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The tackle event in rugby, places both ball-carrier and tackler at a high risk of injury at all levels of play. To reduce this risk of injury, risk factors need to be identified. Attitude and behaviour have been identified as risk factors for injury in other sports, and probably also have a role in rugby. The purpose of this study was to assess the attitude and behaviour of players in training and match play with regards to safety and performance. A questionnaire was designed to assess attitude (importance) and behaviour (frequency and quantity) among junior (under 19) players on a 5-point Likert Scale. Questionnaires were handed out to 220 players (10 schools) at a tournament and 75% (9 schools, n = 164) were returned for analysis. During training and match play, players’ mean ratings were higher for improving performance than for injury prevention. However, a level of importance was evident for injury prevention. When executing a tackle the aim is to dominate the contact situation and prevent the ball-carrier from gaining territory and retaining the ball. Therefore, players, coaches and administrators need to find the most suitable balance between injury prevention and performance during training within their team setting. This process may be facilitated by modifying the current equipment and training drills used to train the tackle, and the time of season during which tackle technique training occurs. Equally important, players should learn proper tackle technique at a younger age, with the importance of safety emphasised from all information sources.  相似文献   
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Blaine Creek is a fifth-order stream located in eastern Kentucky that has been subject to contamination by oil brines, surface mining, and a coal fly ash settling pond discharge. Toxicity tests, effluent and receiving water chemical monitoring, and Blaine Creek benthic sampling were used to evaluate the effect of the ash pond effluent on the creek. Reproductive impairment of Ceriodaphnia was demonstrated at effluent concentrations ranging from 30 to 100%, but no instream impact on benthic invertebrates could be found at effluent flows that provided up to 65% of the creek's discharge. Correlation and regression analysis of physicochemical versus benthic monitoring data indicated that upstream oil brine contamination and scouring of the creek's predominately shifting sand substrate during rainfall events were the primary factors affecting the benthic fauna, and appeared to override potential effects from other sources. These results demonstrated the value of integrated field/laboratory investigations for effluent impact assessments.  相似文献   
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Water quality must be considered in the development and planning aspects of water resource management. To accomplish this, the decision-maker needs to have at his disposal a systematized procedure for simulating water quality changes in both time and space. The simulation model should be capable of representing changes in several parameters of water quality as they are influenced by natural and human factors impinging on the hydrologic system. The objective of this work is two-fold. The first goal is to demonstrate the feasibility of developing and utilizing a water quality simulation model in conjunction with a hydrologic simulation model. The model represents water quality changes in both time and space in response to changing atmospheric and hydrologic conditions and time-varying waste discharges at various points in the system. This model has been developed from and verified with actual field data from a prototype system selected for this purpose. The second aim is to set forth procedural guidelines to assist in the development of water quality simulation models as tools for use in the quality-quantity management of a hydrologic unit.  相似文献   
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INTRODUCTION: It is likely that youth living on minority operated farms (<3% of U.S. farms) face hazards similar to the general farm population; however, since minority youth are not well represented by general farm surveys, this information hasn't been confirmed. METHOD: Nonfatal injury and exposure data were obtained from the 2000 Minority Farm Operator Childhood Agricultural Injury Survey (M-CAIS). RESULTS: On racial minority farms, there were an estimated 28,600 household youth. Of these, about 41% worked, 26% rode a horse, 23% drove an ATV, and 23% operated a tractor. On Hispanic farms, there were an estimated 17,998 household youth. Of these, 44% worked, 30% rode a horse, 27% drove an ATV, and 25% operated a tractor. CONCLUSIONS: These results show the value of conducting a survey of minorities to identify high risk groups and target issues that may be unique to the minority farm population.  相似文献   
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ABSTRACT Minicomputer interfaced, continuous, noncontact sensing of the ventilatory behavior of the bluegill (Lepomis macrochirus) was used to investigate the response to exposure to solutions of copper and zinc under various modes of application. The results of these studies indicate that fish respond to sublethal concentrations of these toxicants by increasing the average ventilatory rate as well as decreasing the amplitude of the ventilatory signal. Appropriate statistics for the analysis of these data are also described.  相似文献   
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Trace element concentrations of the lichen, Flavoparmelia caperata, were determined by neutron activation analysis before and after stringent participate controls were employed in an industrialized section of the Ohio River Valley; Initial studies in 1973 showed elevated concentrations of arsenic, cobalt, iron, vanadium, and titanium in lichens collected near coalfired power plants. Elevated values for cerium, chromium, and lanthanum were found in samples near a ferro-alloys foundry. A repeat study in 1987 demonstrated that lichen trace element concentrations were much lower after improved particulate controls were installed on the power plants and ferro-alloys foundry.  相似文献   
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Since 1972, 10 benthic surveys and 9 static fish bioassays have been conducted to assess the impact of AVTEX Fibers, Inc. effluent on the lower South Fork of the Shenandoah River. AVTEX (formerly FMC Corp.) is a rayon and polyester fibers plant located in Front Royal, Virginia. Benthic samples were taken at four stations, one above and three below the plant discharges. Single surveys in 1972 and 1973 indicated a severe impact on the benthic community along the right side of the river, below the plant, as a result of the channelized effluent. Diversity values (¯d) were low (0–2.42) and numbers of taxa and organisms were reduced. A fish bioassay in 1973 indicated the effluent to be acutely toxic at the 34.5% level (mixture of effluent and river water). In early 1974, FMC Corp. constructed an activated sludge treatment system to reduce BOD and supplement the neutralization and chemical precipitation (zinc hydroxide and liquid-solid separation) facilities that had been used to treat waste waters since 1948. After the new equipment was placed in operation, the previously stressed area became more stable. In 1975 and 1976 the stressed area exhibited greater ¯d values (1.19–3.39) and an increased number of taxa and organisms. Bioassays showed the effluent to be acutely toxic to fish only once since 1973. The major improvements in the effluent were a 70% reduction in BOD5 and a 60% reduction in the amount of zinc entering the river. Community conditions in 1977 indicated a partial remission of improvement, probably due to drought conditions.The rehabilitation of damaged ecosystems is a process important to all biologists. An important factor in encouraging industry to participate in this activity is evidence that improved waste treatment will often have demonstrable biological benefits rather soon. As data accumulate on the recovery process it may be possible to predict the degree of rehabilitation and time required more precisely.  相似文献   
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