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161.
Alexander V. Martynov 《Journal of organometallic chemistry》2011,696(10):1964-1968
Electrophilic addition of SCl2, SeCl2 and SeCl4 to 2 equivalents of allyl trimethyl silane proceeds regioselectively to give bis[2-chloro-3-(trimethylsilyl)propyl] sulfide, selenide and selenium dichloride, respectively. The reaction with TeCl4 affords only diallyl tellurium dichloride. The structures of the compounds were confirmed by 1H, 13C, 77Se and 125Te NMR techniques. 相似文献
162.
1,4-Bis(triphenylphosphonium)-2-butene dichloride(BTPBDC) and 1,4-bis(triphenyl phosphonium)-2-butene dithiocyanate (BTPBDT) were prepared and used as phase-transfer catalysts.Alkyl halides were converted efficiently to the corresponding alkyl thiocyanates under mild reaction conditions in water.No evidence for the formation of isothiocyanates as by-product of the reaction was observed. 相似文献
163.
以对称四甲基六元瓜环为主体,二氯化-二(2,2’-苯并咪唑)丁烷为客体,采用荧光光谱法和紫外吸收光谱法研究了主客体的相互作用。实验结果表明,主体对客体具有较强的包结识别能力,主客体之间可形成1∶1及2∶1的包结配合物,紫外吸收光谱法测得配合物的包结常数为K(1∶1)=4.79±0.01×104 L·mol-1, K(2∶1)=8.51±0.01×1010 L2·mol-2; 荧光光谱法测得配合物的包结常数为K(1∶1)=7.02±0.01×104 L·mol-1, K(2∶1)=2.88±0.01×1010 L2·mol-2,两种方法结果一致。 相似文献
164.
Synthesis and Crystal Structures of 1,1,3,3‐Tetramethylimidazolinium Dichloride and 1,1,4‐Trimethylpiperazinium Chloride Single crystals of 1,1,3,3‐tetramethylimidazolinium dichloride ( 1 ) and 1,1,4‐trimethylpiperazinium chloride ( 2 ) were obtained by reaction of CH2Cl2 with tetramethylethylenediamine (TMEDA) and NNN′N″N″‐pentamethyldiethylenetriamine (PMDETA), respectively. Both compounds are characterized by single crystal X‐ray diffraction and by IR spectroscopy. 1: [C7H18N2]Cl2, space group P21/c, Z = 4, lattice dimensions at 193(2) K: a = 821.97(11), b = 1130.38(8), c = 1143.08(13) pm, β = 100.348(15)°, R1 = 0.0271. The C7N2 heterocyclic ring has envelope conformation like other salts with this dication. 2: [C7H17N2]Cl, space group P212121, Z = 4, lattice dimensions at 100(2) K: a = 1030.37(8), b = 1036.55(6), c = 831.39(4) pm, R1 = 0.0180. Although the heterocyclic mono‐cation is without site symmetry in the crystal, its molecular symmetry is close to Cs, forming chair conformation of the C4N2 six‐membered ring. 相似文献
165.
Alexandru D. Asandei Gobinda Saha 《Journal of polymer science. Part A, Polymer chemistry》2006,44(3):1106-1116
The effects of the reaction conditions and nature of the initiator were investigated in the Cp2Ti(III)Cl‐catalyzed living radical polymerization of styrene initiated by benzoyl peroxide (BPO), tert‐butyl peroxide (TBPO), tert‐butyl peroxybenzoate (TBPOB), dicumyl peroxide (CPO), and tert‐butylperoxy 2‐ethylhexyl carbonate (TBPOEHC). The reversible termination of the growing chains with Cp2Ti(III)Cl affords a linear dependence of molecular weight on conversion over a wide range of temperatures (60–120 °C) with an optimum in polydispersity (Mw/Mn < 1.2) for St/BPO/Cp2TiCl2/Zn = 100/1/3/6 at 60–90 °C. The similarity of the kinetic parameters from polymerizations initiated by peroxides with vastly different half‐life times (t = 1 h, t = 543 h) and the minimum peroxide/Ti = 1/2 ratio required for a living process indicate that initiation occurs primarily by the redox reaction of the peroxide with Cp2Ti(III)Cl rather than peroxide thermal decomposition. This is consistent with one Ti equivalent consumed in the redox initiation and the second one utilized in the reversible termination of the growing chains. Qualitatively, based on the livingness of the process, these initiators ranked as BPO > TBPOB ~ TBPO > CPO > TBPOEHC. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1106–1116, 2006 相似文献
166.
Philip J. Hodges John M. Brown Stephen H. Ashworth 《Journal of Molecular Spectroscopy》2006,240(2):265-268
The 288 nm band system of FeCl2 has been recorded with a sample produced in a warmed, free-jet expansion at moderately high resolution (with a linewidth of 0.28 cm−1). Under these conditions, several hot bands are observed involving excitation of the symmetric and anti-symmetric stretching vibrations. The wavenumbers determined as a result for FeCl2 in its ground 5Δg,4 state are and . No hot, sequence bands in the bending vibration were observed. The most likely explanation is that the wavenumber for ν2 is essentially the same in both the electronic states involved (88 cm−1). Additional strong hot bands are observed that are unrelated to the previously assigned electronic transitions; they appear to emanate from a low-lying electronic state of FeCl2. 相似文献
167.
168.
A convenient 4-step synthesis of calceolarioside-B 1 and eutigoside-A 2 in high overall yield is described. The key step involved the regioselective, Me2SnCl2-catalyzed O-6 acylation of unprotected 2-phenylethyl-β-d-glucosides 5a–b with cinnamoyl chlorides 6a–b in excellent yields. Acylation at O-6 is selective with the acid chlorides used. This work serves as a model for the convenient synthesis of phenylpropanoid glycosides acylated at O-6. 相似文献
169.
Hana Palá?ková Jana Holubová Milan Erben 《Journal of organometallic chemistry》2007,692(17):3758-3764
Vanadocene dichloride (1) reacts with sulfur-containing amino acids, cysteine and methionine, giving new complexes with five- or six-membered chelate ring, but the structure of isolated compounds is affected by the pH value of the reaction mixture. Methionine reacts with aqueous 1 in the pH range of 3-8 affording chelate structure [Cp2V(N,O-met)]Cl (4). Similar reaction with cysteine gives two different products depending on pH. In the acidic solution, the complex [Cp2V(O,S-cys)]Cl (2) is present, whereas in neutral media the compound [Cp2V(N,S-cys)] (3) could be identified. On inspection of spectroscopic measurements, particularly EPR and vibrational spectroscopy, it is evident that sulfur atom of amino acid is bonded directly to the vanadium atom of [Cp2V]2+ moiety. For the purpose of comparison the complexes [Cp2V(O,S-mpa)] (5) and [Cp2V(N,S-csam)]+ (6a) with related chelating ligands, 3-mercaptopropionic acid (mpa) and cysteamine (csam), respectively, were prepared and spectroscopically characterized. The structure of the complex [Cp2V(N,S-csam)]BPh4 (6b) was also determined by X-ray diffraction analysis. 相似文献
170.
Sanae Yoshida 《Tetrahedron letters》2007,48(46):8116-8119
The reaction of dilithiated N,N′-dimethyl-1,2-diphenylethylenediamine with disulfur dichloride (S2Cl2) gave a thiosulfinyl compound (R2N)2SS, 2,5-dimethyl-3,4-diphenyl-1,2,5-thiadiazolidine 1-sulfide, whereas the treatment of dilithiated N,N′-bis(p-toluenesulfonyl)-1,2-diphenylethylenediamine with S2Cl2 furnished a new heterocycle, 3,6-bis(p-toluenesulfonyl)-4,5-diphenyl-4H,5H-1,2,3,6-dithiadiazine. 相似文献