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61.
62.
Kanit Krisnangkura 《Journal of the American Oil Chemists' Society》1991,68(1):56-58
Equations were developed for the estimation of gross heat of combustion (HG) of triglycerides (TGs) and fatty acid methyl
esters (FAMEs) from their saponification number (SN) and iodine value (IV). HG of TG=1,896,000/SN − 0.6 IV — 1600 and HG of
FAME=618,000/SN − 0.08 IV — 430. When these equations were tested on cottonseed oil, soybean oil, partially hydrogenated soybean
oil, peanut oil, sunflower oil, sunflower oil methyl esters, soybean oil methyl esters and cottonseed oil methyl esters, predicted
HG values agreed well with those reported in the literature. 相似文献
63.
The biodegradation of di-n-butyl phthalate (DBP) using immobilized microbial cells was carded out in an internal airlift loop reactor with ceramic honeycomb supports. A strain that is capable of degrading DBP was isolated from the activated sludge and identified as Bacillus sp. using 16S rDNA sequential analysis. Bacillus sp. could be rapidly attached onto the ceramic honeycomb supports. The immobilized cells could effectively degrade DBP in batch and continuous experiments. When the influent concentration of DBP was 50mg·L^-1, the effluent DBP reached less than lmg.L i with 6h hydraulic retention time (HRT) in continuous experiment. The immobilized microbial cells could grow and accumulate through the biodegradation of DBP, and the rate of degradation is accordingly increased. The possible pathway of DBP biodegradation using immobilized cells was tentatively proposed. 相似文献
64.
65.
以壬基酚聚氧乙烯醚(OP-10)、衣康酸(IA)和亚硫酸钠为原料,通过酯化反应和磺化反应成功合成了壬基酚聚氧乙烯醚衣康酸单酯磺酸二钠盐。考察了反应温度、反应时间和物料物质的量比对反应体系的影响,得到的最佳工艺条件为:OP-10与IA的物质的量比为1∶1.05,酯化温度120℃,酯化时间4 h;酯化产物与亚硫酸钠物质的量比为1∶1.05,磺化温度90℃,磺化时间4 h。并通过红外光谱(IR)对产品结构进行对比分析,确定产物结构。 相似文献
66.
Vinyl ester resin is a major thermoset polymer used in low‐temperature composite manufacturing processes such as the Seemann composite resin infusion‐molding process (SCRIMP). Volume shrinkage and residual styrene are important concerns for composites produced in such processes. A low‐shrinkage additive (LSA) is a typical agent added to control the volume shrinkage of vinyl ester resins during molding. In this study, the effects of LSA content and the temperature profile (the temperature gradient and peak temperature) on the volume shrinkage control of a vinyl ester resin were investigated. The reaction kinetics of the resin system were also studied. We achieved good volume shrinkage control if we raised the curing temperature slowly to allow sufficient time for phase separation and if the curing temperature reached a high value after phase separation to allow microvoid formation. On the basis of experimental results, we designed an improved SCRIMP to increase resin conversion, reduce resin shrinkage, and produce composites with better properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1486–1496, 2003 相似文献
67.
Paula Relgio Marie-Thrse Charreyre Jos Paulo S. Farinha Jos M.G. Martinho Christian Pichot 《Polymer》2004,45(26):8639-8649
N,N-dimethylacrylamide (DMA) and N-acryloxysuccinimide (NAS) were copolymerized by the reversible addition–fragmentation chain transfer (RAFT) polymerization technique, to obtain random and block copolymer precursors onto which different side-groups may be statistically grafted via the reactive NAS units. These reactive copolymers have interesting applications in various fields such as coatings and paints, water purification and biology. Random poly(DMA-co-NAS) copolymer chains were synthesized with a 75/25 molar ratio, high conversion, an excellent molecular weight (MW) control from 5000 to 130 000 g mol−1, and low polydispersity index (Mw/Mn<1.1). Poly(DMA-b-NAS) block copolymers were synthesized by a two step method, in which a poly(DMA) homopolymer was prepared first and then used as macro-chain transfer agent to polymerize NAS. For example, a poly(DMA-b-NAS) sample was obtained with an average molecular weight of 44 300/7400 g mol−1 corresponding to 447 DMA and 44 NAS units. Such block copolymers had not yet been synthesized by any controlled polymerization technique. They can be used to prepare polymers with exactly the same backbone and an increasing number of different side groups (e.g. hydrophobic, ionic or fluorescent). 相似文献
68.
植物油制备生物柴油的研究 总被引:11,自引:0,他引:11
分别以菜籽油、大豆油以及芸香籽油为原料,采用碱催化酯交换法制备了脂肪酸甲酯即生物柴油。结果表明,用碱催化酯交换法制备脂肪酸甲酯,原料的酸价低于1.5mgKOH/g时能够保证较高的脂肪酸甲酯收率,采用酸催化预酯化法对高酸价的油脂原料进行脱酸效果比较显著。浓硫酸不仅是油脂预酯化脱酸反应的催化剂,也是油脂与甲醇进行酯交换反应的催化剂,但与甲醇钠等碱性催化剂相比,相同条件下的酯交换反应转化率低。采用减压蒸馏的方法提纯生物柴油,在0.098MPa的真空度下应控制其馏出温度不超过240℃。 相似文献
69.
70.
Keiichi Honda 《Journal of chemical ecology》1981,7(6):1089-1113
The larval osmeterial secretions of sixPapilio species examined displayed a remarkable qualitative change at the fourth larval ecdysis. The secretions of 4th (penultimate) instar larvae ofP. machaon, P. memnon, P. helenus, P. bianor, andP. maackii principally comprised mono- and/or sesquiterpenoids. The compounds identified from these species included -pinene, sabinene, -myrcene, limonene, -phellandrene, (Z)--ocimene, (E)--ocimene, -elemene, -caryophyllene, (E)--farnesene, -selinene, (E,E)--farnesene, germacrene-A, germacrene-B, caryophyllene oxide, methyl 3-hydroxy-n-butyrate, and acetic acid. In contrast, the secretion of 4th larval instar ofP. xuthus, although containing similar terpenic compounds, was accompanied by large amounts of aliphatic acids and their esters: isobutyric acid, 2-methylbutyric acid, methyl isobutyrate and methyl 2-methylbutyrate. On the other hand, the osmeterial secretions of 5th (last) instar larvae varied little in quality among the six species, and the identified compounds consisted of isobutyric acid, 2-methylbutyric acid, methyl isobutyrate, ethyl isobutyrate, methyl 2-methylbutyrate, ethyl 2-methylbutyrate, and isovaleric acid, the last of which was specific toP. bianor andP. maackii. The chemical alteration of osmeterial exudate synchronized at the final larval ecdysis with the larval morphological change (particularly in body coloration) that appears to be of defensive significance against predators. 相似文献