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111.
Summary Both the separation of polycyclic aromatic hydrocarbons (PAH's) on tailor made HPLC phases, and their chromatographic enrichment
and quantitative determination are of great interest. Because of the generally low concentrations of PAH's in the environment,
and the low limiting values in German legislation for drinking water, methods for selective enrichment and sensitive detection
are indispensable. On account of their relatively high amounts in soil, the determination of PAH's is valuable for the assessment
of the potential danger to ground water by waste materials. These requirements can be fulfilled by used of solid phase extraction
on enrichment columns, and fluorescence or UV/VIS diode array detection.
For the detection of PAH's in the picogram range, the wavelengths for excitation and emission were time programmed over the
chromatogram. With this feature, it is possible to detect all the individual compounds at the highest sensitivity, over the
entire analysis. 相似文献
112.
维生素B类药物在薄层原位的近红外付立叶变换表面增强拉曼光谱 总被引:3,自引:0,他引:3
维生素B类药物在薄层原位的近红外付立叶变换表面增强拉曼光谱汪瑗,于秉正张煦(首都师范大学分析测试中心北京100037)(北京大学分析测试中心北京)关键词维生素B_1,维生素B_2,薄层色谱,表面增强拉曼散射,近红外付立叶变换拉曼光谱将薄层色谱(TLC)... 相似文献
113.
离子色谱分离-抑制电导检测吲哚乙酸和吲哚丁酸 总被引:5,自引:1,他引:5
采用新型离子色谱电导检测器对吲哚 3 乙酸和吲哚 3 丁酸在流速为 1.5ml·min- 1,2 .5mmol·L- 1Na2 CO3 和 1.0mmol·L- 1NaHCO3 和 10 % (体积分数 )甲醇水的混合淋洗液下能够较好的分离 ,吲哚 3 乙酸和吲哚 3 丁酸检出限分别为 1.4 5 4和 4 .86 2mg·L- 1(S/N =3) ,具有良好的线性关系和重现性。在土壤样品中其加标的回收率分别为 10 3.7%和 97.9%。 相似文献
114.
Vermeiren K 《Journal of chromatography. A》2005,1085(1):60-65
Since years, ion exclusion chromatography (ICE) has been the standard method to separate strong acid analyte anions from concentrated weak acid matrices such as hydrofluoric acid (HF). In this work, the commercially available IonPac ICE-AS 1 column was used to separate trace levels of chloride, nitrate, sulfate and phosphate from HF solutions at 20% (w/w). The efficiency of the separation was studied in more detail using techniques such as ion chromatography (IC), inductively coupled plasma optical emission spectrometry (ICP-OES) and ICP-mass spectrometry (ICP-MS). For 20% (w/w) HF solutions and at a water carrier flow-rate of 0.50 ml/min, the cut window was set from 8.5 to 14.5 min. Under these conditions, analyte recoveries of better than 90% were obtained for chloride, nitrate and sulfate, but only about 75% for phosphate. The HF rejection efficiency was better than 99.9%. It was found that the ICP techniques, measuring total element levels and not species, yielded significantly higher recoveries for phosphorus and sulfur compared to IC. Evidence will be given that part of the added phosphorus (approximately 15% for an addition of 10 mg PO4/kg) is present as mono-fluorophosphoric acid (H2FPO3). In the case of sulfate, the difference between IC and ICP-MS could be attributed to an important matrix effect from the residual HF concentration. 相似文献
115.
毛细管气相色谱法测定5种中草药中有机氯农药的残留量 总被引:38,自引:0,他引:38
建立了怀牛夕等 5种中草药中六六六及滴滴涕异构体含量的气相色谱分析方法。样品以石油醚 +丙酮在索氏提取器中提取 ,提取液以浓硫酸净化。采用SE 30弹性石英毛细管柱分离样品 ,GC ECD检测六六六、滴滴涕农药的残留量。方法的线性范围为 5 .7× 10 - 7~ 2 .8× 10 - 4μg ;最小检测量为 1.3× 10 - 1 4~ 2 .5×10 - 1 2 g ;加样平均回收率为 88.8%~ 99.1% ;RSD为 0 .9%~ 5 .3%。 相似文献
116.
The multi-component isotherms for human insulin (HI) and desamido human insulin (dHI) over reversed phase packing (C18) and with 29.8% (w/w) ethanol-water as mobile phase have been determined experimentally. The isotherms of HI in ethanol-water differ from those obtained with the more commonly applied methanol-water and acetonitrile-water mobile phase, as described in this paper. The isotherm exhibits anti Langmuirian behavior and can be very well modeled by an anti Langmuir isotherm presented in this paper. The HI and dHI anti Langmuir isotherm are determined as: qHI = (8.4C(HI) + 3C(HI)CdHI)/(1 - 0.05C(HI) - 0.14CdHI + 0.04C(HI)CdHI) and qdHI = (11.4CdHI + 2C(HI)CdHI)/ (1 - 0.05C(HI) - 0.14CdHI + 0.04C(HI)CdHI) 相似文献
117.
Summary An analytical GC method was developed which uses a single packed column consisting of three packings in series prepared with the following liquid phases: dimethyl sulfolane, propylene carbonate, and silver nitrate. This system provides satisfactory resolution of mixtures of C1–C5 hydrocarbons and dimethyl ether obtained when converting methanol to gasoline. Due to the high capacity of the column it is possible to inject larger sample amounts permitting trace analysis. 相似文献
118.
Evaluation of gas chromatography-tandem quadrupole mass spectrometry for the determination of organochlorine pesticides in fats and oils 总被引:1,自引:0,他引:1
Patel K Fussell RJ Hetmanski M Goodall DM Keely BJ 《Journal of chromatography. A》2005,1068(2):289-296
A gas chromatography-tandem quadrupole mass spectrometry multi-residue method for the analysis of 19 organochlorine pesticides in fats and oils has been developed. Gel permeation chromatography was employed to remove lipid material prior to GC-MS/MS analysis. Average recoveries of the pesticides spiked at 10 and 50 microg kg(-1) into fish oil, pork fat, olive oil and hydrogenated vegetable oil were typically in the range 70-110% with relative standard deviations generally less than 10%. Calculated limits of detection are between 0.1 and 2.0 microg kg(-1) and results obtained for the analysis of proficiency test materials are in good agreement with assigned values. The higher selectivity of the GC-MS/MS compared to electron capture detection and GC-MS in selective ion monitoring mode allowed unambiguous identification and confirmation of all the target pesticides at low microg kg(-1) levels in fats and oils in a single analysis. 相似文献
119.
高效液相色谱法测定精对苯二甲酸中微量杂质 总被引:6,自引:0,他引:6
建立了高效液相色谱法(HPLC)同时测定精对-苯二甲酸(PTA)中微量杂质4-羧基苯甲醛(4-CBA)、对-甲基苯甲酸(P-TOL)和苯甲酸(C7H6O2)含量的方法。采用的色谱柱为Shim-PackWAX-1柱,流动相为0.1mol/L NH3H2PO4 6%CH3OH,(pH4.5),检测波长为254nm。PTA中微量杂质4-CBA、P-TOL和C7H6O2的含量分别为0.59-235.20mg/kg、4.52-392.00mg/kg和0.28-24.55mg/kg时线性关系良好,其线性相关系数分别为0.9998、0.9997和0.9999。苯甲酸加样平均回收率99.03%,RSD0.37%。 相似文献
120.
白酒中C_9-C_(18)脂肪酸的气相色谱分析周在德,曾永昌(四川大学化学系成都610064)关键词气相色谱法,白酒,C_9-C_(18)脂肪酸。白酒中脂肪酸的含量及相互比例关系,极大地影响着白酒的色,香,味,风格 ̄([1][2])。一般采用的化学分... 相似文献