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61.
Hirobumi Shibata Tomoaki Morita Taku Ogura Keishi Nishio Hideki Sakai Masahiko Abe Mutsuyoshi Matsumoto 《Journal of Materials Science》2009,44(10):2541-2547
Mesostructured zirconia particles having monoclinic-type crystalline walls were prepared using a low-temperature crystallization
technique. Crystalline zirconia particles with highly-ordered mesostructures were obtained through the sol–gel process of
zirconium sulfate tetrahydrate at 333 K in the presence of molecular self-assemblies of cetyltrimethylammonium bromide (CTAB)
or mixtures of CTAB and anionic molecules such as sodium dodecyl sulfate and sodium p-toluenesulfonate. Variations in the molar ratios of CTAB and the chemical species of anionic molecules led to the variations
in the periods of highly-ordered zirconia having crystalline walls. Calcination of the mesostructured zirconia particles prepared
using templates consisting solely of CTAB yielded crystalline mesoporous zirconia particles. 相似文献
62.
Prepolymerizations of 4,4′‐bismaleimidodiphenylmethane (BMI), diallyl isocyanurate (DAIC), and melamine (ML) at 160–170°C and subsequent compression molding at 200–280°C yielded cured BMI/DAIC/ML resins with feed molar ratios of 4/1/1, 3/1/1, and 2/1/1 (BMI‐DAIC‐ML411, 311, and 211). Similarly, cured BMI/DAIC 1/1 and BMI/ML 3/1 resins (BMI‐DAIC11 and BMI‐ML31) were prepared. The FT‐IR analysis revealed that the maleimide and allyl groups were almost consumed for all the cured resins, and the hydrogen bonding interaction became stronger with decreasing BMI contents for BMI‐DAIC‐MLs. Based on the cured structures elucidated from the FT‐IR result, the numbers of multiple hydrogen bonds and cross‐linking covalent bonds (NMHB and NCB), and total cross‐linking bond energy (ETB) were evaluated to be 0, 7.92, and 618 for BMI‐DAIC‐ML411, 0.71, 7.81, and 627 for BMI‐DAIC‐ML311, and 0.95 mol kg?1, 7.61 mol kg?1, and 617 kcal kg?1 for BMI‐DAIC‐ML211, respectively. A higher order of glass transition and 5% weight loss temperatures for BMI‐DAIC‐MLs was 411 > 311 > 211 in accordance with a higher order of NCB. BMI‐DAIC‐MLs displayed a weak tan δ peak at 70–150°C due to dissociation of the hydrogen bonds. The flexural strength and modulus of BMI‐DAIC‐ML311 were higher than those of BMI‐DAIC‐ML411 in accordance with the difference of ETB. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43121. 相似文献
63.
In the current design practices of steel-strip reinforced earth walls (SSREWs), the length of the reinforcing material is determined based on the equilibrium between the reinforcement tension and the earth pressure acting on the wall. Here, the resistance of the reinforcing material laid in the active failure zone (AFZ) is not considered. Moreover, the mechanical role of the reinforcing material against the integrity of the SSREW has not been sufficiently verified. Regarding the seismic stability of SSREW, although it is investigated by treating the entire reinforced earth wall as a rigid body, this inspection method is for gravity-retaining walls, and the difference in the seismic behavior between the SSREW and the rigid body is not clear. In this study, therefore, dynamic centrifuge model tests on 6 types of SSREWs were conducted to clarify the following items: (1) the basic earthquake behavior of a SSREW, (2) the mechanical role of the reinforcing material laid in the AFZ and (3) the mechanical role of the reinforcing material against the integrity of the SSREW. The results indicated that the reinforcing material laid in the AFZ can restrain the amount of deformation of the wall during earthquakes. Furthermore, the more stable the AFZ is, the smaller the maximum wall displacement will be. 相似文献
64.
Tetsuji Yano Hayato Tateno Tetsuo Kishi Shuichi Shibata Kanae Matsuyama Takeshi Okita Shinya Miyamoto Hirohide Kofuji Munetaka Myochin 《Journal of the American Ceramic Society》2014,97(2):457-464
Surface structures of iron–phosphate glasses were examined using X‐ray photoelectron spectroscopy (XPS). Cr2O3, CoO, and Al2O3 were introduced to the glass by the replacement of a part of Fe2O3, and the simulated fission products are also added. The obtained glasses showed high chemical durabilities by MCC‐1 test. In situ high‐temperature and room‐temperature XPS measurements were conducted on the polished sample surfaces and also those after 1‐week chemical durability test. Unique trends were observed in XPS spectra on heating and after the chemical durability test, respectively. Nature of the glass surface of iron–phosphate glasses was explained from the point of view of surface energy, and the origin of high chemical durability and the effect of chromium ions were discussed based on the changes on surface composition and valence states of transition‐metal ions. 相似文献
65.
针对现有固定宽带有线、无线接入技术存在的不足,本文结合Ad hoc技术和移动IP技术,提出了一种支持IP漫游的多跳接入方式,包括组网设计及协议扩展。其组网方式为:边缘接入采用多跳Ad hoc技术,主干接入采用分层移动IPv6技术。多跳Ad hoc网络大大增加了网络的覆盖范围,减轻了网络铺设成本,且支持宽带接入;分层移动IPv6降低了域内切换的信令开销和时延。同时,对现有的分层移动IPv6协议进行扩展,实现了主干网络与边缘多跳网络的有机结合。移动用户不但能以较低的信令开销实现全局的IP漫游,还能保证进入同一MANET网络中的移动节点直接通信,减轻了主干网络的传输负担,也保证了突发情况下节点能通过边缘MANET网络保持链路畅通。 相似文献
66.
This study investigated whether hydrogels comprising hydrophilic cationic polymers have similar bactericidal effects. Bacteria were seeded on hydrogels and agar and their viability was assessed with time. Cationic hydrogels displayed bactericidal effects upon long-term bacterial contact. Furthermore, we assessed the areal density of cationic monomer unit of the cationic hydrogels, water content, and the initial elastic modulus. We examined correlations between each factor and bacterial death ratios; consequently, the bacterial death ratios were strongly correlated with the areal density of cationic hydrogel monomers. Elastic energy (Wel) generated at the cytomembrane ion-binding region and the cationic hydrogel and the cytomembrane interfacial energy (Wf) were estimated; consequently, Wel exceeded Wf at higher contact areas. The cationic hydrogel may extract cytomembranes with a reasonable adsorption area. Therefore, cationic hydrogels may be used as probes for ultrasonic echo to sterilize medical equipment. 相似文献
67.
There has been continuous progress at the High Energy Accelerator Research Organization (KEK) in R&D on vacuum beam ducts adaptable to future high-current particle storage rings. Here we proposed copper beam ducts with antechambers to deal with the severe issues attributed to the high beam currents. The proposed antechamber scheme can withstand intense synchrotron radiation (SR), provide a beam duct with low beam impedance, and effectively reduce the electron cloud effect (ECE) in positron/proton rings. Several trial models were manufactured by a pressing or cold-drawn method, and assembled with electron beam welding. Special vacuum components, such as connection flanges, distributed pumps, and gate valves, were customized for the beam ducts. TiN coating on the inner surface of the beam duct was also investigated as a mitigating measure for the ECE. Trial models of the copper beam ducts were installed into the KEK B-factory (KEKB), and their performances were evaluated using real positron and electron beams. 相似文献
68.
Yuji Tatemoto Yoshiyuki Bando Koji Oyama Keiji Yasuda Masaaki Nakamura Yasuhiro Sugimura Masahito Shibata 《Drying Technology》2001,19(7):1287-1303
The effects of operational conditions on the drying performance in closed superheated steam drying were examined theoretically and experimentally. The vapor generated from the sample was circulated in the drying chamber. In the theoretical analysis, the replacement of air with vapor in drying chamber and the convective vapor transfer in sample were considered. At the start of drying, the drying chamber was filled with air. As the drying proceeded, the air was replaced with the vapor generated from sample. The calculated results explained the characteristics of experimental data. The pore diameter of sample had little effect on the drying characteristics. During the internal evaporation period, the evaporation occurred in the narrow zone, which moved from the surface to the bottom of sample. The convective vapor transfer in sample had a significant influence on the drying performance. The excess increments in temperature and velocity of drying gas hardly contributed to shortening the drying time. 相似文献
69.
70.
Fumihide Shiraishi Naoya Kamikariya Yuichiro Shibata 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2011,86(6):852-857
BACKGROUND: The authors (Chem Eng J 148, 234 (2009)) previously demonstrated the excellent performance of a photocatalytic reactor with a parallel array of nine light sources. To enhance the possibility of practical application of this reactor, the present work explores the use of a PET (polyethylene terephthalate) sheet as a new cheap material to support TiO2, as an alternative to glass tubes. A method of coating the hydrophobic PET sheet with a TiO2 film using an aqueous coating solution is investigated and the performance of the TiO2‐PET sheet prepared evaluated. RESULTS: The affinity of the coating solution for the PET sheet is greatly enhanced by addition of 0.01% (w/w) nonionic surfactant (polyoxyethylene lauryl ether). A relatively uniform thin TiO2 film is formed on the entire surface of the PET sheet by applying the coating solution to the PET sheet and drying it at 100 °C. Decomposition experiments of gaseous HCHO indicate that the photocatalytic activity, although initially low, is increased with repeated use. This is because surfactant molecules added interfere initially with the decomposition of HCHO. After their decomposition, the TiO2–PET sheet decomposes HCHO at almost the same rate as does the TiO2–glass tube. CONCLUSION: The photocatalytic reactor with a parallel array of nine light sources can utilize a PET sheet as TiO2 support with a reduction in material cost. Copyright © 2011 Society of Chemical Industry 相似文献