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61.
62.
A dicyano-containing [Fe(bpb)(CN)2]- building block has been employed for the synthesis of cyano-bridged heterometallic Ni(II)-Fe(III) complexes. The presence of steric bpb(2-) ligand around the iron ion results in the formation of low-dimensional species: five are neutral NiFe2 trimers and three are one-dimensional (1D). The structure of the 1D complexes consists of alternating [NiL]2+ and [Fe(bpb)(CN)2]- generating a cyano-bridged cationic polymeric chain and the perchlorate as the counteranion. In all complexes, the coordination geometry of the nickel ions is approximately octahedral with the cyano nitrogen atoms at the trans positions. Magnetic studies of seven complexes show the presence of ferromagnetic interaction between the metal ions through the cyano bridges. Variable temperature magnetic susceptibility investigations of the trimeric complexes yield the following J(NiFe) values (based on the spin exchange Hamiltonian H = -2J(NiFe) S(Ni) (S(Fe(1)) + S(Fe(2))): J(NiFe) = 6.40(5), 7.8(1), 8.9(2), and 6.03(4) cm(-1), respectively. The study of the magneto-structural correlation reveals that the cyanide-bridging bond angle is related to the strength of magnetic exchange coupling: the larger the Ni-N[triple bond]C bond angle, the stronger the Ni- - -Fe magnetic interaction. One 1D complex exhibits long-range antiferromagnetic ordering with T(N) = 3.5 K. Below T(N) (1.82 K), a metamagnetic behavior was observed with the critical field of approximately 6 kOe. The present research shows that the [Fe(bpb)(CN)2]- building block is a good candidate for the construction of low-dimensional magnetic materials. 相似文献
63.
Hai Ni Heather A. Nash James G. Worden Mark D. Soucek 《Journal of polymer science. Part A, Polymer chemistry》2002,40(11):1677-1688
The kinetics of the reaction of aliphatic isocyanate with water were investigated with hexyl isocyanate as a model compound. The kinetic study was carried out with a titration method to determine the concentration of the isocyanate group as a function of time. Gas chromatography was used to augment the kinetic data obtained from the titration method. The effects of an organic acid [p‐toluene sulfonic acid monohydrate (p‐TSA)], a tertiary amine {diazabicyclo[2.2.2]octane (DABCO)}, and an organotin compound [dibutyltin dilaurate (DBTDL)] on the reaction were investigated for the conversion of isocyanate to a urea. Under the reaction conditions in this study, urea was the only product observed. The rate constants indicated that p‐TSA had low catalytic activity, DABCO had intermediate catalytic activity, and DBTDL had high catalytic activity. A reaction mechanism was proposed for each of the catalysts. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1677–1688, 2002 相似文献
64.
Dazhang Zhu Shilong Wang Xiaoyu Sun Yaming Ni Side Yao 《Frontiers of Chemistry in China》2007,2(4):354-358
The reaction mechanism between isoquinoline and ·OH radical in aqueous dilute solutions under different conditions was studied
by pulse radiolysis. The main characteristic peaks in these transient absorption spectra were attributed and the growth-decay
trends of several transient species were investigated. Under neutral or alkaline conditions, the reaction of ·OH radical and
isoquinoline produces OH-adducts with respective rate constants of 3.4 × 109 and 6.6 × 109 mol−1 · dm3 · s−1 while under acidic conditions, the isoquinoline was firstly protonated and then ·OH added to the benzene ring and produced
protonated isoquinoline OH-adducts with a rate constant of 3.9 × 109 mol−1 · dm3 · s−1. With a better understanding on radiolysis of isoquinoline, this study is of help for its degradation and for environmental
protection.
__________
Translated from Journal of Fudan University (Natural Science), 2006, 45(6): 774–778 [8BD1;81EA: 590D;65E6;5B66;62A5;(自然科学版)] 相似文献
65.
Tian Xiu-Zhi Yang Rui Ma Jia-Jia Ni Yong-Hao Deng Hai-Bo Dai Lei Tan Jiao-Jun Zhang Mei-Yun Jiang Xue 《高分子科学》2022,40(7):789-798
Chinese Journal of Polymer Science - Antistatic and strength properties are of vital importance for polyurethane rubber used in moving parts of many industrial instruments. Herein, polyurethane was... 相似文献
66.
Herein, a 3D hierarchical structure is constructed by growing NiCo2O4 nanowires on few-layer Ti3C2 nanosheets using Ni foam (NF) as substrate via simple vacuum filtration and solvothermal treatment. Ti3C2 nanosheets are directly anchored on NF surface without binders or surfactants, and NiCo2O4 nanowires composed of about 15 nm nanoparticles uniformly grow on Ti3C2/NF skeleton, which can provide abundant active sites and ion diffusion pathways for enhancing electrochemical performance. Benefiting from the unique structure feature and the synergistic effects of active materials, NiCo2O4/Ti3C2 exhibits a high specific capacitance of 2468 F g−1 at a current density of 0.5 A g−1 and a good rate performance. Based on this, an asymmetric supercapacitor (ASC) based on NiCo2O4/Ti3C2 as positive electrode and activated carbon (AC)/NF as negative electrode is assembled. The ASC achieves a high specific capacitance of 253 F g−1 at 1 A g−1 along with 91.5% retention over 10,000 cycles at 15 A g−1. Furthermore, the ACS presents an outstanding energy density of 90 Wh kg−1 at the power density of 2880 W kg−1. This work provides promising guidance for the fabrication of binder-free, free-standing and hierarchical composites for energy storage application. 相似文献
67.
Wanjun Ni Lizhong Wang Hongjian Song Yuxiu Liu Qingmin Wang 《Molecules (Basel, Switzerland)》2022,27(21)
Matrine derivatives were reported to have various biological activities, especially the ester, amide or sulfonamide derivatives of matrine deriving from the hydroxyl or carboxyl group at the end of the branch chain after the D ring of matrine is opened. In this work, to investigate whether moving away all functional groups from the C-11 branch chain could have an impact on the bioactivities, such as anti-tobacco mosaic virus (TMV), insecticidal and fungicidal activities, a variety of N-substituted-11-butyl matrine derivatives were synthesized. The obtained bioassay result showed that most N-substituted-11-butyl matrine derivatives had obviously enhanced anti-TMV activity compared with matrine, especially many compounds had good inhibitory activity close to that of commercialized virucide Ningnanmycin (inhibition rate 55.4, 57.8 ± 1.4, 55.3 ± 0.5 and 60.3 ± 1.2% at 500 μg/mL; 26.1, 29.7 ± 0.2, 24.2 ± 1.0 and 27.0 ± 0.3% at 100 μg/mL, for the in vitro activity, in vivo inactivation, curative and protection activities, respectively). Notably, N-benzoyl (7), N-benzyl (16), and N-cyclohexylmethyl-11-butyl (19) matrine derivatives had higher anti-TMV activity than Ningnanmycin at both 500 and 100 μg/mL for the four test modes, showing high potential as anti-TMV agent. Furthermore, some compounds also showed good fungicidal activity or insecticidal activity. 相似文献
68.
We report the first amine nucleophilic approach for the modular construction of enantioenriched protected α-quaternary amino acids. The key to success is the use of an alcohol solvent, which makes a rationally designed COOMe-bonded Cu-allenylidene electrophilic intermediate stable enough to couple with amine nucleophiles before its decomposition. The reaction features wide functional group tolerance with high enantioselectivity, typically >90% ee, and is amenable to the modification of commercially available bioactive molecules. The resultant protected α-amino acids could be readily converted into a number of precious enantioenriched amines featuring α-hindered tertiary carbon centers, which are otherwise synthetically quite challenging, including those of α-amino aldehyde, peptides or α-vinyl amino ester with >92% ee in excellent yields. This protocol could be utilized for the synthesis of the protected bioactive α-ethylnorvaline in 3 steps, a significant advancement in comparison to an 11-step sequence reported previously.We report the first amine nucleophilic approach for the modular construction of enantioenriched protected α-quaternary amino acids. 相似文献
69.
Xiao-Xue Jing Da-Qing Li Yong Zhang Xiang-Yu Hou Jie Jiang Xing-Ce Fan Meng-Chen Wang Shao-Peng Feng Yuan-fang Yu Jun-Peng Lu Zhen-Liang Hu Zhen-Hua Ni 《中国物理快报》2021,(7):65-75
Two-dimensional surface-enhanced Raman scattering(SERS) substrates have drawn intense attention due to their excellent spectral reproducibility, high uniformity and perfect anti-interference ability. However, the inferior detection sensitivity and low enhancement have limited the practical application of two-dimensional SERS substrates. To address this issue, we propose that the interaction between the MoTe_2 substrate and the analyte rhodamine 6 G molecules could be remarkably enhanced by the introduced p-doping effect and lattice distortion of MoTe_2 via hydrogen plasma treatment. After the treatment, the SERS is greatly improved, the enhancement factor of probe molecules reaches 1.83 × 10~6 as well as the limit of detection concentration reaches 10-13 M.This method is anticipated to afford new enhancement probability for other 2D materials, even non-metal oxide semiconductor SERS substrates. 相似文献
70.
Chenyue Zhao Zhipeng Ding Yibin Zhang Zhigang Ni Shijun Li Shaolong Gong Bo Zou Kai Wang Ling Yu 《Chemical science》2023,14(5):1089
Different from the conventional piezochromic materials with a mono-redshift of single emission, our well-designed molecule demonstrates a sensitive turn-on and color-tunable piezochromic luminescence in response to the hydrostatic pressure. The molecule PXZ-W-SOF possesses dual-emission and pressure-induced bidirectional shifting characteristics. On the basis of in-depth experimental studies, on one hand, it is confirmed that the origin of the dual-emission behavior is the intramolecular charge transfer, namely thermally activated delayed fluorescence (TADF), and the intermolecular excimer; on the other hand, the emission of the excimer exhibits three-step variations with increasing pressure, which is mainly attributed to the molecular structure and its crystal packing state. The remarkable color change of PXZ-W-SOF from sky-blue to green to deep-blue during the whole process of boosting and releasing pressure is a result of intramolecular and intermolecular energy-transfer interactions. The PXZ-W-SOF molecular model is an extremely rare example of highly sensitive fluorescence tuning driven by TADF and excimer conversion under mechanical stimulation, thus providing a novel mechanism for the field of piezochromism. The unique molecular design also offers a new idea for rare deep-blue and ultraviolet TADF materials.A high-contrast luminescent material exhibits dual-emission and pressure-induced bidirectional shifting, originating from the cooperative effects of TADF and excimers. It provides a novel mechanism for the piezochromic behavior. 相似文献