全文获取类型
收费全文 | 203篇 |
免费 | 6篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 71篇 |
金属工艺 | 4篇 |
机械仪表 | 4篇 |
建筑科学 | 4篇 |
矿业工程 | 1篇 |
能源动力 | 3篇 |
轻工业 | 31篇 |
无线电 | 9篇 |
一般工业技术 | 35篇 |
冶金工业 | 3篇 |
原子能技术 | 2篇 |
自动化技术 | 38篇 |
出版年
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 11篇 |
2011年 | 8篇 |
2010年 | 8篇 |
2009年 | 3篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 5篇 |
1971年 | 2篇 |
1969年 | 2篇 |
1966年 | 1篇 |
1962年 | 1篇 |
1919年 | 1篇 |
排序方式: 共有209条查询结果,搜索用时 15 毫秒
1.
Pakteera Sripokar Yi Zhang Benjamin K. Simpson Egon Bech Hansen Suppasil Maneerat Sappasith Klomklao 《International Journal of Food Science & Technology》2021,56(12):6368-6375
Beardless barb is a common fish species used in fermentation of fish paste Ka-pi-plaa. Autolytic profile of beardless barb muscle showed the maximum autolysis was at 50 °C, at both acidic and alkaline pH values. With augmentation concentration of NaCl, autolytic activity slightly decreased. Endogenous proteinases isolated from fish muscle in crude extract forms were also characterised. The acidic proteinases had optimum activity at pH 3.0 and 50°C, and they showed higher proteolytic activity than the alkaline proteinases which were optimally active at pH 9.0 and 50 °C. Proteinases in peak at pH 3.0 were inhibited by pepstatin A, but those in peak at pH 9.0 were highly inhibited by PMSF, TLCK and soybean trypsin inhibitor, suggesting that both aspartic and serine proteinases were existed in beardless barb muscle. The proteinases were stable in pH range of 2.0-5.0 but unstable at the temperatures higher than 40 °C. NaCl suppressed the proteolytic activity, ATP activated the proteinase activity, while CaCl2, MgCl2 and CoCl2 exhibited no influence on the activity. The results implied that cathepsin D is the predominant proteinase responsible for autolysis in beardless barb. The findings were useful to improve the processing and qualities of Ka-pi-plaa product using beardless barb as raw material. 相似文献
2.
Hans Michael Egon Pabst Franz Ledl und Hans-Dieter Belitz 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1985,181(5):386-390
Summary In addition to the mono- and dipyrrolidinohexosereductones described recently (Z Lebensm Unters Forsch (1984) 178:356) two further bittertasting compounds were isolated from heated mixtures of proline and sucrose (molar ratio 3: 1, 190 °C, 30 min) and also synthesized, namely 2,3-bis-(1-pyrrolidinyl)2-cyclopenten-l-one and 2,3-bis(1-pyrrolidinyl)-5methyliden-2-cyclopenten-l-one. The recognition thresholds (mmol/1) are 0.15–0.25 and 0.06–0.12 respectively. Both compounds have a burning bitter taste character. From a maltose-proline reaction mixture 2--glucosyl-5-hydroxy-5-methyl-4-piperidinyl-2-cyclopenten-1-one was isolated. When the dihydroxypyranone VI was heated with proline, 2,5-dihydroxy-5-methyl-4-prohnyl-2-cyclopenten-1-one and the cyclopent(b)azepinones XI and XII were among the compounds formed. These compounds also have a bitter taste character.Zusammenfassung Zusätzlich zu den kürzlich beschriebenen Mono- and Dipyrrolidinohexosereduktionen (Z Lebensm Unters Forsch (1984) 178:356) wurden zwei weitere bittere Verbindungen aus erhitzten Mischungen von Prolin and Saccharose (Molverhältnis 3:1, 190 °C, 30 min) isoliert and synthetisiert. Es handelt sich um 2,3-Bis-(1-Pyrrolidinyl)-2-cyclopenten-1-on und 2,3-Bis-(1-Pyrrolidinyl)-5-methyliden-2-cyclopenten-1-on. Die Erkennungsschwellenwerte (mmol/1) sind 0,15-0,25 and 0,06-0,12. Beide Verbindungen haben einen brennend-bitteren Geschmack. Aus einem Maltose-Prolin-Umsetzungsgemisch gelang die Isolierung des 2--Glucosyl-5-hydroxy-5-methyl-4-piperidinyl-2-cyclopenten-1-ons. Bei der Reaktion des Dihydropyranons VI mit Prolin wurden u. a. das 2,5-Dihydroxy-5-methyl-4-prolinyl2-cyclopenten-1-on sowie die Cyclopent(b)azepinone XI and XII gebildet. Diese Verbindungen sind ebenfalls mehr oder weniger stark bitter. 相似文献
3.
The experimentally determined chromaticities and reflectance spectra of films consisting of uniform ellipsoidal or spherical colloidal hematite particles are compared with calculated values and are found to be in good agreement. The theoretical treatment of the light-scattering problem involves the Mie theory for the spheres and the T-matrix method for the ellipsoids. The reflectance spectra for the pigment films are calculated through the use of the Kubelka-Munk analysis. 相似文献
4.
Khaled Elbassioni Erik Krohn Domagoj Matijević Julián Mestre Domagoj Ševerdija 《Algorithmica》2011,60(2):451-463
We present a 4-approximation algorithm for the problem of placing the fewest guards on a 1.5D terrain so that every point
of the terrain is seen by at least one guard. This improves on the previous best approximation factor of 5 (see King in Proceedings
of the 13th Latin American Symposium on Theoretical Informatics, pp. 629–640, 2006). Unlike most of the previous techniques, our method is based on rounding the linear programming relaxation of the corresponding
covering problem. Besides the simplicity of the analysis, which mainly relies on decomposing the constraint matrix of the
LP into totally balanced matrices, our algorithm, unlike previous work, generalizes to the weighted and partial versions of
the basic problem. 相似文献
5.
Manuel Grander Alexander Hoffmann Markus Seifert Egon Demetz Philipp Grubwieser Christa Pfeifhofer-Obermair David Haschka Günter Weiss 《International journal of molecular sciences》2022,23(12)
Macrophages are at the center of innate pathogen control and iron recycling. Divalent metal transporter 1 (DMT1) is essential for the uptake of non-transferrin-bound iron (NTBI) into macrophages and for the transfer of transferrin-bound iron from the endosome to the cytoplasm. As the control of cellular iron trafficking is central for the control of infection with siderophilic pathogens such as Salmonella Typhimurium, a Gram-negative bacterium residing within the phagosome of macrophages, we examined the potential role of DMT1 for infection control. Bone marrow derived macrophages lacking DMT1 (DMT1fl/flLysMCre(+)) present with reduced NTBI uptake and reduced levels of the iron storage protein ferritin, the iron exporter ferroportin and, surprisingly, of the iron uptake protein transferrin receptor. Further, DMT1-deficient macrophages have an impaired control of Salmonella Typhimurium infection, paralleled by reduced levels of the peptide lipocalin-2 (LCN2). LCN2 exerts anti-bacterial activity upon binding of microbial siderophores but also facilitates systemic and cellular hypoferremia. Remarkably, nifedipine, a pharmacological DMT1 activator, stimulates LCN2 expression in RAW264.7 macrophages, confirming its DMT1-dependent regulation. In addition, the absence of DMT1 increases the availability of iron for Salmonella upon infection and leads to increased bacterial proliferation and persistence within macrophages. Accordingly, mice harboring a macrophage-selective DMT1 disruption demonstrate reduced survival following Salmonella infection. This study highlights the importance of DMT1 in nutritional immunity and the significance of iron delivery for the control of infection with siderophilic bacteria. 相似文献
6.
Egon Ostrosi Salima Tié Bi Lianda Haxhiaj Didier Klein 《The International Journal of Advanced Manufacturing Technology》2012,60(1-4):29-54
The effective modelling of configurable products must handle the complex problem of representation of the configurable products, learning new configurable products and analysis of their behaviour. However, currently in advanced CAD systems, there exists no systematic and effective method for designing configurations and integrating behavioural aspects and simulations. This paper proposes and develops a grammar-based design approach to support both the computer-aided design for configuration and computing in CAD systems. Two interrelated questions are taken into account: (1) What are the hypothesis, properties and features for product configuration? (2) How can the product based on configuration features be represented and how can the configuration representation method integrate the numerical computing in design? This approach, under the guide of the proposed formal modelling, is implemented in computers. A design case study illustrates the proposed approach. 相似文献
7.
Ernst Schmitz Uwe Heuck Helmut Preuschhof Egon Gründemann 《Advanced Synthesis \u0026amp; Catalysis》1982,324(4):581-588
Synthesis of Heterocyclic Compounds by C C-bond Closure. IV. Synthesis of Heterocyclic Compounds by Intramolecular Dienreaction N-2-Cyclohexenyl-N-isopropylcinnamamide 8 cyclizes at 230°C to give the decahydronaphthindolone 9 . N-Alkyl-N-allylcinnamamides 10 analogously form 1 H-hexahydrobenzisoindolones 11 . N-Alkyl-N-allylsorbamides 14 cyclize at 150°C to 1 H-hexahydroisoindolones 15 . 15b yields the cyclic enamide 16 by alkali catalyzed shift of the double bond. Tricyclic lactames 19 and 20 are formed by thermal isomerization of N-cycloalkenylsorbamides 18a and 18b , respectively. 相似文献
8.
Polymers with characteristic damping properties are obtained by compounding them with additives. The mechanical behavior under vibration conditions of these compounds is characterized by dynamic moduli which depend on the static preload. The test results of a PU-compound are presented in this paper. The obtained results enable one to calculate the complex moduli of a special dynamic constitutive equation, which then enables one to calcualte stress and strain of dynamic deformations of structures under static preload. The paper presents a method to calculate such loading conditions on a system, too. A finite element analysis is used to determine the frequency response which characterizes the damping behavior of the structure. 相似文献
9.
Franz-Hubert Haegel Egon Zimmermann Katrin Breede Walter Glaas Harry Vereecken 《Nuclear Engineering and Design》2011,241(6):1959-1969
Monitoring the distribution of water content is essential for understanding hydrological processes in the lithosphere and the pedosphere. The movement of water in unsaturated rock formations and in the vadose zone is influenced by different processes (mainly infiltration, evaporation, percolation and capillary flow) which may be rate determining depending on the actual conditions. The interdependence of these processes also strongly influences the transport and distribution of solutes in the pore space. In order to gain a better understanding of the movement and distribution of water in unsaturated media, systematic investigations with non-invasive or minimal invasive methods appear to be most suitable. Studies on the distribution of electrical conductivity can improve risk analysis concerning waste disposals in general and nuclear waste repositories in particular. Induced polarization and magnetic flux density determined with two highly sensitive accessories yield additional information and may allow for better discrimination of coupled flow processes. Electrical impedance tomography (EIT) with 20 current injection and 48 voltage electrodes was used here to monitor the evaporation of tap water from a container filled with sand under laboratory conditions at 20 °C. The results are compared with data obtained by determining spectral induced polarization (SIP) of sand during desaturation in a multi-step outflow equipment. Infiltration processes and evaporation from sand saturated with 0.01 M CaCl2 were determined by magneto-electrical resistivity imaging technique (MERIT). The results were obtained from a long-term experiment under controlled conditions. 相似文献
10.
Egon Matijevic 《Journal of the American Oil Chemists' Society》1971,48(10):582-583
The lecture represented a review of the work done in the author’s laboratory dealing with the behavior of a variety of submicronic
particles in the presence of simple and complex ions, surface active agents, polyelectrolytes and polymers. Experimentally,
the stability of colloidal sols, which can be readily followed by optical methods, was investigated as a function of the composition
of the electrolyte environments. This approach offers a number of advantages when the evaluation of solid-solute interactions
is attempted. By selecting various colloidal sols one can study the interactions of counterions with particles of different
surface properties, such as the charge density, type and concentration of stabilizing ions, degree of solvation, surface ionization,
etc.
One of five papers presented at the Symposium, “Basic Aspects of Detergency,” AOCS-ISF World Congress, Chicago, September
1970.
This lecture summary was prepared during the author’s stay at the Swedish Institute for Surface Chemistry, Stockholm. 相似文献