全文获取类型
收费全文 | 1092篇 |
免费 | 150篇 |
国内免费 | 99篇 |
专业分类
电工技术 | 15篇 |
综合类 | 72篇 |
化学工业 | 51篇 |
金属工艺 | 3篇 |
机械仪表 | 20篇 |
建筑科学 | 40篇 |
矿业工程 | 13篇 |
能源动力 | 10篇 |
轻工业 | 260篇 |
水利工程 | 1篇 |
石油天然气 | 184篇 |
武器工业 | 7篇 |
无线电 | 51篇 |
一般工业技术 | 50篇 |
冶金工业 | 46篇 |
原子能技术 | 1篇 |
自动化技术 | 517篇 |
出版年
2024年 | 4篇 |
2023年 | 21篇 |
2022年 | 18篇 |
2021年 | 33篇 |
2020年 | 49篇 |
2019年 | 39篇 |
2018年 | 39篇 |
2017年 | 33篇 |
2016年 | 62篇 |
2015年 | 58篇 |
2014年 | 77篇 |
2013年 | 92篇 |
2012年 | 75篇 |
2011年 | 78篇 |
2010年 | 89篇 |
2009年 | 70篇 |
2008年 | 84篇 |
2007年 | 89篇 |
2006年 | 63篇 |
2005年 | 66篇 |
2004年 | 40篇 |
2003年 | 43篇 |
2002年 | 24篇 |
2001年 | 17篇 |
2000年 | 9篇 |
1999年 | 6篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 7篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 5篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1965年 | 1篇 |
1964年 | 3篇 |
1963年 | 3篇 |
1960年 | 2篇 |
1955年 | 2篇 |
排序方式: 共有1341条查询结果,搜索用时 31 毫秒
1.
针对在传统的客户流失预测数据预处理中,使用one-hot编码处理离散属性导致数据维度增加及数据过于稀疏的问题,提出了两种基于多层感知机的改进后的客户流失预测模型。其主要思想是分别使用堆叠自编码器和实体嵌入两种方法对多层感知机进行改进,通过将离散属性的高维编码数据向低维空间映射,有效地减少了one-hot编码产生的稀疏数据,增加了离散属性值之间的关联度。在对两份公开的数据集进行交叉验证后的实验结果表明,改进后的模型既有效地提高了预测的准确度,又维持了传统多层感知机模型在并行化计算方面的优势。 相似文献
2.
Jiewu Leng 《国际生产研究杂志》2018,56(15):5131-5146
Evaluation on collaborative manufacturing network (CMN) structure characteristics has important implications for network operations such as production decision-making, product recovery, creating consensus. Several recent studies suggest that augmenting network structure with nodes’ attributes can provide a more fine-grained understanding of the network. However, there have been few studies to provide a systematic understanding of these effects in a CMN at scale. This gap is bridged using an industrial printing machinery CMN data-set collected on a web-based producing and outsourcing service platform. Novel phenomena with respect to both interaction and attribute metrics across and within the CMNs are observed. Moreover, although many studies employ either interaction or attribute data to study the relative roles of manufacturers in a CMN, relatively little is known about the relationship between these two types of data. This study explores this relationship by comparing two defined metrics (i.e. relational capability and node capability), which evaluate the manufacturers’ interactions and attributes, respectively. We examine to what extent the two metrics of manufacturers correlate with each other, and how possible dissimilarities and similarities can be explained based on the collected industrial CMN data-set. The insights thereby provide a better basis for efficient operations decision-making in CMN. 相似文献
3.
The aim of the study was to identify the importance of individual food product attributes (the use of preservatives, processing method, shelf-life period and nutritional value) as well as their relation to the purchase behaviour. To achieve this, consumer preferences were decomposed in conditions of full access to information, and data was compared with actual consumer behaviour related to making purchasing decisions in front of the store shelf. Based on data from 338 respondents, conjoint analysis and repeated ANOVA measurements were carried out, allowing to eliminate individual behavioural patterns. The results showed a dissonance between the consumers attitudes towards the attributes and their shopping behaviour. The processing method was the most important declared attribute for consumers, meanwhile this information was the least searched for during purchase. At the same time, shelf-life period marked as the least important was the main information searched for by consumers when shopping. The results also show a clear dislike towards the use of microwaves as a preservation method, while traditional thermal preservation was marked as the most positive for consumers. In addition, consumers were classified into 3 heterogeneous groups, identifying differences in the preferences of food attributes. The obtained results have practical value relating not only to the preferences of individual attributes, but also to their various variants. The results can be a guide for companies to properly label food products. The indicated dissonance illustrates the educational gap and related insufficient motivation to get to know the product before buying it. This is extremely important in connection with technological development and new food processing methods. 相似文献
4.
This research shows the effect of simultaneous contrast on a design solution that generates it, and it also shows how its manifestation affects the shift of perception attributes of the observer's color. In the conducted research, 55 subjects had to harmonize the primary stimuli from the reproduction obtained with the help of digital printing technology, with the primary stimuli presented on two computer screens. As a visual harmonization technique, simultaneous binocular harmonization was used. The primary stimuli were made achromatic, with a 50% Raster Tone value (RTV), and are surrounded by achromatic secondary stimuli whose values increase in steps from 10% RTV up to 100% RTV. A shift in the perceptual attributes of color has been shown with the help of the CIEDE2000 system. Using ANOVA with repeated-measures and Fisher's post hoc analysis, statistically significant differences were found between the perceived means of shift in the ΔC00 chroma and ΔL00 lightness on defined samples on both computer screens, while in the case of the ΔH00 hue, no statistically significant differences were observed. The research also determined colorimetric differences in the ΔE00 color difference. Moreover, the student's t test was used to determine that the effect is stronger when manifested on the Lenovo computer than on the Asus computer screen (P < .05). 相似文献
5.
Sergey G. Kopysov Aleksandr A. Erofeev 《The International journal of environmental studies》2015,72(3):380-385
The landscape conditions for forming the water balance and runoff from catchment areas can change considerably under the pressure of natural and anthropogenic factors. The role of hydromorphic transformation of landscapes is important for most of the Ob basin; it results in the paludification of the area. The specific parameter n is used in calculating water balance according to Mezentsev’s method of hydro-climatic calculations to take account of landscape conditions. We suggest determining this parameter’s value by geomorphological features of the landscapes using GIS tools. 相似文献
6.
《Egyptian Journal of Petroleum》2015,24(2):119-130
The determination of the most unstable areas in oil fields is critical for addressing engineering problems of wellbore and sand production as well as geologic problems such as understanding dynamic constraints on hydrocarbon migration and fracture permeability. In this research work, coherency seismic attribute has been used for the determination of the most critical areas in terms of drilling stabilities in the DQ oil field, Iran. The results obtained have shown that the (1) predominant features are the SSE–NNW and N–S trends (2) the central part of the DQ structure shows the highest concentration of segment bundles, (3) the segment bundles seem to be aligned along some lineaments oriented SE–NW and SSE–NNW, and (4) on the eastern and western margins of the map there is an anomalous concentration of segments oriented E–W. It can be concluded that coherency attribute is a valuable tool for structural analysis highlighting those areas containing unstable features. 相似文献
7.
"三缺一"情境下的空间演绎与营造——广州图书馆新馆设计竞赛评析 总被引:1,自引:0,他引:1
本文简要介绍了广州图书馆新馆设计国际邀请竞赛的背景和概况,分析了项目基地的特殊空间情境,从建筑体量的呼应、空间形态的协调、图书馆文化特性的缔造等几个方面,对竞赛方案的空间环境演绎与营造进行评析,探讨了相应的设计方法和策略,以期对国内类似的工程建设提供参考。 相似文献
8.
With the availability of a myriad of intelligent building components or products in the market, the decision to choose between them becomes significant and crucial in the configuration of building alternative. This results in placing the decision makers in the selection ‘dilemma’. This paper presents the development of a conceptual model for the selection of intelligent building systems which aims at assisting the decision makers to select the most appropriate combination of intelligent building components. The paper commences by reviewing the literature on intelligent building research. A survey is conducted to examine the criticality of selection attributes. Findings of this survey enrich the field of intelligent building research in at least two ways. Firstly, it widens the understanding of the factors, as well as their degree of importance, in affecting the selection of intelligent building systems and components. Second, the identified selection attributes form a conceptual framework which can be used to guide the selection of intelligent building components. 相似文献
9.
10.
Alicia Mazur Anne Pisarski Artemis Chang Neal M. Ashkanasy 《International Journal of Project Management》2014
In this paper we develop and test a model of the associations between major project managers' personal attributes and project success in the context of the Australian Defence industry. In our model, emotional intelligence, cognitive flexibility and systemic thinking were hypothesised to relate to project success, mediated by internal and external stakeholder relationships. The model was tested in an online survey with 373 major project managers. Emotional intelligence and cognitive flexibility were found to be related to the development, quality and effectiveness of major project managers' relationships with both internal and external stakeholders; and these in turn were associated with their ratings of project success. Systemic thinking, however, had no relationship with either stakeholder relationships or project success. Additional research is needed to examine the contribution of a wider range of personal attributes to stakeholder relationships and project success, and to assess whether this model is applicable in other industries and types of projects. 相似文献