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81.
李新学 《大学化学》2019,34(11):27-32
以积累化学知识为基础,以提升综合素质为目标,探讨了化学与社会课程考核中强化育人价值的途径。始终贯穿立德树人的理念,采用形成性评价考核方式,在课堂测试、课堂讨论、课堂辩论、实验课开设、论文写作、期末测试等环节,注重培育大学生的社会责任感、自主学习能力、实践意识和创新精神。  相似文献   
82.
We developed a read-across workflow using the OECD QSAR Toolbox for the prediction of skin irritation and corrosion. In the workflow, we gathered analogues using an improved profiler for skin irritation and corrosion to define valid categories. In addition, we refined categories by removing chemicals based on melting points and structural features. Finally, prediction results were obtained using our self-determined rule for read-across. In this rule, we decided the number of analogues from which the read-across is performed, analogue selection criteria (i.e. high similarity vs. near log Pow) and prediction rule (i.e. majority vs. unanimity). We created a program for the optimization of read-across workflows. We applied this program to 313 chemicals in the training set and sought the optimized workflows among >1000 possible choices of profilers and ways of subcategorization and data gap filling. Use of the optimized workflows provided highly accurate, unbiased, user-independent and reproducible read-across predictions. The prediction results obtained from read-across workflows can be used for the selection of in vitro test methods or as part of the weight-of-evidence approaches in the Integrated Approach on Testing and Assessment for skin irritation and corrosion. Moreover, these results can be used for screening purposes and/or preliminary hazard assessment.  相似文献   
83.
水溶性有机物荧光特性是评价有机废弃物堆肥腐殖化程度的重要手段之一。针对现有方法大都局限于腐殖化程度的定性表征等问题,基于投影寻踪方法,该研究开展了堆肥腐熟程度分级评价的定量表征。通过对不同来源有机废弃物堆肥过程中样品水溶性有机物(DOM)荧光特性参数获取,采用统计分析表明,荧光参数I436/I383,FLR,PHA/Pro,A4/A1,r(A,C)两两之间显著相关(p<0.01),可作为综合评价指标。在此基础上,确定完全腐熟(Ⅰ级)、较腐熟(Ⅱ级)、基本腐熟(Ⅲ级)、未腐熟堆肥(Ⅳ级)4个腐熟等级荧光参数取值区间。模型运算得到各等投影值分别为2.01~2.22(Ⅰ级)、1.21~2.0(Ⅱ级)、0.57~1.2(Ⅲ级)、0.10~0.56(Ⅳ级)。模型验证证实,各样品的实际腐熟度等级与模型所得到腐熟与未腐熟样品的评价结果准确率为100%,因此,该评价方法对有机废弃物的实际堆肥具有重要的指导意义。  相似文献   
84.
In older adults, social participation is an important component of rehabilitation and health promotion. Several studies have attempted to describe the definition and concepts of social participation, and there were many outcomes to measure social participation. This overview provides information about representative social participation and related concepts that have been defined in the literature. A standardized definition of social participation has not been developed; commonly, recognition for social participation was proposed as focused on involvement in social activities that provide interaction with others in a society or community. Many instruments assess the various aspects of social participation. Because of operational definition and diversity in social participation, performance in social participation was adopted as an aspect of assessment. Further discussions are needed to clarify the definition of social participation and evaluate the instruments used to assess social participation for it to be useful for rehabilitation and health promotion. In doing so, determining and developing assessment and intervention based on the purpose or perspective of social participation in older adults with and without disabilities is important.  相似文献   
85.
为了提高小样本下火工品可靠性评估的精度,研究了升降法实验及其数据分析方法。结合火工品升降法实验数据的特点,给出了一种数据填充方法,把二元成败型数据转化为虚拟完全样本数据。模拟结果表明,与基于二元成败型数据的估计相比,基于虚拟完全样本数据的位置参数估计基本一致,而刻度参数估计具有更优的统计性质。利用该虚拟样本数据,结合信仰推断方法,给出了火工品可靠性评估方法。最后将该方法应用于某产品的可靠性评估,并与大样本评估方法进行了比较,表明该方法可以在较小样本下实现对高可靠性火工品的可靠性评估。  相似文献   
86.
矿井突水危险性评价模型   总被引:1,自引:0,他引:1  
王连国  宋扬 《力学学报》2001,9(2):158-163
用数量化理论 (Ⅱ) 〔1〕研究了矿井突水危险性评价问题, 建立了一个实用的矿井突水危险性评价模型, 为煤矿安全评价开辟了一条新途径。  相似文献   
87.
Coffee is a beverage that people enjoy a lot in their daily lives and is an integral part of people's social life. In this study, the detection of ochratoxin A (OTA) in coffee was carried out by High-performance liquid chromatography with fluorescence (HPLC-FLD) detectors. Furthermore, the amount of ochratoxin A (OTA), Margin of exposure (MOEs), and Hazard quotient (HQ) in different types of coffees; instant, classic, and roasted coffee were calculated using Monte Carlo simulation (MCS) method. The average OTA concentration was in the rage of 3.6 to 26.6 µg/kg. The content of classic and instant coffee found to have.OTA, is below the maximum limit defined by the European Union legislation. The maximum limit for these two types of coffee is 10 µg/kg. The daily intakes of the OTA through classic and instant coffee were also found to be lower than the Tolerance daily intake proposed by Joint FAO/WHO Expert Committee on Food Additives (JECFA). MOEs (neoplastic effect) in adults was classic coffee (171026) > roasted coffee (15390) > instant coffee (8549) and also MOEs (non-neoplastic effects) in children was classic coffee (55790) > roasted coffee (5020) > instant coffee (2789). Consumers of instant coffee are at cancer risk based on neoplastic effects and also consumers of instant coffee and roasted coffee are at cancer risk based on non-neoplastic effects (MOEs lower than 10,000 value). HQ (nephrotoxic effect) in adults was instant coffee (0.132) > roasted coffee (0.097) > classic coffee (0.012). HQ due to consumption of coffee products was lower than 1, hence consumers are at safe non-cancer risk. Therefore, it is recommended reducing the concentration of mycotoxins in coffee products.  相似文献   
88.
在某区拟建隧洞沿线的条带状区域进行了放射性环境地质调查。共采集和分析岩土(芯)放射性核素镭、钍、钾样品111组,地下水和地表水样品5组;现场测定岩土放射性样品392组。结果表明,在该区域内,某煤矿巷道中煤层和砂岩接触带煤、砂岩中镭-226比活度出现高值异常,相应的内照射指数和外照射指数也超过相关标准中规定的放射性核素限量,该异常带环境γ辐射剂量率也较高。镭-226的富集可能源于煤中有机质对放射性核素的吸附和解吸过程。建议在隧道选线过程中尽力避让这一地段。  相似文献   
89.
魏振宏  陈虹  孙丰全 《光谱实验室》2010,27(4):1443-1445
在仪器最佳条件下,样品经前处理后,采用ICP-MS和AAS2种方法测定无公害大气总悬浮颗粒物中铅及其化合物的含量,最终2种方法的测定结果一致,但ICP-MS线性范围宽、检出限低、精密度好。  相似文献   
90.
刘祯耀  郭斌  王林平 《力学季刊》2020,41(1):179-186
本文基于中国新车评估规程,对高速车辆正面相撞和高速测试车辆与静态车辆侧面相撞这两种工况进行了碰撞数值模拟,采用HYPERMESH进行建模和LS-DYNA进行仿真分析计算.分析结果表明,在正面碰撞中,前保险杠与阻挡壁接触发生弯曲和变形,随着碰撞时间的持续,发动机的副车架弯曲,导致乘客舱的侵入量明显增加.侧面碰撞中,B柱和测试车辆的蜂窝结构发生严重变形,发动机舱结构的褶皱吸收大量的冲击能量.通过改进车辆结构,A柱的侵入量从80 mm减小到40 mm,脚部空间的侵入量从210 mm减少到150 mm.侧面碰撞时B柱的窗口边缘处的侵入量与下部的侵入量也均满足安全要求.  相似文献   
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