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1.
青藏铁路沿线地形、气候、水文特征及其对沙害的影响 总被引：1，自引：0，他引：1
青藏铁路沿线地形复杂多样、气候差异明显、河湖水系众多,对铁路沙害的物质来源及分布有重要影响。通过野外调查对铁路沿线地形、气候、水文的类型、分布及特征进行研究。发现青藏铁路沿线沙物质来源丰富,沙害在空间上主要分布在河谷、湖盆路段,在时间上集中出现在冬春季,铁路西侧沙害比东侧严重。旨在加深对青藏铁路沙害规律的认识,为防沙提供依据。 相似文献
2.
高速公路沙害防治技术研究-以丹东-拉萨高速公路新地-麻黄沟段为例 总被引：3，自引：0，他引：3
本文以新地—麻黄沟高速公路防沙体系效益为依据,探讨分析了高速公路沙害的特点以及防沙体系建设的基本要求。研究表明,高速公路沙害防治需要采取适当抬高路基,建立稳固的防沙体系并要适当加大防护带宽度的综合措施。该地区公路防沙体系的结构配置对干旱、半干旱沙漠地区高速公路沙害防治具有一定的借鉴作用。 相似文献
3.
青藏铁路主要沙害路段治理技术及成效 总被引：2，自引：0，他引：2
青藏铁路建成以来,沙害日趋严重,危及铁路运营安全,备受关注。通过野外调查和室内分析,对青藏铁路沿线的红梁河、秀水河-北麓河、沱沱河、通天河、扎加藏布、错那湖等6个路段的沙害类型、特征、治理及成效进行研究。提出青藏铁路的防沙应以生物措施为主,机械措施为植被恢复服务。旨在加深对高寒地区铁路沙害的认识,为青藏铁路防沙提供依据。 相似文献
4.
浑善达克沙地公路综合防护技术及其效益分析 总被引：5，自引：0，他引：5
浑善达克沙地省际通道综合防护体系包括:公路沙害快速治理和沙源控制技术及耐风沙植被建植技术。阻沙带、固沙带改变了风沙流结构,降低了输沙强度,增加了地表粗糙度,有效的起到了削弱风速,阻截流沙,控制沙丘前移,保持地表稳定的作用;建立稳定的耐风沙植被是持久固沙和生物防护的核心;首次大规模使用“固沙网”专利技术产品用于公路快速固沙保苗,实践证明采用固沙网与柳条立式沙障的组合固沙技术对于快速固沙和植被恢复的作用更加显著;并提出了公路沙害快速治理技术体系与配套的技术措施。项目实施过程中3年投入产出比为1∶2.6,通过公路沙害治理工程的实施,稳定防护10年的经济总收益为4.67亿元;如将挖方路堑段砂质陡坡用植物固沙措施代替传统石砌护面墙技术推广至其它工程,效益更为显著。该项目技术研究与工程建设紧密结合,操作性强,能快速有效治理荒漠化地区公路沙害,总结出了沙区公路、铁路沙害的治理模式,对于我国荒漠化治理有推广应用价值。 相似文献
5.
塔里木沙漠公路在复合型纵向沙垄区的道路沙害 总被引：7，自引：0，他引：7
塔里木沙漠公路穿越高大复合型纵向沙垄段２７５ｋｍ,占到穿越流动沙漠总长度的６１．６％,公路沙害的类型和程度因地貌部位不同而异。通过大量野外调查和观测,并结合成因地貌分析,给出高大复合型纵向沙垄区典型地貌部位的主要沙害形式。 相似文献
6.
塔里木沙漠公路风沙危害研究 总被引：1，自引：1，他引：0
通过分析沙漠公路不同时段和地段风沙危害的特点 ,找出了从北向南风沙危害强度趋于减弱 ,公路及防沙体系受害程度逐渐降低的规律。注意到防沙体系所受风沙危害类型和程度在公路东西两侧和不同地貌部位差异明显。并且查明随着时间推移 ,公路受害面积扩大 ,重型沙害所占比例明显增长的公路沙害发展状况。 相似文献
7.
拉日铁路沙害成因、分布、特征及防治研究 总被引：2，自引：0，他引：2
随着拉日铁路的建成通车,沙害日趋严重,成为危及铁路安全运营的一大隐患,因此,沿线的风沙防治一直备受关注。通过考察和分析沿线独特的高原河谷风沙环境,从成因、分布、特征、防治等几个方面较系统地研究了拉日铁路的沙害,在此基础上,提出拉日铁路防沙应以生物措施为主,工程措施为辅。 相似文献
8.
塔里木沙漠公路沿线沙物质特征及环境意义 总被引：9，自引：3，他引：6
本文对沙漠公路沿线风沙地貌和沙物质的特征、如粒度特征，矿物成分，化学成分以及微量元素组成等进行了分析，为沙漠公路的生物防沙规划，道路的沙害治理提供科学数据。用聚类分析的方法对沙物质分析特征在沙漠环境研究中的应用进行了初步探讨。 相似文献
9.
塔里木沙漠公路防沙体系建设几个问题的探讨 总被引：9，自引：1，他引：8
沙害主要取决于两个系统因素的共同作用 :动力系统—风力和响应系统—下垫面状况。塔里木沙漠公路沿线风沙地貌形态类型复杂多样 ,沙源充足 ;起沙风频数高 ,作用时间长 ,防沙难度极大。已建成的高立式芦苇阻沙栅栏和 1 m× 1 m半隐蔽芦苇草方格固沙沙障结合的“阻固”体系 ,有效控制了沙害 ,但也存在一定问题。定位观测表明 ,沿线起沙风和输沙方向集中于 NE、ENE、E三个方向 ,占 46%～ 68% ,从理论上说 ,应加大风侧 (路东侧 )防护力度 ,而实际上固沙带内部强烈的风蚀与沙埋过程 ,使其有效年限与设置宽度关系不明显 ,宜采取窄宽度勤维修原则 ,上风侧宽度控制在 3 0 m～ 40 m,每 3～ 4年更新一次并及时维修。下风侧可不设置高立式沙障 ,固沙带宽度控制在 1 0 m～ 1 5 m为宜 ;高立式沙障与半隐蔽方格沙障前沿之间空留宽度控制在 8H以内较为适宜。依沙害程度 ,以单一原状芦苇固定沙障、复膜沙袋阻沙体活动沙障及固定沙障与活动沙障有机结合加强前沿阻沙力度 ;不同沙害部位设置不同规格不同高度的半隐蔽方格沙障、固化路肩边坡创造输沙断面等技术 ,形成立体防护体系 ,足以控制沙害。 相似文献
10.
<正> 中滩站地属内蒙古自治区乌海市,1958年包兰线通车后铁路常遭沙害。曾经采用过卵石复盖、草方格、截沙沟、阻沙堤等多种工程防治措施,但均未得到根除。1981年铁道部西北所与呼铁局乌达治沙站在这里开始了“乳化渣油与植物相结合的固沙试验”,他们在有沙害的线路两侧约150米的范围内,用刺丝围成宽100米、长数百米不等的试验 相似文献
11.
为明确宁夏四类主要草原的蝗虫物种组成、多样性和对天敌、植被、土壤及其气候等生物和非生物因子的响应,2019-2020年在宁夏温性草甸草原、温性草原、温性荒漠草原和温性草原化荒漠四类草原对蝗虫及天敌物种进行了调查采集,通过物种数、个体数、多样性指数、优势度指数、丰富度指数及均匀性指数分析蝗虫、天敌和昆虫的多样性,并就草原蝗虫优势种和多样性对天敌、植被、土壤及气候等生物和非生物因子的响应进行分析。结果表明,共采集鉴定草原蝗虫和天敌个体数分别有743头和3592头,物种数分别有27种和24种;温性草原上发生的蝗虫和天敌物种和数量均最多,蝗虫和天敌的物种分别为23种和21种,数量分别为432头和1682头;温性草原化荒漠上发生的蝗虫和天敌物种和数量均最少,蝗虫和天敌的物种分别为8种和7种,数量分别为34头和132头。蝗虫优势种有白纹雏蝗Chorthippus albonemus、短星翅蝗Calliptamus abbreviatus和亚洲小车蝗Oedaleus asiaticus三种,天敌优势种有直角通缘步甲Pterostichus gebleri、麻步甲Carabus brandti和短翅伪葬步甲Pseudotaphoxenus brevipennis三种。温性草原无论是在草原蝗虫群落中,还是整个昆虫和天敌群落中,其丰富度指数均显著高于其他三类草原;草原蝗虫多样性指数和丰富度指数与天敌多样性指数和丰富度指数间均存在极显著正相关关系,与天敌优势度指数间存在极显著负相关关系;短星翅蝗和亚洲小车蝗发生均与天敌直角通缘步甲呈显著正相关关系,白纹雏蝗与禾本科植被盖度、高度、生物量,菊科植被盖度、生物量、频度、高度、土壤饱和持水量、毛管持水量、田间持水量、毛管孔隙度、总孔隙度、有机质、碱解氮、海拔和降水量间均呈显著正相关关系,与土壤容重、pH、平均气温和最高气温间均呈极显著负相关关系。 相似文献
12.
为进一步提升蠋蝽室内繁育和田间应用技术,本研究以桑蚕蛹、柞蚕蛹为猎物,评价了单一和混合猎物饲养蠋蝽对其生长发育、繁殖和捕食能力的影响。研究发现：猎物并不影响蠋蝽若虫的发育历期,各处理下蠋蝽发育历期平均在26 d;但显著影响蠋蝽的产卵前期,混合猎物饲养的蠋蝽产卵前期为10.3 d,分别是桑蚕蛹猎物的1.54倍、柞蚕蛹猎物的1.34倍。同时,猎物显著影响蠋蝽的体型、繁殖、寿命和耐饥饿时间,混合猎物饲养的蠋蝽体型比单一猎物增加5%～9%、产卵量增加13%～38%、寿命延长2～7 d、捕食量提高15%～20%、耐饥饿时间延长20%～60%。 相似文献
13.
M. Fortass S. Diallo 《European journal of plant pathology / European Foundation for Plant Pathology》1993,99(4):219-226
Broad bean mottle virus (BBMV) was transmitted from infected to healthy faba-bean plants by the curculionid weevilsApion radiolus Kirby,Hypera variabilis Herbst,Pachytychius strumarius Gyll,Smicronyx cyaneus Gyll, andSitona lineatus L. The latter appeared to be an efficient vector: acquisition and inoculation occurred at the first bite, the rate of transmission was c. 41%, and virus retention lasted for at least seven days.S. lineatus transmitted the virus from faba bean to lentil and pea, but not to the three genotypes of chickpea tested. This is the first report on the generaHypera, Pachytychius, andSmicronyx as virus vectors, and onA. radiolus, H. variabilis, P. strumarius, andS. cyaneus as vectors of BBMV.Out of 351 samples of food legumes with symptoms suggestive of virus infection, 16, 11, 19, and 17% of the samples of chickpea, lentil, pea, and common bean, respectively, were found infected when tested for BBMV in DAS-ELISA. This is the first report on the natural occurrence of BBMV in chickpea, lentil, pea, and common bean. The virus should be regarded as a food-legume virus rather than a faba-bean virus solely, and is considered an actual threat to food legume improvement programmes. 相似文献
14.
为明确苹果中残留的烯啶虫胺、噻虫嗪、吡虫啉、噻虫胺、呋虫胺和啶虫脒6种新烟碱类药剂在不同加工过程中的变化情况,采用高效液相色谱法研究了6种药剂在苹果实验室罐头、果酱、果酒和果醋模拟加工过程中的残留量变化。结果表明:在苹果罐头加工过程中,6种药剂在罐头中残留量与初始浓度相比均显著降低,其中吡虫啉和噻虫胺在罐头中的加工因子较高,均为0.8,啶虫脒在罐头中的加工因子最低,为0.1。罐头汁中烯啶虫胺的加工因子最高,为0.5,其次为啶虫脒和噻虫嗪,均为0.4。在果酱加工过程中,烯啶虫胺、噻虫嗪、吡虫啉、噻虫胺、呋虫胺和啶虫脒的加工因子分别为0.8、0.9、0.9、1.0、0.9和0.9。在果酒中除吡虫啉的加工因子为0.1外,其余药剂加工因子均小于0.1。在果醋中除噻虫胺有少量残留(0.05 mg/kg)外,其余药剂均低于检出限。6种新烟碱类药剂在苹果实验室模拟加工过程中,加工因子均小于1,残留降低。 相似文献
15.
V.R. Parshad 《Integrated Pest Management Reviews》1999,4(2):97-126
Eighteen species of rodents are pests in agriculture, horticulture, forestry, animal and human dwellings and rural and urban storage facilities in India. Their habitat, distribution, abundance and economic significance varies in different crops, seasons and geographical regions of the country. Of these, Bandicota bengalensis is the most predominant and widespread pest of agriculture in wet and irrigated soils and has also established in houses and godowns in metropolitan cities like Bombay, Delhi and Calcutta. In dryland agriculture Tatera indica and Meriones hurrianae are the predominant rodent pests. Some species like Rattus meltada, Mus musculus and M. booduga occur in both wet and dry lands. Species like R. nitidus in north-eastern hill region and Gerbillus gleadowi in the Indian desert are important locally. The common commensal pests are Rattus rattus and M. musculus throughout the country including the islands. R. rattus along with squirrels Funambulus palmarum and F. tristriatus are serious pests of plantation crops such as coconut and oil palm in the southern peninsula. F. pennanti is abundant in orchards and gardens in the north and central plains and sub-mountain regions. Analysis of the information available on the damage and economic losses caused by rodents in rice, wheat, sugarcane, maize, pearl millet, sorghum, oil seed, legume and vegetable crop fields, horticulture and forestry, poultry farms, and rural and urban dwellings and storage facilities clearly shows that chronic damage ranging from 2% to 15% persists throughout the country and severe damage, sometimes even up to 100% loss of the field crop, is not rare. Several traditional and modern approaches and methods of rodent control are being used. The existing knowledge of the environmental, cultural, biological, mechanical and chemical methods of rodent control in India is reviewed. Considerable variations exist in the susceptibility of the pest species to different methods, particularly to rodenticides and trapping, their field applicability, efficacy and economics in different crops, seasons and geographical regions, behavioural responses of the pest species to these methods in different ecological conditions and their adoption by farmers in different regions of India. Environmental and cultural techniques, such as clean cultivation, proper soil tillage and crop scheduling, barriers, repellents and proofing which may reduce rodent harbourage, food sources and immigration have long lasting effects but are seldom adopted. However, their significance in relation to normal agricultural practices, intensification and diversification are discussed. Rodenticides, which provide an immediate solution to the rodent problem, form the major component of rodent control strategies in India. Poison baiting of rodents with zinc phosphide and burrow fumigation with aluminium phosphide are common in agricultural fields and recently Racumin (coumatetralyl) and bromadiolone have been introduced for the control of both agricultural and commensal rodent pests in India. Methods and timings of campaigns and successes and problems in implementation of rodent control are also reviewed. 相似文献
16.
毒死蜱、吡虫啉、螺虫乙酯及其代谢物和苯醚甲环唑在梨中的残留消解动态 总被引：2，自引：0，他引：2
利用仪器分析方法和田间试验法,研究了毒死蜱、吡虫啉、螺虫乙酯及其代谢物和苯醚甲环唑在梨中的残留消解动态。样品经乙腈提取,氯化钠盐析净化,毒死蜱采用气相色谱-质谱联用仪检测,其他3种农药采用液相色谱-质谱联用仪检测,外标法定量。结果表明:毒死蜱、吡虫啉、螺虫乙酯及其代谢物和苯醚甲环唑4种农药在梨中的消解动态均满足一级反应动力学方程,半衰期分别为4.4、12.2、13.1和10.3 d。施药后7 d至收获期,4种农药在梨中的最终残留量均未超出中国国家标准中规定的最大残留限量值,按照推荐剂量及其操作规范在梨上施用是安全的。 相似文献
17.
Allelopathy studies the interactions among plants, fungi, algae and bacteria with the organisms living in a certain ecosystem, interactions that are mediated by the secondary metabolites produced and exuded into the environment. Consequently, allelopathy is a multidisciplinary science where ecologists, chemists, soil scientists, agronomists, biologists, plant physiologists and molecular biologists offer their skills to give an overall view of the complex interactions occurring in a certain ecosystem. As a result of these studies, applications in weed and pest management are expected in such different fields as development of new agrochemicals, cultural methods, developing of allelopathic crops with increased weed resistance, etc. The present paper will focus on the chemical aspects of allelopathy, pointing out the most recent advances in the chemicals disclosed, their mode of action and their fate in the ecosystem. Also, attention will be paid to achievements in genomics and proteomics, two emerging fields in allelopathy. Rather than being exhaustive, this paper is intended to reflect a critical vision of the current state of allelopathy and to point to future lines of research where in the authors' opinion the main advances and applications could and should be expected. 相似文献
18.
Toxic metal enrichment characteristics and sources of arid urban surface soil in Yinchuan City,China
To investigate the environmental quality of the urban surface soil in Yinchuan City, the capital of Ningxia Hui Autonomous Region(Ningxia), China, we sampled surface soil and measured the concentrations of 8 toxic metals(Pb, Cr, Cu, Zn, Co, Bi, Ni and V) using X-ray fluorescence spectrometry. The enrichment characteristics and sources of these toxic metals in the soil were analyzed by the enrichment factor(EF) and multivariate statistical analysis. The results showed that the mean concentrations of these toxic metals in the soil samples were 25.0, 109.1, 16.8, 26.0, 37.2, 2.7, 25.3 and 59.9 mg/kg for Pb, Cr, Cu, Zn, Co, Bi, Ni and V, respectively, which were 1.2, 1.8, 0.8, 0.4, 3.2, 8.7, 0.7 and 0.8 times of the corresponding background values of Ningxia soil, respectively. The variations of Pb, Zn, Co, Bi and Ni concentrations in the surface soil of Yinchuan were larger than those of the other metals. Our results also showed that the toxic metals investigated in the soil had different enrichment levels. Both Co and Bi were significantly enriched, whereas Cr was only moderately enriched in the soil. There was a deficiency or minimal enrichment of the other toxic metals in the soil. Source analysis results based on the concentration, enrichment characteristics and multivariate statistical analysis indicated that Cr, V and Ni originated from a combination of fossil fuel combustion, traffic pollution and natural occurrence. Pb, Cu and Zn were predominantly derived from natural and traffic sources, while Co and Bi primarily originated from construction sources. 相似文献
19.
Benjamin DAVIDSON 《干旱区科学》2021,13(6):629-638
Water availability, which enables plant growth and animal activity, regulates dryland ecosystem function. In hyper-arid ecosystems, rain cannot support vascular plant growth. Therefore, hyper-arid vegetation is restricted to the lower topography, where runoff accumulates. Typically, food resources originating from areas of dense vegetation are dispersed across the desert floor, enabling animal life in areas lacking vascular plant growth. However, certain regions, such as the hyper-arid upper topography, may be devoid of plant-derived food resources. The present study examined arthropod activity in the upper topography of a hyper-arid desert, in comparison with arthropod activity in the lower topography. Pitfall traps were utilized to compare arthropod activity along unvegetated ridges with activity in parallel, vegetated riverbeds. Surprisingly, the study revealed dense arthropod communities in the barren upper topography. Arthropods collected in the upper topography represented 26% of total arthropod abundance. In addition, the overlap between arthropod identity in the ridges and wadis(i.e., riverbeds) was low, and certain arthropods were strongly affiliated with the ridges. The upper topographic communities included high numbers of silverfish(Zygentoma: Lepismatidae), malachite beetles(Psiloderes), and predatory mites(Acari: Anystidae), and these arthropods were present at various life stages. It remains unclear how arthropod communities can persist in the unvegetated upper topography of the hyper-arid study area. These results raise the possibility that other food sources, independent from vascular plants, may play a significant role in the life history of hyper-arid arthropods. 相似文献
20.
C. Bertsch M. Ramírez‐Suero M. Magnin‐Robert P. Larignon J. Chong E. Abou‐Mansour A. Spagnolo C. Clément F. Fontaine 《Plant pathology》2013,62(2):243-265
This review presents an overview of eutypa dieback, esca and botryosphaeria dieback, the predominant grapevine trunk diseases worldwide. It covers their symptomatologies in the trunk, leaves and berries; the characteristics of the different fungal species associated with them; and host–pathogen interactions. Here, the host–pathogen relationship is defined at the cytological, physiological and molecular levels. Currently available experimental tools for studying these diseases, both in vitro and in the field, are discussed. Finally, a progress report on their control, which, since the ban of sodium arsenite, comprises chemical, biological and/or sanitation methods, is presented. 相似文献