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161.
Two multidentate ligands: N,N′-di-(propionic acid-2′-yl-)-2,9-di-aminomethylphenanthroline (L1) and N,N′-di-(3′-methylbutyric acid-2′-yl-)-2,9-di-amino-methylphenanthroline (L2) were synthesized and fully characterized by 1H NMR and elemental analysis. The binding ability of L1 and L2 to metal ions such as M(II) (M = Cu, Zn, Co and Ni) and Ln(III) (Ln = La, Nd, Sm, Eu, and Gd) has been investigated by potentiometric
titration in aqueous solution and 0.1 mol dm−3KNO3 at 25.0 ± °C. In view of the structure of L1 and L2, mononuclear metal complexes can be formed in solution. The stability constants of binary complexes of ligands L1 and L2
with metal ions M(II) and Ln(III) have been determined respectively and further discussed. 相似文献
162.
Luo Q Howell RC Bartis J Dankova M Horrocks WD Rheingold AL Francesconi LC 《Inorganic chemistry》2002,41(23):6112-6117
We have isolated the 1:1 Ln:[alpha-2-P2W17O61]10- complexes for a series of lanthanides. The single-crystal X-ray structure of the Eu3+ analogue reveals two identical [Eu(H2O)3(alpha-2-P2W17O61)]7- moieties connected through two Eu-O-W bonds, one from each polyoxometalate unit. An inversion center relates the two polyoxometalate units. The Eu(III) ion is substituted for a [WO]4+ unit in the "cap" region of the tungsten-oxygen framework of the parent Wells-Dawson ion. The point group of the dimeric molecule is Ci. The extended structure is composed of the [Eu(H2O)3(alpha-2-P2W17O61)]214- anions linked together by surface-bound potassium cations. The space group is P, a = 12.7214(5) A, b = 14.7402(7) A, c = 22.6724(9) A, alpha = 71.550(3), beta = 84.019(3)degrees, gamma = 74.383(3), V = 3883.2(3) A3, Z = 1. The solution studies, including 183W NMR spectroscopy and luminescence lifetime measurements, show that the molecules dissociate in solution to form monomeric [Ln(H2O)4(alpha-2-P2W17O61)]7- species. 相似文献
163.
Gallane complexes bearing amido-amine ligands -N(R)CH2CMe2CH2NMe2 [R = H or SiMe3 (TMS)], (H2Ga[N(H)CH2CMe2CH2NMe2])2, 1, H2Ga[N(TMS)CH2CMe2CH2NMe2], 2, (H(Cl)Ga[N(H)CH2CMe2CH2NMe2])2, 3, ([(TMS)2N](H)Ga[N(H)CH2CMe2CH2NMe2])2, 4, and HGa[N(TMS)CH2CMe2CH2NMe2]2, 5, were synthesized from the reactions of the quinuclidine adducts of mono- and dichlorogallane with the corresponding lithium amides. Structural determinations of compounds 1, 3, and 4 showed all were dimeric with bridging amido groups. Rather than bond to gallium the tertiary amine groups in 1 and 4 were hydrogen-bonded to the amino N-H. In the structure of compound 3 the amine group occupied an axial position in the trigonal bipyramidal geometry of the five-coordinate gallium. The results were rationalized in terms of the steric and electronic properties of gallium ligands. 相似文献
164.
Yuan Yang Jinnan Zhang Surong Luo Xiaohong Song Qi Li 《Frontiers of Chemistry in China》2007,2(3):296-302
Two new inclusion compounds (n-C4H9)4N+C18-H13O4
−·B(OH)3 (1) and (n-C4H9)4N+C18H13O4
− (2) were prepared and characterized by X-ray crystallography. Crystal data: compound 1, monoclinic P2(1)/c, a = 1.569 9(1) nm, b = 0.995 5(6) nm, c = 2.293 3(1) nm, β = 109.962(3)°, Z = 4, and R
1 = 0.0434, wR = 0.075 9; compound 2, monoclinic C2/c, a = 1.400 5(3) nm, b = 1,282 1(2) nm, c = 1.765 7(3) nm, β = 100.388(1)°, Z = 4, and R
1 = 0.0584, wR = 0.096 6. In the crystal structure of 1, the tetramers formed by two trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid (EADA) anions and two boric acid molecules were connected through
O—H⋯O hydrogen bonds to generate a channel type host lattice. The tetra-n-butylammonium cations were stacked to give two columns within each channel with cross-sectional size of about 2.30 nm × 0.93
nm. In the crystal structure of 2, similar honeycomb host lattices with big size were also formed along the [101] direction
by three-dimensional accumulation of EADA anions. The tetra-n-butylammonium cations were accommodated in a zigzag fashion within each channel.
Translated from Acta Chimica Sinica, 2006, 64(18): 1904–1910 [译自: 化学学报] 相似文献
165.
Summary Two new cyclodextrin (CD) derivatives, heptakis{2,6-di-O-pentyl-3-O-[3′-(2″-chloro-4″,5″-dioxylmethene)-phenyl-5′-iso-oxazolylmethyl]}-β-CD
(CD I) and heptakis{2,6-di-O-methyl-3-O-[3′-(2″-chloro)-phenyl-5′-iso-oxazolylmethyl]}-β-CD (CD II) were synthesized and coated
on fused-silica capillary columns. Their chromatographic characteristics, including column efficiency, polarity, selectivity
and phase transition were studied and compared with similar β-CD stationary phases. It was found that the heterocycle group
has a significant effect on the selectivity of the CD stationary phases. Both stationary phases can be successfully used to
separate many di- and trisubstituted benzene positional isomers and show stronger separation ability in separating low-polarity
benzene positional isomers than other β-CD stationary phases. 相似文献
166.
The dynamic processes of N(1s) core-hole excitation in gas-phase CH3CN molecule have been studied at both Hartree-Fock and hybrid density-functional theory levels. The vibrational structure is analyzed for fully optimized core-excited states. Frank-Condon factors are obtained using the linear coupling model for various potential surfaces. It is found that the vibrational profile of the N-K absorption can be largely described by a summation of two vibrational progressions: a structure-rich profile of nu(CN) stretching mode and a large envelope of congestioned vibrational levels related to the strong (-C-CN) terminal bending bond. Excellent agreement between theoretical and experimental spectra is obtained. 相似文献
167.
168.
Tsutomu Shiragami Katsunori Tanaka Yoshito Andou Shin-ichiro Tsunami Jin Matsumoto Hongxia Luo Yasuyuki Araki Osamu Ito Haruo Inoue Masahide Yasuda 《Journal of photochemistry and photobiology. A, Chemistry》2005,170(3):287-297
Tetraphenylporphyrinatoantimony(V) complexes, linked to boron-dipyrrin chromophores on axial ligands, were synthesized. The fluorescence spectra of 1a, 1b and 1c (3-[4-(N,N′-difluorobornyl-5-dipyrrinyl)phenyl]propoxo(methoxo)antimony(V) tetraphenylporphyrin bromide (1a); 6-[4-(N,N′-difluorobornyl-5-dipyrrinyl)phenyl]hexyloxo(methoxo)antimony(V) tetraphenylporphyrin bromide (1b); bis{3-[4-(N,N′-difluorobornyl-5-dipyrrinyl)phenyl]propoxo}antimony(V) tetraphenylporphyrin bromide (1c)) were analyzed under the excitations of N,N′-difluorobornyl-5-dipyrrinylphenyl (Bdpy) and tetraphenylporphyrinatoantimony(V) (Sb(TPP)) chromophores. Under the irradiation of Bdpy chromophore, the excitation energy was transferred from Bdpy chromophore to the Sb(TPP) moiety at 0.13–0.40 of the quantum yields, even in a polar solvent. On the other hand, the emission of Sb(TPP) chromophores was quenched by Bdpy chromophores at rate constants of 108–109 s−1, independent of on the solvent polarity. Under the excitation of the Bdpy chromophore of 1d (3-[4-(N,N′-difluorobornyl-5-dipyrrinyl)phenyl]propoxo(phenyloxo)antimony(V) tetraphenylporphyrin bromide) involving both the Bdpy and the phenoxy chromophores on the axial ligands, the excited singlet state of the Sb(TPP) chromophore generated by the energy transfer from the Bdpy chromophore was quenched by the phenoxy ligand via non-radiative processes involving electron transfer. However, rapid back electron-transfer may occur because no absorption of the anion radical of Sb(TPP) was observed by nanosecond laser photolysis. 相似文献
169.
关于统计学中一个新兴化学分支学科的建立、定义和教育 总被引:1,自引:0,他引:1
本文追溯了统计学发展、建立中的大事, 陈述了它的定义及其化学分支发展、建立的梗概; 鉴于化学界对该新兴化学分支学科的名称长期存在争议, 提出了以化学统计学而不以化学计量学为该学科名称的理由, 把化学统计学定义为一个研究有关数据的收集或产生、描述、分析、综合和解释, 以获得新化学知识或信息的学科; 阐明了许多公认属于统计学的方法, 如显著性检验、方差分析、回归和相关, 以及一些尚未认定属于统计学的方法, 如模型建立、蒙特卡罗方法、傅立叶变换和人工神经网络, 都含有统计学5 个内涵中的一个或多个; 探讨了化学统计学家成长的模式, 认为当务之急是把化学统计学纳入化学专业的教学计划, 以培养懂统计学的化学家。 相似文献
170.
本文介绍FAB质谱的原理、功能和优点。综述了FAB机理,讨论了影响FAB谱的因素。归纳了FAB法在金属有机配合物研究中的应用。 相似文献