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.     

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。     

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.     

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。     

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。     

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。     

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。     

Prospects for modeling the behavior and fate of mercury,globally and in aquatic systems

The phenomena of cold condensation and fractionation of chemical contaminants on a global scale are discussed. The net result of these phenomena is that concentrations of certain atmospherically transported contaminants are higher than expected in the condensed, i.e. non gaseous media of water, soils, sediments and biota as a result of the temperature dependence of partitioning and transport phenomena. It is argued that the phenomena are best investigated by a combination of monitoring and modeling. This approach is illustrated in the form of a nine meridional segment model for hexachlorocyclohexane. It is suggested that this approach should be applied to Hg, but this is not presently possible because of the lack of data on Hg species properties and conversion rates. Available data have been used to test the hypothesis that lower temperatures cause enhanced partitioning from the atmosphere to a lake ecosystem at low temperatures by compiling a three species model of an atmosphere-water-sediment-fish system at 25 °C and 0 °C. Preliminary results show that the effect of this drop in temperature is to cause increases in concentrations throughout the aquatic ecosystem of factors of three to four, other factors being equal. Thus it is likely that a comprehensive global model will show that Hg is subject to the global fractionation phenomenon. It is recommended that attempts be made to develop such a model.     

Liquid chromatographic separation and fluorometric determination of cis- and trans-isoeugenol in perfumes, colognes, and toilet waters

A liquid chromatographic (LC)-fluorometric method is described for the determination of cis- and trans-isoeugenol (2-methoxy-4-propenylphenol) in perfumes, colognes, and toilet waters. A test portion of the product is added to diethyl ether, and the isoeugenol isomers are extracted with sodium hydroxide solution. The basic extract is then acidified, and the isoeugenol isomers are extracted with isooctane. Aliquots of the isooctane extract are analyzed by using a silver ion cation exchange LC column interfaced to a spectrophotofluorometer. Each isomer in the product is determined by comparing its fluorescence emission intensity with that of an external standard consisting of a mixture of both isomers in which the relative concentration of each has been determined. Average recoveries from various commercial fragrances fortified with a mixture of cis- and trans-isoeugenol with total isoeugenol content of 0.1, 0.5, and 4.0 mg/mL ranged from 87 to 105% for the trans-isomer (SD = 4.6%) and from 83 to 113% for the cis-isomer (SD = 6.7%). The limit of determination is approximately 0.002 mg/mL.     

Overview of the structure and the challenges of Japanese wildlife law and policy

Japan has a variety of laws to conserve and manage wildlife and biodiversity. This article reviews Japanese laws from conservation of endangered species to the fish and game code, and indicates the issues and challenges they face. It then discusses the issues and challenges for management in the application of the laws.The Japanese statute for conservation of endangered species corresponds to the US Endangered Species Act in appearance, but is much more limited in application and scope. There is no legal channel, such as lawsuits, to assure citizens’ and experts’ input. With respect to general species, management of fish and animals are divided; the fish code’s scope is limited to fishery purposes. Control of wildlife damage is the biggest emphasis in the wildlife code. Reform to bring principles of scientific management into pest control has begun, but conventional culling is still the norm.Japan’ wildlife and fish management is distinctive in relying upon local resource users, instead of on a strong regulatory agency. This is a consequence of traditional communal management, and is apparent in coastal fisheries. The depopulation and exhaustion of rural communities, however, makes it difficult to rely on the community for management. In particular, wildlife management, which relies on aging hunters, is facing a turning point. To address these changes, agencies must be strengthened and lawmakers must enact a mechanism to assure sound science in wildlife policy, while working to revitalize rural communities.     

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     

地理加权回归及其在土壤和环境科学上的应用前景

地理加权回归(GWR)是近些年来出现的一种新的空间局部回归技术。它是将数据的空间位置嵌入线性回归模型中,以此来探测空间关系的非平稳性。在运用于空间数据分析方面,相对于传统的普通最小二乘回归法,具有明显的优势。本文首先介绍了GWR的理论起源并描述了该方法的基本原理、存在的不足以及后来的扩展;然后为了更准确地了解GWR的应用状况和研究进展,进行了一个文献调查;接着回顾了GWR在土壤和环境科学上的初步应用情况;最后对该方法在土壤和环境科学上的应用前景作了展望。目的是为我国土壤和环境科学领域的同行了解和应用GWR提供参考。经过国内外研究者多年的研究和实践,GWR方法已被证明是一个理论上较为成熟,能够应用到实际研究中的优秀空间统计学方法。因此,GWR在土壤和环境科学上将会有着广泛的应用前景。     

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.     

Sodium and potassium effects on cation concentration and yield of lucerne and phalaris grown separately and together

Abstract

Lucerne (Medicago sativa L.) and phalaris (Phalaris aquatica L.) were grown separately and together in a pot trial on a yellow‐brown pumice soil with three rates of sodium (Na) and two rates of potassium (K) in factorial combination. Lucerne alone had a low Na concentration but growing phalaris as a companion grass produced herbage with a Na concentration adequate for stock. Na application increased the Na concentration in phalaris and the mixture of phalaris and lucerne much more than in lucerne alone; had little effect on K concentration; slightly reduced Mg concentration; and greatly reduced Ca concentration but not as much in lucerne as in phalaris or the mixture with lucerne. K application increased K concentration and reduced Na, Ca and Mg concentrations throughout. Yield of phalaris grown alone and in combination with lucerne was increased significantly by Na application when K concentration in the plants was low. Yield of lucerne was not affected by Na application and it is concluded that Na did not substitute for K in this species. It is concluded that field trials are warranted to investigate the possibility of growing a special purpose mixture of lucerne and phalaris on New Zealand yellow‐brown pumice soils to provide feed that has adequate Na for grazing animals.     

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.     

Nitrate and human health

Abstract. Nitrate is widely and mistakenly perceived to threaten human health by causing methaemoglobinaemia in infants and stomach cancer in adults, but it does cause environmental problems. Methaemoglobinaemia is a side-effect of gastroenteritis and is not caused by nitrate but by nitric oxide, which is produced in a defensive reaction stimulated by gastroenteritis. The latter may be caused by a bacterium or a virus. The association of methaemoglobinaemia with nitrate may have arisen because early cases of the condition were often associated with wells polluted with bacteria, and the same pollution increased the nitrate concentration. Four epidemiological studies sought a link between stomach cancer and nitrate but did not find one. The incidence of this cancer has also declined during the last 30 years, while nitrate concentrations in water have increased. Nitrate preserves, rather than threatens, health. It is reduced by microbes on the tongue to nitrite, which generates nitric oxide when acidified in an antibacterial defence mechanism vital to our well-being. This mechanism acts with great effectiveness in the stomach against Salmonella , Escherichia coli and other organisms that cause gastroenteritis. It also acts in our mouths against dental caries and even on our skin against fungal pathogens such as Tinea pedis (athlete's foot). This mechanism is the basis of the centuries-old practice of adding nitrate or nitrite to stored meat to protect against botulism, caused by the most lethal toxin known to mankind.     

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