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排序方式: 共有1005条查询结果,搜索用时 15 毫秒
791.
J. S. Nairne, S. R. Thompson, and J. N. S. Pandeirada (2007) suggested that our memory systems may have evolved to help us remember fitness-relevant information and showed that retention of words rated for their relevance to survival is superior to that of words encoded under other deep processing conditions. The authors present 4 experiments that uncover the proximate mechanisms likely responsible. The authors obtained a recall advantage for survival processing compared with conditions that promoted only item-specific processing or only relational processing. This effect was eliminated when control conditions encouraged both item-specific and relational processing. Data from separate measures of item-specific and relational processing generally were consistent with the view that the memorial advantage for survival processing results from the encoding of both types of processing. Although the present study suggests the proximate mechanisms for the effect, the authors argue that survival processing may be fundamentally different from other memory phenomena for which item-specific and relational processing differences have been implicated. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
792.
Bryan T. Mayer James S. Koopman Edward L. Ionides Josep M. Pujol Joseph N. S. Eisenberg 《Journal of the Royal Society Interface》2011,8(57):506-517
The most commonly used dose–response models implicitly assume that accumulation of dose is a time-independent process where each pathogen has a fixed risk of initiating infection. Immune particle neutralization of pathogens, however, may create strong time dependence; i.e. temporally clustered pathogens have a better chance of overwhelming the immune particles than pathogen exposures that occur at lower levels for longer periods of time. In environmental transmission systems, we expect different routes of transmission to elicit different dose–timing patterns and thus potentially different realizations of risk. We present a dose–response model that captures time dependence in a manner that incorporates the dynamics of initial immune response. We then demonstrate the parameter estimation of our model in a dose–response survival analysis using empirical time-series data of inhalational anthrax in monkeys in which we find slight dose–timing effects. Future dose–response experiments should include varying the time pattern of exposure in addition to varying the total doses delivered. Ultimately, the dynamic dose–response paradigm presented here will improve modelling of environmental transmission systems where different systems have different time patterns of exposure. 相似文献
793.
794.
Frank L. Ward Patrick O'Kelly Fionnuala Donohue Coilín O'Haiseadha Trutz Haase Jonathan Pratschke Declan G. deFreitas Howard Johnson Conall M. O'Seaghdha Peter J. Conlon 《Hemodialysis international. International Symposium on Home Hemodialysis》2015,19(4):601-608
Socioeconomic status (SES) has been linked to worse end‐stage kidney disease survival. The effect of SES on survival on chronic dialysis, including the impact of transplantation, was examined. A retrospective, observational study investigated the association of SES with dialysis patient survival, with censoring at time of transplantation. Adult patients commencing dialysis from 1990 to 2009 in an Irish tertiary center received a spatial SES score using the 2011 Pobal Haase‐Pratschke Deprivation Index and were compared by quartile. Cox proportional hazard models and Kaplan–Meier survival analysis examined any association of SES with survival. The 1794 patients included had a median follow‐up of 3.8 years. Patients in the lowest SES area quartile were significantly younger than the highest, mean age 56.7 vs. 59 years, P = 0.006, respectively. There was no association between SES area score and survival in an unadjusted model (hazard ratio [HR] 1.00, 95% confidence interval [CI] 0.99–1.01). Survival in the highest SES area quartile was superior to the lowest SES in a multivariable adjusted model including age, gender, and dialysis modality (HR 0.83, 95% CI 0.70–0.99, P = 0.04). These results were only mildly attenuated by censoring at time of transplantation (highest SES area quartile deprived vs. lowest SES area quartile, HR 0.85, 95% CI 0.70–1.03, P = 0.09). Superior patient survival was identified in the highest SES areas compared with the lowest following age‐adjusted analyses, despite the older population in the most affluent areas. Further research should focus on identifying modifiable targets for intervention that account for this socioeconomic‐related survival advantage. 相似文献
795.
为了解决标准粒子群算法在无人机三维路径规划中存在的易陷入局部最优、动态化不足和路径平滑性差等问题,提出了一种基于粒子群算法和遗传算法的,融入K均值精英化和柯西变异的优化算法;采用K均值聚类算法进行精英初始化,优化粒子种群的分布;动态化学习因子,强化惯性权重的全局性,保留粒子群算法收敛速度快的优点;融入遗传思想,采用柯西变异的方法,提高寻解最优解的能力;在对比实验中,模拟了实际的复杂三维环境,选取了路径总长度、飞行高度差以及马尔科夫生存状态组成目标函数;结果表明改进算法的鲁棒性提高了98%,求解质量相较于IPSO算法和PSO算法分别提高了5.8%和10.6%,验证了优化后方法的有效性和鲁棒性。 相似文献
796.
针对高通量测序技术因各种原因导致的DNA甲基化测序数据中包含部分缺失值的问题。提出一种基于变分自编码器的DNA甲基化缺失数据填补模型VAE-MethImp。VAE-MethImp是一种深度隐含空间生成模型,由编码层、隐含层和解码层组成,拥有强大的重构输入数据能力。编码层进行均值和方差的推断;隐含层是通过编码层输出的均值和方差计算出的输入数据的专属正态分布;解码层对隐含层包含的特征进行解码生成重构后的数据。通过在肺癌和乳腺癌上的填补实验证明,VAE-MethImp提取的特征更具信息性。在填补精度上,VAE-MethImp比对照方法(均值(Mean)、最近邻(KNN)、主成分分析(PCA)和奇异值分解(SVD))中最优的SVD提升了4.8%。生存分析实验结果显示VAE-MethImp填补的数据具有更好的预测性,同时也证明DNA甲基化与癌症的生存存在直接关联。 相似文献
797.
肺癌是一种严重威胁患者生命的恶性肿瘤。通过对肺癌病人进行生存预测分析并制定针对性治疗方案,对提高病人生存率具有重要意义。提出一种基于病理学图像的肺癌患者生存预测分析方法。首先采用深度学习方法对病理学图片进行肺癌细胞自动检测,并对检测出的肺癌细胞进行特征提取。在特征选取中,引入了反映肺癌细胞间关系和分布特性的拓扑特征的提取方法,将提取的拓扑特征作为生存分析的预测因素。最后采用Cox-Lasso方法对肺癌患者进行生存预测分析。实验结果表明,该方法能够提高细胞检测的效率和准确性,并具有较高的肺癌患者生存预测分析能力。 相似文献
798.
Mohammad Ghasem Akbari 《International journal of systems science》2017,48(15):3305-3315
This paper extends some basic concepts associated to record value based on intuitionistic fuzzy random variables. In this approach, αβ-values of intuituinistic fuzzy numbers are employed to construct intuitionistic fuzzy cumulative distribution function and its common estimator, an extended entropy and its estimator, intuitionistic fuzzy (upper) record value and its common estimator. Main property of the proposed concepts include large sample properties which are investigated in the space of intuitionistic fuzzy numbers. Some numerical examples are also illustrated to clarify the concepts and methods. 相似文献
799.
从通信技术的发展、战场环境的变化、战场生存条件的改变以及对抗技术发展的瓶颈等4个方面,针对与通信电子战密切相关的抗干扰、网络化、新技术及新体制等,针对电磁环境、作战空间、作战样式及对抗思路等的变化,介绍了其发展变化,并分析了其对通信电子战带来的多方面挑战,基于各种挑战分析提出了通信电子战的发展措施。 相似文献
800.
José Peinado Nieves López de Lerma Angela Peralbo-Molina Feliciano Priego-Capote Cristina de Castro Brian McDonagh 《Journal of Functional Foods》2013,5(4):1566-1575
Sunlight exposure is a traditional way to dry postharvested white Pedro Ximenez grapes, and the dried grapes are the basis of a sweet fortified wine elaborated in the South of Spain. In this paper, we have studied the effect of seven days of exposure of grapes to sunlight. The phenolic content in the skins and flesh has been determined. The transient induction of phenolics has been detected and identified in skins by HPLC and MS/MS. Maximum induction was after 2 days exposure with an increase in the levels of quercetin-3-O-glucoside, engeletin (dihydrokaempferol-3-O-rhamnoside) and astilbin (taxifolin 3-O-rhamnoside). We have evaluated the antioxidant and protective effects of the phenolic extracts of these grapes in Saccharomyces cerevisiae after exposure to H2O2. Phenolic extracts reduced the basal intracellular level of peroxides in a concentration dependent manner. There was a corresponding significant reduction in carbonylated proteins in treated and control cells and increased survival of yeast cells exposed to H2O2. Our results indicate that sundried grapes display a high antioxidant capacity resulting in a decrease in the oxidative cellular environment. 相似文献