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171.
In search for new antitumor agents, twelve 6-aziridinylbenzimidazole derivatives were synthesized and their cytotoxicities were tested against three cancer cell lines (mouse lymphocytic leukemia P388 and B16, and human gastric carcinoma SNU-16). From 4-amino-3-nitrotoluene as the starting material, 2-(acetoxymethyl)benzimidazoles (5a-d) were obtained by Phillips reaction. These benzimidazoles were then reacted with Fremy's salt to give a mixture of three 2-(acetoxymethyl) (8a-c) and four 2-(hydroxymethyl)benzimidazole-4,7-diones (9a-d). Addition of these quinones with aziridine afforded 6-aziridinyl-2-(acetoxymethyl) (10a-c) and 6-aziridinyl-2-(hydroxymethyl)benzimidazole-4,7-diones (11a-d). Utilizing 2-(hydroxymethyl)benzimidazole-4,7-diones (9b,d), esters 10d and 13e-h were prepared by the sequential reactions of esterification and addition. The synthesized compounds show potent cytotoxicity against all of three cell lines tested. The cytotoxicities of 10a-d or 11a-d against SNU-16 were superior to those of 13e-h, and were equal to or slightly higher than that of mitomycin C. Compounds 11a-d were slightly more cytotoxic than 10a-d in all cell lines tested. 相似文献
172.
J Barrette R Bellwied P Braun-Munzinger WE Cleland T Cormier G Dadusc G David J Dee O Dietzsch M Fatyga SV Greene JV Germani JR Hall TK Hemmick N Herrmann RW Hogue B Hong K Jayananda D Kraus BS Kumar R Lacasse D Lissauer WJ Llope TW Ludlam R Majka SK Mark JT Mitchell M Muthuswamy E O'Brien C Pruneau FS Rotondo da Silva NC J Simon-Gillo U Sonnadara J Stachel H Takai EM Takagui TG Throwe L Waters C Winter D Wolfe CL Woody N Xu Y Zhang Z Zhang C Zou 《Canadian Metallurgical Quarterly》1995,52(5):2679-2683
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Ten protein and enzyme polymorphic systems, viz. haemoglobin, albumin, transferrin, adenosine deaminase, adenylate kinase phosphoglucomutase, esterase-D, glyoxalase, alkaline phosphatase and amylase were studied in numigall (guinea fowl x chicken hybrids) to assess structural gene expression and regulatory gene divergence between the parental species. The investigation revealed presence of both the maternal and paternal electrophoretic components in case of adenosine deaminase, alkaline phosphatase, amylase, albumin and transferrin although no clear differences could be identified for haemoglobin and glyoxalase. Esterase-D and adenylate kinase phenotypes showed a dominance of the chicken type. 相似文献
176.
R Kirchmair J Marksteiner J Troger SK Mahata M Mahata J Donnerer R Amann R Fischer-Colbrie H Winkler A Saria 《Canadian Metallurgical Quarterly》1994,6(5):861-868
Secretoneurin is a recently discovered neuropeptide derived from secretogranin II (SgII). Since this peptide could be detected in the dorsal horn of the spinal cord we studied whether it is localized in and released from primary afferent neurons. Secretoneurin was investigated with immunocytochemistry and radioimmunoassay in spinal cord, dorsal root ganglia and peripheral organs. SgII mRNA was determined in dorsal root ganglia. Normal rats and rats pre-treated neonatally with capsaicin to destroy selectively polymodal nociceptive (C-) fibres were used. Slices of dorsal spinal cord were perfused in vitro for release experiments. Immunocytochemistry showed a distinct distribution of secretoneurin-immunoreactivity (IR) in the spinal cord and, lower brainstem. A particularly high density of fibres was found in lamina I and outer lamina II of the caudal trigeminal nucleus and of the spinal cord. This distribution was qualitatively identical in rat and human post-mortem tissue. Numerous small diameter and some large dorsal root ganglia neurons were found to contain SgII mRNA. Capsaicin treatment led to a marked depletion of secretoneurin-IR in the substantia gelatinosa, but not in other immunopositive areas of the spinal cord and to a substantial loss of small (< 25 microns) SgII-mRNA-containing dorsal root ganglia neurons. Radioimmunoassay revealed a significant decrease of secretoneurin-IR in the dorsal spinal cord, the trachea, heart and urinary bladder of capsaicin-treated rats. Perfusion of spinal cord slices with capsaicin as well as with 60 mM potassium led to a release of secretoneurin-IR. In conclusion, secretoneurin is a neuropeptide which is stored in and released from capsaicin-sensitive, primary afferent (C-fibre) neurons.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Ji Young Hyun Cheol Wan Park Yanna Liu Daeun Kwon Seong‐Hyun Park Sungjin Park Jaeyoung Pai Prof. Dr. Injae Shin 《Chembiochem : a European journal of chemical biology》2017,18(12):1077-1082
Fifty‐five mono‐ and disaccharide analogues were prepared and used for the construction of microarrays to uncover lectin‐selective ligands. The microarray study showed that two disaccharide analogues, 28′ and 44′ , selectively bind to Solanum tuberosum lectin (STL) and wheat germ agglutinin (WGA), respectively. Cell studies indicated that 28′ and 44′ selectively block the binding of STL and WGA to mammalian cells, unlike the natural ligand LacNAc, which suppresses binding of both STL and WGA to cells. 相似文献
179.
A manganese dioxide (β-MnO2) photocatalyst for light-induced water splitting and hydrogen generation is studied via the impregnation and heat treatment method. The phase and fluorescence characterizations are examined by X-ray diffraction (XRD) and photoluminescence. A series of peaks for its (110) and (200) planes are identified as those for pure β-MnO2 crystals with lattice spacings of 3.11 and 2.19 Å, respectively. The photoluminescence shows that the primary signals are located in the blue-violet spectral region, corresponding to the band-edge emission of β-MnO2 (376 nm). Furthermore, two types of photoelectrochemical cell with added Pt are constructed to compare hydrogen production rates. A significant enhancement of light-induced hydrogen generation by water splitting is observed on Pt/β-MnO2/C, with a hydrogen generation rate of 194.67 μmol cm−1 h−1, greater than that on a Pt/TiO2/C photocatalyst, which can be attributed to the effective inhibiting of CO poisoning, thus maintaining the catalyst's surface area in methanol oxidation. 相似文献
180.