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411.
High levels of accuracy can be achieved in precision machining through the use of highly accurate machine tool elements and under good machining and environmental conditions. To improve the accuracy and stiffness of the machine tool, we proposed a new method using in-process measurement and confirmed its effectiveness. In this work, this method is applied to cylindrical turning. The following were determined: the effectiveness of simulation for estimating the form accuracy, a new function of the corrective servo by changing the feedback gain, and the effectiveness of the new function for correcting the error. These were confirmed by both simulation and experiment. 相似文献
412.
413.
High density polyethylene (PE) was fractionated by the column elution technique and the fractions had molecular weight distribution, and degree of polymerization, n, ranging from 357 to 14 600. These PE fractions were used as parent polymers of chlorinated PE(CPE). CPE samples were prepared by solution chlorination in tetrachloroethane at 120°C. Results of osmometry on the CPE indicated that neither scission nor crosslinking of CPE molecules take place during the chlorination. Solution viscosities of CPE samples varying in chlorine content, x from ~10 to 60% w/w were measured in o-dichloro-benzene (ODCB) at 135°C. Those of parent PE and whole polymers of poly(vinyl chloride) (PVC) were also included in the measurements. The corresponding constants of the Mark-Houwink-Sakurada equation have been determined as a function of x. Unperturbed dimensions and parameters bearing upon the excluded volume effect have been estimated from the Stockmayer-Fixman plot and the recent theory on polymer solutions. It was found that an increase in x of CPE leads to a decrease in the intrinsic viscosity of CPE prepared from the same parent PE. This trend has been attributed to a decreasing ratio of the effective hydrodynamic volume in the unperturbed state to the molecular weight of CPE with increase in x, because the excluded volume parameter changes only slightly regardless of x in the present CPE-ODCB system. Unperturbed dimensions of CPE and PVC have been discussed briefly, and those of CPE having ultimate x and some fluoropolymers have been compared with each other. The molecular dimensions of CPE samples reflect their random sequence distribution of chlorines as well as both x and n, and those of polar polymers are affected by the species of polar groups. 相似文献
414.
Tetsuo Matsumura Takanori Kameyama Yasushi Nauchi Izumi Kinoshita 《Progress in Nuclear Energy》2005,47(1-4):131-138
New concept of a passive-safety reactor “KAMADO” has a negligible possibility of core melting and flexibility of total reactor power. The reactor core of KAMADO consists of fuel elements of graphite blocks, which have UO2 fuel rods and cooling water holes. These fuel elements are located in a reactor water pool of atmospheric pressure (1 atm) and low temperature (< 60°C). In case of LOCA, decay heat from fuel rods is removed by conduction heat transfer to the reactor water pool. Since the cooling water does not contact a fuel rod directly, core design has much flexibility without considering dry-out limitation and Minimum Critical Power Ratio (MCPR). Additionally an effective use of spent fuel is expected. 相似文献
415.
To convert unutilized plant biomass into a useful energy source, methane production from bamboo was investigated using a steam explosion pretreatment. Methane could not be produced from raw bamboo but methane production was enhanced by steam explosion. The maximum amount of methane produced, i.e., about 215 ml, was obtained from 1 g of exploded bamboo at a steam pressure of 3.53 MPa and a steaming time of 5 min. A negative correlation between the amount of methane produced and the amount of Klason lignin was observed in the methane fermentation of steam-exploded bamboo. 相似文献
416.
Manu Chauzar Seiji Tateyama Takanori Ishikura Keitaro Matsumoto Daisaku Kaneko Kohki Ebitani Tatsuo Kaneko 《Advanced functional materials》2012,22(16):3438-3444
Acidolysis polymerization has been used to prepare phenol‐derived polymers such as liquid crystalline (LC) polymers, and is catalyzed by mildly‐alkaline salts. The catalytic effects of hydrotalcites (HTs), which are natural alkalescent minerals with controllable basicity, are investigated on the acidolysis copolymerization of coumarates such as p‐coumaric acid and caffeic acid. As a result, the LC copolymer prepared in the presence of HT with a Mg/Al ratio of 3 shows higher molecular weight values than copolymers prepared in the presence of any other alkalescent salts. On the other hand, the copolymers prepared in the presence of HTs show a clear LC state where the polymer chains are oriented on the surface of the glass fibers. The resin, which is oriented by glass fiber fillers aligning along its longitudinal axis and is annealed at 300 °C for 20 min, shows a softening temperature of 305 °C while keeping a high mechanical strength of 85 MPa and a high mechanical modulus over 1 GPa. 相似文献
417.
Fertility of mice receiving vitrified adult mouse ovaries 总被引:3,自引:0,他引:3
Hani T Tachibe T Shingai S Kamada N Ueda O Jishage K 《Reproduction (Cambridge, England)》2006,131(4):681-687
Cryopreservation of the ovaries is a useful technology for preservation of germ cells from experimental animals, because if the female founder is infertile or has mutated mitochondrial DNA, preservation of female germ cells is necessary. Although it is possible to cryopreserve immature mouse ovaries with a high degree of viability by vitrification with a mixture of several cryoprotectants, the viability of cryopreserved adult mouse ovaries is still unknown. Here, we investigated the viability of mouse ovaries at various ages after cryopreservation by vitrification techniques. Donor ovaries were collected from 10-day-, 4-week-, 10-week- and 7-month-old, female, nulliparous, green fluorescence protein (GFP)-transgenic mice and cryopreserved by vitrification. The vitrified-warmed ovaries were orthotopically transplanted to 4- or 10-week-old mice. GFP-positive pups were obtained in all experimental groups. In the 4-week-old recipients, the percentages of GFP-positive pups among the total pups from recipients transplanted with ovaries of 10-day-, 4-week-, 10-week- and 7-month-old donors were 44%, 9%, 12% and 4% respectively. In the 10-week-old recipients, the percentages of GFP-positive pups among the total pups from recipients transplanted with ovaries of 10-day-, 4-week-, 10-week- and 7-month-old donors were 36%, 16%, 2% and 9% respectively. Furthermore, GFP-positive pups also were obtained from recipients transplanted with ovaries of donors without normal estrous cyclicity. Our results indicate that cryopreservation of mouse ovaries by vitrification is a useful method for the preservation of female germ cells from mice of various ages. 相似文献
418.
Daisuke Iioka Takanori Narita Yasunobu Yokomizu Toshiro Matsumura Norio Hatakeyama 《Electrical Engineering in Japan》2010,172(2):10-19
The influences of uncertainty of the load growth rate and interest rate on the total cost of low‐voltage distribution facilities was investigated. We assumed that the total cost was composed of the initial construction cost, the improvement cost, and the cost of power loss. We also assumed that the distribution facilities were operated for 30 years. Genetic algorithms were used to determine how to construct cost‐effective distribution facilities that did not compromise power quality. Two investment methods were compared: one in which the utility cut down the initial construction cost and improves the initial facilities along with the load growth, and one in which the utility bears the large initial cost without the improvement cost. It was found that the lower cost method depends on the load growth rate and the interest rate. It was also found that the influence of uncertainty in the load growth rate increases with an increase in the differential between the actual load growth rate and the expected one. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 172(2): 10–19, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20976 相似文献
419.
Hironori Yashima Michishige Terasaki Ami Sotokawauchi Takanori Matsui Yusaku Mori Tomomi Saito Naoya Osaka Hideki Kushima Munenori Hiromura Makoto Ohara Tomoyasu Fukui Sho-ichi Yamagishi 《International journal of molecular sciences》2020,21(23)
Advanced glycation end products (AGEs) are localized in macrophage-derived foam cells within atherosclerotic lesions, which could be associated with the increased risk of atherosclerotic cardiovascular disease under diabetic conditions. Although foam cell formation of macrophages has been shown to be enhanced by AGEs, the underlying molecular mechanism remains unclear. Since cyclin-dependent kinase 5 (Cdk5) is reported to modulate inflammatory responses in macrophages, we investigated whether Cdk5 could be involved in AGE-induced CD36 gene expression and foam cell formation of macrophages. AGEs significantly increased Dil-oxidized low-density lipoprotein (ox-LDL) uptake, and Cdk5 and CD36 gene expression in U937 human macrophages, all of which were inhibited by DNA aptamer raised against RAGE (RAGE-aptamer). Cdk5 and CD36 gene expression levels were correlated with each other. An antioxidant, N-acetyl-l-cysteine, mimicked the effects of RAGE-aptamer on AGE-exposed U937 cells. A selective inhibitor of Cdk5, (R)-DRF053, attenuated the AGE-induced Dil-ox-LDL uptake and CD36 gene expression, whereas anti-CD36 antibody inhibited the Dil-ox-LDL uptake but not Cdk5 gene expression. The present study suggests that AGEs may stimulate ox-LDL uptake into macrophages through the Cdk5–CD36 pathway via RAGE-mediated oxidative stress. 相似文献
420.
Li Qing Du Yan Wang Chang Xu Jia Cao Qin Wang Hui Zhao Fei Yue Fan Bing Wang Takanori Katsube Sai Jun Fan Qiang Liu 《International journal of molecular sciences》2013,14(12):24087-24096
The objective of this study was to investigate the underlying mechanisms behind the radiation-sensitising effects of the antennapedia proteins (ANTP)-smacN7 fusion protein on tumour cells. ANTP-SmacN7 fusion proteins were synthesised, and the ability of this fusion protein to penetrate cells was observed. Effects of radiation on the expression of X-linked inhibitor of apoptosis protein (XIAP) were detected by western blotting. The radiation-sensitising effects of ANTP-SmacN7 fusion proteins were observed by a clonogenic assay. The effects of drugs and radiation on tumour cell apoptosis were determined using Annexin V/FITC double staining. Changes in caspase-8, caspase-9 and caspase-3 were detected by western blot before and after ANTP-SmacN7 inhibition of XIAP. The ANTP-SmacN7 fusion protein could enter and accumulate in cells; in vitro XIAP expression of radiation-induced tumour cells was negatively correlated with tumour radiosensitivity. The ANTP-SmacN7 fusion protein promoted tumour cell apoptosis through the activation of caspase3. ANTP-SmacN7 fusion protein may reduce tumour cell radioresistance by inducing caspase3 activation. 相似文献