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991.
采用高分子模板法合成了4种不同形貌的ZnO,分别为球状颗粒(ZnO NPs)、针状(ZnO NRs)、片状(ZnO NSs)和棒状(ZnO NBs).利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和能谱仪(EDS)对产物进行了表征.通过傅里叶变换红外光谱仪(FTIR)和圆二色光谱仪(CD)研究了小牛血清白蛋白(BSA)在不同形貌ZnO上的等温吸附规律、吸附热力学和吸附作用机理.结果表明,4种不同形貌的ZnO对BSA的吸附均较好地符合Langmuir等温吸附模型;吸附量随温度的升高略有增加;从热力学参数(ΔG,ΔH,ΔS)可知,吸附反应为自发进行的吸热反应,作用机理主要为氢键和静电作用.从热力学角度,针状的ZnO更有利于BSA的吸附. 相似文献
992.
ARCHANA Bajracharya WANG Li YE Dong-Mei CHEN Da-Peng DIAO Yun-Peng LIN Yuan 《结构化学》2012,31(8):1105-1110
A new compound,3,5-dihydroxy-N-(3-nitrobenzylidene)benzohydrazide (DNBB) methanol solvate,was synthesized and characterized by single-crystal X-ray diffraction.DNBB crystallizes in a monoclinic system,space group P2 1/c with a=8.387(4),b=23.237(10),c=9.133(3),β=122.10(3)o,Z=4,V=1507.8(12) 3,D c=1.464 g/cm 3,F(000)=696.0,μ=0.116 mm-1,the final R=0.0480 and wR=0.1294.DNBB exhibited low toxicity on Caco-2 cell culture and produced significant inhibitory effect on the contraction of rat jejunal longitudinal smooth muscle (JLSM).The mechanism of DNBB on JLSM was correlated to the stimulation of α and β adrenergic receptors since α receptor antagonist phentolamine and β receptor antagonist propranolol abolished the inhibitory effects of DNBB on the contraction of JLSM,respectively. 相似文献
993.
WU Li-hang MU Dan LIANG Fang-hui TIAN Yuan ZHANG Han-qi YU Ai-min WANG Xing-hua CHEN Ying 《高等学校化学研究》2010,26(2):189-193
Be able to form large particles with protein via electrostatic force to enhance the intensity of resonance light scattering(RLS),(NH4)2SO4 was used as a RLS probe to determine bovine serum albumin(BSA),human serum albumin(HSA) and ovum albumin(OVA).The experimental conditions were investigated,including the acidity and saturation degree of (NH4)2SO4.Under the optimum conditions,the enhanced RLS intensity is proportional to the concentration of BSA,HSA and OVA in the ranges of 5×10-8―1×10-6,2.5×10-8―8×10-7 and 5×10-8―1.5×10-6 mol/L,respectively.The detection limits for BSA,HAS and OVA are 6.6×10-9,3.8×10-9 and 7.4×10-9 mol/L,respectively.The effects of foreign substances were also examined.The practical and synthetic samples were analyzed with satisfactory results. 相似文献
994.
The interaction between tosufloxacin (TELX) and bovine lactoferrin (BLF) in aqueous solution was analyzed by fluorescence spectroscopy and absorbance spectra. The binding parameters and energy-transfer efficiency parameters were determined and the mechanism of interaction was discussed. The effect of tosufloxacin acting on the BLF’s conformation was detected and the unfolding procedure of BLF induced by tosufloxacin was explored by “fluorescence phase diagram”. Following experimental data of fluorescence polarization values P and r, the saturation characteristic of such kind of binding reaction was observed for the first time. The interaction between tosufloxacin and BLF influenced by Ni2+ and Co2+ were also preliminarily explored in this work. 相似文献
995.
996.
The luminol-bovine serum albumin chemiluminescence system was proposed for the first time. It was found that the hydrophilic luminol bound to the hydrophilic domain at Trp134 of BSA with accelerating the electrons transferring rate of excited 3-aminophthalate, which led to the enhancement CL intensity of luminol at 425 nm. The increment of chemiluminescence intensity was proportional to the concentrations of bovine serum albumin from 5.0 × 10−11 to 1.0 × 10−8 mol L−1 with the linear equation of ΔI = 7.47CBSA + 4.89 (R2 = 0.9950). Based on the remarkable quenching effect of cephalosporin on the luminol-bovine serum albumin chemiluminescence system, the interaction of bovine serum albumin-cephalosporin was studied by flow injection-chemiluminescence method. A valuable model for studying the interaction of bovine serum albumin-cephalosporin was constructed and the formula lg[(I0 − I)/I] = lg KD + n lg[D] was obtained. The binding parameters calculated by the model did agree very well with the results obtained by fluorescence quenching method. The major binding force of bovine serum albumin with cephalosporins was the hydrophobic effect. The binding ability of cephalosporin analogues to bovine serum albumin followed the pattern: cefoperazone, ceftriaxone and cefotaxime > cefuroxime and cefaclor > cefadroxil, cefradine and cefazolin, which was close to the order of their antibacterial ability. Using flow injection chemiluminescence method also obtained the stoichiometric ratio, the average of association constant KP and dissociation degree α of luminol-bovine serum albumin were 1:1, 1.12 × 107 L mol−1 and 0.086, respectively. 相似文献
997.
998.
pH对氟喹诺酮药物与BSA之间相互作用影响的研究 总被引:2,自引:0,他引:2
采用毛细管区带电泳法,通过测定在不同pH值、不同牛血清白蛋白(BSA)浓度缓冲溶液的条件下药物迁移时间的变化,并分别计算出了pH为6.8、7.4和8.0时培氟沙星、左氧氟沙星、氧氟沙星、环丙沙星等四种氟喹诺酮类药物与BSA相互作用的结合常数.结果表明:pH对结合常数有较大影响,四种药物分子结合常数的最大值均出现在pH=6.8时,并随着pH的增大,结合常数值明显下降.根据实验结果,还对四种氟喹诺酮类药物与BSA之间相互作用的类型、作用位置进行了分析探讨.研究结果对于进一步阐明药用机理并迅速开发出更高效的广谱抗菌药物具有较强的理论意义. 相似文献
999.
Jun Hee Lim Hee Jung Um Jong-Wook Park In-Kyu Lee Taeg Kyu Kwon 《Experimental & molecular medicine》2009,41(10):757-764
Monocyte chemoattractant protein-1 (MCP1) plays a key role in monocyte/macrophage infiltration to the sub-endothelial space of the blood vessel wall, which is a critical initial step in atherosclerosis. In this study, we examined the intracellular signaling pathway of IL-1β-induced MCP1 expression using various chemical inhibitors. The pretreatment of a phosphatidylcholine (PC)-specific PLC (PC-PLC) inhibitor (D609), PKC inhibitors, or an NF-κB inhibitor completely suppressed the IL-1β-induced MCP1 expression through blocking NF-κB translocation to the nucleus. Pretreatment with inhibitors of tyrosine kinase or PLD partially suppressed MCP1 expression and failed to block nuclear NF-κB translocation. These results suggest that IL-1β induces MCP1 expression through activation of NF-κB via the PC-PLC/PKC signaling pathway. 相似文献
1000.
Kee Hun Do Min Sung Kim Jae Ho Kim Byung-Yong Rhim Won Suk Lee Chi Dae Kim Sun Sik Bae 《Experimental & molecular medicine》2009,41(8):569-576
Angiotensin II (AngII) is a crucial hormone that affects vasoconstriction and exerts hypertrophic effects on vascular smooth muscle cells. Here, we showed that phosphatidylinositol 3-kinase-dependent calcium mobilization plays pivotal roles in AngII-induced vascular constriction. Stimulation of rat aortic vascular smooth muscle cell (RASMC)-embedded collagen gel with AngII rapidly induced contraction. AngII-induced collagen gel contraction was blocked by pretreatment with a phosphatidylinositol 3-kinase (PI3K) inhibitor () whereas ERK inhibitor (PD98059) was not effective. AngII-induced collagen gel contraction was significantly blocked by extracellular calcium depletion by EGTA or by nifedipine which is an L-type calcium channel blocker. In addition, AngII-induced calcium mobilization was also blocked by nifedipine and EGTA, whereas intracellular calcium store-depletion by thapsigargin was not effective. Finally, pretreatment of rat aortic ring with LY294002 and nifedipine significantly reduced AngII-induced constriction. Given these results, we suggest that PI3K-dependent activation of L-type calcium channels might be involved in AngII-induced vascular constriction. LY294002相似文献