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91.
92.
Si对盐胁迫下水稻根系活力、丙二醛和营养元素含量的影响(Effects of Si on the Index of Root Activity, MDA Content and Nutritional Elements Uptake of Rice under Salt Stress) 总被引:4,自引:1,他引:4
为深入了解盐胁迫下外源硅(Si)对水稻生长的作用,采用溶液培养法研究了外源Si对盐(NaCl)胁迫下野生型水稻和硅突变体水稻(不能正常吸收Si)营养元素和生理指标的影响.结果表明:1)外源Si可显著提高盐胁迫下两种水稻的生物量.当NaCl的浓度为100mmol·L-1时,添加1.0mmol·L-1的Si可使野生型水稻茎叶和根系干重提高12.81%和15.25%,硅突变体水稻茎叶干重提高12.31%.2)外源Si可提高盐胁迫下两种水稻茎叶和根系中营养元素含量,降低Na的含量.3)外源Si可显著降低盐胁迫下野生型水稻叶片MDA含量,但对突变体水稻叶片MDA含量影响不大.4)外源Si可显著提高盐胁迫下两种水稻的根系活力.盐胁迫下,与不加Si的对照相比,添加1.0mmol·L-1的Si可分别使野生型和突变体水稻根系活力指数提高60.47%和42.42%. 相似文献
93.
以栽培大豆和野生大豆的基因组DNA为材料,利用PCR技术扩增并克隆了豆类胰岛素基因,分析了两者的DNA序列.结果表明,测定的DNA序列分别为841bp和903bp,有4个核苷酸差异;在信号肽编码区域内各存在一个内含子,大小分别为368和370个核苷酸;在ORF范围内,与前人报导的cDNA序列分别有1个和2个位点的核苷酸差异,从而导致相应位点的氨基酸发生变化.Southern杂交表明,栽培大豆和野生大豆的豆类胰岛素基因分别以单拷贝和多拷贝形式存在于基因组中 相似文献
94.
研究了青岛崂山野生草本药用花卉的生物学特征、生态分布、观赏及药用价值 ,讨论了它们的开发利用途径 ,以期为青岛崂山野生草本药用花卉的合理开发和持续利用提供可靠、详实的依据。 相似文献
95.
Guangxue WU Zhenhu HU Mark G. HEALY Xinmin ZHAN 《Frontiers of Environmental Science & Engineering》2009,3(3):300-306
Since the solubilization of meat and bone meal (MBM) is a prerequisite in many MBM disposal approaches, enhancement of the solubilization by means of thermochemical pretreatment was investigated in this study at two temperatures (55°C and 131°C) and six sodium hydroxide (NaOH) concentrations (0, 1.25, 2.5, 5, 10 and 20 g/L). The MBM volatile solid (VS) reduction ratio was up to 66% and 70% at 55°C and 131°C, respectively. At the same temperature, the VS reduction ratio increased with the increase in the dosage of NaOH. The study on the methane (CH4) production potential of pretreated MBM shows that the addition of NaOH at 55°C did not cause the inhibition of the succeeding CH4 production process. However, CH4 production was inhibited by the addition of NaOH at 131°C. The CH4 production potential was in the range of 389 to 503 mL CH4/g VS MBM and 464 to 555 mL CH4/g VS MBM at 55°C and 131°C, respectively. 相似文献
96.
In 2016, Swedish climate reporting declined in quantity and shifted focus somewhat from climate change as such to the harmful climate impacts of meat consumption. The latter prompted discussions in social media—an increasingly important forum for public debate but infrequently studied in environmental communication research. Despite strong evidence that a meat and dairy-based diet is harmful for the environment, meat consumption is increasing, and this qualitative study aims to—through the lens of social representation theory—contribute knowledge about how livestock production is legitimized in everyday discourse on Facebook. The article identifies representations that legitimize livestock production through polarization between (1) livestock production and other (environmental) issues, (2) environmentally “good” and “bad” countries, and (3) “reliable” and “unreliable” information. It concludes by discussing the influence of national ideology on the legitimization of livestock production and the potential of social media to counter the post-politicization of environmental issues. 相似文献
97.
Zuzanna Magdziak Marek Siwulski Mirosław Mleczek 《Journal of environmental science and health. Part. B》2017,52(10):784-789
The aim of study was to determine 9 organic acids in nine aboveground and seven wood-growing wild edible mushroom species originated from an area under the direct influence of a busy trunk road in Poland. The organic acids in the extracts of samples were identified by reversed-phase column liquid chromatography (RPLC). The presented results show that all the mushroom species were characterized by high variation in the profile and content of the analyzed acids. Each of mushroom species contained oxalic acid, the profiles of the other acids strictly depended on mushroom species. Among aboveground species, the highest total content of organic acids was found in Lepista gilva (267.5 ± 26.6 mg g?1 dry weight (DW)), while Laccaria amethystina was characterized by the lowest content (37.7 ± 6.5 mg g?1 DW). Within wood-growing species, the highest content of organic acids was determined in Flammulina velutipes (171.9 ± 26.7 mg g?1 DW), whereas the lowest content (34.2 ± 2.9 mg g?1 DW) of the studied acids was observed in Grifola frondosa. 相似文献
98.
黑岱沟露天煤矿复垦土地野生植物侵入规律及对生态系统的影响 总被引:2,自引:0,他引:2
以黄土高原区露天煤矿复垦地为对象,于2005年8月对准格尔旗黑岱沟露天煤矿1992-2005年复垦的364hm2排土场野生植物入侵的种类进行了调查与研究,分析了42个样地上不同野生植物侵入的多度、频度、侵入规律及对生态系统的影响.结果表明:1992-2005年的近15年中,共有115种野生植物自然侵入到排土场内,群落中以1年生植物占优势(>50%),但多年生植物已比复垦初期(<5%)增加了很多,在组成上约占总种数的40%~50%,多度高的植物已有多年生植物,且分布于植物群落中.影响复垦植被生长的主要侵入种是披碱草和拂子茅.复垦地野生杂草侵入,表现为①平台侵入种数>边坡侵入种数,阴坡侵入种数>阳坡侵入种数;②纯林侵入种数>混交林侵入种数;③沙棘灌丛侵入种数>油松侵入种数>杨树林侵入种数;④黄土覆盖区侵入种数>土石混排区侵入种数. 相似文献
99.
L. NEIL FRAZER 《Conservation biology》2009,23(3):599-607
Abstract: A sea cage, sometimes referred to as a net pen, is an enclosure designed to prevent farm fish from escaping and to protect them from large predators, while allowing a free flow of water through the cage to carry away waste. Farm fish thus share water with wild fish, which enables transmission of parasites, such as sea lice, from wild to farm and farm to wild fishes. Sea lice epidemics, together with recently documented population‐level declines of wild salmon in areas of sea‐cage farming, are a reminder that sea‐cage aquaculture is fundamentally different from terrestrial animal culture. The difference is that sea cages protect farm fish from the usual pathogen‐control mechanisms of nature, such as predators, but not from the pathogens themselves. A sea cage thus becomes an unintended pathogen factory. Basic physical theory explains why sea‐cage aquaculture causes sea lice on sympatric wild fish to increase and why increased lice burdens cause wild fish to decline, with extirpation as a real possibility. Theory is important to this issue because slow declines of wild fish can be difficult to detect amid large fluctuations from other causes. The important theoretical concepts are equilibrium, host‐density effect, reservoir‐host effect, and critical stocking level of farmed fish (stocking level at which lice proliferate on farm fish even if wild fish are not present to infect them). I explored these concepts and their implications without mathematics through examples from salmon farming. I also considered whether the lice‐control techniques used by sea‐cage farmers (medication and shortened grow‐out times) are capable of protecting wild fish. Elementary probability showed that (where W is the abundance of wild fish, W* is the prefarm abundance, F is the abundance of farm fish, and is the ratio of lice per farm fish to lice per wild fish). Declines of wild fish can be reduced by short growing cycles for farm fish, medicating farm fish, and keeping farm stocking levels low. Declines can be avoided only by ensuring that wild fish do not share water with farmed fish, either by locating sea cages very far from wild fish or through the use of closed‐containment aquaculture systems. These principles are likely to govern any aquaculture system where cage‐protected farm hosts and sympatric wild hosts have a common parasite with a direct life cycle. 相似文献
100.