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881.
Large grain niobium has the potential of simplifying the production sequence and consequently reducing the cost of the superconducting RF cavities for ILC. To investigate the feasibility of fabrication and the possibility to achieve high gradient by large grain cavities, two 1.3GHz cavities were made of China large grain niobium and a series of vertical tests were carried out following several different
surfaces treatment procedures. Two cavities have both reached the high
gradient of more than 43MV/m repeatedly and the maximum accelerating field of 47.9MV/m has been achieved by China large grain niobium. This paper introduces the features of the fabrication and surface treatments on the large grain cavities and presents the preliminary results of the research. 相似文献
882.
Jeong Ho Ryu Kang Min Kim Sung Wook Mhin Gyeong Seon Park Jong Won Eun Kwang Bo Shim Chang Sung Lim 《Applied Physics A: Materials Science & Processing》2008,92(2):407-412
Pulsed laser ablation in a liquid phase was successfully employed to synthesize a barium molybdate (BaMoO4) nanocolloidal suspension. The nanocolloidal suspension was composed of well-dispersed and horizontally assembled BaMoO4 aggregates. The BaMoO4 aggregates showed predominantly elliptically shaped nanorods with sizes between 100 and 200 nm. The preferential elliptical
growth was rationalized from the viewpoint of the intrinsic structure of BaMoO4. The optical properties of the prepared BaMoO4 colloidal nanoparticles were investigated using Raman spectroscopy, UV–vis spectroscopy and photoluminescence (PL) spectrophotometry.
The optical band gap was estimated by Tauc and Menth’s law. The PL emission feature was decomposed into several individual
Gaussian components, which could be interpreted by a Jahn–Teller splitting effect on the [MoO4]2- tetrahedron of the BaMoO4 colloidal nanoparticles.
PACS 42.62.-b; 82.70.Dd; 78.55.Hx; 81.07.Wx 相似文献
883.
884.
885.
Dong Seok Kim Sang Chul Shim 《Journal of polymer science. Part A, Polymer chemistry》1999,37(15):2933-2940
Poly(silylenevinylene(bi)phenylenevinylene)s were synthesized by chloroplatinic acid-catalyzed hydrosilylation polymerization between α,ω-diethynylarenes and methylphenylsilane or diphenylsilane. The polymer structure was dependent on the substituent size of silane reagent. Poly(silylenevinylenephenylenevinylene)s showed fluorescence emission in the blue region. Optical and thermal properties of the polymers were extensively investigated. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2933–2940, 1999 相似文献
886.
Dong Seok Kim Edwin Kroke Ralf Riedel Andreas O. Gabriel Sang Chul Shim 《应用有机金属化学》1999,13(7):495-499
Pyridine‐catalyzed reactions of methyldichlorosilane with bis(trimethylsilyl)carbodiimide afford a dichlorosilane‐derived anhydrous sol–gel material. Both trimethylchlorosilane formation and Si–H disproportionation act as crosslinking mechanisms. The dried gels form amorphous or crystalline materials, depending on the sample history. The xerogels gave Si/C/N ceramics when pyrolyzed at 1200 °C. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
887.
Junyoung Seo Jae Do Yoo Minseong Kim Gayong Shim Yu-Kyoung Oh Rang-Woon Park Byungheon Lee In-San Kim Soyoun Kim 《Experimental & molecular medicine》2021,53(10):1592
Fibrin, one of the components of the extracellular matrix (ECM), acts as a transport barrier within the core of tumors by constricting the blood vessels and forming clots, leading to poor intratumoral distribution of anticancer drugs. Our group previously developed a microplasmin-based thrombolytic ferritin nanocage that efficiently targets and dissolves clots without causing systemic fibrinolysis or disrupting hemostatic clots. We hypothesized that the thrombolytic nanocage-mediated degradation of fibrin clots in the tumor ECM can lead to enhanced intratumoral drug delivery, especially for nanosized anticancer drugs. Fibrin clot deposition worsens after surgery and chemotherapy, further hindering drug delivery. Moreover, the risk of venous thromboembolism (VTE) also increases. Here, we used thrombolytic nanocages with multivalent clot-targeting peptides and fibrin degradation enzymes, such as microplasmin, to dissolve fibrin in the tumor microenvironment and named them fibrinolytic nanocages (FNCs). These FNCs target tumor clots specifically and effectively. FNCs efficiently dissolve fibrin clots inside of the tumor vessels, suggesting that they can mitigate the risk of VTE in cancer patients. Coadministration of FNC and doxorubicin led to improved chemotherapeutic activity in a syngeneic mouse melanoma model. Furthermore, the FNCs increased the distribution of Doxil/doxorubicin nanoparticles within mouse tumors. These results suggest that fibrinolytic cotherapy might help improve the therapeutic efficacy of anticancer nanomedicines. Thus, microplasmin-based fibrinolytic nanocages are promising candidates for this strategy due to their hemostatic safety and ability to home in on the tumor.Subject terms: Drug development, Drug delivery 相似文献
888.
DooSung Lee MyungSeob Shim SungWan Kim Hyunjung Lee Insun Park Taihyun Chang 《Macromolecular rapid communications》2001,22(8):587-592
The BAB‐type triblock copolymers composed of a central poly(ethylene oxide) (PEO, M̄nPEO = 1 000) block and two poly[(D ,L ‐lactic acid)‐co‐(glycolic acid)] end blocks with molecular weights between 900 and 1 600 exhibited an interesting phase transition behavior. The copolymer aqueous solution can form micelles with PLGA loops in the core and a PEO shell and groups of micelles because of bridging between micelles caused by the PLGA blocks with raising temperature. A possible micellar gelation mechanism was suggested. 相似文献
889.
Sang Chul Shim Min Chul Suh Dong Seok Kim 《Journal of polymer science. Part A, Polymer chemistry》1996,34(15):3131-3139
1,4-Diphenyl-1-buten-3-yne was metathesis polymerized over NbCl5- or TaCl5-based catalysts followed by pyrolysis to obtain graphite-like pyropolymers. The brown metathesis polymer, poly(1,4-diphenyl-1-buten-3-yne), has the structure of fully conjugated backbone and was annealed at 250°C to obtain partially crosslinked polymer which showed 20% increase of carbon residue on pyrolysis over 400°C than the pyrolyzed poly(1,4-diphenyl-1-buten-3-yne) without annealing. The polymers were characterized by GPC, EA, NMR, XPS, TGA, DSC, FT-IR, laser-Raman, x-ray diffraction, and SEM studies. © 1996 John Wiley & Sons, Inc. 相似文献
890.