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131.
陈祝青 《湖南环境生物职业技术学院学报》1997,(1)
水濂洞是南岳风景区系中的一个重要组成部分,本文就水濂洞景区的规划、设计和建筑提出了一些看法。指出在设计时,要重点突出:静、险、古、幽、奇五个特点。 相似文献
132.
Effluent monitoring typically requires a large number of analytes and samples during the initial or startup phase of a facility. Once a baseline is established, the analyte list and sampling frequency may be reduced. Although there is a large body of literature relevant to the initial design, few, if any, published papers exist on updating established effluent monitoring programs. This paper statistically evaluates four years of baseline data to optimize the liquid effluent monitoring efficiency of a centralized waste treatment and disposal facility at a large defense nuclear complex. Specific objectives were to: (1) assess temporal variability in analyte concentrations, (2) determine operational factors contributing to waste stream variability, (3) assess the probability of exceeding permit limits, and (4) streamline the sampling and analysis regime. Results indicated that the probability of exceeding permit limits was one in a million under normal facility operating conditions, sampling frequency could be reduced, and several analytes could be eliminated. Furthermore, indicators such as gross alpha and gross beta measurements could be used in lieu of more expensive specific isotopic analyses (radium, cesium-137, and strontium-90) for routine monitoring. Study results were used by the state regulatory agency to modify monitoring requirements for a new discharge permit, resulting in an annual cost savings of US $223,000. This case study demonstrates that statistical evaluation of effluent contaminant variability coupled with process knowledge can help plant managers and regulators streamline analyte lists and sampling frequencies based on detection history and environmental risk. 相似文献
133.
Beauchemin S Hesterberg D Chou J Beauchemin M Simard RR Sayers DE 《Journal of environmental quality》2003,32(5):1809-1819
Knowledge of phosphorus (P) species in P-rich soils is useful for assessing P mobility and potential transfer to ground water and surface waters. Soil P was studied using synchrotron X-ray absorption near-edge structure (XANES) spectroscopy (a nondestructive chemical-speciation technique) and sequential chemical fractionation. The objective was to determine the chemical speciation of P in long-term-fertilized, P-rich soils differing in pH, clay, and organic matter contents. Samples of three slightly acidic (pH 5.5-6.2) and two slightly alkaline (pH 7.4-7.6) soils were collected from A or B horizons in two distinct agrosystems in the province of Québec, Canada. The soils contained between 800 and 2100 mg total P kg(-1). Distinct XANES features for Ca-phosphate mineral standards and for standards of adsorbed phosphate made it possible to differentiate these forms of P in the soil samples. The XANES results indicated that phosphate adsorbed on Fe- or Al-oxide minerals was present in all soils, with a higher proportion in acidic than in slightly alkaline samples. Calcium phosphate also occurred in all soils, regardless of pH. In agreement with chemical fractionation results, XANES data showed that Ca-phosphates were the dominant P forms in one acidic (pH 5.5) and in the two slightly alkaline (pH 7.4-7.6) soil samples. X-ray absorption near-edge structure spectroscopy directly identified certain forms of soil P, while chemical fractionation provided indirect supporting data and gave insights on additional forms of P such as organic pools that were not accounted for by the XANES analyses. 相似文献
134.
Strategic 3-hydroxy-2-butanone release in the dominant male lobster cockroach, <Emphasis Type="Italic">Nauphoeta cinerea</Emphasis> 总被引:3,自引:1,他引:2
In the lobster cockroach Nauphoete cinerea, the dominant–subordinate hierarchy formed via the agonistic interactions is unstable, and changes in rank order are common.
Our previous results showed that in the first encounter fight during initial rank formation, microgram levels of 3H-2B are
released by the aggressive posture (AP)-adopting dominant male. In the present study, the pattern of daily pheromone (3H-2B)
release during the domination period and on the day of rank switch, rank duration, and rank switch frequency were investigated
in three-male groups and six-male groups to examine the effect of higher frequency of agonistic encounters. The results showed
that, in the three-male groups (50-day observation period), daily 3H-2B release rate was not constant, but fluctuated, the
average duration of dominant rank was 16.6 ± 2.0 days, rank switch occurred in 58.8% of groups, and the frequency of rank
switching (average number of rank switches/group/50 days) was 1.4 ± 0.2. For the six-male groups (30-day observation period),
the daily 3H-2B release rate also fluctuated, but the duration of dominant rank was significantly shorter at 4.2 ± 0.6 days,
rank switch occurred in 100% of groups, and the frequency of rank switching (average number of rank switches/group/30 days)
was significantly higher at 6.9 ± 0.6. The results for both sets of male groups showed that as a new rank formed (either on
the first encounter day or on the day of rank switching), the dominant status was significantly associated with a higher 3H-2B
release rate. In the animal kingdom, fighting usually involves communication or the exchange of signals, and the results of
this study indicated that the fluctuating daily 3H-2B release rate adopted by the dominants is a kind of strategic release
and the 3H-2B release rate is a signal used to determine dominance. 相似文献
135.
采用零排放新工艺处理蚀刻废液 总被引:1,自引:0,他引:1
广州市某化工厂开发出一套对线路板蚀刻废液进行大规模集中资源化处理的零排放处理新工艺,该工艺通过在固相条件下生成氧化铜并用重力分选的方法将其分离出来,克服了原有工艺的缺陷,使废液中所有的成分能够在较低的处理成本下全部分离回收,无三废排出,达到了清洁生产的要求.对其工艺条件进行深入研究,通过正交试验优化了工艺条件. 相似文献