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81.
为评估VOCs在线监测设备原始监测数据的准确性,建立了一种VOCs在线监测设备数据识别能力的评估方法。结果表明:8种VOCs在线监测设备在数据识别方面的表现存在一定的差异,原始数据与人工审核数据的平均相对偏差为−100%~56 652%;相较于高碳物种,低碳物种的原始数据与人工审核数据平均相对偏差更大;根据应用案例分析提出“数据识别指数”,对不同VOCs在线监测设备的数据识别能力进行定量区分。该方法可为今后VOCs在线监测设备评估工作提供一种全新的考核指标,还可以科学评判其他在线监测设备的快速分析应用能力。  相似文献   
82.
Summary The geometric isomers (E,E)-, (E,Z)-, (Z,E)-, and (Z,Z)-8,10-dodecadien-1-yl acetate were identified as sex pheromone components or sex attractants in the tribes Eucosmini and Grapholitini of the tortricid subfamily Olethreutinae. Species belonging to the more ancestral Tortricinae were not attracted. Each one isomer was behaviourally active in males ofCydia andGrapholita (Grapholitini), either as main pheromone compound, attraction synergist or attraction inhibitor. Their reciprocal attractive/antagonistic activity in a number of species enables specific communication with these four compounds.Pammene, as well as otherGrapholita andCydia responded to the monoenic 8- or 10-dodecen-1-yl acetates. Of the tribes Olethreutini and Eucosmini,Hedya, Epiblema, Eucosma, andNotocelia trimaculana were also attracted to 8,10-dodecadien-1-yl acetates, but several otherNotocelia to 10,12-tetradecadien-1-yl acetates. The female sex pheromones ofC. fagiglandana, C. pyrivora, C. splendana, Epiblema foenella andNotocelia roborana were identified. (E,E)- and (E,Z)-8,10-dodecadien-1-yl acetate are producedvia a commonE9 desaturation pathway inC. splendana. CallingC. nigricana andC. fagiglandana females are attracted to wingfanning males.  相似文献   
83.
为解析再生水补水对城市内河水质的影响,以合肥市塘西河为例,采用一维水动力水质模型,结合模糊模式识别方法,研究再生水补水位置、水质和补水量对塘西河水质的影响。模拟结果表明:再生水补水改变了河流水动力特征、污染物负荷及其扩散降解过程,影响河流水质空间分布,且对补给点附近的河流水质影响最为显著;通过模糊模式识别分析发现,补给点越靠近上游对河流水质的改善作用越大,提高补水水质或增大补水水量均可进一步改善河流水质。  相似文献   
84.
Objective: The purpose of this study was to statistically determine which combination(s) of drug-related signs and symptoms from the Drug Evaluation and Classification (DEC) protocol best predict the drug category used by the suspected drug-impaired driver.

Methods: Data from 1,512 completed DEC evaluations of suspected impaired drivers subsequently found to have ingested central nervous system (CNS) depressants, CNS stimulants, narcotic analgesics, and cannabis were analyzed using a multinomial logistic regression procedure. A set of evaluations completed on drug-free subjects was also included. The relative importance of clinical, behavioral, and observational measures in predicting drug categories responsible for impairment was also examined.

Results: Thirteen drug-related indicators were found to significantly contribute to the prediction of drug category, including being under the care of a doctor or dentist, condition of the eyes, condition of the eyelids, mean pulse rate, assessment of horizontal gaze nystagmus (HGN), convergence, performance on the One Leg Stand (OLS) Test, eyelid tremors, pupil size in darkness, reaction to light, presence of visible injection sites, systolic blood pressure, and muscle tone. Indicators related to the appearance and physiological response of the eye contributed the most to the prediction of drug category, followed closely by clinical indicators and performance on the psychophysical tests.

Conclusions: The findings from this study suggest that drug recognition experts (DREs) should be careful to review a set of key signs and symptoms when determining the category of drug used by suspected drug-impaired drivers. Drug use indicators related to the appearance and physiological response of the eye were found to contribute the most to the prediction of the drug category responsible for the impairment. These results could help form the basis of a core set of indicators that DREs could initially consult to form their opinion of drug influence. This in turn may enhance the validity, effectiveness, and efficiency of drug detection and identification by DREs and lead to a more effective and efficient DEC program, improved enforcement of drug-impaired driving, and greater acceptance of the DEC program by the courts.  相似文献   

85.
王冠宁  邓亮 《火灾科学》2019,28(1):49-59
为实现火灾现场中多股铜导线熔痕的自动识别,采用主成分分析(PCA)和反向传播(BP)神经网络算法对四种多股铜导线熔痕(一次短路熔痕、二次短路熔痕、过负荷熔痕和火烧熔痕)的金相组织进行了识别研究。利用Image-Pro Plus 6.0和Axio-Imaging软件获取每种熔痕30组17维金相组织参数数据,采用PCA对四种熔痕共120组数据降维,获得前6个主成分得分矩阵,建立具有6个输入层节点,10个隐层节点和4个输出节点的神经网络模式识别模型。随机抽取每种熔痕的20组样品的主成分得分矩阵作为训练集,将每种熔痕的剩余10组主成分得分为测试数据,输入最终训练完成的模型进行识别,其识别准确率达到92.5%。实验结果表明采用PCA+BP神经网络的算法,可以较好地实现多股铜导线熔痕识别,为火灾物证鉴定工作提供了有力的工具。  相似文献   
86.
为深入研究PM2.5和PM10质量浓度异常“倒挂”现象的成因及影响,在苏州市相城区国控点开展比对监测分析,回顾性分析了2016—2020年苏州全部国控点颗粒物浓度数据。苏州市相城区国控点PM2.5浓度的比对分析结果表明:该国控点频繁出现PM2.5浓度高于其他国控点PM2.5浓度和高于该站点PM10浓度(“倒挂”率高达34%)的“双高”现象,PM2.5平均浓度比其他9个国控点高12.5%~37.2%,比位于同一站点的备用监测仪器(“倒挂”率为0)高38.1%。2016—2020年,苏州全部国控点“倒挂”时间的总体趋势都是逐年递增,且集中发生在相对湿度较高的20:00至次日07:00。这5年间各国控点PM2.5浓度异常偏高导致的异常“倒挂”现象对全市年均浓度产生的正误差分别为1.6%、2.8%、6.0%、6.2%和4.1%,基本呈现出逐年递增的趋势。上述结果表明:苏州PM2.5浓度偏高是由动态加...  相似文献   
87.
The establishment of fighting rules and the ability to recognise individual conspecifics and to assess their fighting ability and/or roles may help to reduce costs of fighting. We staged encounters between males of the lizard Podarcis hispanica to examine whether lizards used fighting strategies and whether a previous agonistic experience affects the outcome and characteristics of a subsequent encounter. The results showed that simple rules such as body size differences and residence condition were used to determine the outcome of agonistic interactions as quickly as possible. Thus, larger males were dominant in most encounters. However, when size differences between opponents are smaller, they may be more difficult to estimate and, then, residence condition was more important. In addition, the intensity of interactions between males could be explained according to the ”sequential assessment game”, supporting the idea that P. hispanica males acquire information about fighting ability gradually during the progress of a fight. Our results also showed that the second fight of the same pair of males was less aggressive, even when its outcome was the opposite of the first. This result suggests that male P. hispanica can recognise individual opponents and that they use this information to reach a contest outcome more quickly, thus reducing unnecessary aggression levels in subsequent interactions. These fighting strategies and assessment mechanisms may help to stabilise the social system of this lizard. Received: 2 November 1999 / Revised: 26 August 2000 / Accepted: 4 September 2000  相似文献   
88.
A honey bee (Apis mellifera) queen mates with about ten haploid drones, thus producing colonies composed of about ten subfamilies of super-sisters. An increasing but controversial body of literature supports the views that: (1) Members of each subfamily within a colony can recognise each other, and distinguish supersisters from half-sisters. (2) Members of each subfamily use this recognition information and increase the reproductive fitness of their own subfamily at the expense of half-sisters through behaviour termed nepotism. A mathematical model is developed that shows that task specialisation by subfamilies, and bees that repeatedly undertake the behaviour within subfamilies, can influence the numbers of interactions among super-sisters, relative to the numbers of interactions between half-sisters. The model is then evaluated using a data set pertaining to trophallaxis behaviour in a two-subfamily colony. It is concluded that with this data set, task specialisation and subfamily recognition were indeed confounded, suggesting that the apparent subfamily recognition could easily have been an artefact of task specialisation. Correspondence to: B.P. Oldroyd  相似文献   
89.
电子鼻在环境监测中的应用与进展   总被引:6,自引:0,他引:6  
方向生  施汉昌  何苗  蔡强 《环境科学与技术》2011,34(10):112-117,122
电子鼻是一种模拟生物嗅觉工作原理的新形仿生检测系统,通常由交叉敏感的气体传感器阵列和适当的模式识别算法组成,可用于检测、分析和鉴别简单或复杂气味.作为新近发展的检测方法,它具有通用、快速、多功能、使用简单、低成本、便携、可自动化和在线监测等优势,在食品加工、环境临测、公共安全和医学诊断等诸多领域得到广泛的应用.随着在线...  相似文献   
90.
边坡稳定性分析是不确定性问题,伴有随机性的同时兼具模糊性.本文通过运用主成分分析法优选影响岩质边坡稳定性的特性指标,进而构建边坡稳定性模式和待识别边坡的隶属函数,并确定计算贴近度的方法,以此建立了边坡稳定性的模糊识别模型.在通过模型进行实例仿真的过程中,为综合考虑各种因素对边坡稳定性影响程度的大小,用德尔菲(Delph...  相似文献   
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