全文获取类型
收费全文 | 370篇 |
免费 | 27篇 |
专业分类
电工技术 | 8篇 |
综合类 | 1篇 |
化学工业 | 150篇 |
金属工艺 | 8篇 |
机械仪表 | 8篇 |
建筑科学 | 10篇 |
能源动力 | 22篇 |
轻工业 | 59篇 |
无线电 | 27篇 |
一般工业技术 | 60篇 |
冶金工业 | 9篇 |
原子能技术 | 1篇 |
自动化技术 | 34篇 |
出版年
2023年 | 3篇 |
2022年 | 37篇 |
2021年 | 51篇 |
2020年 | 16篇 |
2019年 | 18篇 |
2018年 | 10篇 |
2017年 | 19篇 |
2016年 | 18篇 |
2015年 | 15篇 |
2014年 | 14篇 |
2013年 | 19篇 |
2012年 | 20篇 |
2011年 | 32篇 |
2010年 | 11篇 |
2009年 | 20篇 |
2008年 | 16篇 |
2007年 | 10篇 |
2006年 | 14篇 |
2005年 | 9篇 |
2004年 | 12篇 |
2003年 | 8篇 |
2002年 | 8篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有397条查询结果,搜索用时 15 毫秒
231.
Mariusz Szreder 《化学工程与技术》2019,42(4):889-895
Operation tests of an air heat pump used for domestic hot water (DHW) heating were performed. The influence of the supply air temperature in the evaporator cycle and the variable heat load of the condenser on the heating power of the heat pump and the coefficient of performance (COP) was evaluated and discussed. In order to ensure conditions for efficient compressor operation, it is advisable to gradate the heat load of the heat pump using a circulating pump with smooth capacity regulation. The economic analysis demonstrates that the usage of air heat pumps for DHW in comparison with installations equipped with solar collectors provides no measurable economic benefits. 相似文献
232.
Handkiewicz Andrzej Naumowicz Mariusz 《Analog Integrated Circuits and Signal Processing》2021,108(2):323-333
Analog Integrated Circuits and Signal Processing - The main goal of this paper is to design an efficient 2D FIR digital filter for digital image processing and digital signal processing... 相似文献
233.
Boena Szulc Yelyzaveta Zadorozhna Mariusz Olczak Wojciech Wiertelak Dorota Maszczak-Seneczko 《International journal of molecular sciences》2021,22(1)
Congenital disorders of glycosylation (CDG) are a group of rare genetic and metabolic diseases caused by alterations in glycosylation pathways. Five patients bearing CDG-causing mutations in the SLC35A1 gene encoding the CMP-sialic acid transporter (CST) have been reported to date. In this study we examined how specific mutations in the SLC35A1 gene affect the protein’s properties in two previously described SLC35A1-CDG cases: one caused by a substitution (Q101H) and another involving a compound heterozygous mutation (T156R/E196K). The effects of single mutations and the combination of T156R and E196K mutations on the CST’s functionality was examined separately in CST-deficient HEK293T cells. As shown by microscopic studies, none of the CDG-causing mutations affected the protein’s proper localization in the Golgi apparatus. Cellular glycophenotypes were characterized using lectins, structural assignment of N- and O-glycans and analysis of glycolipids. Single Q101H, T156R and E196K mutants were able to partially restore sialylation in CST-deficient cells, and the deleterious effect of a single T156R or E196K mutation on the CST functionality was strongly enhanced upon their combination. We also revealed differences in the ability of CST variants to form dimers. The results of this study improve our understanding of the molecular background of SLC35A1-CDG cases. 相似文献
234.
Chmielewski Leszek J. Nieniewski Mariusz Orłowski Arkadiusz 《Pattern Analysis & Applications》2021,24(4):1475-1487
Pattern Analysis and Applications - The concept of black-and-white visual cryptography with two truly random shares, previously applied to color images, was improved by mixing the contents of the... 相似文献
235.
236.
237.
Marcin Pisarek Agata Roguska Andrzej Kudelski Mariusz Andrzejczuk Maria Janik-Czachor Krzysztof J. Kurzydłowski 《Materials Chemistry and Physics》2013
In this paper, we present recent results of investigations of hybrid materials consisting of nanoporous oxides layers loaded with Ag nanoparticles: Ag/TiO2-n/Ti and Ag/Al2O3-n/Al (where “n-“stands for nanotubes), which could be used as active SERS substrates or as bioactive materials in medicine (implants). Simple electrochemical, chemical and physical methods appear suitable for fabricating such hybrid materials having different functional properties. 相似文献
238.
Lesław Juszczak Mariusz Witczak Teresa Fortuna Beata Solarz 《International Journal of Food Properties》2013,16(6):1364-1372
The study investigates the viscosity of clarified beetroot juice as dependent on temperature and soluble solids content. Rheological research was carried out using a rotational rheometer with a system of coaxial cylinders. Flow curves were obtained in the temperature range from 10 to 60°C and at the soluble solids content of 50° to 67.1°Bx. The concentrate under study showed a Newtonian behaviour. Dynamic viscosity ranged from 5.2 to 320 mPa·s and depended on soluble solids content and temperature of measurement. The effect of temperature was described using an Arrhenius equation. Activation energy values were between 24.68 and 39.96 kJ/mol. The effect of soluble solids content was described employing a power-law function and an exponential function. In addition, two equations were proposed to describe the combined effect of temperature and soluble solids content on the viscosity of beetroot juice concentrate. 相似文献
239.
The various components of crude oil were structurally resolved using an atmospheric-pressure solids analysis probe (ASAP) coupled with ion mobility mass spectrometry (IM-MS). An ASAP source was used to broadly fractionate compounds according to their boiling points, thereby simplifying the resulting mass spectra for easier data interpretation. The m/z-mobility plots obtained by IM-MS analysis of crude oil could be used to find the structural relationship between crude oil molecules. That was demonstrated using ion mobility mass spectra from a homologous series of compounds, differing only by the number of alkyl units, found in crude oil. The peaks from this series were linearly aligned in the plot, suggesting a continuous increase of the collisional cross section with an increase of mass values and hence the absence of significant structural differences within the series. In contrast, peaks in a homologous series differing only in the number of pendant hydrogen atoms were not linearly aligned, suggesting a discontinuous increase of the collisional cross section with an increase of mass values and hence significant structural differences due to the addition or removal of hydrogen. Cases in which a slope change was observed at three- or four-peak intervals may be related to the addition of an aromatic ring to existing structures. Overall, ion mobility mass spectrometry demonstrates a useful tool that can be used to elucidate structural relationships between molecules comprising crude oil. 相似文献
240.
Oleh Shpotyuk Adam Ingram Zdenka Bujkov Peter Bal Yaroslav Shpotyuk Dmytro Slobodzyan Mariusz Wo
ny Catherine Boussard‐Pledel Bruno Bureau 《Polymer Engineering and Science》2019,59(12):2438-2442
The method of positron annihilation lifetime (PAL) spectroscopy was first employed to study atomic‐deficient free‐volume structure of nanocomposites prepared by high‐energy mechanical milling of glassy g‐As2Se3 in water solution of polyvinylpyrrolidone (PVP). The formalism of x3‐x2‐CDA (coupling decomposition algorithm) describing conversion of bound positron‐electron (positronium Ps) states into positron traps was applied to identify free‐volume elements in pelletized PVP‐capped g‐As2Se3 nanocomposite in respect to parent dry‐milled g‐As2Se3. Under wet milling, the internanoparticle Ps‐decaying sites in preferential PVP environment were shown to replace free‐volume positron traps in dry‐milled g‐As2Se3 with defect‐specific positron lifetime of 0.352 ns, corresponding to diatomic/triatomic vacancies in g‐As‐Se matrix. POLYM. ENG. SCI., 59:2438–2442, 2019. © 2019 Society of Plastics Engineers 相似文献