首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   108篇
  免费   12篇
化学   103篇
数学   4篇
物理学   13篇
  2023年   3篇
  2022年   3篇
  2021年   4篇
  2020年   3篇
  2019年   6篇
  2018年   4篇
  2017年   2篇
  2016年   2篇
  2015年   6篇
  2014年   6篇
  2013年   8篇
  2012年   7篇
  2011年   18篇
  2010年   5篇
  2009年   7篇
  2008年   8篇
  2007年   9篇
  2006年   1篇
  2005年   4篇
  2004年   6篇
  2003年   2篇
  2002年   4篇
  2000年   1篇
  1998年   1篇
排序方式: 共有120条查询结果,搜索用时 0 毫秒
91.
The quest for new functional nanomaterials is one of the defining purposes of nanoscience and nanotechnology. A large number of metal nanoparticles (NPs) are extensively exploited for biomedical applications. Metal NPs, in particular platinum NPs (PtNPs), possess remarkable properties that make them a potential candidate as a diagnostic or therapeutic agent. Due to potential technological interest over the last decade, PtNPs have attracted much attention in the field of anticancer research. PtNPs, when conjugated with many functionalizing agents such as polymers, ligands, drugs, peptides, and surfactants, exhibit improved targeting and reduced cytotoxic effects in various cancers. The PtNPs conjugated with folic acid, graphene oxide, and iron NPs are gained more attention due to their stability, large surface area, and reduced toxicity. To achieve this goal, PtNPs are co-loaded with drugs or other modalities that offer an opportunity for multimodal activity in the frame of treating cancer types focusing on breast, blood, lung, ovarian, skin, liver, etc. However, a review of PtNPs’ function in diagnosis and treatment is still lacking. In this review, the effectiveness of PtNPs toward inducing and elevating death of the cancerous cells proving its delivery approaches and antitumor nature, concluding with future perspectives, are summarized.  相似文献   
92.
Poojary  Sudheer  Sharma  Vinod 《Queueing Systems》2019,91(1-2):171-203
Queueing Systems - In this paper, we derive an expression for computing the average window size of a single TCP CUBIC connection under random losses. For this we consider a throughput expression...  相似文献   
93.
We characterize the compatibility of a collection of unrooted phylogenetic trees as a question of determining whether a graph derived from these trees — the display graph — has a specific kind of triangulation, which we call legal. Our result is a counterpart to the well-known triangulation-based characterization of the compatibility of undirected multi-state characters.  相似文献   
94.
On or off? A new excimer band at λ=570 nm was visualized during the noncovalent host–guest interaction between thioflavin T (ThT) and cucurbit[8]uril (CB8). Controlled dissociation of this assembly in the presence of Ca2+ was demonstrated as an on/off fluorescence switch (see picture).

  相似文献   

95.
Laser flash photolysis studies were carried out on two types of silver nanoparticles prepared byγ-radiolysis of Ag+ solutions in the presence of polyphosphate as the stabiliser. Type I silver nanoparticles displayed a surface plasmon band at 390 nm. Type II silver nanoparticles showed a 390 nm surface plasmon band with a shoulder at 550 nm. On photoexcitation in the surface plasmon band region, using 35 picosecond laser pulses at 355 nm and 532 nm, the type II solutions showed transient bleaching and absorption signals in the 450–900 nm region, which did not decay appreciably up to 5 nanoseconds. These transient changes were found to get annealed in the intervalt where 5 ns<t< 100 ns. Extended photolysis of the nanoparticle solutions with repetitive laser pulses resulted in a decrease in the values of the average particle size which were measured by employing the dynamic light scattering technique.  相似文献   
96.
Polymer‐based nanodiscs are valuable tools in biomedical research that can offer a detergent‐free solubilization of membrane proteins maintaining their native lipid environment. Herein, we introduce a novel ca. 1.6 kDa SMA‐based polymer with styrene:maleic acid moieties that can form nanodiscs containing a planar lipid bilayer which are useful to reconstitute membrane proteins for structural and functional studies. The physicochemical properties and the mechanism of formation of polymer‐based nanodiscs are characterized by light scattering, NMR, FT‐IR, and TEM. A remarkable feature is that nanodiscs of different sizes, from nanometer to sub‐micrometer diameter, can be produced by varying the lipid‐to‐polymer ratio. The small‐size nanodiscs (up to ca. 30 nm diameter) can be used for solution NMR spectroscopy studies whereas the magnetic‐alignment of macro‐nanodiscs (diameter of > ca. 40 nm) can be exploited for solid‐state NMR studies on membrane proteins.  相似文献   
97.
98.
Dash J  Lechel T  Reissig HU 《Organic letters》2007,9(26):5541-5544
A mechanistically unique three-component synthesis provides a variety of functionalized pyridine derivatives in fair to excellent yields. The scope of this reaction was studied with respect to the alkoxyallene, the nitrile, and the carboxylic acid. Due to the 4-hydroxy group, these pyridine derivatives are suitable precursors for subsequent palladium-catalyzed reactions. Suzuki couplings of the corresponding pyridyl nonaflates lead to a variety of pyridine and bipyridine derivatives.  相似文献   
99.
LTA reaction of homoallyl alcohols derived from norbornyl alpha-diketones exclusively furnished the corresponding alpha-diketones via beta-fragmentation of the allyl group in refluxing benzene while changing the solvent to MeOH resulted in the formation of novel methoxy substituted spirocyclic tetrahydrofuran products.  相似文献   
100.
A short and stereoselective synthesis of 2-hydroxymethyl-4-deoxypentenomycin and 2-hydoxymethylpentenomycin derivatives is accomplished in five and seven steps starting from tetrabromonorbornyl derivatives in overall yields of 41% and 38%, respectively.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号