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101.
以负载了1-苯基-3-甲基-4-苯甲酰基-吡唑酮[5](PMBP)的纳米氧化铝为微柱吸附材料,采用电感耦合等离子体-原子发射光谱法(ICP-AES)研究了动态条件下对稀土离子Sc3+、Y3+和La3+的吸附性能,确定了最佳吸附及解脱条件。在pH为4.5时,分析物均可被上述吸附材料定量吸附;用0.5mol.L-1盐酸溶液可将吸附在微柱上的稀土离子完全解脱。本法对Sc3+、Y3+和La3+的检出限分别为0.15、0.18和0.34μg.L-1;相对标准偏差(RSD)分别为2.5%、3.0%和1.7%(n=12,C=0.5mg·mL-1)。方法应用于绒柄牛肝菌(Boletus tomentipes)中痕量Sc、Y和La的测定,结果满意。 相似文献
102.
D. Banerjee S.V. Thakare R. Menon K. Krishnan 《Journal of Physics and Chemistry of Solids》2010,71(7):983-987
Phase transition from anatase to rutile for the 70 nm TiO2 crystallite has been investigated by the time differential perturbed angular correlation (TDPAC) technique. The study involved the annealing of the TiO2 nanocrystals, adsorbed with the nuclear probe (181Hf/181Ta) at trace level, at different temperatures for different durations. The TDPAC measurement was also supported by XRD measurement where the width of the peaks increases with the increase in annealing temperature indicating a crystal growth. The samples annealed up to 823 K for 4 h showed no phase transition, except for the growth of the crystallites. However, it showed phase transition at the same temperature (823 K), when annealed for longer duration, indicating the slower kinetics of the phase transition process. Further the sample, when annealed at 1123 K for 4 h, showed phase transition. It has also been observed that the 181Hf tracer, adsorbed on 70 nm anatase TiO2, diffuses from surface to bulk during the phase transition process and the extent of diffusion in anatase differs from that in rutile phase. However, surface to bulk mass-transfer is found to play a significant role in the phase transition process. 相似文献
103.
采用流动注射技术和催化分光光度法相结合,研究了在磷酸介质中,亚硝酸根对溴酸钾氧化孔雀石绿褪色反应的催化作用及其动力学条件,建立了催化动力学光度法测定痕量亚硝酸根的新方法。方法检出限为0.9ng/mL,测定的线性范围为5—60ng/mL,且线性相关系数为0.9983,对于浓度为30ng/mL的亚硝酸根标准液测定的相对标准偏差仅为1.0。该方法适用范围广,具有较好的准确性、稳定性和灵敏度,且实验操作方便、快速。利用此方法测定不同水样中的亚硝酸根,加标回收率在88.6%—104.8%之间,分析结果令人满意。 相似文献
104.
The repassivation kinetics of pure aluminium have been explored in aqueous alkaline solutions as functions of applied anodic
potential and pH by using an abrading electrode technique and a rotating disc electrode. The repassivation rate of the abraded
bare surface of pure aluminium increased with increasing applied anodic potential in aqueous alkaline solutions, while it
decreased with increasing pH. These results revealed that the growth rate of the passivating oxide film is enhanced by an
applied electric field, but it is lowered due to the chemical attack by hydroxyl ions. A potentiostatic anodic current decay
transient obtained from the abraded electrode surface showed a constant repassivation rate in neutral and weakly alkaline
solutions. In contrast, in concentrated alkaline solutions it was observed to consist of three stages: a high repassivation
rate in the initial stage due to a high formation rate of the oxide film on the abraded bare surface; a zero value of the
repassivation rate in the second stage due to the dissolution of the oxide film by the attack of OH−; a high repassivation rate in the third stage due to a lowered dissolution rate of the oxide film. The dissolution rate of
the passivating oxide film was observed to depend on the removal rate of aluminate ions from the oxide/solution interface.
Received: 1 April 1998 / Accepted: 3 July 1998 相似文献
105.
106.
Glen B. Deacon Alex Gitlits Gerd Zelesny Dirk Stellfeldt Gerd Meyer 《无机化学与普通化学杂志》1999,625(5):764-772
The complexes [K(H2O)2LnL2] (Ln = La or Nd; L = 1,2‐benzenedisulfonate) and [K(H2O)Yb(H2O)4L2] were initially isolated fortuitously from attempts to prepare the corresponding Ln2L3 complexes from Ln2O3 and H2L in water. Indeed the bulk products from these reactions have the composition Ln2L3. Subsequently, deliberate syntheses by reacting equimolar amounts of Ln2L3 with K2L in water gave the complexes in good yield. X‐ray crystal structures of [K(H2O)2LnL2] (Ln = La or Nd) showed the complexes to be isostructural with a two dimensional polymeric network structure in which LnL2 units are linked into chains crosslinked by potassium ions. Each Ln is nine coordinate with solely sulfonate oxygen donor atoms. Between adjacent lanthanoid ions there are three different types of sulfonate bridges and two examples of each. Most noteworthy is highly unsymmetrical bridging through μ‐η2‐sulfonate oxygen atoms. Consequently, one Ln–O bond is ca. 0.5 Å longer than the other eight. Potassium is nine‐coordinate with seven sulfonate oxygen atoms and two aqua ligands, and surprisingly <K–O(sulfonate)> is much longer than <K–O(H2O)>. Pairs of potassium ions are linked by two μ‐η2‐sulfonate oxygen atoms, which are unsymmetrically bridging. The structure of [K(H2O)Yb(H2O)4L2] comprises discrete tetranuclear units containing two independent ytterbium ions, each coordinated by four water molecules and two chelating (via seven membered rings) disulfonate ligands, and two potassium ions, each coordinated by six sulfonate oxygen atoms and a water molecule. For each potassium, four of the coordinated sulfonate oxygen atoms are from sulfonate ligands bonded to one ytterbium atom and two from sulfonate ligands attached to the other ytterbium atom. In contrast to the Nd and La complexes, <K–O(sulfonate)> is shorter than <K–O(H2O)>. 相似文献
107.
Rafael Schiwon Beatrice Braun Ramona Metzinger Christian Limberg 《无机化学与普通化学杂志》2016,642(21):1198-1206
While addition of [Cp2ReH] to [Bi(OtBu)3] leads to an equilibrium containing [Cp2Re‐Bi(OtBu)2], [{Cp2Re}2Bi(OtBu)], tBuOH and [CpRe(μ‐η5,η1‐C5H4)Bi–ReCp2], in the presence of water [{(Cp2Re)2Bi}2O] ( 1 ) is formed selectively. Also [FpH] [Fp = (η5‐C5H5)(CO)2Fe] can be employed as a precursor to form heterometallic bismuth compounds. Synthesis of [FpBi{OCH(CF3)2}2]2 ( 5 ) can be achieved by reaction of [FpH] with [Bi{OCH(CF3)2}3(thf)]2 and carboxylates [FpBi(O2CR)2]2 are generated upon treatment of [FpH] with [Bi(O2CR)3] (R = CH3, tBu). While the compounds [Fp‐Bi(O2CR)2]2 can also be obtained from reactions with Fp‐Fp, they are formed far more readily using [FpH] as the precursor. They typically crystallize as dimers, like the alkoxide 5 . A monomeric compound of the type [Fp‐BiX2] ( 6 ) could be isolated for X = thd (tetramethylheptanedionate), that is, after the reaction of [FpH] with [Bi(thd)3]. Altogether, the results demonstrate the potential of [FpH] as a precursor for [Fp‐BiX2] compounds, which are formed in reactions with bismuth alkoxides, carboxylates and diketonates. 相似文献
108.
Hong Zhang Chenxu Zhao Jianxi Yao Wallace C. H. Choy 《Angewandte Chemie (International ed. in English)》2023,62(24):e202219307
Advancing inverted (p-i-n) perovskite solar cells (PSCs) is critical for commercial applications given their compatibility with different bottom cells for tandem photovoltaics, low-temperature processability (≤100 °C), and promising operational stability. Although inverted PSCs have achieved an efficiency of over 25 % using doped or expensive organic hole transport materials (HTMs), their synthesis cost and stability still cannot meet the requirements for their commercialization. Recently, dopant-free and low-cost non-stoichiometric nickel oxide nanocrystals (NiOx NCs) have been extensively studied as a low-cost and effective HTM in perovskite optoelectronics. In this minireview, we summarize the synthesis and surface-functionalization methods of NiOx NCs. Then, the applications of NiOx NCs in other perovskite optoelectronics beyond photovoltaics are discussed. Finally, we provide a perspective for the future development of NiOx NCs for the commercialization of perovskite optoelectronics. 相似文献
109.
Jiahui Xian Suisheng Li Hui Su Peisen Liao Shihan Wang Runan Xiang Yawei Zhang Prof. Qinghua Liu Prof. Guangqin Li 《Angewandte Chemie (International ed. in English)》2023,62(30):e202306726
The conversion of industrial exhaust gases of nitrogen oxides into high-value products is significantly meaningful for global environment and human health. And green synthesis of amino acids is vital for biomedical research and sustainable development of mankind. Herein, we demonstrate an innovative approach for converting nitric oxide (NO) to a series of α-amino acids (over 13 kinds) through electrosynthesis with α-keto acids over self-standing carbon fiber membrane with CoFe alloy. The essential leucine exhibits a high yield of 115.4 μmol h−1 corresponding a Faradaic efficiency of 32.4 %, and gram yield of products can be obtained within 24 hours in lab as well as an ultra-long stability (>240 h) of the membrane catalyst, which could convert NO into NH2OH rapidly attacking α-keto acid and subsequent hydrogenation to form amino acid. In addition, this method is also suitable for other nitrogen sources including gaseous NO2 or liquidus NO3− and NO2−. Therefore, this work not only presents promising prospects for converting nitrogen oxides from exhaust gas and nitrate-laden waste water into high-value products, but also has significant implications for synthetizing amino acids in biomedical and catalytic science. 相似文献
110.
Chathuranga S. L. Rathnamalala Selena Hernandez Dr. Melissa Y. Lucero Chelsea B. Swartchick Dr. Abdul Kalam Shaik Prof. Dr. Nathan I. Hammer Amanda K. East Prof. Dr. Steven R. Gwaltney Prof. Dr. Jefferson Chan Prof. Dr. Colleen N. Scott 《Angewandte Chemie (International ed. in English)》2023,62(13):e202214855
Shortwave infrared (SWIR) dyes are characterized by their ability to absorb light from 900 to 1400 nm, which is ideal for deep tissue imaging owing to minimized light scattering and interference from endogenous pigments. An approach to access such molecules is to tune the photophysical properties of known near-infrared dyes. Herein, we report the development of a series of easily accessible (three steps) SWIR xanthene dyes based on a dibenzazepine donor conjugated to thiophene ( SCR-1 ), thienothiophene ( SCR-2 ), or bithiophene ( SCR-3 ). We leverage the fact that SCR-1 undergoes a bathochromic shift when aggregated for in vivo studies by developing a ratiometric nanoparticle for NO ( rNP-NO ), which we employed to successfully visualize pathological levels of nitric oxide in a drug-induced liver injury model via deep tissue SWIR photoacoustic (PA) imaging. Our work demonstrates how easily this dye series can be utilized as a component in nanosensor designs for imaging studies. 相似文献