全文获取类型
收费全文 | 2758篇 |
免费 | 36篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 125篇 |
综合类 | 1篇 |
化学工业 | 548篇 |
金属工艺 | 131篇 |
机械仪表 | 88篇 |
建筑科学 | 32篇 |
矿业工程 | 14篇 |
能源动力 | 96篇 |
轻工业 | 124篇 |
水利工程 | 6篇 |
无线电 | 243篇 |
一般工业技术 | 386篇 |
冶金工业 | 744篇 |
原子能技术 | 54篇 |
自动化技术 | 203篇 |
出版年
2023年 | 8篇 |
2022年 | 30篇 |
2021年 | 54篇 |
2020年 | 19篇 |
2019年 | 20篇 |
2018年 | 29篇 |
2017年 | 22篇 |
2016年 | 32篇 |
2015年 | 23篇 |
2014年 | 52篇 |
2013年 | 111篇 |
2012年 | 70篇 |
2011年 | 106篇 |
2010年 | 64篇 |
2009年 | 87篇 |
2008年 | 110篇 |
2007年 | 108篇 |
2006年 | 77篇 |
2005年 | 80篇 |
2004年 | 58篇 |
2003年 | 61篇 |
2002年 | 83篇 |
2001年 | 49篇 |
2000年 | 50篇 |
1999年 | 88篇 |
1998年 | 285篇 |
1997年 | 199篇 |
1996年 | 103篇 |
1995年 | 96篇 |
1994年 | 76篇 |
1993年 | 73篇 |
1992年 | 30篇 |
1991年 | 47篇 |
1990年 | 37篇 |
1989年 | 32篇 |
1988年 | 25篇 |
1987年 | 24篇 |
1986年 | 18篇 |
1985年 | 29篇 |
1984年 | 23篇 |
1983年 | 16篇 |
1982年 | 20篇 |
1981年 | 17篇 |
1980年 | 19篇 |
1979年 | 22篇 |
1978年 | 16篇 |
1977年 | 29篇 |
1976年 | 29篇 |
1975年 | 6篇 |
1973年 | 8篇 |
排序方式: 共有2795条查询结果,搜索用时 15 毫秒
991.
M Mori M Aihara K Kume M Hamanoue S Kohsaka T Shimizu 《Canadian Metallurgical Quarterly》1996,16(11):3590-3600
Cellular localization of platelet-activating factor (PAF) receptor in the rat brain was determined by (1) in situ hybridization, (2) Northern blot analysis in primary cell cultures of neurons, microglia, astrocytes, and fibroblasts, and (3) Ca2+ imaging in hippocampal culture. In situ hybridization revealed that the PAF receptor mRNA is expressed intensely in microglia and moderately in neurons. Northern blot analysis revealed that PAF receptor mRNA is the most abundant in microglia. In primary hippocampal cultures, PAF elevated intracellular Ca2+ concentration in microglia and also in neurons, but to a lesser extent. These results suggest predominant presence of PAF receptor in microglia. Cultured microglia also expressed cPLA2 mRNA the most intensely. PAF-activated microglia released arachidonic acid in a Ca(2+)-dependent manner and without conversion to its derivatives. We propose that microglia as well as neurons contribute to PAF-related events in the CNS by releasing arachidonic acid. 相似文献
992.
M Mori K Oota K Nagata H Tsutsumi T Okada T Kumakawa 《Canadian Metallurgical Quarterly》1997,34(10):789-792
Fifty patients, aged 60 years or more, who had been admitted to a hematology ward for more than 1 month, were studied in regard to their understanding of informed consent. The doctors informed 74% of their patients about the disease for which they were being treated. The rate of informing patients remained low in those with advanced age or with malignant tumors. However, only 42% of the patients realized that they had been informed of their diagnosis and clinical condition. The comprehension rate remained low at 43.2% even in patients who were informed by their doctors. While 60% of patients declared that they understood what the doctors described, only 36% could write something about the name or the state of their disease. Even among the patients who could understand the doctor's explanation, the comprehension rate was 43.3%. Sixty-six percent of patients demonstrated their wish to have a correct explanation of their diagnosis, 36% of patients wanted to be treated according to their own wishes, and 48% of patients left the decisions regarding their treatment to the doctors. 相似文献
993.
H Itoh N Sagawa M Hasegawa T Mori S Suga M Mukoyama T Yoshimasa H Itoh K Nakao 《Canadian Metallurgical Quarterly》1995,7(6):1515-1519
Guanosine 3',5'-cyclic phosphate (cGMP) is known to be the second messenger of natriuretic peptides and nitric oxide (NO). To investigate the involvement of natriuretic peptides in the regulation of the feto-placental circulation, specific radioimmunoassays were used to measure the concentrations of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and cGMP in the umbilical venous plasma of normal and asphyxiated newborns. The plasma concentrations of ANP, BNP and cGMP in asphyxiated newborns were 48.3 +/- 12.9 pm, 24.5 +/- 9.4 pm and 4.4 +/- 1.6 nM (mean +/- s.e.m., n = 10), respectively. These values were significantly higher than those in the normal newborns (17.4 +/- 1.9 pm, 4.7 +/- 1.0 pm, and 0.78 +/- 0.14 nM, respectively). Moreover, the expression of both ANP-A and ANP-B receptor, biologically active receptors for natriuretic peptides, was detected in term human placenta by Northern bolt analysis. The expression of natriuretic peptide receptors was further confirmed by binding assay using [125I]-labelled ANP and solubilized crude membrane preparations of placental tissue. These findings suggest that cGMP is produced in the placenta, at least partly, by the action of ANP and BNP secreted from fetal heart, in pathophysiological conditions such as fetal hypoxia. 相似文献
994.
Ultra high strength steel and aluminium alloy sheets were plastically joined by a self piercing rivet driven through the upper sheet and spread in the lower sheet with a die. The self piercing rivet directly pierces into the sheets without drilling the sheets beforehand unlike the conventional rivets. Insufficient driving though the upper sheet and fracture of the lower sheet occur due to the high hardness and low ductility of the ultra sheet, respectively. An ultra high strength steel sheet having a tensile strength of 980MPa and an aluminium alloy sheet were successfully joined by optimising shapes of the die. 相似文献
995.
The influence of diglycerides (DG’s) and trisaturated glycerides (P-P-P) on tempering and the hardness of confectionery products
are described. Palm oil and its processed products in confectionery fats have been reported (1,2). Palm oil contains a symmetric
triglyceride (P-O-P) as a main component which has polymorphic changes similar to those of cocoa butter, so a mixture of these
is able to use a tempering process similar to that used for cocoa butter.
Details for fat crystals and polymorphism have been reported (3,4). Okada (5) used a mixture of tristearin and tripalmitin
and studied the behavior of polymorphism using X-ray diffraction. The effects of DG’s on polymorphic change in palm oil also
have been reported (6,7), and Okiy (8) suggested that DG’s have an inferior effect on the quality of palm oil when used in
the solidified phase. However, there have not been many papers regarding how the above influence works in the production process
or how it affects confectionery products.
Palm oil contains about 10% trisaturated glycerides together with a few percent of mono- and diglycerides as minor components,
which have been produced during the maturation of palm fruits and processing of fats. It is very difficult to eliminate these
completely during the refining process.
This paper reports a study of the influence of these minor components on tempering and hardness of products by using a simulated
tempering machine. We have found that DG’s lower the temperature of tempering and soften the hardness of products and that
P-P-P increased the viscosity of products during tempering process but increased the hardness of products very little. 相似文献
996.
Yukishige Kitano Yuuji Mori Akira Ishitani Takaki Masaki 《Journal of the American Ceramic Society》1988,71(1):34-C-
Tetragonal-to-rhombohedral stress-induced phase transformation was studied by X-ray diffraction on the ground surfaces of tetragonal zirconia polycrystals and partially stabilized zirconia containing 2.0 to 5.0 mol% Y2 O3 prepared by hot isostatic pressing. The rhombohedral phase increased with Y2 O3 content and also with hot isostatic pressing temperature. The stability of the rhombohedral phase was studied with regard to surface finish and thermal annealing. The subsequent heat treatment of the specimens was found to cause the reverse rhombohedral-to-tetragonal transformation. 相似文献
997.
Imamura K. Takatsu M. Mori T. Adachihara T. Ohnishi H. Muto S. Yokoyama N. 《Electron Devices, IEEE Transactions on》1992,39(12):2707-2710
Full adders are demonstrated using InGaAs-In(AlGa)As RHETs. The RHET's emitter and base electrodes were self-aligned using a SiO2 sidewall and angled beam ion milling. The common-base current gain was about 0.9 and the emitter current peak-to-valley ratio was 10. The RHET full adder was constructed using a three-input exclusive-OR logic gate and a three-input majority logic gate. The authors confirmed normal operation of the full adder at 77 K. Only seven RHETs were needed for the full adder, about one-quarter of bipolar transistors that would have been required 相似文献
998.
We report a case with idiopathic edema accompanied with excessive sweating on bathing. The subject is a 26 year-old male. He was admitted to our hospital because of pretibial edema. He complained of excessive sweating only after daily bathing. Sweating on daily bathing reduced pretibial edema after long-term standing. Daily urine volume decreased by about 200 to 500 mL/day on bathing everyday. Plasma renin, aldosterone and bradykinin levels increased. Subcutaneous injection of pilocarpine increased sweating around the injection site. The cessation of daily bathing restored plasma renin, aldosterone and bradykinin levels; urine volumes increased. However, pretibial edema appeared and body weight increased by 8.5 Kg. Serum triiodothyronine (T3), thyroxine (T4) levels and basal metabolic rate (BMR) decreased. Circulating plasma volume increased with the cessation of bathing. Alterations in the autonomic nervous system may be involved in the appearance of general edema through increased plasma volume due to altered sweating function. 相似文献
999.
1000.
Toraichi Kazuo Katagishi Kazuki Mori Ryoichi 《IEEE transactions on bio-medical engineering》1987,(5):317-328
This paper describes the design of an image processor for the total evaluation of cardiac function. The system quantitatively evaluates cardiac function efficiently and accurately. Its functions include automatic boundary extraction, computation of volume, and three-dimensional display of a left ventricle. The method of automatic boundary extraction comprises: 1) processing to vignette and then correct blur using a Hadamard transformation, and 2) processing to extract the boundary automatically and reliably. 相似文献