全文获取类型
收费全文 | 151篇 |
免费 | 8篇 |
国内免费 | 5篇 |
专业分类
综合类 | 22篇 |
化学工业 | 11篇 |
金属工艺 | 3篇 |
机械仪表 | 1篇 |
矿业工程 | 2篇 |
能源动力 | 19篇 |
轻工业 | 25篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
一般工业技术 | 17篇 |
冶金工业 | 4篇 |
原子能技术 | 14篇 |
自动化技术 | 44篇 |
出版年
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 5篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 5篇 |
2013年 | 8篇 |
2012年 | 13篇 |
2011年 | 11篇 |
2010年 | 9篇 |
2009年 | 8篇 |
2008年 | 10篇 |
2007年 | 5篇 |
2006年 | 9篇 |
2005年 | 3篇 |
2004年 | 3篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
排序方式: 共有164条查询结果,搜索用时 796 毫秒
11.
得到了生成元为闭算子的n次积分半群的表示定理,并根据积分半群的C半群的关系,进而得到了n次积分半群的谱映射定理。 相似文献
12.
研究PC12细胞内精脒含量在浓缩铀诱导细胞凋亡中的作用。在PC12细胞中加入浓缩铀DMEM/F12工作液,计算PC12细胞的内照射吸收剂量,运用丹磺酰氯薄层分析技术测定细胞内游离精脒含量。结果表明,随着浓缩铀内照射时间的延长,细胞增殖活性迅速下降,DNA链断裂明显增多,放射性核素迅速渗入细胞核中,AO/EB染色可见凋亡细胞,同时细胞内游离精眯随内照射时程的延长而显著减少。表明浓缩铀可致PC12细胞的凋亡,细胞内游离精脒的含量可能与细胞活性有一定作用。 相似文献
13.
揭示了无穷维线性反应扩散过程和偏微分方程这两种描述反应扩散现象的基本工具的关系,证明了无穷维线性反应扩散过程的大数定理,给出了无穷维线性反应扩散过程的极限状态.讨论了当无穷维线性反应扩散过程的无穷小算子中的参数随指标n变化时,反应扩散过程依概率收敛于一偏微分方程的解的条件,揭示了此偏微分方程的系数与过程的无穷小算子中的参数之间的关系. 相似文献
14.
食品硒源的生物学研究进展 总被引:34,自引:1,他引:34
硒是人体必需的微量元素,对人类健康有重要意义,机体硒的来源主要是食品,本文概述了食品硒源的地域性,硒含量及硒形态差异,并对硒的代谢、生物利用度、组织细胞分布、膳食硒的适宜范围,硒的营养状态评价和富硒功能性食等生物学研究进展进行了综述。 相似文献
15.
把在群论中占有重要地位的同态基本定理和三个同构基本定理推广到幂等元唯一的扭半群中,建立了幂等元唯一的扭半群的同态基本定理和同构基本定理。 相似文献
16.
Piotr Grabowski 《International journal of control》2013,86(8):1539-1563
A model of a heavy chain system with a punctual load (tip mass) in the form of a system of partial differential equations is interpreted as an abstract semigroup system on a Hilbert state space. Our aim is to solve the output motion planning problem of the same nature as in the case of an unloaded heavy chain (Grabowski, P. (2003), ‘Abstract Semigroup Model of Heavy Chain System with Application to a Motion Planning Problem’, in Proceedings of 9th IEEE International Conference: Methods and Models in Automation and Robotics, 25–28 August, Mi?dzyzdroje, Poland, pp. 77–86 (IS1-2-3.PDF)). In order to solve this problem we first analyse its well-posedness and some basic properties. Next, we solve the output motion planning problem using a substitute of the inverse of the input–output operator represented in terms of the Laplace transforms. A problem of exponential stabilisation is also formulated and solved using a stabiliser of the colocated type. The exponential stabilisation is proved using the method of Lyapunov functionals combined with some frequency-domain tools. The method of Lyapunov functionals can be replaced by the spectral or exact controllability approach as shown in the second part (Grabowski, P. (2008), ‘The Motion Planning Problem and Exponential Stabilisation of a Heavy Chain. Part II’, Opuscula Mathematica, 28 (2008) (Special issue dedicated to the memory of Professor Andrzej Lasota), 481–505) of the present article. A laboratory setup which allows verification of the results in practice is described in detail. Its dynamical model is used as an example to illustrate the theoretical results. 相似文献
17.
A fortified food that was rich in protein, vitamins and iron made of chickpea, bovine lung and corn was developed with the aim of controlling iron-deficiency anaemia in children from poorer areas. It was tested in Teresina, State of Piauí, Northeastern Brazil, on a population with high anaemia prevalence. Two local daycare units with similar characteristics were selected and the children at one of them received a 30 g pack three times a week, representing a total iron daily intake of 6.96 mg. The other daycare unit was followed as a control. The capillary haemoglobin concentration was determined for the children at both daycare units, at the beginning of the study and after a two-month intervention period. The mean haemoglobin concentration in the test group at the beginning of the intervention was 11.8 g/dL, which increased to 13.1 g/dL at the end of the intervention. In the control group these figures remained practically constant (11.6–11.8 g/dL). These represented a dramatic and significant drop in anaemia prevalence, from 61.5% to 11.5% in the test group, and an insignificant reduction (63.1–57.7%) in the control group. The acceptance of the fortified snack was excellent and no undesirable effects were observed. 相似文献
18.
I. Sugai Y. TakedaH. Kawakami N. OhtaH. Makii H. Miyatake 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,655(1):24-33
Accurate measurement of the cross-section of the 12C(α, γ)16O reaction is very important in nuclear astrophysics. Enriched 12C targets prepared with the high energy vibrationl powder plating [HIVIPP] method for this purpose have been used successfully. Initially, however, the 12C deposits for studying this small cross-section partially peeled from their Au backings when irradiated with beam currents≥2 times the 7 μA pulsed α-beam used previously. This problem was solved when the amorphous 12C powders were converted to graphite by heat-treatment in a high-temperature furnace. We investigated powder heat treatments at temperatures of 2600-3500 °C to reveal, which conditions resulted in uniform and highly adhesive depositions on Au backings. 相似文献
19.
Development of intelligent decision-making systems which operate in complex environments like an automated factory, needs effective procedures for combining evidence from a variety of sources. Currently there are many ad-hoc evidence combination formulae as well as those based on specific methodologies such as the Bayesian, likelihood, etc. However, the limitations of these approaches have been well documented. In this paper, we begin with the testable and desirable properties required in a special problem. These properties are termed as axioms. We then systematically develop various families of combination rules obeying subsets of these axioms. The existing combination formulae form a subset of the rules mentioned here. We discuss the appropriateness of the different families of combination formulae.Partially supported by the Office of Naval Research under the grant N00014-85K-0611 and NSF under the grant IST 8405052. 相似文献
20.
T. Sanz A. Salvador A. Jiménez S. M. Fiszman 《European Food Research and Technology》2008,227(5):1515-1521
In the asparagus-processing industry, the by-products constitute around 50% of the total weight. These by-products are rich
in fibre and bioactive compounds which could be advantageously employed in human nutrition. In the present work, yogurts were
enriched with fibre obtained from the non-edible part of asparagus shoots to assess how the method of extraction (water or
ethanol) and then drying (oven or lyophilisation) affects its performance. Fibre incorporation increased the consistency of
the yogurts (higher η, G′, G″), especially if the fibres had been extracted in ethanol and lyophilised. However, there were no significant changes in
the viscoelastic behaviour (tan δ) for any of the fibre types. Fibres diminished the clarity and imparted a yellow-greenish
colour to the yogurt, which also varied depending on the method of extraction and drying, the yogurts with water-extracted
fibres being more colourful. The sample more liked according to a consumer test was the yogurt containing water-extracted
and oven-dried fibre for aroma, taste, texture, and overall acceptance, and ethanol-extracted and lyophilised for colour.
The consumer panel scored all the samples around to the neutral point “neither like nor dislike”, demonstrating that fibre
obtained by all methods were equally compatible with yoghurt enrichment. 相似文献