辽宁省水土流失现状、动态变化及防治对策

辽宁省通过第 3次水土流失遥感调查 ,对全省水土流失现状及水土流失的动态变化有了更深入的了解。辽宁省水土流失具有水土流失面积大 ,强度以上级水土流失面积增加速度快 ,人为破坏严重 ,风蚀、河海滩地水土流失面积扩延迅速等特点。水土流失动态变化主要表现在 :①与 1995年遥感调查结果对比 ,5a间净减少水土流失面积 6 814 6 7km2 ,水土流失强度梯次降低面积 432 4 5 3km2 ,合计有效治理面积 11139 2km2 ,但由于人为水土流失的加剧 ,又新增水土流失面积 34 78km2 。②强度以下级别水土流失面积有所减少 ,而极强度、剧烈水土流失面积则呈现增加趋势 ,水土流失强度的变化呈现“整体减缓 ,局部恶化”的态势。③与 1995年相比总水土流失量呈下降趋势 ,而水土流失模数则呈上升趋势。针对辽宁省水土流失现状和动态变化情况 ,应采取加强法制宣传 ,提高水土流失的忧患意识 ;加快辽西地区水土流失的治理步伐 ;实行坡耕地退耕还林还草工程 ;加强林地水土流失治理工作 ;加大水保执法力度 ,遏制人为破坏 ;重视沟壑治理 ,加大治理力度等防治对策。     

浅谈河津市水土保持生态环境建设

河津市地处山西省西南部的吕梁山南麓,总土地面积592.3 km2,水土流失面积308 km2,占52%。截至2005年底,全市累积治理水土流失面积182.50 km2,治理度59%。由于开发建设项目较多,人为造成的新的水土流失较严重。今后的水土保持对策:一要明确思路,加强领导;二要明确方向,分区治理;三要依法管理,加强保护;四要推广科技,提高水平;五要培育大户,封禁治理。     

加强丹江口库区综合治理 确保南水北调供水安全

河南省淅川县总面积2789.4km2,其中2616km2属丹江口水库水源区,水土流失面积1568km2,年均土壤侵蚀模数4118t/km2。为减轻丹江口水库淤积、提高水质、确保南水北调中线工程供水安全,计划用25年时间使全县水土流失面积全部得到治理,并提出了保证措施。     

新形势下开展水土保持工作的建议

朝阳市位于辽宁省西部,十年九旱,水土流失十分严重。全市总面积19 698.0 km2,水土流失面积11 954.1 km2,占总面积的60.7%。到2004年底,共治理水土流失面积11 322.7 km2,占总面积的57.5%。面对农村实行税费改革的新形势,要搞好水土保持工作:业务部门要转变职能,变单纯管理为加强技术服务;地方政府制定出台相关政策,以激发社会成员治理水土流失的积极性;因地制宜制定符合农民意愿的水土保持规划,突出综合效益;建立多元化投入机制,运作过程实行公示制;重点治理工程,走基建项目程序。     

黄泛平原风沙区水土流失治理技术措施

冠县地处黄泛平原风沙区 ,水土流失严重 ,水土流失面积达 462 87km2 。根据当地水土流失特点 ,因地制宜 ,采取推广旱作农业技术、节水工程灌溉技术、实施退耕还林等措施 ,完成治理面积 3 3 4 96km2 ,治理区经济效益、社会效益显著 ,生态环境得到明显改善 ,促进了乡村经济的可持续发展     

焦家梁、小五台山北麓小流域综合治理的成效与做法

涿鹿县焦家梁、小五台山北麓小流域综合治理工程经过3年施工建设,治理水土流失面积119.04 km2,初步实现了规划的建设目标,生态、经济和社会效益显著提高:水土流失基本得到控制,生态环境逐步改善;主导产业逐步形成,促进了流域经济的快速发展;农业生产条件得到较大改善,促进了社会进步;积累了综合治理经验,起到了典型示范作用。其主要经验及做法是:强化领导,健全组织;因地制宜确定治理模式;治理开发紧密结合,发展流域经济;加强项目管理,确保工程质量;加强工程管护和预防监督,巩固治理成果。     

搞好水保生态建设 实现运城山川秀美

运城市水土流失面积8491km2,年输入黄河泥沙4110.6万t"十五”期间全市水土流失初步冶理面积每年以1.33万hm2的速度增加,到2000年底已累计完成水土流失初步治理面积4369km治理水土流失、改善生态环境是山丘区群众脱贫致富的基础工程,把水保与水利有机结合起来是发展山丘区高效农业的有效途径,21世纪前10年拟抓好治理、监督两个重点,推行治理机制、投资体制改革,抓好小流域和"四荒”治理开发     

与时俱进 加快发展 再铸“长治”工程新的时代丰碑

20 0 2年 ,“长治”工程共治理水土流失面积 4160 8km2 。其特点是大示范区建设初见成效 ,改革创新力度加大 ,预防监督进入新的发展阶段 ,生态修复取得可喜进展 ,基础工作得到加强。在新形势下 ,要与时俱进 ,改革创新 ,努力实现“长治”工程的新跨越。 2 0 0 3年 ,“长治”工程计划治理水土流失面积 4180km2 。其工作要点是狠抓落实 ,更有力地推进大示范区建设 ,做好三项前期工作 ,抓好水土保持预防监督工作 ,积极推进生态修复 ,大力加强监测工作。     

深化灵丘县水土流失防治的思考

灵丘县总土地面积2 732 km2,水土流失面积2 402 km2,占87.9%。至2012年底,累计治理水土流失面积808.7 km2,治理度33.67%。根据水土保持现状与目前存在的问题,提出了强化沟道水土流失防控、加强生态清洁型小流域建设、加强自然修复与生态植被建设、扎实开展水土保持新技术推广、建立稳定的投入保障机制、抓好水土保持法制与监督管理、强化乡镇政府的水土保持责任等水土保持思路。     

以法为盾 保护水土 全面推进黑龙江省水土保持生态建设

黑龙江省水土流失严重 ,水土流失面积占全省总面积的 2 9 8% ,年土壤侵蚀总量达 2亿多t。到 2 0 0 0年底 ,累计审批水土保持方案 870 0件 ,收缴水土流失防治费近 2 819万元 ,收罚没款 181 2万元。全省共治理水土流失面积32 2 80 6km2 ,转让“四荒”面积 12 0 95万hm2 (其中 6 1 4%已得到开发治理 )。近期目标是每年治理水土流失面积 2 2 0 0km2 ,到 2 0 10年重点地区的水土流失得到初步治理     

Comparing the effects of pH on the sorption of metals by soil and by goethite, and on uptake by plants

The effects of soil pH on sorption of cadmium, zinc, nickel and cobalt were studied by changing the pH of a soil and measuring sorption. Results were compared with published results for effects of pH on sorption of cadmium, zinc and nickel by goethite. In a further experiment, the effects of pH on the uptake of zinc and cobalt by subterranean clover were measured. Effects of pH on sorption were described in terms of the concentration of metal ions required to produce equal sorption. Where the metal ions were incubated with the soil, unit increase in pH decreased the concentration of metal ions required about 10-fold for zinc, about 7-fold for nickel, about 6-fold for cobalt, and about 4-fold for cadmium. When the soil was mixed with a large volume of solution, the effects were similar for zinc and cadmium but slightly smaller for cobalt and slightly larger for nickel. In all cases, the magnitude of the effect varied somewhat with pH. Sorption was greater with a dilute background electroiyte than with a concentrated one and the effects of pH were greater. The effects for soil were smaller than effects of pH on sorption by iron oxides for which unit increase in pH can decrease the required concentration of Zinc 35-fold and cadmium 11-fold. These results are consistent with adsorption of divalent ions on a variable charge surface that is negatively charged. They are not consistent with the adsorption of monovalent metal ions on a variable charge surface. This mechanism requires at least a 10-fold effect of pH. They show that the change in electric potential with change in pH is smaller for reacting surfaces in soil than for goethite. The effects of changing pH on the amounts of zinc and cobalt fertilizer required for equal uptake by plants was even smaller with unit increase in pH, causing a 1.4-fold increase in the amount of fertilizer required, that is, a 1.4-fold decrease in fertilizer effectiveness.     

Quantitation of the hydroxycinnamic acid derivatives and the glycosides of flavonols and flavones by UV absorbance after identification by LC-MS

A general approach was developed to quantify hydroxycinnamic acid derivatives and the glycosides of flavonols and flavones using UV molar relative response factors (MRRFs). More than 90 standards were analyzed by LC-MS and divided into five groups based on the λ(max) of their band I absorbance profiles. For each group, a commercially available standard was chosen as the group reference standard. Response factors were determined for each standard in each group as purchased (MRRF) and, when possible, after vacuum drying (MRRF(D)). The MRRF(D) values for 17 compounds whose λ(max) values fell within ±2 nm of the group reference standard were 1.01 ± 0.03. MRRF values for compounds whose λ(max) values fell within ±10 nm of the group reference standard were 0.96 ± 0.13. Group reference standards were used to quantify 44 compounds in Chinese lettuce, red onion, and white tea. This approach allows quantitation of numerous compounds for which there are no standards.     

后台操作、管理技术构建网络课件的优点与实现技术——以土壤资源调查与评价网络课件为例

大学生核心课程"土壤资源调查与评价"内容多、应用技术多,讲授内容需随时加以更新,并且该课程需要的教学环节多,有课堂讲授,在实验室进行的实验,还有野外教学实习,因此创建该课程基于网络课件的教学模式很有必要。本文采用ASP动态网页技术进行了"土壤资源调查与评价"课程网络课件的开发与管理。此网络后台可以支持整个网络课件正常、高效、高度安全的运行,也便于管理者(教师)对课件进行日常管理和信息维护与发布。运用后台系统管理的方法构建网络课件,可以使网络课件更有生命力。ASP动态网页技术具有占用系统资源少、信息量大、便于课件维护、扩充和更新、易于继承和保护历史数据的优点,构建的网络课件可以实现在建立前台信息发布的同时,还建立有一套具有友好用户界面的后台管理维护系统。     

Aspects of the adsorption of pirimicarb by smectites and soils

A study was conducted to examine the adsorption and interaction mechanism of pirimicarb with smectites and soils. Studies were carried out in pesticide-smectite or soil-water systems and in pesticide-smectite-organic solvent systems, using homoionic samples of montmorillonite, smectites of different layer charge and soils with smectite in their clay fraction. The adsorption isotherms obtained at 30° and 45°C follow the empirical equation of Freundlich. In the adsorption of the pesticide by soils a highly significant correlation was seen between adsorption (distribution coefficient) and the content of smectite in them. In the studies in organic medium the formation of a smectite-pirimicarb bilayer complex with a basal d₀₀₁ spacing of 18.55 Å was observed; the formation of this is also related to the nature of the interlayer cation and the layer charge of the smectite. According to the I.R. results, the interlayer cations of the silicate and the oxygen atom of the C–O group of the pesticide molecule are involved in the interaction mechanism.     

生物质炭的加入对土壤吸附菲能力以及玉米幼苗对菲吸收量的影响

通过等温吸附试验以及玉米幼苗的盆栽试验,研究了加入生物质炭对土壤吸附菲的性能以及玉米幼苗对土壤中菲的吸收量的影响。结果表明,生物质炭的加入使土壤对菲的吸附能力显著增强：不加炭〈炭A〈炭B〈炭C,相应的分配系数Kd值分别为0.16、0.31、0.34 L.g-1和0.42 L.g-1;生物质炭的加入能有效地减少玉米幼苗对土壤中菲的吸收,通过玉米幼苗栽培试验可以看出,加入生物质炭A、炭B和炭C后,玉米幼苗对土壤中菲的吸收量都有明显的下降。     

Absorption of nitrogen by Japanese mint from mineralization and immobilization by the soil microbial biomass

Abstract

Laboratory incubation and greenhouse experiments were conducted with two soils having contrasting physico‐chemical characteristics to evaluate nitrogen (N) mineralization, immobilization in soil microbial biomass, and accumulation in Japanese mint (Mentha arvensis L.) using labeled (¹⁵NH₄)₂SO₄, applied at 0, 50, and 100 mg#lbkg^‐1 soil. Rate of mineralization in soils varied from 0.08 to 2.21 μg#lbg^‐1#lbday^‐1. Fertilizer application increased the mineralization of native soil N. About 22 to 60% of the applied ¹⁵N was recovered in the soil microbial biomass during the growth period of mint (January‐June). Relative contribution of fertilizer ¹⁵N towards total N uptake by mint at maturity was 42–54% in soil I and 35 to 55% in soil II. Contribution of soil N towards total N accumulation increased with the doses of ¹⁵N application.     

Aluminium speciation: Variations caused by the choice of analytical method and by sample storage

We have compared a new FIA method (M1) for aluminium speciation in natural waters and a manual one based on one of Driscoll's proposals (M2). In synthetic solutions, aluminium's fluoro complexes were measured as ‘labile monomeric AP (Al _i ) by M2, but not as ‘quickly reacting Al’ (Al _qr ) by M1. Aluminium's complexes with Nordic Reference Humic Acid were measured neither as Al _i nor as Al _qr , and the same result was obtained for Al's citrato complexes. After excluding aluminium's fluoro complexes from Al _i , the results of the two methods agreed well for soil leaching samples and fairly well for natural water samples. Detection limits: 10μg L^?1 (ca. 0.4 μM) for both methods. Sample throughputs: M1∶66 injections h^?1; M2∶5 samples h^?1. Repeatabilities (RSD) on natural water samples: M1∶0.6–5.8% and M2 0.7–4.6%. Sample storage studies on soil solutions (FIA method) indicated that storage effects were ‘sample type specific’. A sample with a low level of Al _qr and a high DOC level (P2A) was more sensitive to storage than one with a high [Al] _qr and a low [DOC] (P2B^*). The decrease in [Al] _qr was statistically significant after 10 h (P2A) and 24 h (P2B^*), respectively. After 3 days' storage, [Al] _qr had decreased by some 40% in P2A, while the decrease in P2B^* was less than 10% after 8 days. The results of this part of the study also emphasize the importance of careful method standardization in sample storage studies.     

高校图书馆如何培养和引导大学生的阅读兴趣

阐述了阅读兴趣的定义,分析了大学生在阅读中存在的问题,提出高校图书馆培养大学生阅读兴趣的具体措施和对策。     

Influence of the simultaneous addition of the protease flavourzyme and the lipase novozym 677BG on dry fermented sausage compounds extracted by SDE and analyzed by GC-MS

A dry fermented sausage (chorizo de Pamplona) was elaborated with the simultaneous addition of a lipase (Novozym 677BG) and a protease (Flavourzyme) and ripened during 21 days, in contrast to the control without enzymes and ripened during 35 days. Faster and more intense lipolytic and proteolytic activities were observed in the modified sausage, despite its shorter maturation time. At the end of the ripening, a determination of the profile of compounds extracted by simultaneous distillation-extraction with dichloromethane was carried out. The total amounts of extracted compounds (expressed in milligrams of dodecane per gram of dry matter) were 2.5 in the sausage with enzymes and 1.9 in the control. The chemical groups showing increments due to the use of enzymes were esters (103.5% increment) and acids (87% increment) in both cases due to the greater presence of long-chain fatty acid products. However, development of substances originated from further degradation process of amino acids and free fatty acids did not seem to have taken place.