全文获取类型
收费全文 | 2300篇 |
免费 | 2篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 18篇 |
金属工艺 | 2篇 |
矿业工程 | 1篇 |
能源动力 | 2篇 |
轻工业 | 12篇 |
水利工程 | 3篇 |
无线电 | 3篇 |
一般工业技术 | 16篇 |
冶金工业 | 2236篇 |
原子能技术 | 2篇 |
自动化技术 | 5篇 |
出版年
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2014年 | 3篇 |
2013年 | 6篇 |
2012年 | 5篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 77篇 |
1998年 | 712篇 |
1997年 | 435篇 |
1996年 | 252篇 |
1995年 | 131篇 |
1994年 | 100篇 |
1993年 | 127篇 |
1992年 | 19篇 |
1991年 | 18篇 |
1990年 | 17篇 |
1989年 | 25篇 |
1988年 | 33篇 |
1987年 | 19篇 |
1986年 | 19篇 |
1985年 | 12篇 |
1983年 | 4篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 16篇 |
1978年 | 3篇 |
1977年 | 61篇 |
1976年 | 146篇 |
1975年 | 7篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1968年 | 1篇 |
1964年 | 1篇 |
1962年 | 1篇 |
1956年 | 1篇 |
1955年 | 3篇 |
排序方式: 共有2302条查询结果,搜索用时 0 毫秒
1.
2.
3.
The effects of α‐form and β‐form nuclei on polymorphic morphology of poly(butylene adipate) (PBA) upon recrystallization from the molten state up to various Tmax values were examined by differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD) and polarized light microscopy (PLM). In this study, PBA with complex melting and polymorphism behaviour was used as a model for examining different types and extents of residual nuclei. As the PBA initially containing the sole α‐crystal was brought to a molten state of various Tmax, the extents of trace α‐form crystal nuclei varied and were dependent on Tmax. Furthermore, it did not matter whether, initially, the PBA contained α‐ or β‐form crystals (or both) because only a single type of α‐nuclei could be left upon treatment to the molten liquid state at Tmax. Therefore, only the α‐crystal in PBA had ‘memory capacity’ in the molten liquid state while the β‐crystal did not. This was so because the latter had been completely transformed into the solid state prior to being heated into a liquid. PBA crystallized before α‐nuclei could be packed into α‐crystal, regardless of the crystallization temperature (Tc). For recrystallization from molten PBA without any nuclei, the crystalline polymorphism was correspondingly influenced by Tc. Copyright © 2005 Society of Chemical Industry 相似文献
4.
5.
EM Makogonenko 《Canadian Metallurgical Quarterly》1997,69(5-6):109-116
Heparin was studied for its effect on the hydrolysis time of clots from desAA fibrin (FB), desAABB fibrin (F0) and fibrinogen (Fg) of a bull and a man by gly-or lys-plasminogen which is activated by the tissue activator. It is shown that heparin in the concentration to 4.6 M does not affect that hydrolysis time of clots from human and bovine Fg and human Fg by gly-plasminogen which is activated by the tissue activator. Heparin increases the hydrolysis time of clots from bovine Fg and F0 by gly-and lys-plasminogen, the tissue activator being present. It firstly increases (in concentrations below 0.5 (microM), and then decreases (in concentrations above 0.5 (microM) the hydrolysis time of clots from human FB, F0 and Fg and bovine FB and F0 by plasmin. In concentration 4.6 microM heparin increases the hydrolysis time of clots from human fibrinogen by fibrinolytic systems. Effect of heparin on fibrinolytic process from the viewpoint of affine interactions between the components of fibrin clots is discussed. 相似文献
6.
EM Bosque 《Canadian Metallurgical Quarterly》1995,18(2):67-75
This article describes the theoretical underpinnings that preceded the design of a new neonatal pulse oximeter alarm that differentiates true from false alarms based on an artificial intelligence theory called "fuzzy logic." The connection between the intuition and sense of advocacy gained through neonatal primary nursing and the application of fuzzy logic to solve the problem of false alarms--that is, the symbiosis between nurse and machine--are explained. Emphasis is placed throughout on the importance of involving nurses in the development of the technology for which they are responsible. 相似文献
7.
EM Bevis 《Canadian Metallurgical Quarterly》1993,24(4):56-61
As the whole context of nursing continues to change radically in the face of unmet societal needs, nothing short of total revolution will suffice. Nurses must take control of nursing practice and be critical of the nation's inadequate "sick-care" system in order to effect sweeping changes in the scope, availability and efficacy of healthcare in the U.S. To do this requires an acknowledgment that true nursing education cannot exist without nursing practice. The transformation of curriculum must center on caring, which characterizes what nurses really do in a medically dominated system focused exclusively on curing. 相似文献
8.
9.
Two alkylating (cyclophosphamide and 036.5122 Asta) and two antiproliferative agents (6-mercaptopurine and azathioprine) have been compared for their immuno-suppressive potency on the primary and secondary humoral immune response of mice. If equitoxic dosages of the respective drugs are compared, the alkylating agents proved to be of much higher immunosuppressive potency than the antiproliferative agents. In non toxic dosages alkylating agents were able to completely inhibit a primary or secondary immune response, whilst a similar effect with antiproliferative drugs could not be obtained even within toxic dose ranges. Induction of immunological tolerance was possible only by use of the alkylating agents. The significance of these comparative studies is discussed in view of the frequent use of the tested drugs in clinical immunosuppression. 相似文献
10.
4-(Methoxymethyl)-1,4-cyclohexadiene-1-carboxaldehyde syn-oxime is a new sweetening agent developed by systematic synthesis and taste evaluation of 80 new oximes analogous to the little-used osime sweetener, perillartine. 相似文献