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991.
利用动态力学分析(DMA)方法,研究了吡啶基官能化的SBS(极性化SBS或SBSVP)热塑弹性体与数种增粘树脂共混物的动态力学性能,以此表征SBSVP与不同增粘树脂的相容性.试验结果表明,SBSVP与不同增粘树脂共混后,共混物的玻璃化转变温度(Tg)会发生相应的变化,表明不同种类的增粘树脂与SBSVP中PS及PB相的相容性各不相同.其相客性为以下几种情况不同程度的组合:树脂与SBSVP中的PB相相容;树脂与PS相相容;树脂与PB、PS相都相容;树脂与PB、PS相都不相容.同时可能会有过渡相和中间相的产生. 相似文献
992.
993.
Hyuk‐Sung Kwon Eunyong Chung Dong‐Ig Lee Chang‐Ha Lee Ik‐Sung Ahn Ju‐Young Kim 《应用聚合物科学杂志》2009,112(5):2935-2941
For the reasonable comparison of chemical and enzymatic polymerization, manganese(III) acetate and manganese peroxidase (MnP)‐catalyzed synthesis of polystyrenes were chosen and studied with respect to the yield and the polydispersity of polymer particles. MnP allowed the production of polystyrene in a higher yield and higher polydispersity (82.34% and 2.61) than manganese(III) acetate (77.90% and 1.75). This is believed to be due to a gradual supply of initiator radicals via a catalytic cycle in MnP‐catalyzed polymerization, whereas radicals are generated all at once in Mn(III)‐mediated polymerization. NMR spectroscopy revealed that atactic polystyrene was produced by emulsion polymerization using Mn(III) or MnP. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
994.
Yen‐Ju Su Tes‐Hao Ko Shu‐Hui Cheng Wan‐Shu Chen Tzu‐Hsien Han Jui‐Hsiang Lin 《应用聚合物科学杂志》2009,111(3):1615-1623
Activated carbon fibers (ACFs) contain pores with a weak resistance to electrolyte migration but with high electrical resistance between the fibers. The ACFs used herein were prepared from ultra‐thin polyacrylonitrile (PAN) fibers, to be used as electrodes in electrochemical double layer capacitors (EDLCs), by varying the activation temperatures and the holding times during steam activation. As the activation temperature and holding time were increased, the specific surface area increased along with the specific capacitance (F g?1). A maximum specific capacitance as high as 283 F g?1 can be obtained using the ultra‐thin ACFs fabricated at 1000°C for 10 min with a specific surface area of 1408 m2 g?1. This investigation demonstrates that the surface area, pore structure, and surface functional groups of ACFs were all significant factors in determining the capacitive characteristics of ACFs. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
995.
Min Ju Cho Jung-Il Jin Dong Hoon Choi Young Min Kim Young Wook Park Byeong-Kwon Ju 《Dyes and Pigments》2009,83(2):218-224
The ligands, 9-((6-phenylpyridin-3-yl)methyl)-9H-carbazole and 9-(4-(pyridin-2-yl)benzyl)-9H-carbazole were synthesized by attaching a carbazolyl group to the pyridine and phenyl rings of 2-phenylpyridine, respectively. Ir(III) complexes were prepared by a simple procedure and the solubility of the novel complexes was significantly better than that of the conventional, green-emitting conventional fac-tris(2-phenylpyridinato-C2,N)iridium(III). The Ir(III) complexes were used to prepare electrophosphorescent polymer light-emitting devices. The device comprising 10% of fac-tris(2-(4′-((9H-carbazol-9-yl)methyl)phenyl)pyridinato-C2,N)iridium(III) exhibited an external quantum efficiency of 7.88%, luminous efficiency of 23.01 cd/A, and maximum brightness of 32,640 cd/m2. The color of the emissions of fac-tris(2-(4′-((9H-carbazol-9-yl)methyl)phenyl)pyridinato-C2,N)iridium(III) was similar to that of conventional fac-tris(2-phenylpyridinato-C2,N)iridium(III). This work shows that integration of a rigid hole-transporting carbazole and phosphorescent complex in one molecule provides a new route to highly efficient, solution-processable complexes for electrophosphorescent applications. 相似文献
996.
997.
Seung Won Choi Dong Myeong Shin Joo Sung Lee Ju Min Kim Hyun Wook Jung Jae Chun Hyun 《Korean Journal of Chemical Engineering》2009,26(1):26-31
The sensitivity of two-dimensional isothermal film casting processes to ongoing sinusoidal disturbances has been investigated
by using the frequency response method with transient simulation techniques. Amplitude ratios of state variables such as cross-sectional
area, film width and film thickness at the take-up position with respect to a sinusoidal disturbance show resonant peaks along
the frequency domain. Effects of operating conditions, such as drawdown ratio and aspect ratio, on the process sensitivity
have been examined. Increasing drawdown ratio and decreasing aspect ratio make the system more sensitive to disturbances.
Also, the dichotomous behavior in the sensitivity analysis using viscoelastic Phan-Thien and Tanner fluids has been elucidated.
This frequency response method can be a useful tool to optimally design process systems for better processability and product
quality.
This article is dedicated to Professor Chul Soo Lee in commemoration of his retirement from Department of Chemical and Biological
Engineering of Korea University. 相似文献
998.
Hyun Ju Park Young-Kwon Park Jong-In Dong Joo-Sik Kim Jong-Ki Jeon Seung-Soo Kim Jinsoo Kim Byungho Song Junhong Park Kyung-Jin Lee 《Fuel Processing Technology》2009
The kinetic parameters for the pyrolysis of Oriental white oak were evaluated by thermogravimetric analysis (TGA). The white oak was pyrolyzed in a fluidized bed reactor with a two-staged char separation system under a variety of operating conditions. The influence of the pyrolysis conditions on the chemical and physical characteristics of the bio-oil was also examined. TGA showed that the Oriental white oak decomposed at temperatures ranging from 250 to 400 °C. The apparent activation energy ranged from 160 to 777 kJ mol− 1. The optimal pyrolysis temperature for the production of bio-oil in the fluidized bed unit was between 400 and 450 °C. A much smaller and larger feed size adversely affected the production of bio-oil. A higher fluidizing gas flow and higher biomass feeding rate were more effective in the production of bio-oil but the above flow rates did not affect the bio-oil yields significantly. Recycling a part of the product gas as a fluidizing medium resulted the highest bio-oil yield of 60 wt.%. In addition, high-quality bio-oil with a low solid content was produced using a hot filter as well as a cyclone. With exception of the pyrolysis temperature, the other pyrolysis conditions did not significantly affect the chemical and physical characteristics of the resulting bio-oil. 相似文献
999.
传统的结构设计理论只针对使用阶段的结构在不同荷载工况及其组合作用下的效应进行分析,以此来保证建筑结构具有一定的安全性和适用性,实际上,结构的自重等恒荷载是在施工过程中随着施工步的推进逐步施加在结构上的。文中以深圳证券交易所广场工程为背景,采用ANSYS中的单元生死技术按照拟定的施工方案对结构施工进行全过程跟踪分析,并与一次成型下结构位移变化情况进行对比,以此说明研究裙楼巨形悬挑钢桁架结构成型过程中位移变化及位移控制的必要性。 相似文献
1000.