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101.
A. M. Demchenko V. A. Yanchenko V. V. Kisly M. S. Lozinskii 《Chemistry of Heterocyclic Compounds》2005,41(5):668-672
We have developed a method for synthesis of aryl isothiocyanates by means of thiocarbamoylation of aromatic amines by tetramethylthiuram disulfide followed by degradation of the intermediate N(1)-aryl-N,N-dimethylthiourea by concentrated HCl. We have shown that thiocarbamoylation of 4-amino-5-ethyl-4H-1,2,4-triazole-3-thiol occurs at the 2 position of the triazole ring, while thiocarbamoylation of 4-amino-3-methyl-6-phenyl-4,5-dihydro-1,2,4-triazin-5-one leads to the dihetaryl-substituted thiourea. We consider the possibility of using N(1)-aryl-N,N-dimethylthioureas as analogs of isothiocyanates in reactions with N-nucleophiles.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 775–780, May, 2005. 相似文献
102.
Jalal A.?Zahra Bassam Abu?Thaher Mustafa M.?El-Abadelah Hans-Hartwig?OttoEmail author 《Monatshefte für Chemie / Chemical Monthly》2005,136(4):567-570
Summary. Nitrilimines prepared from N-arylhydrazono chlorides reacted with 2-mercaptonicotinic acid yielding the corresponding addition products, 2-[(2-oxo-1-arylhydrazonopropan-1-yl)mercapto] nicotinic acids, which were treated with 1,1-carbonyldiimidazole in THF affording by cyclocondensation the corresponding hitherto unknown 2-arylhydrazono-3-oxothieno[2,3-b]pyridines. 相似文献
103.
F. N. Guseinov R. N. Burangulova E. F. Mukhamedzyanova B. P. Strunin O. G. Sinyashin I. A. Litvinov A. T. Gubaidullin 《Chemistry of Heterocyclic Compounds》2006,42(7):943-947
Heterocyclization of 2-chloroepoxy-1,1-diethoxy-2.3-butane with 2-amino-4-methylpyridine occurred with participation of all
three potential electrophilic centers to give 3,7-dimethyl-2-[N-(4-methylpyridyl-2)-4-hydroxy-3-methyl-5-oxopyrrolen-3-yl]imidazo[1,2-a]pyridine,
the structure of which was determined by X-ray crystallography.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, 1089–1094, July 2006. 相似文献
104.
F. Sauter J. Fröhlich A. Z. M. S. Chowdhury C. Hametner 《Monatshefte für Chemie / Chemical Monthly》1997,128(5):503-508
Summary A variety of partly novel tri- and tetracyclic hetero systems were obtained by reaction of heteroaromatic 2-aminoesters with 2-(methylthio)-2-thiazoline, yielding double-annelation of a thiazolo[2,3-b]pyrimido moiety in a one-pot process.On leave from University of Chittagong, Bangladesh 相似文献
105.
A. A. Balandina V. A. Mamedov E. A. Khafizova Sh. K. Latypov 《Russian Chemical Bulletin》2006,55(12):2256-2264
The combined use of 2D NMR correlation methods and ab initio chemical shift calculations is efficient and, in some cases, virtually the only way to determine the structures of new organic
compounds. This approach enabled us to establish the structure of the major unusual product of the three-component reaction
of imidazo[1,5-a]quinoxalin-4-one, bis(2-chloroethyl)amine hydrochloride, and potassium carbonate in DMF.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2172–2179, December, 2006.
Dedicated to Professor A. V. Il’yasov on the occasion of his 70th birthday. 相似文献
106.
Rong-Bin Huang Nan-Feng Zheng Su-Yuan Xie Lan-Sun Zheng 《Journal of inclusion phenomena and macrocyclic chemistry》2001,40(1-2):121-124
Crystal structure analysis shows that the p-tert-butylcalix[8]arene host and its four pyridine guests sit around an inversion center in the P21/c crystal lattice. The monoclinic cell parameters and its volume are: a = 19.617(4), b = 9.912(2), c = 25.178(5) , = 101.03(3)°, V =4805.27(17) 3. For Z = 2 and Mw = 1614.18, the calculated density Dcalc = 1.116 g/cm3. A host calixarene molecule includes four pyridine guests in two different ways: by hydrogen bonding and by possible C–H· interaction between the molecules. The hydrogen bonding drives the host macrocycle into a chair-like conformation. 相似文献
107.
Helmut Spreitzer 《Monatshefte für Chemie / Chemical Monthly》1992,123(6-7):593-597
Summary The acetale-ketone9 was synthesized as precursor for the preparation of -santalol derivatives posessing a bicyclo[2.2.2]octane nucleus. After methylenation of the keto-group the subsequent acidic hydrolysis of the acetal leads via a Prins reaction of the liberated aldehyde with the methylene group to tricyclo[6.2.2.02, 7]dodecane derivatives. Their olfactory properties are described. 相似文献
108.
A detailed singlet potential energy surface(PES) of [Si,C,O,O] system including a van der Waals (vdW) comples SiO……CO2,eight isomers,and twelve transiton states is investigated by MP2 and QCISD(T) (single-point)methods.At the final QCISD(T)/6-311 G(2df)//MP2/6-311G(d) level with zero-point energy included,the complex SiO……CO is found to be thermodynamically and kinetically the most stable species.Although eight ismoers are located as local energy minima,they are rather unstable toward isomerization to the dissociation fragments or comples.For the reaction of silocon atoms with carbon dioxide,two competitive reaction channels are found,and the primary pathway,which leads to the products of SiO and CO fragments,is the direct oxygen-abstraction process from carbon dioxide by silicon atom with a41.16 kJ/mol reaction barrier height.Our predications are in good agreement with previous experimental and theoretical studies. 相似文献
109.
本文从商品化的间溴苯甲醚和对甲氧基苯甲醛出发,通过傅-克酰基化反应、串联的羟醛缩合及1,4-迈克尔加成反应,得到三芳基取代的1,5-二酮,然后用查尔酮(Chalcone)作氧化剂,二酮与BF3.Et2O 反应形成吡喃鎓盐,再与苯基乙酸钠盐缩合得到芳香二溴代衍生物,产物的DMA溶液在DBU和钯催化剂的作用下,160°C 加热12 h进行脱卤化氢环化反应, 生成四甲氧基取代的二苯并并四苯(DBN)类衍生物。并报道了产物的晶体结构和在溶液中的聚集效应。 相似文献
110.
根据在自由基引发剂存在下,8,9-苯并-2-亚甲基-1,4,6-三氧螺(4,4)壬烷(Ⅰ)可能存在的竞争反应,推导了动力学方程式。用红外光谱法测定了单体的消失速率和苯酞的生成速率。实验结果与推导动力学方程式相符。进一步证明了单体(Ⅰ)的增长反应由加成聚合和开环—异构化—加成这两个反应组成。这两个反应对总速率的相对贡献与单体浓度有关。得到了共聚物的结构。 相似文献