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排序方式: 共有227条查询结果,搜索用时 15 毫秒
221.
Xuebin Ma Fumin Guo Zhen Li Min Wang Wu Zhou 《Journal of Dispersion Science and Technology》2013,34(11):1540-1547
The phase behavior and rheological properties of the concentrated lecithin aqueous solutions were investigated at 37°C. When adding Isopropyl myristate (IPM) to lecithin solutions, besides an anisotropic liquid crystal (LC) phase, an isotropic liquid (L2) region and an isotropic viscous (I) phase are found. By continuously adding Brij 97, the LC region shifts towards higher water content and the L2 region is extended to the area of lower IPM concentration, meanwhile the I phase disappears. By analyzing the shear rate (ηγ=0.1) and yield stress (σ0), adding IPM to lecithin solutions increases the values of ηγ=0.1 and σ0, and after further adding Brij 97, the ηγ=0.1 and σ0 decrease dramatically. Notably, different from the lecithin/DDAB/water system studied by Youssry and Montalvo, in lecithin/Brij 97/IPM/H2O system, at the relatively higher water content area of the LC phase, the water content has little effect on the critical stress. It is also found that the change of dynamic storage modulus (G′) is similar with that of ηγ=0.1 and σ0 parameters when adding IPM and Brij 97. Maxwell model fitting results show that in the LC phase, the relaxation of the water molecule is prolonged by adding IPM and Brij 97 to lecithin solutions. 相似文献
222.
《Journal of Dispersion Science and Technology》2013,34(6):841-847
Abstract Lecithin liposomes were studied by transmission electron microscopy (TEM), selected‐area electron diffraction (SAED), IR, and GC‐MS. Results indicate that titanium dioxide (TiO2) nanoparticles can gain access into lecithin liposomes during sonication and the lecithin liposomes can be effectively decomposed upon illumination with near‐UV light. 相似文献
223.
Kashiwada A Tsuboi M Takamura N Brandenburg E Matsuda K Koksch B 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(22):6179-6186
A weakly acidic pH-responsive polypeptide is believed to have the potential for an endosome escape function in a polypeptide-triggered delivery system. For constructing a membrane fusion device with pH-responsiveness, we have designed novel polypeptides that are capable of forming an α2 coiled coil structure. Circular dichroism spectroscopy reveals that a polypeptide, AP-LZ(EH5), with a Glu and His salt-bridge pair at a staggered position in the hydrophobic core forms a stable coiled coil structure only at endosomal pH values (pH 5.0 to 5.5). On the basis of their endosomal-pH responsiveness, a boronic acid/polypeptide conjugate (BA-H5-St) was also designed as a pilot molecule to construct a pH-responsive, one-way membrane fusion system with a sugarlike compound (phosphatidylinositol: PI)-containing liposome as a target. Membrane fusion behavior was characterized by lipid-mixing, inner-leaflet lipid-mixing, and contents-mixing assays. These studies reveal that membrane fusion is clearly observed when the pH of the experimental system is changed from 7.4 (physiological condition) to 5.0 (endosomal condition). 相似文献
224.
We give some details about the periodic cylindrical solution found by Zhang and Ou-Yang in [1996 Phys.Rev.E 53 4206] for the general shape equation of vesicle.Three different kinds of periodic cylindrical surfaces and a special closed cylindrical surface are obtained.Using the elliptic functions contained in mathematic,we find that this periodic shape has the minimal total energy for one period when the period-amplitude ratio β 1.477,and point out that it is a discontinuous deformation between plane and this periodic shape.Our results also are suitable for DNA and multi-walled carbon nanotubes(MWNTs). 相似文献
225.
脂肪酸囊泡(FAV)是一类重要的纳米容器,然而其形成pH范围较窄且偏碱性环境,限制了其应用。 本文将共轭亚油酸(CLA)与海藻酸钠(SA)在近中性环境下共同自组装囊泡化纳米容器并提高其膜稳定性。动态激光光散射(DLS)和透射电子显微镜(TEM)结果表明,当SA质量分数为25%~50%时复合体系可在近中性条件下自组装形成50~250 nm尺寸的囊泡化纳米容器,且pH=7.4时随着质量分数增加囊泡化纳米容器直径增大。 根据SA和CLA在中性环境的物种存在形式推测,二者通过氢键作用驱动形成囊泡化纳米容器。 体外模拟释放实验表明,囊泡化纳米容器具有较高包覆率和较优缓释效果,有望应用于药物传输领域。 相似文献
226.
Natural and artificially prepared nanorods' surfaces have proved to have good bactericidal effect and self-cleaning property. In order to investigate whether nanorods can kill the enveloped virus, like destroying bacterial cell, we study the interaction between nanorods and virus envelope by establishing the models of nanorods with different sizes as well as the planar membrane and vesicle under the Dry Martini force field of molecular dynamics simulation. The results show that owing to the van der Waals attraction between nanorods and the tail hydrocarbon chain groups of phospholipid molecules, the phospholipid molecules on virus envelope are adsorbed to nanorods on a large scale. This process will increase the surface tension of lipid membrane and reduce the order of lipid molecules, resulting in irreparable damage to planar lipid membrane. Nanorods with different diameters have different effects on vesicle envelope, the larger the diameter of nanorod, the weaker the van der Waals effect on the unit cross-sectional area is and the smaller the degree of vesicle deformation. There is synergy between the nanorods in the nanorod array, which can enhance the speed and scale of lipid adsorption. The vesicle adsorbed in the array are difficult to desorb, and even if desorbed, vesicle will be seriously damaged. The deformation rate of the vesicle adsorbed in the nanorod array exceeds 100%, implying that the nanorod array has a strong destructive effect on the vesicle. This preliminarily proves the feasibility of nanorod array on a surface against enveloped virus, and provides a reference for the design of corresponding nanorods surface. 相似文献
227.
Macromolecularly crowded coacervate is useful in protein delivery for tissue engineering and regenerative medicine. However, coacervate tends to aggregate easily, which impedes their application. Here, this work presents a method to prepare coacervate with enhanced stability. This work assembles phospholipids on the surface of a coacervate to form lipocoacervate (LipCo). The resultant LipCo possesses a discrete spherical structure with a coacervate interior and phospholipid outer shell. The size of LipCo does not change over the four-week observation window, whereas coacervate coalesced into one bulk phase within 30 min. This work uses vascular endothelial growth factor-C (VEGF-C) and fibroblast growth factor-2 (FGF-2) as examples to test LipCo's ability to maintain protein bioactivity. The in vitro lymphangiogenesis assay demonstrates that human dermal lymphatic endothelial cells (LECs) formed increased network of cord in VEGF-C and FGF-2 loaded LipCo group compared to free proteins and proteins loaded in coacervate. Overall, LipCo could serve as a protein delivery vehicle with improved colloidal stability. 相似文献