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151.
Mamdouh R. Rezk Emad B. Basalious Mohammed E. Amin 《Biomedical chromatography : BMC》2016,30(9):1354-1362
A novel and sensitive LC–MS/MS method was developed and validated for determination of sofosbuvir (SF) using eplerenone as an internal standard. The Xevo TQD LC–MS/MS was operated under the multiple‐reaction monitoring mode using electrospray ionization. Extraction with tert‐butyl methyl ether was used in sample preparation. The prepared samples were chromatographed on Acquity UPLC BEH C18 (50 × 2.1 mm, 1.7 μm) column by pumping 0.1% formic acid and acetonitrile in an isocratic mode at a flow rate of 0.35 mL/min. Method validation was performed as per the US Food and Drug Administration guidelines and the standard curves were found to be linear in the range of 0.25–3500 ng/mL for SF. The intra‐ and inter‐day precision and accuracy results were within the acceptable limits. A very short run time of 1 min made it possible to analyze more than 500 human plasma samples per day. A very low quantification limit of SF allowed the applicability of the developed method for determination of SF in a bioequivalence study in human volunteers. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
152.
This paper presents a simple, specific, and precise high-performance liquid chromatographic method for the simultaneous determination of paracetamol (PCM), chlorzoxazone (CXZ), and their related impurities in bulk raw materials and solid dosage forms. The mobile phase consisted of water-methanol-glacial acetic acid (60 + 40 + 2, v/v/v). A column containing octadecylsilane chemically bonded to porous silica particles (Spherisorb ODS 1, 25 cm x 4.6 mm, 5 microm) was used as stationary phase. Detection was performed using a variable wavelength ultraviolet-visible detector set at 272 nm for all compounds. Solutions were injected into the chromatograph under isocratic condition at a constant flow rate of 1.2 mL/min. The method was validated according to International Conference on Harmonization requirements and demonstrates good accuracy and precision and a wide linearity range. The method separates PCM, CXZ, and 3 major impurities [4-aminophenol (4AP), 4'-chloracetanilide (4CA), and p-chlorophenol (PCP)] with fair resolution in less than 15 min. The developed method is rapid and sensitive (limit of detection for 4AP, 4CA, and PCP established at 31.25, 39.06, and 65.16 ng/mL, respectively) and, therefore, suitable for quality control and stability studies of these compounds in dosage forms. 相似文献
153.
Subhi A. Al-Jibori Afra S. S. Al-Zaubai Modher Y. Mohammed Talal A. K. Al-Allaf 《Transition Metal Chemistry》2007,32(3):281-286
Palladium(II) and platinum(II) complexes containing the mixed ligands tertiary diphosphines Ph2P(CH2)
n
PPh2, (n = 1–4) and benz-1,3-imidazoline-2-thione, benz-1,3-oxazoline-2-thione or benz-1,3-thiazoline-2-thione have been prepared
and characterized by elemental analysis, magnetic susceptibility, molar conductance and i.r. spectral data. 31P–{1H}-n.m.r. data have been applied to characterize the produced linkage isomers. 相似文献
154.
Toubas D Essendoubi M Adt I Pinon JM Manfait M Sockalingum GD 《Analytical and bioanalytical chemistry》2007,387(5):1729-1737
The incidence of fungal infections, in particular candidiasis and aspergillosis, has considerably increased during the last
three decades. This is mainly due to advances in medical treatments and technologies. In high risk patients (e.g. in haematology
or intensive care), the prognosis of invasive candidiasis is relatively poor. Therefore, a rapid and correct identification
of the infectious agent is important for an efficient and prompt therapy. Most clinical laboratories rely on conventional
identification methods that are based on morphological, physiological and nutritional characteristics. However, these have
their limitations because they are time-consuming and not always very accurate. Moreover, molecular methods may be required
to determine the genetic relationship between the infectious strains, for instance in Candida outbreaks. In addition, the latter methods require time, expensive consumables and highly trained staff to be performed adequately.
In this study, we have applied the FTIR spectroscopic approach to different situations encountered in routine mycological
diagnosis. We show the potentials of this phenotypic approach, used in parallel with routine identification methods, for the
differentiation of 3 frequently encountered Candida species (C. albicans, C. glabrata and C. krusei) by using both suspensions and microcolonies. This approach, developed for an early discrimination, may help in the initial
choice of antifungal treatment. Furthermore, we demonstrate the feasibility of the method for intraspecies comparison (typing)
of 3 Candida species (C. albicans, C. glabrata and C. parapsilosis), particularly when an outbreak is suspected. 相似文献
155.
Mohammed A. Bari Siddiqui Shakeel Ahmed Musaed S. Al-Gharami Chistopher F. Dean 《Reaction Kinetics and Catalysis Letters》2007,91(1):61-67
Sulfur reduction ability of alumina supported zinc, gallium and zinc-gallium additives for fluid catalytic cracking catalysts
was evaluated in a micro-activity test unit (MAT). Gallium/alumina showed the highest sulfur reduction of 31%, but the cracking
activity of the catalyst was decreased. Zinc-gallium/alumina reduced sulfur in 24 wt.% without decreasing the base catalyst
activity. 相似文献
156.
Bicyclic δ-lactones with a carbon group at the bicyclic junction C-7a, designed as pseudoiridolactones, were synthesized from α-alkyl-α-hydroxymethylcyclopentanones via an intramolecular Horner-Wadsworth-Emmons reaction. 相似文献
157.
Muhammad Sajid Chanbasha Basheer Abdulnaser Alsharaa Kothandaraman Narasimhan Abdelbaset Buhmeida Mohammed Al Qahtani Mahmoud Shaheen Al-Ahwal 《Analytica chimica acta》2016
In the present study, a natural sorbent based micro-solid phase extraction (μ-SPE) was developed for determination of phthalate esters in milk samples. For the first time, an efficient and cost effective natural material (seed powder of Moringa oleifera) was employed as sorbent in μ-SPE. The sorbent was found to be naturally enriched with variety of functional groups and having a network of interconnected fibers. This method of extraction integrates different steps such as removal of proteins and fatty stuff, extraction and pre-concentration of target analytes into a single step. Thirteen phthalate esters were selected as target compounds for the development and evaluation of method. Some key parameters affecting the extraction efficiency were optimized, including selection of membrane, selection and amount of sorbent, extraction time, desorption solvent, volume of desorption solvent, desorption time and effect of salt addition. Under the optimum conditions, very good linearity was achieved for all the analytes with coefficient of determinations (R2) ranging between 0.9768 and 0.9977. The limits of detection ranged from 0.01 to 1.2 μg L−1. Proposed method showed satisfactory reproducibility with relative standard deviations ranging from 3.6% to 10.2% (n = 7). Finally, the developed method was applied to tetra pack and bottled milk samples for the determination of phthalate esters. The performance of natural sorbent based μ-SPE was better or comparable to the methods reported in the literature. 相似文献
158.
Suresh Babu Meruva Raghavendra Rao K. Aaseef Mohammed Vilas H. Dahanukar U. K. Syam Kumar P. K. Dubey 《合成通讯》2016,46(2):187-196
A concise and enantioselective syntheses of antileukemic natural products such as (–)-(S)-goniothalamin and (–)-leiocarpin A has been accomplished in excellent yields. By employing reported conditions on suitable substrates via Julia–Kocienski olefination, intramolecular lactonization, and subsequently dehydroxylative olefination, (–)-(S)-goniothalamin was synthesized. Then Sharpless asymmetric dihydroxylation–intramolecular Michael addition on (–)-(S)-goniothalamin provided (–)-leiocarpin A. 相似文献
159.
160.
Da Eun Kim Jong Min Lee Christian D. Ahrberg Mohammed R. Shaker Ju‐Hyun Lee Woong Sun Bong Geun Chung 《Electrophoresis》2019,40(3):419-424
The inability of neurons to undergo mitosis renders damage to the central or peripheral nervous system. Neural stem cell therapy could provide a path for treating the neurodegenerative diseases. However, reliable and simple tools for the developing and testing neural stem cell therapy are still required. Here, we show the development of a micropillar‐based microfluidic device to trap the uniform‐sized neurospheres. The neurospheres trapped within micropillar arrays were largely differentiated into neuronal cells, and their neurite networks were observed in the microfluidic device. Compared to conventional cultures on glass slides, the neurite networks generated with this method have a higher reproducibility. Furthermore, we demonstrated the effect of thapsigargin on the neurite networks in the microfluidic device, demonstrating that neural networks exposed to thapsigargin were largely diminished and disconnected from each other. Therefore, this micropillar‐based microfluidic device could be a potential tool for screening of neurotoxins. 相似文献