity, at leaflet and flush scales. Clonal resistance was found to have a noticeable effect on disease severity, asexual sporulation and stromatal density at both leaflet and flush levels, and on disease dynamics at a leaflet level; time for symptom and sporulation appearance were longer on the moderately susceptible clone than on the susceptible clones. On the moderately susceptible clone, the stromatal density was largely dependent on disease severity. The phenology did not differ among the three clones and could not be considered as a factor in genetic resistance to SALB. However, for the three clones, the position of the leaflet in the flush affected the duration of the immature stages and the disease: the shorter the duration of leaflet development, the lower the disease severity, the sporulation intensity and the stromatal density.     

Pathogenesis by fungi and by parasitic plants: Similarities and differences

The processes by which fungi and parasitic plants infect their plant host are compared. The steps considered are: location of the host by the pathogen, the concept of the haustorium, attachment of the pathogen to the host, mechanism of penetration into the host, responses of the host to infection by fungi and by parasitic plants, and the suppression of the host response by the pathogen. Although superficially similarities between fungal infection and infection by parasitic plants exist, the underlying mechanisms appear to be different and only in the penetration step are similar strategies used, including the use of lytic enzymes. These differences are important when seeking ways of combating the parasitic plants. The strategies used against the parasitic plants must be different from those used to combat fungal infections and should not be based only on analogies with host resistance to fungal pathogens. http://www.phytoparasitica.org posting Nov. 2, 2005.     

麻黄属的地理分布与起源演化

文中对麻黄属的世界分布现状作了分析,并在此基础上对麻黄属的地理分布和起源、演化及散布途径作了推断;对中国的麻黄属进行种的分布、麻黄碱含量的地区差异进行分析;最后针对该属资源的利用提出了建议。     

Evaluation of various methods for the detection of barley yellow dwarf virus by the tissue-blot immunoassay and its use for virus detection in cereals inoculated at different growth stages

Various modifications of the tissue-blot immunoassay (TBIA) for the detection of barley yellow dwarf virus (BYDV, luteovirus) were compared. Similar results were obtained by using three different labelled molecules; goat anti-rabbit antibodies conjugated to alkaline phosphatase, protein A conjugated with alkaline phosphatase and goat anti-rabbit antibodies conjugated with colloidal gold. Blocking the nitrocellulose membrane with polyvinyl alcohol for 1 min was effective and allowed the procedure to be shortened by one hour. TBIA was sensitive enough to detect BYDV in old dry tissue wich had been soaked in water for 1 h.BYDV was monitored by TBIA in wheat, oat and barley after inoculation at heading, flowering and grain filling growth stages. The later the inoculation date, the greater the chance of detecting the virus in stem bases rather than in the upper part of the stem. The later the inoculation the less virus moved, from the inoculated tiller to other tillers of the same plant.     

Fate of the insecticide lambda-cyhalothrin in ditch enclosures differing in vegetation density

Use of the insecticide lambda-cyhalothrin in agriculture may result in the contamination of water bodies, for example by spray drift. Therefore, the possible exposure of aquatic organisms to this insecticide needs to be evaluated. The exposure of the organisms may be reduced by the strong sorption of the insecticide to organic materials and its susceptibility to hydrolysis at the high pH values in the natural range. In experiments done in May and August, formulated lambda-cyhalothrin was mixed with the water body of enclosures in experimental ditches containing a bottom layer and macrophytes (at different densities) or phytoplankton. Concentrations of lambda-cyhalothrin in the water body and in the sediment layer, and contents in the plant compartment, were measured by gas-liquid chromatography at various times up to 1 week after application. Various water quality parameters were also measured. Concentrations of lambda-cyhalothrin decreased rapidly in the water column: 1 day after application, 24-40% of the dose remained in the water, and by 3 days it had declined to 1.8-6.5%. At the highest plant density, lambda-cyhalothrin residue in the plant compartment reached a maximum of 50% of the dose after 1 day; at intermediate and low plant densities, this maximum was only 3-11% of the dose (after 1-2 days). The percentage of the insecticide in the ditch sediment was 12% or less of the dose and tended to be lower at higher plant densities. Alkaline hydrolysis in the water near the surface of macrophytes and phytoplankton is considered to be the main dissipation process for lambda-cyhalothrin.     

Amino acids in loose silky-bent (Apera spica-venti (L.) Beauv.) responding to prosulfocarb exposure and the correlation with physiological effects

Eleven free amino acids were identified in the grass weed loose silky-bent (Apera spica-venti) after exposure to four rates of the thiocarbamate herbicide prosulfocarb. A new HPTLC method was developed for quantification of amino acids in raw plant extracts. A pattern of significant changes in the content of glutamine, glycine, alanine, and proline due to exposure were detected. The content of all four amino acids increased at increasing exposure rates. Quantitative analyses 7 and 21 days after herbicide application showed that over time the amount of proline increased, the alanine and glycine content decreased, and that at high exposure rates the amount of glutamine increased. Visual effects were evaluated and the biomass was measured. The visual symptoms increased and the biomass decreased with increasing exposure rates. A significant correlation between the changes in the content of the four amino acids and the visual effects and the biomasses were found.     

除草剂安全剂作用机理研究进展

除草剂安全剂是一类可在不影响除草剂对靶标杂草活性的前提下,有选择性地保护作物免受除草剂伤害的特殊用途化合物,有关安全剂作用机理的研究对新安全剂的开发具有重要意义。目前关于除草剂安全剂的作用机理主要有4种观点:1）影响除草剂在作物体内的吸收和转运;2）与除草剂竞争靶标位点;3）影响靶标酶的活性;4）增强作物对除草剂的代谢。文章对近年来安全剂作用机理及安全剂对杂草的影响等研究进展进行了综述,并分析了当前存在的问题及未来的研究方向,旨在为深入研究安全剂的作用机理及新安全剂开发提供参考。     

Induction of a defense response in strawberry mediated by an avirulent strain of <Emphasis Type="Italic">Colletotrichum</Emphasis>

In the strawberry crop area of Tucumán (north-west Argentina) the three species of Colletotrichum causing anthracnose disease (C. acutatum, C. fragariae and C. gloeosporioides) were detected. Among all isolates characterized, one of them identified as C. acutatum (M11) and another as C. fragariae (F7) were selected due to their conspicuous interaction with the strawberry cultivar Pájaro. Whereas isolate M11 produced a strong compatible interaction in cv. Pájaro with clear disease symptoms (DSR = 5.0), the isolate F7 brought about a typical incompatible interaction (DSR = 1.0). When plants of cv. Pájaro were inoculated with F7 prior to the inoculation with M11, the former avirulent strain prevented the growth of the latter virulent pathogen. Experimental evidence indicated that the time elapsed between the first inoculation with the avirulent pathogen and the second inoculation with the virulent one was crucial to inhibit the growth of the latter. The growth of F7 on the plant without provoking damage and the fact that there was no in vitro antagonistic effect between the pathogens, suggests that the avirulent strain triggers a plant defensive response against M11. The defense response was further confirmed by the detection of an early oxidative burst occurring within 4 h after the first inoculation and by the observation of anatomical changes associated with defense mechanisms that lasted 50 days after the inoculation with F7. Results obtained support the hypothesis that the plant resistance against the virulent strain M11 is elicited by one or more diffusible(s) compound(s) produced by the avirulent strain F7.     

A simple diffusion model of the effect of droplet size and spread area on foliar uptake of hydrophilic compounds

The uptake of a hydrophilic active ingredient through the leaves of plants is mathematically modelled as a simple diffusion process. A three layer model is considered consisting of the droplet, the cuticle and the subcuticle. Translocation of the active ingredient from the subcuticle is allowed for as is depletion of the active ingredient from the droplet. Both the effect of the size of the droplets on the leaf surface and surfactant enhanced spreading of the droplet is examined. It is found that decreasing the size of the droplet leads to an increase in the percentage uptake of the active ingredient. Increasing the spread area of the droplet is found to increase the percentage uptake with the effect greatest in larger droplets.