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991.
渤海湾津唐沿海野生大豆(Glycine soja)种群高盐碱胁迫反应   总被引:2,自引:0,他引:2  
以渤海湾津唐沿海地带895份野生大豆种群在高盐碱(3%)环境下的全生育期鉴定试验,分析不同种群(株系)的生长发育动态以及对盐碱土壤生态适应性的分化。结果表明,出苗阶段存在3种耐盐碱能力类型:耐高盐碱胁迫发芽出苗;耐低盐碱胁迫发芽出苗;盐胁迫不能发芽出苗。在高盐胁迫下营养生长早期阶段种群死亡率最高,中期以后相对降低,成熟期死亡率较低。种群植株形态建成和生殖生长受到高盐胁迫的强烈抑制,表现早期严重而后期较轻。植株和产量性状的受害程度由大到小依次为:单株的地上干物质重、单株产量、种子数、百粒重和收获指数。株系间变异系数从大到小依次为:单株产量、种子数、荚数、收获指数、地上干物质重、百粒重。研究揭示该地域种群内对盐碱土壤有很高的适应性分化,存在高耐盐碱生态型。  相似文献   
992.
第十二次全国环境微生物学术研讨会于2009年11月在武汉华中科技大学顺利召开,本次会议围绕"环境微生物与人类健康"的主题,在环境微生物学前沿、微生物与环境健康及人类健康、环境微生物资源挖掘与利用,以及环境微生物技术与环境污染防治、生态修复、废弃物资源化利用和再生能源等诸多领域展开深入研讨,充分反映了我国环境微生物学界取得的最新进展,为了展现国内环境微生物及相关交叉领域科研工作者取得的最新进展,《微生物学通报》针对"第十二次全国环境微生物学术研讨会"组织出版了这期"环境微生物专刊",期望该专刊的出版有助于促进我国环境微生物学相关领域的交流和发展。  相似文献   
993.
首冠藤的生态生物学特征   总被引:2,自引:0,他引:2  
通过样地调查,对首冠藤(Bauhinia corymbosa)的生态生物学特征进行研究.结果表明,首冠藤是阳生性藤本植物,主要分布于热带亚热带地区光照较好的山坡、疏林边缘或村旁;耐贫瘠,适宜生长的土壤为红壤和赤红壤.其平均光合速率为3.306 μmolm~(-2)s~(-1),气孔导度为0.25 molm~(-1)s~(-1),蒸腾速率为4.10 mmolm~(-2)s~(-1).首冠藤对营养元素的利用率较高,植株体内N、P、K、Ca、Na、Mg加权平均养分含量分别为1.11%、0.09%、0.56%、0.86%、0.21%、0.06%,其中叶片N含量最高,枝Na含量最高,根部P和Mg含量最高.首冠藤的生态生物学特征有利于其快速生长、攀附和适应环境.  相似文献   
994.
Frequent resuspension of sediments is recognized as an important process in large shallow lakes, impeding the recovery of eutrophic lakes. A large-scale project, including a wave barrier (3.3 km long) and a soft enclosure, was implemented to reduce wave energy and sediment resuspension in Lake Taihu, eastern China. The effects of the wave-reduction engineering on sediment resuspension and internal nutrient loading were investigated. Results showed that sediment resuspension rates as well as suspended solids (SS) in the areas protected by the wave barrier and the soft enclosure were significantly lower than in the unprotected areas. There was a positive relationship between total phosphorus (TP) and SS; thus internal loading of phosphorus was significantly reduced by the wave-reduction structure. High nutrient levels and phytoplankton biomass persisted during the experiment period, suggesting that additional measures, such as re-establishment of the macrophyte community, must be included to help restore the water quality in such a large, shallow and eutrophic lake.  相似文献   
995.
Emergy evaluation of organic rice-duck mutualism system   总被引:6,自引:1,他引:6  
Yun-Guan Xi  Pei Qin   《Ecological Engineering》2009,35(11):1677-1683
Rice-duck mutualism is one form of ecological engineering which makes use of the symbiotic relationship between rice and ducks to more effectively utilize materials, reduce chemical fertilizer and pesticide inputs, increase product safety and overall productivity and decrease the pollutants discharged from rice-fields. This is becoming a popular mode for organic rice production in China and it can be used as one measure taken in the drainage area to assist in the ecological rehabilitation of lakes. This study applied the emergy evaluation method to analyze the resource use and environmental impact of organic rice-duck mutualism (mode 1) compared with the conventional wheat/rice rotation system (mode 2) in the same farm to evaluate its sustainability and ecological and economic benefits and provide suggestions for optimizing this system. The results showed that mode 1 produced greater emergy benefits, and had higher self-organization, lower environmental pressure and higher product safety. The net emergy yield ratio (EYR), feedback ratio of yield emergy (FYE) and emergy sustainable index (ESI) of mode 1 were 1.57 times, 14.10 times and 8.71 times those of mode 2, respectively, and the emergy index of product safety (PSI) was 0 in mode 1 and −0.66 in mode 2. The emergy investment ratio (EIR) and environmental loading ratio (ELR) were 40.1 and 18.3% of those of mode 2. The economic benefit of mode 1 was lower than mode 2. The economic output, gross income and net income of mode 1 were 15.7, 10.8 and 35.4% less than those of mode 2, respectively, but using Em$, the output, gross income and net income of mode 1 were 47.4, 161.2, 87.3% higher than mode 2. With the development of markets for organic foods, mode 1 has the potential to achieve better economic benefits.  相似文献   
996.
寡营养细菌及其生态作用和应用的研究进展   总被引:1,自引:0,他引:1  
寡营养细菌是自然环境中特别是在寡营养环境中广泛分布的一种细菌,对寡营养生态环境起着至关重要的作用。近年来,随着分子生物学技术的飞速发展,寡营养细菌开始被广泛深入的研究。其分离培养技术,细菌形态特征,在生态中的作用和应用是目前微生物领域和环境科学领域的前沿课题,本文对这几个方面近年来的研究状况进行了综述,并展望了未来的发展趋势。  相似文献   
997.
Three estuarine macroalgae (Ulva rotundata,Enteromorpha intestinalis, Gracilariagracilis) of economic potential were cultivated in the laboratory toassess their biofiltering capacities for ammonium in waste effluents from a seabass (Dicentrarchus labrax) cultivation tank. The studywasdeveloped to investigate the functioning of N nutrition of the three species.Atlow water flow (< 2 volumes d–1) the three species strippedefficiently the ammonium dissolved in the waste water from the fish tank, withaminimum biofiltering efficiency estimate of 61% in unstarved cultures ofG. gracilis at a water flow of 2 volumesd–1. Maximum velocity for ammonium uptake (89.0 molNH4 + g–1 dry wth–1) was found in U. rotundata,whereas G. gracilis showed the highest affinity for thisnutrient. The net ammonium uptake rate was significantly affected by the waterflow, being greatest at the highest flow assayed (2 volumesd–1). Variations of tissue N and C:N ratios during aflow-through experiment suggested that N was not limiting macroalgal growth.However, when ammonium was supplied at a flow rate of 0.5 volumesd–1, specially in a three-stage design, the marked reductionintissue N and the biomass C:N:P ratios suggested a more general nutrientdeficiency. A significant correlation was found between growth rates and the Nbiomass gained in the cultures. The three-stage design under low water flow(0.5volumes d–1) showed that the highest ammonium uptake rates (upto 80.9 mol NH4 + g–1 dry wtd–1 in U. rotundata) were found inthe first stage, with decreasing rates in the following ones. As a result, lowincrements or even losses of total N biomass in these stages were found,suggesting that ammonium was excreted from the algae. We conclude that thesespecies present a potential ability to biofilter the ammonium dissolved inwastewater from a D. labrax cultivation tank, suggesting thatscaling up the biofiltration designs, future practises using these macroalgaemay be implemented in the local fish farms, resulting in both environmental andeconomical advantages.  相似文献   
998.
潮滩红树植物抗低温适应的生态学研究   总被引:21,自引:0,他引:21       下载免费PDF全文
采用电导法定量测定了中国东南沿海红树植物叶片的抗寒力变化。结果表明;(1)海南琼山东寨港主要红树种类冬季抗寒力(半致死温度)介于-2.3~-6.8℃之间,其中红树科植物抗寒力较强,多数种类属于低温敏感性相对较弱的L类型;海桑科和楝科红树种类抗寒力较弱,属于低温敏感性较强的H类型。(2)随纬度升高(个别地点除外),秋茄(Kandelia candel)、桐花树(Aegiceras corniculatum)和红海榄(Rhizophors,stylosa)抗寒力增强,呈现种群分化趋势。(3)同一地点,秋茄和桐花树抗寒力有明显季节变化:夏季最低,秋冬两季高于春季。(4)同一群落内,生长于中潮区滩面的秋茄抗寒力强于高潮区,但桐花树抗寒力在各个滩面相差木大。(5)秋茄和桐花树树冠上不同部位叶片的抗寒力不同,由表及里,由上至下,呈降低趋势。红树叶片抗寒力的种群分化、季节变化和部位差异是其趋异适应的结果,有益于红树植物的生存和繁育。  相似文献   
999.
Ecological design applied   总被引:2,自引:0,他引:2  
Over the past three decades ecological design has been applied to an increasingly diverse range of technologies and innovative solutions for the management of resources. Ecological technologies have been created for the food sector, waste conversion industries, architecture and landscape design, and to the field of environmental protection and restoration. The five case studies presented here represent applications of ecological design in five areas: sewage treatment, the restoration of a polluted body of water, the treatment of high strength industrial waste in lagoons, the integration of ecological systems with architecture, and an agriculturally based Eco-Park. Case #1 is an Advanced Ecologically Engineered System (AEES) for the treatment of sewage in Vermont, a cold climate. The facility treated 300 m3 per day (79,250 gallons per day) of sewage to advanced or tertiary wastewater standards, including during the winter months. A number of commercial byproducts were developed as part of the treatment process. Case #2 involved the treatment of a pond contaminated with 295 m3 per day (77,930 gallons per day) of toxic leachate from an adjacent landfill. A floating Restorer was built to treat the polluted pond. The Restorer was powered by wind and solar based energy sources. Over the past decade the pond has improved. There has been a positive oxygen regime throughout the water column, bottom sediments have been digested and the quality of the sediment chemistry has improved.The biodiversity of the macrobenthos of the pond has increased as a result of the improved conditions. Case #3 involved the treatment of 37,850 m3 per day (1 million gallons per day) of high strength waste from a poultry processing plant utilizing a dozen AEES Restorers. The technology has resulted in a 74% drop in energy requirements for treatment and has dramatically reduced the need for sludge removal. Currently, sludge degradation is proceeding faster than sludge accumulation. Case #4 includes several examples of buildings that utilize ecologically engineered systems to treat, recycle and permit the reuse of wastewater. The new Lewis Center for Environmental Studies at Oberlin College is a recent example of this trend. Case #5 describes the work that is leading to the creation of an urban, agriculturally based, Eco-Park in Burlington, Vermont. Waste heat from a nearby power station will provide year round climate control in a structure developed for food processing businesses, including a brewery, and for the onsite growth of diverse foods in integrated systems. We also describe a project to amplify the value of waste organic materials through biological conversion to high value products such as fish, flowers, mushrooms, soils amendments, and livestock and fish feeds. An ecologically designed fish culture facility will be an integral part of the Eco-Park complex. The project is intended to demonstrate the economic viability of integrative design in an urban setting and to address the important issue of locally based food production.  相似文献   
1000.
基于投入产出分析的中国生态足迹模型   总被引:31,自引:0,他引:31  
曹淑艳  谢高地 《生态学报》2007,27(4):1499-1507
基于投入产出分析技术的生态足迹(EF)核算模型是目前国际生态承载力研究的热点模型之一。在已有研究的基础上,引入土地利用差异转化系数(某类土地利用的产量因子与其均衡因子的乘积)改进模型,以保证投入产出表的行、列组分加和操作的有效性。研究以货币型投入产出表为基础核算中国1997年的EF,分析表明:(1)1997年中国为EF净出口国,人均EF贸易逆差0.050hm^2,占生产包含足迹的3.4%;(2)最终使用的人均EF为1.435hm^2(能源足迹占45.1%),其中,2/3缘于居民消费,另1/3缘于资本形成;(3)第一、二、三产业包含的人均EF依次为0.499、0.721hm^2和0.183hm^2。其中,第一产业以直接占用生态空间为主,而第二、三产业以间接占用为主,如第二产业的隐藏性非能源足迹是其直接值的140余倍;(4)三大产业部门中,第三产业最终产品消费的EF最小,人均0.183hm^2,而其土地利用的经济效率最高,为0.898万元hm^-2。实践表明基于投入产出分析的EF模型不仅承袭了EF基本模型的优点,而且结构性能好,能同时识别社会各生产和消费部门的生态压力及其在不同部门之间的流转情况,并可有效避免足迹组分的重复计算。  相似文献   
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