全文获取类型
收费全文 | 433篇 |
免费 | 15篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 125篇 |
金属工艺 | 16篇 |
机械仪表 | 20篇 |
建筑科学 | 22篇 |
矿业工程 | 1篇 |
能源动力 | 51篇 |
轻工业 | 42篇 |
石油天然气 | 4篇 |
无线电 | 10篇 |
一般工业技术 | 109篇 |
冶金工业 | 18篇 |
原子能技术 | 5篇 |
自动化技术 | 23篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 7篇 |
2021年 | 15篇 |
2020年 | 23篇 |
2019年 | 7篇 |
2018年 | 18篇 |
2017年 | 13篇 |
2016年 | 18篇 |
2015年 | 7篇 |
2014年 | 25篇 |
2013年 | 34篇 |
2012年 | 39篇 |
2011年 | 37篇 |
2010年 | 33篇 |
2009年 | 30篇 |
2008年 | 15篇 |
2007年 | 23篇 |
2006年 | 9篇 |
2005年 | 8篇 |
2004年 | 12篇 |
2003年 | 13篇 |
2002年 | 4篇 |
2001年 | 5篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1977年 | 2篇 |
1965年 | 2篇 |
1962年 | 1篇 |
排序方式: 共有449条查询结果,搜索用时 0 毫秒
441.
Onur Nane Bekir ?z?elik Sel?uk Kervan U?ur Topal 《Journal of Superconductivity and Novel Magnetism》2012,25(4):1065-1070
Physical properties of the Sm1?x Tb x Ni4B (0??x??0.8) compounds have been investigated by means of the X-ray powder diffraction, AC-susceptibility and DC-magnetization techniques. All the compounds studied crystallize in CeCo4B-type structure with P6/mmm space group. The substitution of Tb for Sm leads to a decrease of the unit-cell parameters a,c and the unit-cell volume V. The magnetic phase transition temperatures are found as 39, 30, 26, 22 and 15 K, for x=0, 0.2, 0.4, 0.6 and 0.8, respectively. In addition, we have seen the second magnetic phase transition around 230 K, at the ac-susceptibility results. We have concluded that this behavior may arise from the Tb?CTb interaction in crystal structure. 相似文献
442.
The buckling behavior of size-dependent microbeams made of functionally graded materials (FGMs) for different boundary conditions is investigated on the basis of Bernoulli–Euler beam and modified strain gradient theory. The higher-order governing differential equation for buckling with all possible classical and non-classical boundary conditions is obtained by a variational statement. The effects of the power of the material property variation function, boundary conditions, slenderness ratio, ratio of additional material length scale parameters for two constituents, beam thickness-to-additional material length scale parameter ratio on the buckling response of FGM microbeams are investigated. Some comparative results are presented in tabular and graphical form in order to show the differences between the results obtained by the present model and those predicted by modified couple stress and classical continuum models. 相似文献
443.
The electrochemical and photoelectrochemical detection of tyrosinase (TR) activity (an indicative marker for melanoma cancer cells) is reported, using Pt nanoparticles (NPs) or CdS NPs as electrocatalytic labels or photoelectrochemical reporter units. The Pt NPs or CdS NPs are modified with a tyrosine methyl ester, (1), capping layer. Oxidation of the capping layer by TR/O2 yields the respective L-DOPA and dopaquinone products. The reduction of the resulting mixture of products with citric acid yields the L-DOPA derivative,(3), as a single product. The association of the (3)-functionalized Pt NPs or CdS NPs to a boronic acid monolayer-modified electrode enables the electrochemical transduction of TR activity by the Pt-NPs-electrocatalyzed reduction of H2O2 or the photoelectrochemical transduction of TR activity by the generation of photocurrents in the presence of triethanolamine as a sacrificial electron donor. The detection limits for analyzing TR corresponds to 1 U and 0.1 U by the electrochemical and photoelectrochemical methods, respectively. The association of the Pt NPs or CdS NPs to the functionalized monolayer electrode is followed by quartz crystal microbalance measurements. 相似文献
444.
Ferrous based materials manufactured by powder metallurgy (P/M) method are widely used in industry. These materials are very important because they do not require machining, have self-lubricated properties as journal bearing material, find applications in medical industry. In this study, powder metal parts were manufactured from ferrous based FeCu–Graphite composites by P/M method. Wear and mechanical test samples were manufactured and boronizing and boronizing + shot peening was applied to samples. Wear properties of these parts were investigated by wearing at 17 N load and 50 rpm on pin-on-disc wear test rig under dry conditions. Moreover, mechanical properties of powder parts were investigated in detail. 相似文献
445.
In this study, natural zeolite (clinoptilolite) was used as an aggregate and bubble-generating agent in autoclaved aerated concrete (AAC) production. The crushed and grinded samples were classified into two different particle sizes: 100 μm (fine-ZF) and 0.5–1 mm (coarse-ZC) before using in AAC mixtures. The effects of particle size, replacement amount (25%, 50%, 75% and 100% against quartz) and curing time on the AAC properties were experimentally investigated. It was found that usage of natural zeolite, especially with a coarser particle size, has beneficial effect on the physical and mechanical properties of AAC. The optimum replacement amount was determined as 50% and at this rate the compressive strength, unit weight and thermal conductivity of AAC were measured as 3.25 MPa, 0.553 kg/dm3 and 0.1913 W/mK, respectively. Scanning electron microscopy analysis also confirmed the above findings. Denser C–S–H structures were obtained up to a replacement amount of 50%. Finally, the test results demonstrated that calcined zeolite acts as both an aggregate and a bubble-generating agent, and that AAC with a compressive strength of 4.6 MPa and unit weight of 0.930 kg/dm3 can be produced without aluminum powder usage. 相似文献
446.
Sarıtaş Sevda Çakıcı Tuba Muğlu Günay Merhan Yıldırım Muhammet 《Journal of Materials Science: Materials in Electronics》2022,33(14):11246-11256
Journal of Materials Science: Materials in Electronics - In this study, firstly, ZnO thin film was produced on glass substrate by chemical spray pyrolysis method at 450 °C and then... 相似文献
447.
L Engmann A Shaker E White JS Bekir HS Jacobs SL Tan 《Canadian Metallurgical Quarterly》1998,13(4):836-840
The purpose of this study was to compare the clinical efficacy of gonadotrophins administered s.c. or i.m., in a prospective randomized study of women undergoing in-vitro fertilization (IVF) treatment at a tertiary referral centre. In all, 71 patients undergoing a total of 162 IVF treatment cycles were randomized to receive either s.c. (n = 41) or i.m. (n = 30) administration of gonadotrophins. Up to three cycles of IVF were assessed for each patient. The main outcome measures were the number of oocytes retrieved, the total amount of gonadotrophins used, the number of follicles recruited and the cumulative pregnancy and live birth rates. The mean number of oocytes retrieved was 10.5 for each group. The number of days of stimulation was significantly shorter for the s.c. group (11.7 +/- 1.9 days, mean +/- SD) than the i.m. group (12.6 +/- 2.3 days). The cumulative conception and live birth rates after three cycles of treatment were similar between the two groups. Our results suggest that the clinical efficacy of s.c. and i.m. administration of gonadotrophins is comparable. Both routes are well tolerated by patients. 相似文献
448.
This study examined the usability of thin plates cut from rocks of volcanic origin as new decorative indoor and outdoor coating material when used instead of ceramic saddle. The study examined the basic material characterization of andesites and the glazability of andesites with glaze coating materials containing boron minerals. The series of characterization tests were conducted on andesite samples. Then, the samples were applied glaze for trial purposes. Analysis indicated that the andesite samples consisted of sanidine, mica and pyroxene minerals and its apparent porosity, density, water absorption, salt crystallization resistance, compressive strength, frost after compressive strength, bending strength and impact resistance values were 15.75 %, 2,640 kg/m3, 7.41 %, 1.06 %, 47.03 MPa, 45.25 MPa, 10.16 MPa and 9.87 kPa respectively. In heat microscope measurements, maximum sintering was recorded at 1,182 °C. Linear expansion coefficient (α) of the andesite at 400 °C was 4.69 × 10?6 K?1. Firing performed by using the prepared glaze recipe at approximately 1,055 and 1,000 °C produced good results in terms of body-glaze harmony. 相似文献
449.
Emre Ordukaya Bekir Karlik 《IEEJ Transactions on Electrical and Electronic Engineering》2016,11(Z1):S171-S176
The aim of this study is to analyze the raw data collected from a fruit juice–alcohol mixture (a fruit juice–alcohol mixture and a fruit juice–multiple alcohol mixture) and the Halal authentication of a fruit juice–alcohol mixture with electronic nose. Machine learning techniques such as naïve Bayesian classifier, K‐nearest neighbors (K‐NN), linear discriminant analysis (LDA), decision tree, artificial neural network (ANN), and support vector machine (SVM) were used to classify the feature of these collected raw data. There are three types of classification: the first one is a fruit juice and an alcohol mixture type; the second is a fruit juice and multiple alcohol mixture types, and the third is a Halal authentication of a fruit juice and alcohol mixture. We aimed at making cocktails with more successful results on the first two types of classification in the work. Also, we focused on Halal authentication of fruit juice–alcohol mixture in the third classification. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献