青海省水土流失与荒漠化的发展趋势及防治对策

地处青藏高原腹地的江河源头的生态环境保护问题已成为社会关注的焦点,直接关系到全流域社会经济的发展。青海省荒漠化面积以每年13.3万hm²的速度增加,年增长率2.2%,防治水土流失和荒漠化面临的形势十分严峻,任务非常艰巨。防止土地荒漠化,保持水土是一项涉及到多部门、多行业的综合社会系统工程。因此要进一步强化环境意识,明确指导思想,加大宏观调控力度。在工作中要紧紧抓住“提高认识、严格执法、行政干预、政策引导、经济调控、科技配套”,使青海省防止荒漠化保。持水土工作逐步走向持续、稳定、健康发     

Detection and semiquantitative estimation of thyroxine and diiodothyronine in liothyronine sodium.

A method is presented for the detection and semiquantitative estimation of thyroxine and diiodothyronine in liothyronine sodium. Thyroxine is detected by thin layer chromatography, using silica gel H plates developed in butanol-acetone-ammonia (30 + 55 + 15) and sprayed with a 2,7-dichlorofluorescein solution, and estimated by comparison with standard spots. For quantitative results, a larger amount of sample is applied as a streak on a fluorescent silica gel H plate. After a 5 hr development, the band is scraped off and extracted in a small volume of 0.1N NaOH; the extract is centrifuged, transferred to a 2 cm microcell, and examined spectrophotometrically. The diiodothyronine content of liothyronine sodium is estimated by liquid chromatography on a Bondapak C18 column with 0.01N sodium perchloratebutanol-acetonitrile (1000 +62 + 188) as the eluting solvent.     

Glyphosate degradation in glyphosate-resistant and -susceptible crops and weeds

High levels of aminomethylphosphonic acid (AMPA), the main glyphosate metabolite, have been found in glyphosate-treated, glyphosate-resistant (GR) soybean, apparently due to plant glyphosate oxidoreductase (GOX)-like activity. AMPA is mildly phytotoxic, and under some conditions the AMPA accumulating in GR soybean correlates with glyphosate-caused phytotoxicity. A bacterial GOX is used in GR canola, and an altered bacterial glyphosate N-acetyltransferase is planned for a new generation of GR crops. In some weed species, glyphosate degradation could contribute to natural resistance. Neither an isolated plant GOX enzyme nor a gene for it has yet been reported in plants. Gene mutation or amplification of plant genes for GOX-like enzyme activity or horizontal transfer of microbial genes from glyphosate-degrading enzymes could produce GR weeds. Yet, there is no evidence that metabolic degradation plays a significant role in evolved resistance to glyphosate. This is unexpected, considering the extreme selection pressure for evolution of glyphosate resistance in weeds and the difficulty in plants of evolving glyphosate resistance via other mechanisms.     

Liquid chromatographic determination of free and added niacin and niacinamide in beef and pork

A simple liquid chromatographic (LC) method is described for the determination of free and added niacin and niacinamide in meats. A sample is homogenized and extracted with water, and the water extract is centrifuged, deproteinized with zinc hydroxide, and filtered first through a fluted paper and then through a microporous filter. The filtrate is subjected to liquid chromatography with UV detection at 263 nm. Different ion-pair systems are needed for the measurement of niacin and niacinamide on a reverse phase column. Methanol-water (1 + 9) containing 5mM tetrabutyl ammonium ion is used to separate niacin. Water containing 10mM heptane sulfonic acid is recommended for niacinamide. Recoveries (CV,%) are 104.8% (2.9%) for niacin and 96.3% (2.7%) for niacinamide at a 10 mg/100 g fortification level. Detection limit is 1 mg/100 g sample for niacin and niacinamide.     

含氮、磷包膜缓释肥的制备及其缓释性能研究

采用红外光谱(FTIR)对以尿素、甲醛和磷酸一铵为原料,制备了以磷酸一铵为核心,脲醛肥为膜材料,同时含有氮、磷两种营养元素的包膜缓释肥的结构进行了研究。通过其在土壤中的养分释放特性表明,在土壤中,氮元素的缓释期为100 d,磷元素的缓释期为30 d;而在水中,氮元素在100 d时只释放了70%,磷元素在10 d时则达到100%。说明作为膜材料的缓释肥通过聚合物降解的化学过程,使氮元素获得了明显的缓释效果;作为核心的磷酸一铵,受包膜的物理保护,其分子中的磷元素也获得了一定的缓释效果。     

温室水肥一体化营养液调控装备设计与试验

针对当前温室生产中用水效率普遍较低、肥料使用量较高的问题,有必要对水肥一体化营养液调控及灌溉技术进行深入研究,探索适合中国具体情况的,低成本的水肥一体化营养液灌溉模式和相关农业装备。该文设计了一种水肥一体化营养液调控装备,根据营养液制备装置特点和制备过程,建立了营养液制备系统二阶数学模型,并利用增量式PID(proportion integration differentiation,比例-积分-微分)算法和改进Smith预估器对营养液的制备过程进行精确控制;利用EC传感器和p H传感器实时检测营养液的制备情况,并且通过驱动相应的继电器实现营养液的调控。试验结果表明,该水肥一体化营养液调控装备30 s左右可以进入营养液调控的稳定阶段(EC值误差在±0.1 m S/cm),系统达到规定的EC值的响应时间不超过60 s,使用该装备能够快速、精确的实现营养液的调控。     

Erosion and soil productivity in Australia and New Zealand

Soil erosion assumes a different form in Australia and New Zealand. Sheet, rill and gully erosion are common in eastern Australia and wind erosion in the dry cropland areas. In New Zealand, mass movement dominates the erosion landscape but other kinds, including wind erosion, do occur. It is unclear how much of the mass movement is a natural phenomenon and how much is human-induced. In either case, it causes long-term reductions in soil productivity. A landmark analysis of the soil productivity loss due to land degradation was conducted by the Australian state of New South Wales. Water erosion was a greater problem than wind erosion, but soil structure deterioration was more costly than either kind of erosion.     

农田景观规划设计及3S技术应用

农田景观规划设计是一项系统工程，可用于协调农田生产与农田持续利用的关系，是维护农田生物多样性的一个重要途径。在全球生态农业发展趋势下，要求农田生态系统满足生产功能时，合理协调农田的社会、经济、生态效益，满足人与自然协调发展。通过对关于文献的分析，结合可持续发展对农田景观规划设计的要求，该文阐述了农田景观规划设计层次、原则、步骤、规划设计内容与方法，并介绍了3S技术在农田景观规划设计中的应用，以期对我国的农田景观规划设计起到借鉴和促进作用。     

反疏浚理论、反疏浚工程与抗旱

分析了防洪与抗旱之间的关系 ,认为用反疏浚理论与反疏浚工程增大地下水蓄积量是根治正在年年升级的旱情的重要举措 ,传统工程与反疏浚工程相结合 ,安全、科学地调控地下水在陆地空间场的时间分布可解除旱情对海河等流域工农业的瓶颈制约     

木质素酶及其生产菌的筛选育种

木质素酶降解木质纤维素材料中的木质素,使木质素-半纤维素-纤维素结构解体,纤维素得以暴露出来供后续步骤处理。它广泛应用于生物制浆、生物漂白、废水处理等工业过程中。由于近年利用可再生木质纤维素材料用酶法水解生产酒精成了研究热点,因而作为纤维素材料生物转化工艺预处理过程中的关键角色,木质素酶也极大地唤起人们的研究兴趣。本文介绍了木质素与白腐真菌（phanerochaete chrysosporium）木质素降解酶系的特征以及锰过氧化物酶、木质素过氧化物酶、漆酶等3种木质素酶的催化作用机理,归纳了目前流行的木质素酶产生菌的筛选方法及近年来从自然界筛选木质素酶高产菌的种类,并对产木质素酶野生菌株的诱变育种与基因工程改造的进展进行了阐述。     

论生态恢复与水土保持

 生态恢复是研究生态整合性的恢复和管理过程的科学,现已成为世界各国的研究热点。目前,恢复已被用作一个概括性的术语,包括重建、改建、改造、再植等含义,一般泛指改良和重建退化的生态系统,使其重新有益于利用,并恢复其生物学潜力。生态恢复的原则包括自然法则、社会经济技术原则和美学原则。我国的水土保持小流域治理是通过工程的手段进行生态恢复的典范。水土保持小流域治理应以生态经济系统理论作指导,正确处理好人口再生产、自然再生产和经济再生产三者之间的关系,才能真正做到人与自然的和谐共处。水土保持小流域治理的方法是系统工程方法,包括综合调查与系统诊断、模型开发与治理规划、防治体系与模式设计、组织机构与运行机制等方面的内容。我国的水土保持工作亟需开拓创新,创新是水土保持工作的灵魂。只有认真纠正目前水土保持工作中存在的2种偏向,全面贯彻人与自然和谐共处的发展方针,把当地人民群众的社会需求与水土保持工作有机结合起来,才能实现“山川秀美”的宏伟目标。     

Simple and rapid spectrophotometric method for determination of adrenaline and isoprenaline

A simple, rapid, and specific method for determination of adrenaline bitartrate and isoprenaline sulfate was developed. The method is based on the oxidation reaction in aqueous solution of either adrenaline bitartrate or isoprenaline sulfate in the presence of silver oxide to give a red aminochrome measurable at 490 nm. The color is stable for 2 h. Beer's law is valid within a concentration range of 5-80 micrograms/mL for each drug. All variables were studied to optimize the reaction conditions. The method is specific for catecholamine drugs having a secondary amine in the side chain. Other catecholamines such as orciprenaline and noradrenaline do not interfere, and no interference was observed in the presence of common pharmaceutical adjuvants. Interference due to sodium metabisulfite and sodium chloride was circumvented. The validity of the method was tested by analyzing adrenaline injections and isoprenaline tablets. Good recoveries were obtained for these preparations. The results were comparable to those obtained by official procedures. The proposed method is also recommended as a stability indicating assay for oxidative degradation of both drugs.     

黄土高原水土保持在黄河流域水资源开发利用中的地位和作用

黄河流域水资源十分短缺,已成为制约流域经济发展的主要因素。近年来黄河下游日趋严重的断流现象,引起了中央领导、国家主管部门和有关学术界的高度重视。解决黄河流域水资源短缺问题,合理开发利用水资源,必须上、中、下游兼顾,近、中、远期结合,开源与节流并重,实行降水资源与河川径流开发利用并举。在黄河流域水资源开发利用中,黄土高原水土保持具有不可忽视的积极作用和十分重要的战略地位     

Indexing and display of soil survey data by means of feature-cards and boolean maps

A system is described for indexing information from soil survey by punched feature-cards. Soil and more general site information is recorded in the field, and other information is added to the records from published sources, air photographs and laboratory determinations. The records are numbered systematically by geographic location and stored in numerical sequence. The information on each record is analysed into a number of simple attributes or “features”, which are then used for indexing. For each feature there is a feature-card bearing a matrix of numbered positions corresponding to record numbers in the store. Each card is punched in the positions of all records that possess the feature. To identify and retrieve records, feature-cards are used either singly or superimposed in combination.The system has been applied to grid surveys in which sites at intersections of the National Grid are examined. The feature-card grid is oriented so that it represents to scale the National Grid. Each feature-card thus constitutes a map. By carrying out logical operations using the cards in combination, “Boolean” maps are swiftly derived.The system has been used satisfactorily in the Aberystwyth office of the Soil Survey of England and Wales for 7 years. Ultimately full automation is likely to bring advantages, but a punched feature-card system will be a useful aid for indexing soil survey information in any local soil survey office for some time to come.     

液态地膜和植生带对土壤水温和玉米成苗的影响

简要介绍了固化剂的特点及工程应用情况,通过击实、无侧限抗压强度、水稳定性和抗冻试验等方 法,探讨了固化剂用于渠道防渗工程的可行性,得出抗冻性能成为土壤固化剂用于渠道防渗工程的制约因 素这一结论,可供同行参考。     

Some tools for parsimonious modelling and interpretation of within-field variation of soil and crop systems

Parsimony is a guiding principle in scientific investigation which goes back to the medieval schools. It is proposed in this paper that, in different guises, the principle of parsimony (using no more complex a model or representation of reality than absolutely necessary) is essential for agricultural research at the scale of the field or larger regions. Two examples of the principle are given, illustrated with examples from research on precision agriculture:

1. The spatio-temporal variability of a sequence of yield maps is considerable, and often defeats simple approaches to interpretation and analysis. Reducing the variability to a small number of basic temporal patterns with spatial expression allows useful information to be extracted. The normalised fuzzy partition entropy is a parsimonious criterion appropriate for identifying the number of distinct patterns in the data. It is shown in a case study how this can aid interpretation of a complex data set.

2. Models of the joint effect of different factors on crop yield can take various forms. A simple assumption is that the different factors are additive, the most complex models describe interactions. Justus von Liebig’s ‘Law of the minimum’ is a model of little complexity and may often be a parsimonious and powerful tool for modelling crop responses. A comparison of these models on some crop response data, using the Akaike information criterion to measure the parsimony of the different models, is given.

     

澜沧江流域水土流失及防治对策

该文根据大量的水文及监测数据，分析了澜池江流域水土流失的现状及水土流失的原因，得出以下结论：（１）澜沧江流域水土流失从总体上看较轻，但局部地区较严重；（２）澜沧江流域局部地区水土流失呈发展趋势，其主要原因，是人为破坏，根据上述结论、提出了防治水土流失的对策。     

Managing and learning with multiple models: Objectives and optimization algorithms

The quality of environmental decisions should be gauged according to managers’ objectives. Management objectives generally seek to maximize quantifiable measures of system benefit, for instance population growth rate. Reaching these goals often requires a certain degree of learning about the system. Learning can occur by using management action in combination with a monitoring system. Furthermore, actions can be chosen strategically to obtain specific kinds of information. Formal decision making tools can choose actions to favor such learning in two ways: implicitly via the optimization algorithm that is used when there is a management objective (for instance, when using adaptive management), or explicitly by quantifying knowledge and using it as the fundamental project objective, an approach new to conservation.This paper outlines three conservation project objectives – a pure management objective, a pure learning objective, and an objective that is a weighted mixture of these two. We use eight optimization algorithms to choose actions that meet project objectives and illustrate them in a simulated conservation project. The algorithms provide a taxonomy of decision making tools in conservation management when there is uncertainty surrounding competing models of system function. The algorithms build upon each other such that their differences are highlighted and practitioners may see where their decision making tools can be improved.     

Appraising and selecting conservation measures to mitigate desertification and land degradation based on stakeholder participation and global best practices

Most desertification research focuses on degradation assessments without putting sufficient emphasis on prevention and mitigation strategies, although the concept of sustainable land management (SLM) is increasingly being acknowledged. A variety of already applied conservation measures exist at the local level, but they are not adequately recognised, evaluated and shared, either by land users, technicians, researchers, or policy makers. Likewise, collaboration between research and implementation is often insufficient. The aim of this paper is to present a new methodology for a participatory process of appraising and selecting desertification mitigation strategies, and to present first experiences from its application in the EU‐funded DESIRE project. The methodology combines a collective learning and decision approach with the use of evaluated global best practices. In three parts, it moves through a concise process, starting with identifying land degradation and locally applied solutions in a stakeholder workshop, leading to assessing local solutions with a standardised evaluation tool, and ending with jointly selecting promising strategies for implementation with the help of a decision support tool. The methodology is currently being applied in 16 study sites. Preliminary analysis from the application of the first part of the methodology shows that the initial stakeholder workshop results in a good basis for stakeholder cooperation, and in promising land conservation practices for further assessment. Study site research teams appreciated the valuable results, as burning issues and promising options emerged from joint reflection. The methodology is suitable to initiate mutual learning among different stakeholder groups and to integrate local and scientific knowledge. Copyright © 2009 John Wiley & Sons, Ltd.     

Distribution and Concentration of Pb and Cd in Two Adjacent Luvisols under Grassland and Forest in Denmark

The effect of land use (forest and grassland) on the deposition and mobility of Pb and Cd has been studied by extraction with 1M HCl, 1M NH₄Ac/HAc and 1M NH₄Ac. The soils were described pedologically and the main physical and chemical parameters were determined. The Pb concentration in the A horizon is higher in the profile under forest than in the profile under grassland. We assign this difference to the filter action of the forest. The Cd concentration is highest in the grassland profile because the forest soil is more degraded and Cd is leached to a higher degree in this soil. Both metals are more mobile (easier to extract) in the forest because the forest soil is most acidic, and because a greater part is bound to organic compounds (humic and fulvic acids) which are more abundant in the forest than in the grassland. The concentrations of Pb and Cd in the A horizons are 26 ppm and 0.1 ppm under the forest and 9 ppm and 0.2 ppm under grassland, respectively.