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101.
Cristian Peptu Valeria Harabagiu Bogdan C. Simionescu Grazyna Adamus Marek Kowalczuk Jean‐Michel Nunzi 《Journal of polymer science. Part A, Polymer chemistry》2009,47(2):534-547
The synthesis of novel azofunctional oligoesters through bulk ring opening of ε‐caprolactone and D ,L ‐lactide (LA) at 100 and 130 °C, respectively, mediated by N‐ethyl‐N‐(2‐hydroxyethyl)‐4‐(4‐nitrophenylazo)aniline (Disperse Red 1) (DR1) is described. The synthetic procedure allows “clean” products because no catalysts were used in the reaction. Moreover, DR1 moiety is showed for the first time to promote the ring opening of cyclic esters. The molecular structure of the obtained oligoesters was established by NMR spectroscopy, MALDI ToF MS and electrospray ionization mass spectrometry (ESI MS). ESI‐MS/MS fragmentation experiments were used to demonstrate the nature of the chain end groups (hydroxyl and DR1). Intermolecular transesterification reactions were proved by mass spectrometry studies at least in the case of LA oligomerization. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 534–547, 2009 相似文献
102.
Hiroki Hotta Kazuya Tatsuno Yoji Hattori Takuya Hashimoto Masayuki Uehara Kin-ichi Tsunoda 《Electrochemistry communications》2008,10(9):1351-1354
The H+ concentration change was monitored near an electrode surface through an electrolysis using a slab optical waveguide technique. Indium tin oxide transparent electrode modified by porous insulating polymer to which methyl red was covalently immobilized was used as a guiding layer, and the absorbance change of the polymer film was monitored. H+ generation at the vicinity of the electrode through the oxidation of ascorbic acid could be monitored by this technique. 相似文献
103.
Study on the cationic modification and dyeing of ramie fiber 总被引:2,自引:0,他引:2
Zhao-Tie Liu Yani Yang Lili Zhang Zhong-Wen Liu Heping Xiong 《Cellulose (London, England)》2007,14(4):337-345
A modification procedure for ramie fiber using 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (CHPTAC) as a cationic
agent and NaOH as a catalyst was developed in this paper. The morphological and structural transformations of the fiber induced
by modification were determined by XRD (XRD), differential scanning calorimetry (DSC), and thermogravimetry analysis (TGA).
XRD results show that the crystal structure of the modified fiber was still preserved although its crystallinity was decreased,
which was confirmed from the TGA results. The mechanisms for the modification and dyeing of ramie fiber were analyzed, and
the optimum modification conditions were determined to be the CHPTAC concentration of 30 g L−1, the NaOH concentration of 15 g L−1, the reaction temperature of 50 °C, and the reaction time of 60 min. The raw and the modified fibers were dyed with C.I.
reactive red 2. The K/S values for the cationic modified fiber increased to be three times as high as the unmodified fiber. The dye uptakes increased
greatly with an increase in the nitrogen contents up to 0.4% on the modified fibers. 相似文献
104.
Xiaoyong Chen Zeyu Zhang Jiajie Wu Jiale Wang Aolong Gao 《Particle & Particle Systems Characterization》2021,38(7):2100076
Red fluorescent carbon dots (R-CDs) are special desirable for biochemical analysis due to good biological compatibility and deep penetration; however, they remain as bottlenecks due to difficulties in expanding the sp2 domain, especially those are fused from rigid polycyclic conjugated molecules (RPCMs) with heteroatom substituents due to huge steric hindrance and heteroatom blockage toward graphic lattice. Here, an RPCM with heteroatom substituents, 1,5-diamino-4,8-dihydroxyanthraquinone (DDAQ), based self-doped R-CDs with PL emission at 635 nm is reported. Further investigations reveal that the expanding, hybrid sp2 domain with indanthrone tannin structure from DDAQ is mainly responsible for the obtained red fluorescence of R-CDs. Taking advantage of optical properties, R-CDs are considered to construct a colorimetric/fluorescent dual mode sensing array for quantifying trace levels of Fe3+ and glyphosate based on the static quenching, and a biomarker for cell imaging. The CD-based sensors exhibit outstanding recovery, high selectivity, and sensitivity, also facilitated dual-mode detection with the naked-eye. The R-CDs have low cytotoxicity, good cell membrane penetration for rapid cell entry, and high resolution, demonstrating their potential for biolabeling and bioanalytic applications. 相似文献
105.
In the paper the wave attenuation in a two layer fluid system is studied. The fluid in the top layer is ideal and that in
the lower layer is the Voigt model of the viscoelastic medium. A dispersion relation is derived and the rate of the wave decay
is computed. The approximate explicit expressions of the decay rate for different water depth are given, where the viscoelasticity
is either very large or very small. Compared with the numerical results, our results are very accurate, which can be used
by an engineer.
The project supported by the National Natural Science Foundation of China and by the Lianyungang Port Office, China 相似文献
106.
明胶固定辣根过氧化物酶制备H_2O_2传感器 总被引:2,自引:0,他引:2
用明胶将辣根过氧化物酶(HRP)固定于多壁碳纳米管(MWNT)和茜素红(AR)修饰的玻碳(GC)电极上,制成HRP生物传感器(HRP/AR/MWNT/GC),然后在3%戊二醛(GA)中进行交联改性,以克服明胶膜易溶胀的缺点,并提高膜的稳定性.同时详细探讨了该传感器对H2O2的响应性能,并优化了实验条件.结果表明,该传感器对H2O2的线性响应范围为5.0×10-6~1.0×10-3mol/L,线性相关系数为0.9932,检出限为1.0×10-7mol/L,且放于4℃环境30d后,峰电流值约为原来的72.1%.该传感器响应快速,灵敏度高,且具有良好的重现性、稳定性及较长的使用寿命,具有潜在的应用价值. 相似文献
107.
采用凝胶-燃烧法制备了稀土Eu3+掺杂的LaMgAl11O19红色荧光粉的前驱粉末,在低于700℃退火处理时,得到非晶态样品,而高于850℃退火处理后为单一六方相结构LaMgAl11O19:Eu3+样品.SEM结果表明,该法制备的样品为颗粒分布均匀,粒径在200~400nm之间的超细粉末.通过激发光谱和发射光谱研究了Eu3+在LaMgAl11O19基质中的发光性能,结果显示,非晶态和晶态La1-xMgAl11O19:xEu3+样品都可发光,在613nm波长光的监测下所得荧光粉的激发光谱为一宽带和系列锐峰,其最强激发峰出现在蓝光465nm处,次强峰为394nm,表明该荧光粉与广泛使用的紫外和蓝光LED芯片的输出波长相匹配.在465nm波长光的激发下观察到超细LaMgAl11O19粉末中Eu3+的613nm(5D0→7F2)强的特征发射,且随着粉末逐渐成相5D0→7F2跃迁明显增强,说明LaMgAl11O19:Eu3+超细粉末可作为白光LED的红色补偿荧光粉. 相似文献
108.
Antonella De Palma Antonella Roveri Mattia Zaccarin Louise Benazzi Simone Daminelli Giorgia Pantano Mauro Buttarello Fulvio Ursini Massimo Gion Pier Luigi Mauri 《Journal of chromatography. A》2010,1217(33):5328-5336
Since red blood cells (RBCs) lack nuclei and organelles, cell membrane is their main load-bearing component and, according to a dynamic interaction with the cytoskeleton compartment, plays a pivotal role in their functioning. Even if erythrocyte membranes are available in large quantities, the low abundance and the hydrophobic nature of cell membrane proteins complicate their purification and detection by conventional 2D gel-based proteomic approaches. So, in order to increase the efficiency of RBC membrane proteome identification, here we took advantage of a simple and reproducible membrane sub-fractionation method coupled to Multidimensional Protein Identification Technology (MudPIT). In addition, the adoption of a stringent RBC filtration strategy from the whole blood, permitted to remove exhaustively contaminants, such as platelets and white blood cells, and to identify a total of 275 proteins in the three RBC membrane fractions collected and analysed. Finally, by means of software for the elaboration of the great quantity of data obtained and programs for statistical analysis and protein classification, it was possible to determine the validity of the entire system workflow and to assign the proper sub-cellular localization and function for the greatest number of the identified proteins. 相似文献
109.
建立了一种基于胶束增敏缔合反应水相测定乳制品中三聚氰胺的分光光度法,研究了在阴离子表面活性剂十二烷基硫酸钠(SDS)形成的胶束体系中,茜素红(AR)阴离子与三聚氰胺阳离子反应产物的紫外-可见光谱特性。实验发现,加入三聚氰胺后,体系λmax由426nm红移到516nm,加入SDS对缔合物有显著的增稳、增敏效应。三聚氰胺质量浓度在1.9~25mg/L范围内符合比尔定律,缔合物的表观摩尔吸光系数为6.9×103L.mol-1.cm-1。本方法用于液态奶及奶粉中三聚氰胺的测定,回收率分别为94.5%~104.8%和95.5%~100.4%,相对标准偏差分别为1.6%~2.2%和1.7%~2.6%。考察了酸效应、胶束对体系的作用机理,发现三聚氰胺与AR缔合物之间主要是通过静电引力和疏水作用力相结合。 相似文献
110.
荧光法快速检测有机磷农药残留总量 总被引:1,自引:0,他引:1
在pH4.60的B-R缓冲溶液中,中性红(NR)与一定浓度的十二烷基苯磺酸钠(SDBS)发生荧光增强反应,在该体系中加入有机磷农药后,在激发波长560 nm,发射波长604 nm处体系的荧光强度明显降低,且降低程度与有机磷农药的加入量呈良好的线性关系,其线性范围和检出限分别为0.024~0.40 mg/L,0.014 mg/L。据此建立了测定有机磷农药残留总量的新方法。方法已用于面粉和土壤中有机磷农药残留总量的检测,回收率在92.0%~100.5%之间,RSD在1.1~1.9%之间。 相似文献