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本文上篇阐述了CLEAR算法的推导过程和计算步骤,本文下篇通过五个二维不可压缩流动和传热的算例,对CLEAR算法和SIMPLER算法进行了比较,比较的内容为,在相同的收敛条件下, CLEAR算法和SIMPLER算法收敛所需的迭代次数的比值和对应的CPU时间的比值,以及这两个比值和时步倍率的关系,从而进一步研究了CLEAR算法的健壮性。计算结果表明,CLEAR算法可以在很大程度上加速迭代收敛,就所比较的算例而言,其可以节省迭代次数31%-85%,节省CPU时间17%-78%,而且该算法的健壮性可以通过引入第二松弛因子而得以提高。 相似文献
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制备型高速逆流色谱分离纯化香菇多糖 总被引:2,自引:0,他引:2
利用高速逆流色谱仪,研究了双水相系统对香菇多糖的分离.溶剂系统为w(PEG1000):w(K2HPO4):w(KH2PO4):w(H2O)=0.5:1.25:1.25:7.0,在转速为500 r/min,流速为1.5 mL/min的条件下,成功分离了香菇多糖粗品(700 mg),得到LenⅠ(95 mg)、LenⅡ(45 mg)两个组分.用Sephadex G-100凝胶色谱柱检测纯度,结果显示:LenⅡ为单一峰,凝胶渗透色谱法测定; LenⅡ分子量为293 kDa;经酸水解后液相色谱分析表明,其单糖组成为葡萄糖和甘露糖,摩尔比为2.7:1; 红外光谱显示其具有多糖类的特征吸收峰. 相似文献
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以硝酸铜为前驱体, 不采用任何模板, 通过逐步水热法合成了花状Cu2O/Cu复合纳米材料. 用扫描电镜(SEM)、X射线衍射(XRD)和紫外-可见漫反射光谱(DRS)对样品进行表征. 结果表明, 花状纳米Cu2O/Cu材料是由长为300-500 nm, 宽为30-70 nm的带状花瓣构成, 在可见光区域有很强的吸收. 复合材料中Cu的含量可以通过反应时间进行调控. 对染料Procion Red MX-5B(PR)的可见光催化降解, Cu能明显提高Cu2O的光催化性能. 当Cu质量分数为27%-71%时, 复合材料Cu2O/Cu的催化活性明显高于单相Cu2O. 与立方体形貌的Cu2O/Cu复合材料相比, 花状纳米Cu2O/Cu复合材料对染料PR有更高的催化降解性能. 且该复合材料有较高的循环回收利用率. 相似文献
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Min Wang Zhi-Guo Song Hong Gong Heng Jiang 《Monatshefte für Chemie / Chemical Monthly》2009,140(2):177-179
Abstract Tetrahydropyranylation of alcohols and phenols was accomplished successfully using copper nitrate and acetic acid as a synergistic
catalyst at room temperature under solvent-free condition. Compared with other synergistic catalytic systems, copper nitrate/acetic
acid proved to be the most efficient. Both alcohols (primary, secondary, tertiary, benzylic, cyclic, allyl, cinnamyl, and
furyl) and phenols reacted smoothly in high yields.
Graphical abstract
相似文献
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Uniform-sized biodegradable PLA/PLGA microcapsules loading recombinant human insulin (rhI) were successfully prepared by combining a Shirasu Porous Glass (SPG) membrane emulsification technique and a double emulsion-evaporation method. An aqueous phase containing rhI was used as the inner water phase (w1), and PLA/PLGA and Arlacel 83 were dissolved in a mixture solvent of dichloromethane (DCM) and toluene, which was used as the oil phase (o). These two solutions were emulsified by a homogenizer to form a w1/o primary emulsion. The primary emulsion was permeated through the uniform pores of a SPG membrane into an outer water phase by the pressure of nitrogen gas to form the uniform w1/o/w2 droplets. The solid polymer microcapsules were obtained by simply evaporating solvent from droplets. Various factors of the preparation process influencing the drug encapsulation efficiency and the drug cumulative release were investigated systemically. The results indicated that the drug encapsulation efficiency and the cumulative release were affected by the PLA/PLGA ratio, NaCl concentration in outer water phase, the inner water phase volume, rhI-loading amount, pH-value in outer water phase and the size of microcapsules. By optimizing the preparation process, the drug encapsulation efficiency was high up to 91.82%. The unique advantage of preparing drug-loaded microcapsules by membrane emulsification technique is that the size of microcapsules can be controlled accurately, and thus the drug cumulative release profile can be adjusted just by changing the size of microcapsules. Moreover, much higher encapsulation efficiency can be obtained when compared with the conventional mechanical stirring method. 相似文献
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Zhi-Guo Wang Peng Ying Pei-Ying Li Hua-Yan Lan He-Qing Huang Hao Tian Jian-Ping Song Yan-Peng Zhang 《Frontiers of Physics》2014,9(2):153-156
We experimentally study the phase regulated switch between elcctromagnctically induced trans- parency and electromagmetically induced absorption in probe transmission signal and the conver- sion between enhancement and suppression in four-wave mixing and fluorescence signals for the first time. By changing the relative phase, electromagnetically induced transparency can be eonverted into electromagnetically induced absorption. In this process, the conversion from suppression to enhancement is also obtained in four-wave mixing and fluorescence signals. This research can be applied in non-linear optical device like optical switch and optical wavelength convertor. 相似文献