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21.
本文围绕好氧触媒在造纸法再造烟叶污水处理中的应用展开分析。如对好氧触媒在再造烟叶污水处理中的应用必要性及好氧触媒作用原理予以介绍,并对好氧触媒在造纸法再造烟叶污水处理中应用展开试验。  相似文献   
22.
五爪金龙凋落叶腐解物的化感潜力研究   总被引:8,自引:0,他引:8  
采用莴苣种子为受体,测试了五爪金龙凋落叶早期腐解物的化感作用,并与其鲜叶及凋落叶的化感潜力进行了比较分析。结果如下:凋落叶40d的腐解物、鲜叶及凋落叶的水提取液均具有较强的化感潜力,并表现出低促高抑的浓度效应,在FW0.1g﹒mL-1高质量浓度下的综合化感抑制强度为凋落叶未能加土壤的腐解物>鲜叶>凋落叶加土壤的腐解物>凋落叶,而在FW0.005g﹒mL-1低质量浓度下的综合化感促进作用是凋落叶>鲜叶>凋落叶加土壤的腐解物>凋落叶未加土壤的腐解物。鲜叶的抑制强度较凋落叶的大,表明叶片在衰老过程中抑制作用减弱。凋落叶未加土壤仅在空气微生物作用下的腐解物抑制作用最强,促进作用最小,而加入土壤后在土壤微生物作用下的腐解物的抑制作用却有所减弱,抑制强度介于鲜叶和凋落叶的之间,促进作用却小于鲜叶和凋落叶,说明凋落叶腐解过程中微生物的参与对化感作用产生了复杂的影响。  相似文献   
23.
本文以桑树和家蚕为试验生物,采用静态模拟熏气和自然污染调查相结合的方法,对大气苯酚污染蚕桑引起家蚕生长发育障碍进行了观察、分析,认为大气苯酚以间歇性较高浓度侵入蚕室时,会直接致蚕中毒;大气中苯酚以持续较低浓度作用时桑叶内会累积苯酚,间接对象蚕有毒害。家蚕受害后,轻则表现力食欲不振,群体发育不齐,体色灰暗、体重减轻、主要经济性状下降,重则死亡。,F_(0.01)=2.80说明因熏气处理次数引起盛食蚕体重变化的差异极显著,也即较高浓度的苯酚气会直接危害家蚕生长、发育。综上所述,在有关工厂附近大气内苯酚浓度虽然不是很高,也没有被正式列入监测范围,因此也没有监测指标。但此浓度下桑叶内会累积苯酚,家蚕食叶则会间接遭受其危害;如急性排放的苯酚气侵入蚕室,则会对家蚕直接致害,造成经济性状下降,甚至死亡。苯酚是有机毒物,食品上禁用早有规定,如何防止大气苯酚在生态系统中积累、迁移,保障陆地生物包括人类免受其毒害,是值得引起重视的环境问题。  相似文献   
24.
浙江天台山茶树光合日变化及光响应   总被引:18,自引:1,他引:18  
自然条件下使用LCA-4型便携式光合测定系统研究了栽培天天台山主峰华顶山的茶树连体叶片的光合日变化及光响应。结果表明:在初夏晴天,上年越冬叶片(下称二年生叶)的光合速率,表观量子效率,羧化效率和饱和光强比展叶红16d的一年生叶高,CO2补偿点和光补偿点比一年生叶低,两者的净光合速率日进程曲线均为“双峰”型,午间胞间CO2浓度上升表明,此时净光合速率下降主要受非气孔限制因素的影响。一年生叶蒸腾速率高于二年生叶,它们日进程曲线为单峰河,午间最高,而气孔阻力进间最低。不同时段作光响应和CO2响应试验表明,上午茶树的表观量子效率,饱和光强和羧化效率较高,光补偿点和CO2补偿点较低。图3表4参26  相似文献   
25.
Summary Components of the green leaf volatile complex (Z-3-hexenyl acetate andE-2-hexenyl acetate) were shown to enhance responses of tobacco budworm,Heliothis virescens, males to the sex attractant pheromone of conspecific females in the field. The results are discussed with regard to green leaf volatiles which enhance the attractant pheromone of a cohabiting species, and serve as attractants of a parasitoid of conspecific larvae.  相似文献   
26.
Summary. We report field and laboratory evidence indicating that the defensive compounds secreted by the millipedes Amplinus bitumidus (Diplopoda: Polydesmida) and Anadenobolus putealis (Diplopoda: Spirobolida) attract the carrion scarab Canthon morsei (Scarabaeidae: Scarabaeinae). In a Mexican tropical rain forest, C. morsei was mostly caught in pitfall traps baited with the carcasses of both millipede species. Only a few beetles were attracted to fish carrion. Experimental evidence indicates that C. morsei is attracted to freshly dead millipedes. Benzaldehyde and HCN were identified from Amplinus bitumidus; but 2-methyl-1,4-benzoquinone (toluquinone) and 2-methoxy- 3-methyl-1,4-benzoquinone from Anadenobolus putealis. Benzaldehyde attracted significantly more C. morsei individuals than fish meat, or millipedes of both species did after rinsing in hexane. This is the first report of Polydesmida attracting dung beetles.  相似文献   
27.
A review of the chemical ecology of the Cerambycidae (Coleoptera)   总被引:15,自引:0,他引:15  
Summary. This review summarizes the literature related to the chemical ecology of the Cerambycidae and provides a brief overview of cerambycid biology, ecology, economic significance, and management. Beetles in the family Cerambycidae have assumed increasing prominence as pests of forest and shade trees, shrubs, and raw wood products, and as vectors of tree diseases. Exotic species associated with solid wood packing materials have been notable tree killers in North American urban and peri-urban forests. In forested ecosystems native species respond to disturbances such as fires and windstorms, and initiate the biodeterioration of woody tissue. Eggs are laid by females, on or through the bark surface of stem and branch tissue of moribund, recently killed or decomposing woody plants; larval cerambycids (roundheaded woodborers) typically feed in the phloem and later in the xylem. Females will also, in some cases, select living hosts, e.g. adult conifer and angiosperm trees, for oviposition. Research on the chemical ecology of over 70 species has revealed many examples of attractive kairomones (such as floral volatiles, smoke volatiles, trunk and leaf volatiles, and bark beetle pheromones), repellents and deterrents, oviposition stimulants, short- and long-range sex pheromones, and defensive substances. Emerging generalities are that attractants tend to be monoterpenoids and phenolic esters; oviposition stimulants are monoterpenoids and flavanoids; short-range sex pheromones are female-produced, methyl-branched cuticular hydrocarbons; and long-range sex pheromones are male-produced -hydroxy ketones and (,)-diols ranging in length from 6 to 10 carbons. The latter compounds appear to originate from glands in the male thorax; putative defensive substances originate from metasternal secretory pores or mandibular glands. In one unusual case, a flightless, subterranean female that attacks sugar cane produces a sex pheromone that is derived from the amino acid isoleucine. With significantly more than 35,000 species of Cerambycidae worldwide, these generalities will be subject to change as more species are examined. Addendum The authors would like to point out that the electronic version is more accurate than the printed version.  相似文献   
28.
Summary. Ponderosa pine, Pinus ponderosa Laws. (Pinaceae), forests in Arizona have suffered from a nine-year period of drought and bark beetle, Ips lecontei Swaine (Coleoptera: Scolytidae), outbreaks. Abiotic and biotic stress in ponderosa pine results in the induced synthesis of certain monoterpenes that may in turn affect bark beetle behavior and survival. In this study, we investigate whether induced monoterpene production could result in a different monoterpene composition that remains stored in the needles or the trunk resin of the tree. Needle and resin samples in addition to trunk cores were collected from ponderosa pines at three locations in Arizona. Ungulate browsing induced a significant increase in limonene (P=0.010) and in chemodiversity (P=0.009), a measure of the evenness of distribution among the monoterpenes present in needles. We compared the level of ‘stress’ of the trees by measuring the thickness of annual rings in living trees and those that were killed by bark beetles. Where drought occurred, the spacing of annual rings from the last 10 years of trees killed by bark beetles was significantly smaller (P=0.020) compared to living trees. There was no difference in the monoterpene composition between the core sections of closest spacing of annual rings (stressed years) compared to the sections of widest spacing, which indicates that monoterpenes are distributed evenly throughout the extended resin system. In the area where the degree of drought was less overall, none of the individual monoterpenes present in the resin was related to bark beetle killed trees. However, about half the living pines had resin in which one of the major monoterpenes (α-pinene, Δ3-carene, and limonene) was absent, and these trees had a lower monoterpene chemodiversity compared to trees killed by bark beetles. Trees with these three major monoterpenes, corresponding to the average relative proportion in living pines at that location, may sustain higher selection and colonization by bark beetles.  相似文献   
29.
叶片微观结构变化对其颗粒物滞纳能力的影响   总被引:1,自引:1,他引:0  
魏文俊  王兵  牛香 《环境科学》2020,41(7):3136-3147
叶片作为植物滞留大气颗粒物最主要的载体,其表面微观结构特征和粗糙度的差异是颗粒物滞纳能力的重要决定因素.叶片微观结构会随着生长(内部因素)以及环境污染强度(外部因素)发生变化,然而现有的粉尘喷洒模拟实验,一般持续时间较短,而微观结构变化响应具有明显的滞后性,其结果无法客观反映由内外因素作用引起的微观结构变化对颗粒物滞纳能力的影响.本研究利用新叶和老叶研究叶片生长,并选择自然状态下不同污染源条件研究污染强度,分析叶片表面微观结构的变化及其对颗粒物滞纳能力的影响.研究得到3种常绿树种(矮紫杉Taxus cuspidata var.、侧柏Platycladus orientalis和油松Pinus tabuliformis)的老叶滞纳TSP、 PM_(10)、 PM_(2.5)和PM_1量均高于新叶,随着叶片的生长其颗粒物滞纳量在增大,且新叶与老叶对不同粒径颗粒物的滞纳量间均存在极显著的差异.生长中叶片粗糙度Rq值的增大是老叶颗粒物滞纳能力增大的主要原因. 5个树种(侧柏、油松、国槐Sophora japonica、毛白杨Populus tomentosa和银杏Ginkgo biloba)TSP和PM_(10)滞纳量为重度污染区高于相对清洁区.而PM_(2.5)和PM_1滞纳量则是油松、银杏和侧柏为重度污染区高于相对清洁区,国槐和毛白杨为相对清洁区高于重度污染区.不同污染强度区域间叶片TSP、PM_(10)和PM_(2.5)滞纳量存在着极显著的差异,PM_1滞纳量也存在着差异.主要归因于与相对清洁区相比,重度污染区叶片的气孔指数降低,蜡质层退化,表面纹理和细胞边界更加不规则,绒毛变长,变硬,叶片微观结构的这些变化使得重度污染区叶片粗糙度Rq值高于相对清洁区,且叶片背面的增加较正面更明显.研究结果将为深入揭示叶片颗粒物滞纳能力的驱动因素,以及提出更科学地提升净化颗粒物功能的城市森林管理措施提供数据支持.  相似文献   
30.
植物叶表尘及重金属对城市大气颗粒物污染的指示与评估   总被引:1,自引:0,他引:1  
城市大气颗粒物污染问题日渐突出,目前主要依靠大气站点的直接观测数据反映污染的即时状况,而植物叶表尘及重金属的监测为评价大气颗粒物阶段性污染状况提供了新的途径.本研究通过分析北京交通带和公园共7个样点的臭椿(Ailanthus altissima)、槐(Sophora japonica)、北京杨(Populus beijingensis)、榆树(Ulmus pumila)、紫叶李(Prunus cerasifera f.atropurpurea)等5种常见绿化树种的叶表尘及重金属Cd、Cr、Cu、Mn、Ni、Pb、Zn含量,并计算尘金属综合累积指数(MAI),进而与邻近站点大气颗粒物观测数据对比并进行统计分析,尝试量化评价植物所处环境的大气颗粒物及尘重金属综合污染状况.结果表明:采用榆树叶表尘可量化评价大气可吸入颗粒物PM10的月均质量浓度,相对误差为1.2%~10.6%;臭椿叶表尘可量化评价大气细颗粒物PM2.5的月均质量浓度和月均空气质量指数(AQI),相对误差分别为0.18%~3.7%和0.26%~5.7%.MAI值可指示大气尘重金属综合污染状况,本研究中京承高速和朝阳公园大气尘重金属综合污染较重,其次为念坛公园、望京公园和玉蜓桥,最轻为岳各庄桥和麋鹿苑.  相似文献   
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