首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   69篇
  免费   0篇
化学工业   3篇
建筑科学   6篇
轻工业   49篇
一般工业技术   6篇
冶金工业   2篇
自动化技术   3篇
  2021年   1篇
  2013年   4篇
  2012年   1篇
  2011年   2篇
  2010年   1篇
  2008年   1篇
  2007年   2篇
  2006年   3篇
  2005年   3篇
  2004年   3篇
  2002年   1篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1998年   1篇
  1997年   5篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1988年   1篇
  1986年   2篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1981年   2篇
  1980年   1篇
  1978年   3篇
  1977年   1篇
  1976年   1篇
  1974年   1篇
  1973年   4篇
  1971年   2篇
  1970年   1篇
  1967年   3篇
  1964年   1篇
  1962年   1篇
  1961年   1篇
  1960年   1篇
  1957年   1篇
  1939年   1篇
排序方式: 共有69条查询结果,搜索用时 15 毫秒
1.
2.
3.
探讨了瑞典南部的斯堪尼亚在建设多功能绿道时,在改善高强度管理农业区域可达性、休闲活动可能性和生物多样性等方面所面临的挑战和机遇。通过网络检索、与政府部门进行联系,与相关人员进行讨论及召开研讨会,并对绿道的生物多样性进行实地调查,指出了瑞典绿道的实际问题与改善的可能性。  相似文献   
4.
Two α-amylase inhibitors from black bean (Phaseolus vulgaris) were purified to homogencity using ammonium sulfate fractionation, DEAE-Sephadex chromatography, phenyl-Sepharose hydrophobic interaction chromatography and gel filtration with Sephadex G-100. The inhibitors were designated I–1 and I–2 based on their order of elution from the phenyl-Sepharose column. Both inhibitors are mannose containing glycoproteins, composed of subunits; active against porcine pancreatic, human salivary, and insect α-amylases and inactive against bacterial, mold, and plant α-amylases. The inhibitors I-1 and I–2 have molecular weights of 49,000 and 47,000 and isoelectric points 4.93 and 4.86, respectively. Both inhibitors have similar amino acid compositions and are rich in aspartic acid, serine, glutamic acid, valine, and threonine and are low in sulfur containing amino acids. I–2 is more resistant to heat denaturation than I-1.  相似文献   
5.
Superposition coded symmetric relaying is a bandwidth-efficient cooperative scheme where each source node simultaneously transmits both its own "local" packet and "relay" packet that originated at its partner by adding the modulated local and relay signals in Euclidean space. This paper investigates the power allocation and outage probability of a superposition coded symmetric relaying system with finite-constellation signaling. We first derive the mutual information (MI) metrics for the system. The derived MI metrics consist of two parts: one represents the MI conveyed by the modulated signal corresponding to its own data, and the other represents the MI conveyed by the modulated signal corresponding to its partner’s data. Using MI based effective signal-to-noise ratio mapping technique, we attain expressions for the outage probability. Furthermore, we discuss power allocation policies that minimize the outage probability. Simulation results are presented to verify the correctness of the outage probability analysis and the benefits of the power allocation.  相似文献   
6.
A test for the rapid identification of raw pollock surimi (TRIPS) was developed. This was an adaptation of previously developed field screening agar-gel immunodiffusion tests for speciation of meat products. It was specific for Alaska pollock surimi at 2% concentration and other surimis at higher concentrations, showed detectable sensitivity to surimi in meat at 2–4%, and was 100% accurate in detection in laboratory trials.  相似文献   
7.
Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.  相似文献   
8.
Graphic scaling (GS) and magnitude estimation (ME) of hedonic and intensity responses to 4–30% sucrose in lemonade and 0–16% fat in milk gave similar conclusions about the beverages, but GS was simpler to perform and responses were influenced less by numerical and contextural effects. More restricted ranges were used for ME than for GS, and for hedonic than for intensity responses. Good reproducibility was obtained, except for GS of hedonic responses to lemonade, which were bimodally distributed. Use of a higher sucrose reference (R) in lemonade decreased ME values, and increased the intensity exponent from 0.651 when R was 4% sucrose to 0.973 when R was 10% sucrose. Individual intensity exponents varied from 0.068–0.372 for milk, and from 0.146–1.075 for lemonade when R was 4% sucrose, and from 0.373–2.635 when R was 10% sucrose.  相似文献   
9.
Grapevine moth Lobesia botrana is the economically most important insect of grapevine Vitis vinifera in Europe. Flower buds, flowers, and green berries of Chardonnay grapevine are known to attract L. botrana for oviposition. The volatile compounds collected from these phenological stages were studied by gas chromatography—mass spectrometry, and the antennal response of L. botrana females to these headspace collections was recorded by gas chromatography—electroantennography. The compounds found in all phenological stages, which consistently elicited a strong antennal response, were pentadecane, nonanal, and -farnesene. In a wind tunnel, gravid L. botrana females flew upwind to green grapes, as well as to headspace collections from these berries released by a piezoelectric sprayer release device. However, no females landed at the source of headspace volatiles, possibly due to inappropriate concentrations or biased ratios of compounds in the headspace extracts.  相似文献   
10.
The bone formation around titanium implants with varied surface properties was investigated after 1 year in rabbits. Machined and electropolished samples with and without thick, anodically formed surface oxides were prepared, surface characterized and inserted in the cortical bone of rabbits. Scanning electron microscopy, scanning Auger electron spectroscopy and atomic force microscopy revealed marked differences in oxide thickness, surface topography and roughness, but no significant differences in surface chemical composition between the different groups of implants. Light microscopic morphology and morphometry showed that all implants were in contact with bone and had a large proportion of bone within the threads. There were no significant differences between the differently prepared implant groups. Our study shows that a high degree of bone contact and bone formation is achieved after 1 year with titanium implants which are modified with respect to oxide thickness and surface topography. There is no indication that a reduction of surface roughness, which in the initial phase decreases the rate of bone formation, had any influence on the amount of bone after 1 year in rabbit cortical bone.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号