生态修复的探索与实践   总被引：37，自引：3，他引：37  

焦居仁 《中国水土保持》2003,(1):10-12

几年来 ,水土保持司认真学习贯彻党中央、国务院一系列关于生态建设的指示精神 ,按照水利部治水新思路 ,积极探索 ,调整思路 ,推动传统水保向现代水保转变 ,密切关注、及时总结各地在退耕还林、封山禁牧、舍饲养羊、围栏封育和休牧轮牧的实践 ,提出了生态修复的水土保持生态建设新思路 ,并迅速在全国各地开展生态修复试点工作 ,效果良好。  相似文献   

吴旗县水土保持生态建设调查报告   总被引：5，自引：1，他引：5  

焦居仁  蒲朝勇  王保安  李少毅  苗光忠  陈谦 《中国水土保持》2001,(11):10-12

吴旗县确立“封山退耕、植树种草、舍饲养羊、林牧主导、强农富民”的开发思路 ,将全县 10 3万hm2 坡耕地全部退耕 ,只保留 2万hm2 耕地发展高效农业 ,农村经济呈现出蓬勃发展的势头。该县在全国率先实施了“封山禁牧、舍饲养羊” ,走出了西部开发的新路子 ,是黄土高原水土保持生态建设的创举。建议总结推广其典型经验 ,加大黄土高原水土保持生态建设力度等  相似文献   

全补偿微灌系统灌水均匀度参数之间的关系分析     

翟国亮  陈刚  鞠花  冯俊杰  邓忠  刘杨 《农业工程学报》2007,23(6):61-65

该文采用数理统计学方差估计理论，针对全补偿微灌系统的灌水均匀度系数进行了研究分析，从理论上推导出全补偿微灌系统均匀度系数与流量偏差系数之间基本关系式，同时采用传统的随机数字模拟方式对导出的公式进行了验证和分析，并且探讨了均匀度系数和流量偏差率之间的关系规律，最后通过实例说明了上述公式的运用价值。该研究成果为全补偿微灌系统的设计、工程灌水均匀度评价和补偿式灌水器制造偏差控制等提供了参考依据。  相似文献   

Succession and phylogenetic profile of eukaryotic communities in rice straw incorporated into a rice field: Estimation by PCR-DGGE and sequence analyses     

Atsuo SUGANO  Hidetaka TSUCHIMOTO  Cho Cho TUN  Susumu ASAKAWA  Makoto KIMURA 《Soil Science and Plant Nutrition》2007,53(5):585-594

  相似文献   

The Distribution of <Emphasis Type="Italic">Perilla</Emphasis> Species     

Miyuki?NittaEmail author  Ju?Kyong?Lee  Churl?Whan?Kang  Masumi?Katsuta  Satoko?Yasumoto  Dajun?Liu  Tsukasa?Nagamine  Ohmi?Ohnishi 《Genetic Resources and Crop Evolution》2005,52(7):797-804

Perilla (Lamiaceae) contains one tetraploid species, P. frutescens (L.) Britt. and three diploid species, P. citriodora (Makino) Nakai, P. hirtella Nakai and P. setoyensis G. Honda. Tetraploid species have been traditionally cultivated in Asia for their seed oil and for their fragrant leaves that are used as medicine or as a garnish for fish. The center of diversity is still obscure. To conserve the genetic resources, it is important to know the diversity of the tetraploid species. The three diploid species, which are possible parents of the tetraploid species, are all believed to be indigenous to Japan. Their distribution in China and Korea was clarified on the basis of herbarium and field surveys. The tetraploid species is assumed to have originated somewhere around the mid-to downstream area of the Changjiang River. Though Perilla is not cultivated as often in these areas as in northern China, Korea, the Himalayan region, or Myanmar, these areas should also be important for the conservation of genetic resources of tetraploid Perilla crops because of the expected high genetic diversity.  相似文献   

The Role of Soil Properties in Pyrene Sorption and Desorption     

Hwang  S.  Ramirez  N.  Cutright  T. J.  Ju  L.-K. 《Water, air, and soil pollution》2003,143(1-4):65-80

Soil type will greatly affect the sorption and subsequent desorptionof hydrophobic contaminants. To gain a better understanding of theimpact of soil type on sorptive behavior, the sorption-desorption of pyrene (PYR) with three different soils was studied. The first soil originated from Colombia and is classified as silty sand with3.54% soil organic matter (SOM) and 18% clay materials (<2 microns). The New Mexico soil is a sandy lean clay comprisedof 8.4% SOM and 10% clay. The last soil originated fromOhio and is a silty sand with 1.84% SOM and 9.6% clay. Based on soil mineralogy and sorption-desorption isotherms,the Colombia soil had the greatest binding potential followedby the New Mexico and Ohio soils. The Freundlich model couldfit both the Colombia and New Mexico soils. For the Ohiosoil, a two-stage Freundlich model was required. For allthree soils, PYR desorption was slow and resistant, anddepicted an apparent hysteresis. The extent of sorption-desorption for each soil was attributed to its individual classification.For instance, the SOM present in the New Mexico soil (8.4%) enabled a relatively easy desorption in comparison to the other two soils. For the Ohio and Colombia soils, the interaction with the clay fractions rendered a stronger sorptive bond.  相似文献   

Model Intercomparison Study of Long Range Transport and Sulfur Deposition in East Asia (MICS-ASIA)     

Carmichael  Gregory R.  Hayami  Hiroshi  Calori  Giuseppe  Uno  Itsushi  Cho  Seog Yeon  Engardt  Magnuz  Kim  Seung-Bum  Ichikawa  Yoichi  Ikeda  Yukoh  Ueda  Hiromasa  Amann  Markus 《Water, air, and soil pollution》2001,130(1-4):51-62

To help improve the use of models in science & policy analysis in Asia it is necessary to have a better understanding of model performance and uncertainties. Towards this goal an intercomparison exercise has been initiated as a collaborative study of scientists interested in long-range transport in East Asia. An overview of this study is presented in this paper. The study consists of a set of prescribed test calculations with carefully controlled experiments. Models used the same domain, emission inventory, model parameters, meteorological conditions, etc. Two periods (January and May 1993) were selected to reflect long-range transport conditions under two distinct seasons. During these periods measurements of sulfur concentrations and deposition were made throughout the study region using identical sampling and analysis protocols. The intercomparison activity consists of four tasks (Blind Test, Fixed Parameter Test, Source Receptor test, and Tuning Test). All participants were asked to do Task A, and as many of the other tasks as possible. To date seven different models have participated in this study. Results and key findings are presented.  相似文献   

电磁感应土地测量技术及其在农业领域的应用   总被引：27，自引：4，他引：27       下载免费PDF全文

刘广明  杨劲松  鞠茂森  聂杰 《土壤》2003,35(1):27-29

本文系统地介绍了电磁感应土地测量技术。对其工作原理,基本架构,可能的农业领域应用以及该技术的特点进行了较为详尽的阐述。这对于提高我国农业领域的高新技术含量,促进我国农业的快速发展具有较为深远的意义。  相似文献   

Effective deacetylation of chitin under conditions of 15 psi/121 degrees C     

No HK  Cho YI  Kim HR  Meyers SP 《Journal of agricultural and food chemistry》2000,48(6):2625-2627

Deacetylation of chitin under autoclaving conditions (15 psi/121 degrees C) was evaluated for the preparation of chitosan under different NaOH concentrations and reaction times. Deacetylation was effectively achieved by treatment of chitin under elevated temperature and pressure with 45% NaOH for 30 min and a solids/solvent ratio of 1:15. Treated chitosan showed similar nitrogen content (7.42%), degree of deacetylation (90.4%), and molecular mass (1560 kDa) but significantly higher viscosity values (2025 cP) compared with those (7.40%, 87.6%, 1304 kDa, and 143 cP, respectively) of a commercial chitosan. Reduction of the solids/solvent ratio from 1:15 to 1:10 did not affect degree of deacetylation, viscosity, and molecular mass of chitosan.  相似文献   

Anthocyanin profile of Korean cultivated kidney bean (Phaseolus vulgaris L.)     

Choung MG  Choi BR  An YN  Chu YH  Cho YS 《Journal of agricultural and food chemistry》2003,51(24):7040-7043

This investigation was conducted to determine the structures and amounts of anthocyanins obtained from seed coats of kidney bean (Phaseolus vulgaris L.) cultivated in Korea. Anthocyanins in the seed coat of kidney bean were extracted with 1% HCl/20% CH(3)OH, and the crude anthocyanin extracts were purified by semipreparative HPLC. Five major anthocyanins were isolated, and their chemical structures were identified by spectroscopic methods (UV-vis, LC/ES-MS, and 1H and 13C NMR). The structures of these five anthocyanins were elucidated as cyanidin 3,5-diglucoside, delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, and pelargonidin 3-glucoside. Using RP-HPLC with photodiode array detection, each of the five anthocyanins was separated within 12 min by using a gradient elution. It was proved that the application of RP-HPLC could be an excellent method for determining the composition and contents of anthocyanins in kidney bean. The preponderance of pelargonidin 3-glucoside and delphinidin 3-glucoside are observed in red and black kidney beans, respectively. However, in this study, it is reported for the first time that the contents and composition of anthocyanins in speckled seed depend on the classes of speckle color. The contents of cyanidin 3,5-diglucoside, delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, pelargonidin 3-glucoside, and total anthocyanins in seed coats of 16 kidney beans cultivated in Korea were in the ranges of 0-0.04, 0-2.61, 0-0.12, 0-0.17, 0-0.59 and 0-2.78 mg/g of dried seed coats, respectively.  相似文献