全文获取类型
收费全文 | 259篇 |
免费 | 23篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 168篇 |
金属工艺 | 17篇 |
机械仪表 | 5篇 |
建筑科学 | 5篇 |
能源动力 | 3篇 |
轻工业 | 34篇 |
石油天然气 | 1篇 |
无线电 | 2篇 |
一般工业技术 | 31篇 |
冶金工业 | 8篇 |
原子能技术 | 1篇 |
自动化技术 | 6篇 |
出版年
2023年 | 5篇 |
2022年 | 32篇 |
2021年 | 32篇 |
2020年 | 5篇 |
2019年 | 8篇 |
2018年 | 8篇 |
2017年 | 14篇 |
2016年 | 11篇 |
2015年 | 11篇 |
2014年 | 13篇 |
2013年 | 18篇 |
2012年 | 11篇 |
2011年 | 15篇 |
2010年 | 10篇 |
2009年 | 13篇 |
2008年 | 10篇 |
2007年 | 11篇 |
2006年 | 4篇 |
2005年 | 7篇 |
2004年 | 7篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1987年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1977年 | 1篇 |
排序方式: 共有282条查询结果,搜索用时 15 毫秒
71.
Kinetics of ion removal from wastewaters by ion exchange on a commercial synthetic zeolite has been investigated. Dynamic breakthrough profiles have been registered and exploited to determine ion exchange equilibria and mass transport resistances.A simplified dynamic model based on the equation of solid-film driving force has been employed to determine coefficients of mass transport kinetics in the presence of different solutions of regenerating salt. Two diffusional resistances have been found to govern the mass transport kinetics: interparticle diffusion (external film diffusion) and the solid phase diffusion within micropores of the zeolite crystals. At low solution concentration interparticle mass transfer was dominant in the mass transport mechanism, whereas solid phase diffusion dominated at higher concentration. The influence of the salt concentration on mass transfer kinetics has been analyzed using the Nernst-Planck and the Maxwell-Stefan models.The kinetic and isotherm coefficients determined were used to simulate the cyclic process of ion removal: ion exchange and the column regeneration.To verify analysis a generalized dynamic model has been used accounting for directly all the diffusion resistances. 相似文献
72.
Jolanta Lis-Kuberka Paulina Kubik Agnieszka Chrobak Jarosaw Pajk Anna Chemoska-Soyta Magdalena Orczyk-Pawiowicz 《International journal of molecular sciences》2021,22(21)
The diagnosis of endometriosis and fertility disorders is difficult; therefore, it is necessary to look for reliable biomarkers. Analysis of the molecular status of fibronectin as a key player in repair and wound healing processes, as well as in coagulation and fibrinolysis pathways, is justified. ELISA and SDS-agarose immunoblotting were applied to determine the fibronectin concentration and presence and occurrence of soluble FN-fibrin complexes in the blood plasma of women with endometriosis (n = 38), fertility disorders (n = 28) and the healthy group (n = 25). The concentration of fibronectin in the blood plasma of women with endometriosis (292.61 ± 96.17 mg/L) and fertility disorders (287.53 ± 122.68 mg/L) was significantly higher than in the normal group (226.55 ± 91.98 mg/L). The presence of FN-fibrin complexes of 750, 1000, 1300, 1600 and 1900 kDa in the plasma of women with endometriosis and fertility disorders was shown. The presence of FN-fibrin complexes with a molecular mass of more than 1300 kDa in women with endometriosis and infertility and the complete absence of these complexes in healthy women may indicate an increased and chronic activation of coagulation mechanisms in these patients. The presence of complexes of high molecular mass may be one of the biomarkers of fertility disorders in women. 相似文献
73.
Katarzyna Piechowska Angelika Baranowska-czkowska Krzysztof Z. czkowski Jolanta Konieczkowska Mariola Siwy Marharyta Vasylieva Pawe Gnida Pawe Nitschke Ewa Schab-Balcerzak 《International journal of molecular sciences》2022,23(10)
The paper presents synthesis and characterization of nine new thiazolyl-(phenyldiazenyl)-2H-chromen-2-one dyes. The impact of substituent structure in thiazole ring in the synthesized azocoumarin derivatives on electrochemical properties, photoisomerization process and photovoltaic response was examined. The dyes were electrochemically active and undergo reduction and oxidation processes. They showed low electrochemically estimated energy band gap in the range of 1.71–2.13 eV. Photoisomerization process of the synthesized molecules was studied in various solvents such as ethanol, chloroform and N,N-dimethylformamide (DMF) upon the UV illumination. It was found that novel azodyes showed reversible trans-cis-trans isomerization and exhibited long thermal back to the trans form, that was even 7 days in DMF. Selected azocoumarin were molecularly dispersed in polystyrene for preparation of guest-host azopolymer systems to study the cis-trans thermal isomerization of obtained dyes in solid state. The photovoltaic activity of the azochromophores was tested in bulk-heterojunction solar cells. They acting as weak donors in device with structure ITO/PEDOT:PSS/dye:PC70BM/Al. No photovoltaic response of cells with azocoumarin derivatives bearing 4-fluorobenzene, 3,4-dichlorobenzene, or 4-(1-adamantyl) unit was found. Additionally, dye which showed the best activity was examined in three-component solar cells ITO/PEDOT:PSS/PTB7:PC70BM:dye/PFN/Al. 相似文献
74.
Elbieta mudzka Klaudia Lustyk Agata Siwek Magorzata Wolak Adam Gauszka Jolanta Jakowska Marcin Koaczkowski Jacek Sapa Karolina Pytka 《International journal of molecular sciences》2023,24(1)
Cardiovascular diseases remain one of the leading causes of death worldwide. Unfortunately, the available pharmacotherapeutic options have limited effectiveness. Therefore, developing new drug candidates remains very important. We selected six novel arylpiperazine alkyl derivatives of salicylamide to investigate their cardiovascular effects. Having in mind the beneficial role of α1-adrenergic receptors in restoring sinus rhythm and regulating blood pressure, first, using radioligand binding assays, we evaluated the affinity of the tested compounds for α-adrenergic receptors. Our experiments revealed their high to moderate affinity for α1- but not α2-adrenoceptors. Next, we aimed to determine the antiarrhythmic potential of novel derivatives in rat models of arrhythmia induced by adrenaline, calcium chloride, or aconitine. All compounds showed potent prophylactic antiarrhythmic activity in the adrenaline-induced arrhythmia model and no effects in calcium chloride- or aconitine-induced arrhythmias. Moreover, the tested compounds demonstrated therapeutic antiarrhythmic activity, restoring a normal sinus rhythm immediately after the administration of the arrhythmogen adrenaline. Notably, none of the tested derivatives affected the normal electrocardiogram (ECG) parameters in rodents, which excludes their proarrhythmic potential. Finally, all tested compounds decreased blood pressure in normotensive rats and reversed the pressor response to methoxamine, suggesting that their hypotensive mechanism of action is connected with the blockade of α1-adrenoceptors. Our results confirm the antiarrhythmic and hypotensive activities of novel arylpiperazine derivatives and encourage their further investigation as model structures for potential drugs. 相似文献
75.
Effect of production season on protein fraction content in milk of various breeds of goats in Poland
Aneta Brodziak Jolanta Król Joanna Barłowska Zygmunt Litwińczuk 《International Journal of Dairy Technology》2014,67(3):410-419
Milk of various goat breeds was analysed to assess the effect of production season on content of basic chemical components, with regard to whey proteins. Milk of goats in the productive herds (white and coloured coat) contained significantly (P < 0.01) more total protein, casein, fat, dry matter and functional whey proteins. The production season significantly determined the content of total protein (P < 0.01), casein (P < 0.01) and whey proteins (P < 0.05), including α‐lactalbumin (P < 0.01) and lactoferrin (P < 0.01). A higher content of total protein and casein was found in the autumn–winter season and the content of whey proteins was higher in the spring–summer period. 相似文献
76.
77.
Alina Jakób Jolanta BryjakHalina Wójtowicz Viera IlleováJúlius Annus Milan Polakovič 《Food chemistry》2010
Ohmic heating of milk and fruit and vegetable juices was carried out at several incubation temperatures to investigate inactivation of alkaline phosphatase, pectin methylesterase and peroxidase. Mechanisms of inactivation of these enzymes and corresponding kinetic models were verified for each food material, using the multitemperature evaluation of inactivation data. Compared to inactivation by conventional indirect heating, kinetic parameters were changed but inactivation mechanisms remained the same. The kinetic parameter changes were relatively minor for pectin methylesterase and alkaline phosphatase. A significant destabilization of the labile isozyme fraction of peroxidase occurred by the effect of ohmic heating when the greatest decrease of stability was obtained for carrot juice. 相似文献
78.
The main objective of this research is to develop and apply state-of-the-art computational tools to achieve an understanding of intermolecular interactions in molecular imprinting of chemical warfare (CW) agents into complex monomeric systems. Molecular dynamic (MD) simulations were carried out for different monomeric molecular systems in order to predict the interaction energies, the closest approach distances and the active site groups between the simulated molecular systems and different CW agents. The minimized structures of CW agents have been obtained with the use of molecular mechanics approach. NVT MD simulations at room temperature were carried out to obtain equilibrated conformations in all cases. The simulated molecular systems consisted of a ligand (CW agents) and commonly used functional monomers.During this study, it was found that electrostatic interactions play the most significant role in the formation of molecular imprinting materials. The simulated systems indicate that the functional groups of monomers interacting with ligands tend to be either -COOH or CH2CH-. 相似文献
79.
ABSTRACTWe investigate the commemorative debate in Polish newspapers about how the Katyń massacre and the presidential plane crash near Smoleńsk, Russia, should be remembered. We demonstrate that a psychoanalytic discursive analysis elucidates the insistence on remembering past wounds, nationalist politics of victimhood, and the difficulties in reaching rapprochement in intercultural relations. To this end, we analyze the commemorative debates in two main Polish newspapers and a news magazine. We argue that an emotive discourse of “Katyń as a wound” yearns for a therapeutic healing of the rifts in Polish national mythology and postcommunist identity. This discourse revolves around a demand for recognition from the Russian Other of a wounded subject by employing evocative metonymies and transposing logics of equivalence and difference. 相似文献
80.
Connecting modern extra-lightweight materials requires the use of technology which cannot be provided by traditional gas-shielded welding methods. It is, therefore, necessary to develop variants of the arc welding method, which would deliver a very small amount of heat to the material but which would still ensure that the resulting joints would be tough. coldArc welding is a modification of the MIG/MAG method, which meets those requirements. With this method, all interventions in the process are made directly at the source of the power supply, without mechanical intervention in the feeding of the solder wire. As such, it is possible to use standard holders, and this method may also be successfully used in manual welding. 相似文献