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171.
Hydrogels have attracted large attention in wastewater treatment fields due to their low-cost and good interaction with pollutants, among which novel double network hydrogel is an outstanding class. To expand the application of double network hydrogel in water treatment, in this study, eco-friendly physically cross-linked double network polymer hydrogel beads (DAP) are prepared and studied in depth on the mechanism of Methylene Blue (MB) adsorption; and then the polymer hydrogels are further functionalized by inorganic materials. MB adsorption on DAP favors alkaline condition which is due to the increase of electrostatic attraction and adsorption site, and it reaches equilibrium within 10?hr, which is faster than that of the single network hydrogel beads (SAP). Through thermodynamics study, the process shows to be an exothermic and spontaneous process. The adsorption isotherms are well fitted by Langmuir model, with a maximum monolayer adsorption capacity of 1437.48?mg/g, which is larger than SAP (1255.75?mg/g). After being functionalized with common inorganic materials including activated carbon, Fe3O4 and graphene oxide (GO), the composites show to have larger pore sizes and have obvious increases in adsorption capacity especially the one contains GO. Then the composites contains Fe3O4 are used as heterogeneous Fenton catalyst which shows to have excellent performance in MB degradation. The results indicate the potential of polymer double network to be functionalized in environmental areas.  相似文献   
172.
硫氰酸汞分光光度法测定大气中的氯化氢,所使用的硫氰酸汞-乙醇溶液配置时间长,浓度低,曲线线性不好,不适用于环境现场监测。通过对氯化氢测定过程中遇到的问题进行分析,对硫氰酸汞-乙醇溶液的配置方法进行改进,提高该溶液的浓度。实验证明,使用定性滤纸过滤后的0.40%硫氰酸汞-乙醇溶液,曲线线性关系好,标样准确度高,适用于现场监测分析。  相似文献   
173.
PROBLEM: A prior study indicated that zero tolerance laws differ in their enforceability and likelihood of enforcement, with California's law being easier to enforce than New York's, and New Mexico's being the hardest of all. The question is, do these differences in enforcement affect teenagers' knowledge and perception of these laws? METHOD: A telephone survey was conducted to investigate awareness of the laws among 17-20 year olds in these three states and perceptions of enforcement. RESULTS: Estimated percentages of teenagers who knew of the laws were much higher in New York and California (71% and 65%, respectively) than in New Mexico (34%). Perceptions that police were enforcing the law, that licenses could be suspended, and that penalties were often applied were also lowest in New Mexico. IMPACT ON INDUSTRY: The potential of zero tolerance laws will not be realized without better awareness among young people. Full enforcement of the laws accompanied by publicity about the enforcement is recommended. Changes to the laws and their application may encourage enforcement efforts.  相似文献   
174.
175.
Synthetic polymers are important to the packaging industry but their use raises aesthetic and environmental concerns, particularly with regard to solid waste accumulation problems and the threat to wildlife. Some concerns are addressed by attention to problems associated with source reduction, incineration, recycling and landfill. Others are addressed by the development of new biodegradable polymers either alone or in blends. Materials used for biodegradable polymers include various forms of starch and products derived from it, biopolyesters and some synthetic polymers. Starch is rapidly metabolised and is an excellent base material for polymer blends or for infill of more environmentally inert polymers where it is metabolised to leave less residual polymer on biodegradation. This should help to improve the environmental impact of waste disposal. A number of standard methods have been developed to estimate the extent of biodegradability of polymers under various conditions and with a variety of organisms. They tend to be used mainly in the countries where they were developed but there is much overlap between the standards of different countries and wide scope for development of consistent and international standards.  相似文献   
176.
In this study, a Poly(vinyl alcohol)(PVA)/compost composite bead is prepared and is indicated suitable as a filter material for biofiltration. The optimal preparation process is with the compost size of 16–35 mesh, the ratio of water to compost of 40 g/15 g compost, and the immersion time in the phosphate solution of 60 min. The composite bead prepared by this process is a porous spherical particle with a diameter between 2.4 and 6.0 mm and a density of 0.96 g/cm3. It contains 9.43 mg P/g dry solid and 12.1 mg N/g dry solid. The equilibrium moisture content of the composite bead bed from adsorption and holding experiments is 50.5 and 54.6% on a wet basis respectively, which is about 1.74 times higher than that of swine manure compost bed. It corresponds to the optimal filter material required and is sufficient to sustain biological activity as the composite bead adsorbs equilibrium moisture. The bulk compressive strength of the composite bead bed is about 1.15 times larger than that of swine manure compost bed to ensure even distribution of air flow and reduce the head loss as the air flow stream passed through. The pH value of the filter bed could maintain in the 6.9–7.2 range during the operation period due to the composite bead has the phosphate buffer capacity. The percentage of ethyl acetate removal could remain at over 99% for 40 days operation while the composite beads adsorbed inorganic nitrate nutrients. The pressure drop of two kind composite beads and pig manure compost filter beds are 0 and 2 mm H2O, respectively, after operating for 40 days.  相似文献   
177.
Several composite blends of poly(vinyl alcohol) (PVA) and lignocellulosic fibers were prepared and characterized. Cohesive and flexible cast films were obtained by blending lignocellulosic fibers derived from orange waste and PVA with or without cornstarch. Films were evaluated for their thermal stability, water permeability and biodegradation properties. Thermogravimetric analysis (TGA) indicated the suitability of formulations for melt processing, and for application as mulch films in fields at much higher temperatures. Composite films were permeable to water, but at the same time able to maintain consistency and composition upon drying. Chemical crosslinking of starch, fiber and PVA, all hydroxyl functionalized polymers, by hexamethoxymethylmelamine (HMMM) improved water resistance in films. Films generally biodegraded within 30 days in soil, achieving between 50–80% mineralization. Both starch and lignocellulosic fiber degraded much more rapidly than PVA. Interestingly, addition of fiber to formulations enhanced the PVA degradation.  相似文献   
178.
Objective: We examined the prevalence of and characteristics associated with drink-driving in China. We compared this study's drink-driving findings with those from the United States to explore how effective traffic safety interventions from Western cultures might be adapted for use in China.

Methods: Data from the 2010 China Chronic Disease and Risk Factor Survey were analyzed to describe the prevalence and characteristics associated with drink-driving in China.

Results: Overall, 1.5% of Chinese adults reported drink-driving in the past 30 days—3% of males and 0.1% of females. However, among males who had driven a vehicle in the past 30 days and consumed at least one alcoholic beverage in the past 30 days, 19% reported drink-driving during the 30-day period. Excessive drinking, binge drinking, nonuse of seat belts, and having been injured in a road traffic crash in the past year were most strongly associated with drink-driving among males.

Conclusions: Drink-driving is prevalent among male drivers in China. Although large differences exist between China and the United States in the proportion of adults who drive, the proportion who consume alcohol, and some of the personal characteristics of those who drink and drive, similarities between the 2 countries are present in patterns of risk behaviors among drink-driving. To reduce injuries and deaths from drink-driving, effective interventions from Western cultures need to be tailored for adoption in China.  相似文献   

179.
Objective: This study investigates the prevalence and characteristics of first drink driving convictions among young Aboriginal and Torres Strait Islander (Indigenous) Australians (aged from 14 to 24) and considers some of the risk factors associated with recidivism.

Methods: Convictions recorded between 2006 and 2013 were extracted from the Queensland Department of Justice and Attorney General database. Convictions were regrouped by gender, age, Accessibility/Remoteness Index of Australia classification, and sentence severity. Chi-square analyses and logistic regression were conducted to identify group differences in offense characteristics for gender and recidivism (recidivists versus nonrecidivists).

Results: The sample consisted of 1,583 individuals (74.1% males) convicted in the 8-year period. Gender comparisons showed that there was no significant difference in age at time of first offense, blood alcohol concentration (BAC) level at apprehension, or type of penalty received between males and females. However, males received larger fines and longer periods of license disqualification. Comparisons for reoffending and non-reoffending revealed that males, drivers aged 14–17 years of age and 18 to 20 years of age, and inner regional drivers were more likely to reoffend.

Conclusions: There were limited differences between females and males or recidivists and nonrecidivists at first conviction. Convictions for drink driving may provide an opportunity for early alcohol intervention with Indigenous young drivers (<20 years) because it is likely to be an individual's first alcohol-related conviction.  相似文献   

180.
Objective: Drunk driving is one of the major behavioral issues connected with problematic alcohol consumption. The objective of this study was to evaluate the relationship between personality traits and social problem-solving skills of individuals who drive while intoxicated.

Method: One hundred forty-four individuals apprehended twice while driving drunk and sent to a driver behavior training program (9 females and 135 males) participated in our study. The Eysenck Personality Questionnaire Revised–Abbreviated (EPQ-RA) composed of 4 subscales (Extroversion, Neuroticism, Psychoticism, and Lying) and the Social Problem Solving Inventory (SPSI) composed of 7 subscales (Cognitive, Emotion, Behavior, Problem Definition and Formulation, Creating Solution Options, Solution Implementation and Verification, and Decision Making) were used to evaluate the participants.

Results: A positive relationship was found between the Extroversion subscale of the EPQ-RA and the Cognition subscale (P <.01), Emotion subscale (P <.01), Behavior subscale (P <.01), Generation of Alternatives subscale (P <.01), Decision Making subscale (P <.05), and Solution Implementation and Verification subscale (P <.01). For individuals who repeated intoxicated driving, all subscales of the EPQ-RA (Extroversion, Lying, Neuroticism, and Psychoticism subscales) explained 12% of the scores of the Cognition subscale and 16.2% (P <.001) of the Emotion subscale of the SPSI. There was no significant relationship between the first and second incident alcohol blood levels (P >.05).

Conclusion: Drinking and driving behaviors appear to be negative or maladaptive behaviors closely related to personality traits and may represent an effort to avoid negative emotions. Evaluation of negative emotions may have an important place in training programs intended to change drunk driving behavior.  相似文献   

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