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81.
以硝酸铈铵(CAN)为引发剂,采用固相半干法合成了玉米淀粉(CS)接枝甲基丙烯酸甲酯(MMA)共聚物。考察了含水量、反应体系的酸性、反应时间与温度、MMA单体和引发剂CAN用量等因素对接枝共聚反应的影响。结果表明,体系含水质量分数为35%左右,CAN用量为CS质量的1.5%~3%,反应温度在40~50℃,反应时间为0.5h左右,可得到接枝率、接枝效率和单体转化率均较高的接枝共聚物。 相似文献
82.
83.
Preparation of glycol derivatives of partially hydrogenated soybean oil fatty acids and their potential as lubricants 总被引:1,自引:0,他引:1
Hemendra N. Basu Ellen M. Robley Max E. Norris 《Journal of the American Oil Chemists' Society》1994,71(11):1227-1230
Glycol diesters and mixtures of mono- and diesters have been prepared from methyl esters of partially hydrogenated soybean
oil fatty acids and diethylene, dipropylene, neopentyl and triethylene glycols. The catalyst used in these reactions was a
mixture of calcium acetate/barium acetate (3∶1, w/w). The reactions were carried out under nitrogen with 0.5% catalyst at
temperatures in the range of 190–275°C. Borated esters of mixed mono- and diesters were prepared with 0.33 equivalent of boric
acid per 1.0 equivalent hydroxyl group on the ester. Refractive indices, viscosities, and flash and fire points were determined
for diesters, mixed mono- and diesters, and mixed diesters and borated esters. The viscosities, flash points and fire points
indicate that these esters can be used as a component of lubricating oils. Wear-prevention characteristics of mixed diesters
and borated esters indicated that they can be used as antifriction additives in lubricating oils.
Lecture presented at the joint meeting of the International Society for Fat Research and the American Oil Chemists' Society
in Toronto, May 10, 1992. 相似文献
84.
85.
从中国的甲基氯硅烷建设热、金属硅对甲基氯硅烷生产的影响、下游产品的布局和发展、提高企业自主创新能力和知识产权保护意识、加强企业与.研究机构的合作、建立以企业为主体、产学研相结合的技术创新体系等几个侧面对中国有机硅工业的现状、存在问题及发展空间等进行了初步探讨。 相似文献
86.
对碱土金属氧化物和两性氧化物等10种氧化物作为合成1 甲氧基 2 丙醇固体催化剂进行了催化性能筛选。发现在碱土金属氧化物MgO、CaO和BaO中,中强碱MgO具有较高的环氧丙烷(PO)转化率(71 07%)和1 甲氧基 2 丙醇(PPM)选择性(92 53%)。在两性氧化物中,ZnO具有较高的PO转化率(55 26%)和PPM选择性(92 37%)。系统考察了反应温度、催化剂用量、反应时间和原料摩尔配比对MgO、ZnO的催化作用特点的影响,发现MgO在催化性能和1 甲氧基 2 丙醇选择性方面表现出的综合性能优于其他催化剂。 相似文献
87.
A rapid test to measure performance,emission and wear of a diesel engine fueled with palm oil diesel
H. Masjuki A. M. Zaki S. M. Sapuan 《Journal of the American Oil Chemists' Society》1993,70(10):1021-1025
Results of performance, emission and tribological evaluations of palm oil methyl ester and its blends with conventional diesel
in an automobile diesel engine test bed are presented. Polymerization and carbon deposits on the fuel injector were monitored.
CO, CO2, O2, combustion efficiency and temperature of exhaust gases were also measured. Palm oil methyl ester and its blends have great
potential as alternative diesel fuel. Performance and exhaust gas emission for palm oil methyl ester and its blends with conventional
diesel are comparable with those of conventional diesel fuel. Palm oil methyl ester does not pose a severe environmental problem
and will not deteriorate engine and bearing components. 相似文献
88.
89.
The effects of the molecular weights (molecular weight of polystyrene, Mw,PS, varying from 2.9 to 129 k) on the surface morphologies of spin-coated and annealed polystyrene/poly (methyl methacrylate) (PS/PMMA=50/50, w/w) blend films were investigated by atomic force microscopy and X-ray photoelectron spectroscopy. For the spin-coated films, when the Mw,PS varied from 2.9 to 129 k, three different kinds of surface morphologies (a nanophase-separated morphology, a PMMA cellular or network-like morphology whose meshes filled with PS, a sea-island like morphology) were observed and their formation mechanisms are discussed, respectively. Upon annealing, two different morphology-evolution processes were observed. It is found that a upper PS-rich phase layer is formed when Mw,PS<4 k, and this behavior is mainly attributed to the low interfacial tension between PS and PMMA component. When Mw,PS>4 k, the PS-rich phase forms droplets on top of the PMMA-rich phase layer which wets the SiOx substrate. These results indicate that the surface morphology of the polymer blend films can be controlled by the polymer molecular weight and annealing conditions. 相似文献
90.
This work examines low-temperature properties of triglyceride-based alternate fuels for direct-injection compression-ignition
engines. Methyl esters from transesterified soybean oil were studied as neat fuels and in blends with petroleum middle distillates
(No. 1 or No. 2 diesel fuel). Admixed methyl esters composed of 5–30 vol% tallowate methyl esters in soyate methyl esters
were also examined. Pour points, cloud points, and kinematic viscosities were measured; viscosities at cooler temperatures
were studied to evaluate effects of sustained exposure. Low-temperature filterability studies were conducted in accordance
with two standard methodologies. The North American standard was the low-temperature flow test (LTFT), and its European equivalent
was the cold-filter plugging point (CFPP). With respect to cold-flow properties, blending methyl esters with middle distillates
is limited to relatively low ester contents before the properties become preclusive. Under most conditions, cold-flow properties
were not greatly affected by admixing the methyl esters with up to 30 vol% tallowate (before blending). Least squares analysis
showed that both LTFT and CFPP of formulations containing at least 10 vol% methyl esters are linear functions of cloud point.
In addition, statistical analysis of the LTFT data showed a strong 1:1 correlation between LTFT and CP. This result may prove
crucial in efforts to improve low-temperature flow properties of alternate diesel fuels that contain methyl esters derived
from triglycerides. 相似文献