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951.
Novel hydrogels based on core-shell structured macro-crosslinkers were synthesized,which exhibited high toughness and multiple responsiveness.Sodium dodecyl sulfate (SDS) micelles mediated by NaC1 were used to encapsulate hydrophobic stearyl methacrylate (C18) in the core,and hydrophilic 2-acrylamido-2-methyl-1-propanesulfonic (AMPS)monomers in the corona.Such core-shell micelles were simultaneously copolymerized with acrylamide monomers through free radical polymerization.As a result,hydrogels crosslinked by amphiphilic "poly(C 18)-PAMPS" macro-crosslinkers were obtained.These hydrogels showed excellent tensile and compression strength and toughness.Cyclic compression loadingunloading tests demonstrated that the hydrogels were of outstanding fatigue resistance,and showed partial damage of energy dissipation mechanism.The damaged energy dissipation mechanism could be recovered at room temperature and the recovery could be accelerated at elevated temperatures.The hydrogels were sensitive to the change in pH and ion strength,showing reversible swelling/deswelling behaviors. 相似文献
952.
953.
设计合成了一个以四苯乙烯为核心,四端连接长烷基链的咔唑基四苯乙烯衍生物(TPECz),该化合物具有典型的聚集诱导发光(AIE)特性.紫外光谱(UV-Vis)、荧光光谱(PL)、热重(TG)和示差扫描量热(DSC)研究表明,该化合物属于深蓝光材料、具有较好的热稳定性,并且对金属Fe3+具有很好的识别作用,有望用于金属离子检测;同时,该化合物外围的咔唑基团具有电化学活性,采用电化学聚合方法可制备其聚合物交联荧光薄膜,扫描电镜(SEM)和原子力显微镜(AFM)研究表明,该荧光薄膜表面平整,有望用于制备有机电致发光器件(OLED),可见该化合物是一种多功能材料. 相似文献
954.
研究了三磷酸腺苷(ATP)及其代谢物在细胞内的含量以及2-叔丁基-1,4-苯醌(TBBQ)对ATP及其代谢产物在细胞内含量的影响。建立了一种高效液相色谱法(HPLC)用于快速分离、检测细胞内ATP及其代谢产物(二磷酸腺苷(ADP)和一磷酸腺苷(AMP))的含量。使用岛津高效液相系统及艾杰尔Venusil MP C18柱,采用等度洗脱的方式。流动相A相为50 mmol/L磷酸氢二钠和15 mmol/L三甲胺(TEA),用醋酸(HAc)调节pH至7.88;流动相B相为甲醇。采用建立的高效液相色谱法得到了3种代谢物的工作曲线,相关系数高(R~2≥0.999 6),MRC-5细胞中3种代谢物的含量均在线性范围(0.1~100μmol/L)内。该方法检出限低。采用预冷的80%(体积分数)甲醇水溶液提取细胞内的代谢物。该研究建立的方法成功地应用于检测MRC-5细胞中的ATP、ADP和AMP的含量,结果表明,TBBQ会对ATP、ADP、AMP在细胞内的含量产生影响,但TBBQ浓度和ATP、ADP以及AMP在MRC-5细胞内浓度的关系比较复杂。 相似文献
955.
956.
The main goal of this work is to study an initial boundary value problem for a quasilinear parabolic equation with logarithmic source term. By using the potential well method and a logarithmic Sobolev inequality, we obtain results of existence or nonexistence of global weak solutions. In addition, we also provided sufficient conditions for the large time decay of global weak solutions and for the finite time blow-up of weak solutions. 相似文献
957.
958.
We provide an explicit example of a pair of weights and a dyadic sparse operator for which the Hardy–Littlewood maximal function is bounded from \(L^p(v)\) to \(L^p(u)\) and from \(L^{p'}(u^{1-p'})\) to \(L^{p'}(v^{1-p'})\) while the sparse operator is not bounded on the same spaces. Our construction also provides an example of a single weight for which the weak-type endpoint does not hold for sparse operators. 相似文献
959.
960.
Can Tetrylone Act in a Similar Fashion to Tetrylene in Ni(CO)2 Complexes? A Theoretical Study based on a Comparison using DFT Calculations 下载免费PDF全文
Thi Ai Nhung Nguyen Duc Sy Tran Thi Phuong Loan Huynh Thi Hoa Le Tuan Quang Duong Tien Trung Nguyen Thanh Cong Vo Van Tat Pham Tan Hiep Dang 《无机化学与普通化学杂志》2017,643(13):826-838
A comparison was made to investigate the structures and bonding of nickel complex that carry tetrylone and tetrylene ligands [(CO)2Ni‐{E(PH3)2}] ( Ni1E ) and [(CO)2Ni‐{NHEMe}] ( Ni2E ) (E = C to Pb) using quantum chemical calculations at the BP86 level with various basis sets (SVP, TZVPP, TZ2P+). The nature of the Ni–E bonds was analyzed with charge‐ and energy decomposition methods. The structures of tetrylone complexes Ni1E exhibit an interesting trend with the ligands E(PH3)2 are bonded in a tilted orientation relative to the fragment Ni(CO)2. In contrast, the calculated equilibrium structures of complexes Ni2E exhibit the NHEMe ligands (E = C to Sn) bonded in a head‐on way to the Ni(CO)2 fragment, while the bending angle gives the strongest side‐on bonded ligand NHPbMe when E = Pb. The interesting trend of the bond dissociation energy (BDE) is observed for the tetrylone, which has the same trend BDEs compared with tetrylene complexes. The EDA‐NOCV results indicate that the tetrylone ligands {E(PH3)2} in complexes are similar to the tetrylene ligands NHEMe as strong σ‐donors and weak π‐acceptors. The BDEs calculated for the Ni–E bonds in Ni1E and Ni2E show that the effect of bulky ligands may obscure the intrinsic Ni–E bond strength. The bonding analysis shows that the tetrylone ligands in Ni1E may act in a similar fashion to the tetrylene ligands in Ni2E . All complexes Ni1E and Ni2E are suitable targets for synthesis. 相似文献