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991.
采集了阳泉市城区2017年10月15日~2018年1月23日PM2.5样品,分析了优良天和污染天PM2.5及其化学组分特征,并利用富集因子分析法(EF)和正定矩阵因子分析法(PMF)对PM2.5进行来源分析.结果表明,采样期间污染天二次无机离子(SO42-、 NO-3和NH+4)在PM2.5中的比例为23.83%,是优良天的2.43倍,污染天二次无机污染严重,污染天人为源相关的元素Cd、 Sb、 Sn、 Cu、 Pb、 Zn和As富集程度大于优良天;主要的污染源对PM2.5的贡献分别是燃煤29.26%、扬尘23.83%、机动车19.34%、二次源16.01%和工业源11.57%,其中,污染天机动车排放对PM2.5的贡献20.57%,高于优良天时17.82%,而燃煤源的贡献23.04%明显低于优良天时33.75%,静稳天气时机动... 相似文献
992.
南通市某钢丝绳行业集中区降尘中重金属污染状况评价 总被引:1,自引:1,他引:0
针对南通市钢丝绳行业集中区重金属污染问题,分析降尘中的铅、镉、铬、铜、镍、铁、锌、锰等重金属含量,并采用污染指数法和地累积指数法对降尘中重金属污染状况进行评价。结果表明,该集中区降尘中重金属污染程度依次为Zn>Pb>Cd>Cu>Fe>Mn>Ni>Cr,铅、锌为主要污染因子,铅、锌污染级别均处于重污染级别。 相似文献
993.
丰水期东洞庭湖超微型浮游藻类时空分布特征及其影响因子 总被引:2,自引:1,他引:1
超微型浮游藻类(<3μm)主要包括超微蓝藻(PCY)和超微真核藻(PPEs),是浮游生态系统的重要组成部分,在水体物质循环和能量流动中起着重要作用.为了解通江湖泊中超微藻动态变化特征及其关键影响因子,于2019年洞庭湖丰水期(5~8月)每月对东洞庭湖进行采样调查,研究了丰水期间东洞庭湖超微藻生物量和丰度的时空演变规律及其与环境因子的关系.结果表明,东洞庭湖丰水期超微藻生物量和丰度均表现出显著的时空演变规律(P<0.05).整个丰水期间,超微藻Chla平均浓度为8.52μg·L-1,其对总浮游藻类Chla的贡献率平均为41.6%;从5~8月,随着水温的增加,超微藻Chla浓度不断增加,尤其是东洞庭湖北部湖区和南部湖区;东部行洪道超微藻Chla浓度全湖最低.PCY是东洞庭湖超微藻的主要优势藻,其丰度平均是PPEs的3.4倍.PCY和PPEs丰度表现出相似的时空分布规律:时间上,从5~8月均呈现先增加后降低的趋势;空间上,随着丰水期的推移,超微藻丰度峰值由北部湖区向南部湖区迁移,到8月丰水期末期超微藻丰度逐渐降低,北部湖区超微藻丰度最高.分析结果表明,丰水期... 相似文献
994.
鞍山市道路扬尘碳组分特征及来源解析 总被引:4,自引:4,他引:0
为研究鞍山市道路扬尘PM2.5中碳组分污染特征及来源,于2014年10月采集鞍山市9条道路的扬尘样品,通过再悬浮得到PM2.5滤膜样品,利用热光碳分析仪测定PM2.5中OC(有机碳)和EC(元素碳)并分析其特征.结果表明,道路扬尘PM2.5中ω(TC)为9.78%(外环路)~14.00%(千山西路),ω(OC)为8.15%(外环路)~10.84%(千山西路),ω(EC)为1.63%(外环路)~2.85%(千山西路),ω(OC)明显高于ω(EC),说明各道路扬尘中含有较多的有机碳;采样期间OC/EC的值均大于2,说明道路扬尘中均可能存在二次污染;通过Spearman相关分析及线性拟合可知,鞍山市道路扬尘PM2.5中OC和EC来源大致相同;聚类分析表明,鞍山市道路扬尘PM2.5中碳组分主要来源于机动车尾气排放、生物质燃烧和煤炭燃烧. 相似文献
995.
北京西北城区春季PM10单颗粒形貌类型及成分特征 总被引:1,自引:1,他引:0
主要对北京西北城区2010年度春季大气可吸入颗粒物的理化特征进行分析研究,通过利用高分辨率场发射扫描电镜和图像分析技术研究了区内可吸入颗粒物的微观形貌类型及百分含量特征,利用扫描电镜及能谱分析研究矿物颗粒的元素组成及富集类型。结果表明,在西北城区春季大气PM10中可识别出烟尘集合体、球形颗粒、矿物和其他未知颗粒等4种单颗粒类型,沙尘暴天气对矿物颗粒的数量比例影响较大,同时影响颗粒物粒度分布。矿物颗粒按成分可分为"富Si"、"富Ca"、"富Fe"、"富S"、"富Na"、"富Ti"、"富Al"、"富Cl"和"富Mg"颗粒九大类,沙尘天气与非沙尘天气的矿物颗粒均以"富Si"颗粒、"富Ca"颗粒、"富Fe"颗粒、"富S"颗粒等为主。 相似文献
996.
2005—2010年沙尘天气影响我国城市环境空气质量分析 总被引:5,自引:3,他引:2
根据2005年建成较完整的环保重点城市空气质量日报监测网后的监测数据,分析2005—2010年期间,影响113个环保重点城市空气质量的沙尘天气过程次数范围在每年5~14次之间,平均每年10次左右,总计59次。在此期间,影响113个重点城市空气质量的沙尘天气过程累计的影响时间总计130 d,平均在每年22 d左右。影响环保重点城市的沙尘天气过程主要集中在3—5月,在部分年份的1—2月、6月和11—12月也有出现。受沙尘天气影响,113个重点城市总共的超标天次平均每年在332 d次左右,每年范围在147~546 d次之间。其中,受沙尘暴天气影响的重污染天次平均每年在40 d次左右,每年范围在14~78 d次之间。受沙尘暴天气影响的超标天和重污染天主要出现在3~5月。近年来沙尘天气对我国尤其是北方地区的影响程度很大。每年沙尘天气过程对我国城市空气质量影响的时间不短,尤其在春季对我国东中部地区城市造成了很严重的影响,近年大范围的沙尘天气过程还影响到了我国东南包括台湾地区和香港澳门地区。 相似文献
997.
JACLYN M. HALL NEIL D. BURGESS SALLA RANTALA HEINI VIHEMÄKI GEORGE JAMBIYA ROY E. GEREAU FORTUNATUS MAKONDA FADHILI NJILIMA PETER SUMBI ADAM KIZAJI 《Conservation biology》2014,28(6):1512-1521
Balancing ecological and social outcomes of conservation actions is recognized in global conservation policy but is challenging in practice. Compensation to land owners or users for foregone assets has been proposed by economists as an efficient way to mitigate negative social impacts of human displacement from protected areas. Joint empirical assessments of the conservation and social impacts of protected area establishment involving compensation payments are scarce. We synthesized social and biological studies related to the establishment of the Derema forest corridor in Tanzania's biodiverse East Usambara Mountains. This lengthy conservation process involved the appropriation of approximately 960 ha of native canopy agroforest and steep slopes for the corridor and monetary compensation to more than 1100 claimants in the surrounding villages. The overarching goals from the outset were to conserve ecological processes while doing no harm to the local communities. We evaluated whether these goals were achieved by analyzing 3 indicators of success: enhancement of forest connectivity, improvement of forest condition, and mitigation of negative impacts on local people's livelihoods. Indicators of forest connectivity and conditions were enhanced through reductions of forest loss and exotic species and increases in native species and canopy closure. Despite great efforts by national and international organizations, the intervention failed to mitigate livelihood losses especially among the poorest people. The Derema case illustrates the challenges of designing and implementing compensation schemes for conservation‐related displacement of people. Resultados Ecológicos y Sociales de un Área Protegida Nueva en Tanzania 相似文献
998.
At present, many rural enterprises in China's mountainous areas are developing rapidly, and due to poor planning and improper
management, in an uncontrolled manner. These small enterprises are making atmospheric pollution far more serious and more
difficult to control than before. Thus, as is the case with most developing countries, China is facing the challenge of managing
the increased environmental pollution that is accompanying its economic development. This paper examines the case of cement
dust pollution in the town of Wenquan in Sichuan province in order to determine how to adjust the relationship between development
of rural enterprises and atmospheric environmental pollution in mountainous areas. Using the single objective linear programming
method, and based on the principle of overall optimization, an optimal control plan for different pollution sources was worked
out and an economic assessment on reclamation of cement dust was completed. According to our analysis, after implementation
of this plan for four years, two months, the concentrations of suspended particles in Wenquan will achieve the requirement
of the national third-order ambient air quality standard; the current serious dust pollution will be completely controlled;
and the reclamation of cement dust will totally compensate for the cost of dust control and will result in 92,000 yuan of
pure profit per year. At that time, the economy and environment will be in harmony. 相似文献
999.
Helen Young 《Disasters》1987,11(2):102-109
A survey of thirty-four feeding programmes in Ethiopia and East Sudan was undertaken. Wie differences were found between the two countries and also within Ethiopia. Irrelugar general ration distribution was commonplace in Ethiopia, thus placing an extra strain on selective feeding programmes. The principal admission criteria to Selected Feeding Programmes (SFPs) were weight for height categories. The cut-off stages of the emergency. Useful compasirions between programmes were hampered by such differences, as well as by the different methods of reporting data.
The types of food usd in programmes depended on availability and included high energyu drinks, poridges, take-home pre-mixes and sometimes indigenous foods. A large number of foods e.g. cornedbedef, chicken paté, noodles, da4tes etc. Some added interesting variety and added nutritional value to the diet, while others caused more problems than they solved due to their low acceptability, inappropriate packaging, limited accompanying information and complex an costly preparation. The imlementation of food dination policies by donors and consignees regarding appropriate foodstuffs and their recommended use was considered to be the major solution to this problem. 相似文献
The types of food usd in programmes depended on availability and included high energyu drinks, poridges, take-home pre-mixes and sometimes indigenous foods. A large number of foods e.g. cornedbedef, chicken paté, noodles, da4tes etc. Some added interesting variety and added nutritional value to the diet, while others caused more problems than they solved due to their low acceptability, inappropriate packaging, limited accompanying information and complex an costly preparation. The imlementation of food dination policies by donors and consignees regarding appropriate foodstuffs and their recommended use was considered to be the major solution to this problem. 相似文献
1000.