全文获取类型
收费全文 | 87篇 |
免费 | 1篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 26篇 |
金属工艺 | 3篇 |
机械仪表 | 3篇 |
轻工业 | 25篇 |
水利工程 | 3篇 |
无线电 | 2篇 |
一般工业技术 | 7篇 |
冶金工业 | 6篇 |
原子能技术 | 4篇 |
自动化技术 | 8篇 |
出版年
2020年 | 1篇 |
2018年 | 1篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 4篇 |
2012年 | 6篇 |
2011年 | 5篇 |
2010年 | 8篇 |
2009年 | 3篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 1篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 4篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有88条查询结果,搜索用时 31 毫秒
1.
We present a two-sorted algebra, called aPeirce algebra, of relations and sets interacting with each other. In a Peirce algebra, sets can combine with each other as in a Boolean algebra, relations can combine with each other as in a relation algebra, and in addition we have both a set-forming operator on relations (the Peirce product of Boolean modules) and a relation-forming operator on sets (a cylindrification operation). Two applications of Peirce algebras are given. The first points out that Peirce algebras provide a natural algebraic framework for modelling certain programming constructs. The second shows that the so-calledterminological logics arising in knowledge representation have evolved a semantics best described as a calculus of relations interacting with sets. 相似文献
2.
Diffuse villous hyperplasia of the choroid plexus, which is distinct from bilateral choroid plexus papillomas, is extremely rare and is often associated with hydrocephalus due to the overproduction of cerebrospinal fluid (CSF). The authors describe an infant with hydrocephalus, diagnosed by computerized tomography scanning, who developed ascites following placement of a ventriculoperitoneal shunt and, subsequently, demonstrated excessive CSF production when the shunt was externalized. The patient was later successfully treated by placement of a ventriculoatrial shunt. Magnetic resonance imaging demonstrated diffuse villous hyperplasia of the choroid plexus as the cause of the patient's hydrocephalus. The literature on diffuse villous hyperplasia of the choroid plexus is reviewed. 相似文献
3.
Philip V. Yaneff Karlis Adamsons Rose A. Ryntz Dottie Britz 《Journal of Coatings Technology》2002,74(933):135-141
Flexible automotive coatings are susceptible to scratch and mar damage, especially during finishing and assembly operations.
One-component (1K) flexible clearcoats exhibit very good scratch and mar resistance, but unfortunately suffer from poor durability
and environmental etch resistance. Two-component clearcoats offer improvements in both etch and durability, but at the expense
of scratch and mar. In this paper, the concept and properties of 1K flexibilized silane clearcoats for use on automotive plastics
will be introduced and their structure/property relationships examined as they apply to scratch and mar.
The role of coating crosslink density, toughness, glass transition temperature (Tg), and surface profile on the scratch damage of coated plastic substrates will be described. In addition, a new scratch methodology,
termed Scratcho, is utilized to determine relative scratch performance and is compared to conventional scratch resistance
testing. Results to date indicate that hardness, as affected by the glass transition temperature, and crosslink density, as
it contributes to higher essential work values, both affect resultant scratch propensity of the flexible coatings. The relative
ranking of different coating systems employing alternate crosslinkers (e.g., isocyanate and melamine) is also presented and
compared to the newly developed silane crosslinked coatings.
Presented at the 28th International Waterborne, High-Soids, and Powder Coatings Symposium, Feb. 21–23, 2001, in New Orleans.
LA.
377 Fairall St., Ajax, Ont., L1S 1R7, Canada.
401 Southfield Rd., P.O. Box 6231, Dearborn, MI 48121-6231. 相似文献
4.
J. K. Krü ger W. Possart R. Bactavachalou U. Mü ller T. Britz R. Sanctuary P. Alnot 《The Journal of Adhesion》2004,80(7):585-599
The newly developed Brillouin microscopy is used for the first time to measure in situ the longitudinal elastic stiffness coefficient in the GHz-range inside of glass-epoxy-metal joints as a function of distance from the substrates. Interphases with a local variation of mechanical properties are quantitatively characterized. These interphases possess unexpected widths of tens to hundreds of microns. Inside the interphases, the spatial variation of the longitudinal stiffness coefficient depends on the type of substrate, on the curing conditions for the epoxy and probably on the distribution of internal stresses. The obtained spatial mechanical profiles provide valuable insight into the morphology-driven mechanics of the interphase, but additional information is needed for a full understanding of their physical and chemical origin. The presented results prove the sensitivity of the Brillouin microscopy; the elastic stiffness coefficients are detected with an accuracy in the subpercentage range. The spatial resolution is better than 10 µm. 相似文献
5.
SUMMARY A circuit is described which, when fed with an alternating voltage whose amplitude may vary, produces an accurately settable, continuously variable output amplitude. The error in the output amplitude is within 0.1% for inputs from 3 V to 7 V rms, between 30 Hz and 4 kHz, and within 1% between 16 Hz and 10 kHz. By connection to this inexpensive circuit, any simple, inexpensive audio oscillator is effectively converted into a multirange, precision-amplitude ac source. 相似文献
6.
Tinplate corrosion in nitrate containing media: The role fo nitrite The role of nitrite in the corrosion of tinplate in media containing nitrate was examined. If nitrite is initially absent, the corrosion is initially slow, but as nitrite is generated the corrosion, in turn, accelerates. This slow startup does not occur if nitrite is initially present in sufficient concentration. These observations agree with the autocatalytic mechanisms suggested for the reduction of nitrate by Schmid and Vetter. 相似文献
7.
Reference values of the chronoamperometric response at cylindrical and capped cylindrical electrodes
This work provides accurate solutions of the cylinder flux function I(0,1;T), first solved by Jaeger and Clarke, which can serve as reference values for electrochemical amperometric diffusion limited currents at a cylinder, as well as heat fluxes under equivalent conditions (fixed temperature at the cylinder surface). For the capped cylinder of varying lengths, reference values of time-dependent electrochemical currents are provided. Steady state currents at capped cylinders are presented and a function is provided that fits the simulated values to within 1%. All of these are more accurate than in previous works. 相似文献
8.
Bruising on ostrich carcasses reduces meat yield. These bruises are usually removed as part of the primary meat inspection, performed directly after evisceration. Three separate studies were conducted to determine the advantages and disadvantages of removing the bruises at primary meat inspection or after overnight cooling of the ostrich carcasses (0–4 °C). The bruised areas were also investigated to determine their frequency and distribution and to establish the most obvious causes and possible preventative measures. The neck bruises represented 52.58% of all bruises; the high side railings of the transport vehicles being the most probable cause. Large and multiple bruising were probably from the trampling of birds lying down. It was established that trimming bruises on warm carcasses caused higher total aerobic viable counts on the trimmed surfaces than cold trimming. Cold trimming together with better management of trimming practices also led to a decrease in meat yield losses. 相似文献
9.
The effect of ozonation and enzyme combination pre-treatments on the composition of grain distillery wastewater (GDWW) was investigated. Exposure of UASB granules to these pre-treated GDWW was evaluated by determining the effect on granule activity, visual appearance and lipid content of the granules. Pre-treatments involving a pre-ozonation step were found to be more effective in reducing the lipid and COD content of GDWW. The higher the lipid and COD reduction achieved by the pre-treatments the higher the granule activity after 24 d exposure, the lower the lipid content in the granule and the less severe the formation of an encapsulating layer. 相似文献
10.
Molecules in carbon nanotubes 总被引:2,自引:0,他引:2
This Account focuses on structural and dynamic behavior of molecules encapsulated in carbon nanotubes. The impact of the confinement on the molecular packing, orientation, translation, rotation, and reactivity is demonstrated for a range of fullerene and nonfullerene molecules. These phenomena are described and analyzed using the current understanding of molecule-nanotube and intermolecular interactions. 相似文献