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111.
建立了液相色谱-串联质谱(LC-MS/MS)检测人尿中去氨加压素的方法。样品经Waters C_(18)固相萃取净化,Phenomenex Onyx Monolothic C_(18)色谱柱分离,以10 mmol/L甲酸铵水溶液(用甲酸调至p H 3.5)-乙腈作为流动相进行梯度洗脱,流速为0.4 m L/min,串联质谱正离子模式电离(ESI~+),多反应监测模式(MRM)检测。收集8名志愿者在服用单次单剂量去氨加压素后留取3 d内全部尿液样本,使用建立的方法进行检测并绘制代谢曲线。结果表明:尿中去氨加压素的检出限为0.2μg/L;线性范围为0.5~20μg/L,相关系数(r~2)大于0.997;在低、中、高3个加标浓度下,回收率均高于59%,日内及日间精密度均小于10%,基质效应在20%以内。8名志愿者的阳性尿中去氨加压素浓度峰值在服药后70~150 min之间,最高浓度为0.2~2.4μg/L,检测窗口期最长可至服药后13 h左右。该法对于尿中去氨加压素具有特异性,能显著降低实验时间和成本,完全满足世界反兴奋剂组织对该药物的检测要求。该实验考察了服药后阳性尿中去氨加压素的浓度变化,研究了去氨加压素在人体内的消除情况。 相似文献
112.
Pál?SohárEmail author Antal?Csámpai Gábor?Magyarfalvi Angela E.?Szabó Géza?Stájer 《Monatshefte für Chemie / Chemical Monthly》2004,135(12):1519-1527
Summary. t-2-Benzoyl-t-4-phenylcyclohexane-r-1-carboxylic acid reacts with hydrazine to give the saturated 1,7-diphenyl-trans-phthalazin-4(3H)-one. The reaction of the acid with ethylenediamine yields diastereomeric trans-imidazo[2,3-a]isoindoles, which differ in their C-1 configuration. The cyclizations of the acid with cis-2-aminocyclohexane- or 4-cyclohexenemethanol result in trans-isoindolo[2,1-a][3,1]benzoxazines, while in its reactions with the analogous di-endo- and di-exo-norbornane- and -norborneneamino alcohols, the acid gives methylene-bridged isomeric di-endo-norbornanes or a norbornene derivative; the corresponding diastereomeric di-exo derivatives have also been prepared. After isolation, the structures were established by means of 1H and 13C NMR spectroscopy, with application of DIFFNOE, DEPT, HMQC, HMBC, and 2D-COSY techniques. 相似文献
113.
Márta?Palkó Elvira?Sándor Pál?Sohár Ferenc?Fül?pEmail author 《Monatshefte für Chemie / Chemical Monthly》2005,136(12):2051-2058
Summary. All-endo-3-amino-5-hydroxybicyclo[2.2.1]heptane-2-carboxylic acid and two epimers of 3-amino-6-hydroxybicyclo[2.2.1]heptane-2-carboxylic
acid were prepared via 1,3-oxazine or γ-lactone intermediates by the stereoselective functionalization of endo-3-aminobicyclo[2.2.1]hept-5-ene-2-carboxylic acid derivatives. Their structures were proved by IR and NMR spectroscopy, with
the use of HMQC, HMBC, DEPT, and DIFFNOE techniques. 相似文献
114.
115.
Zsolt?Ajtony Norbert?Szoboszlai Zsuzsanna?Bella Szilvia?Bolla Pál?Szakál László?BencsEmail author 《Mikrochimica acta》2005,150(1):1-8
A flow injection hydride generation graphite furnace atomic absorption spectrometric (FI-HG-GFAAS) method was applied to the determination of Se in Se-doped and undoped cereals and bakery products. For the purpose of doping, the soils used for the cultivation of the cereals were dosed with Se-doped foliar fertilizers. The samples were dissolved in a mixture of HNO3 and H2O2 solutions using microwave-assisted digestion. The decomposition of H2Se generated from the sample solutions and the trapping of elemental Se were performed at a temperature of 300°C on an Ir-pretreated integrated graphite platform of a transversally heated graphite atomizer (THGA). For release of the trapped Se within a fairly short atomization time (5s), an atomization temperature of 2200°C was observed to be optimal. The overall efficiency of hydride generation, transport and trapping was 86%.The upper limit of the linear dynamic range of calibration was 10µgL–1, which corresponds to 0.5µgg–1 for solid samples. Recovery of the samples spiked with SeVI solutions was found to be 93±6% on average. The relative standard deviation of the determinations was less than 8%. The limit of detection was found to be 0.06µgL–1, corresponding to 3ngg–1 for solid samples. The accuracy of the method was verified with the use of IAEA-155 (whey powder) certified reference material. End-capped THGA tubes resulted in an extension of the linear calibration range compared to that of standard THGAs.The Se content in bakery products made of undoped cereals ranged from 7.7 to 68ngg–1 (wet weight) in 18 samples, whereas the Se content of the corresponding cereals was found to be below 100ngg–1 (wet weight). The Se level of cereals grown on soils treated with Se-doped fertilizers ranged from 128 to 1046ngg–1 (wet weight), and it depended linearly on the Se concentration of the corresponding foliar fertilizer. 相似文献
116.
Eszter?Gács-Baitz Orsolya?EgyedEmail author Aldo?Taticchi Lucio?Minuti Assunta?Marrocchi 《Structural chemistry》2005,16(6):581-585
Our ongoing study on cycloaddition reactions of dienes with different dienophiles afforded a great variety of derivatives
with interesting molecular structures and electronic behavior. A new type of angularly annelated [2.2]paracyclophane (3) has been synthesize by the Diels–Alder reaction of 4-(2-propenyl[2.2]paracyclophane (1) and 1,4-benzoquinone (2) under high pressure conditions. The structure determination of this compound has been achieved by NMR measurements and semiempirical
calculations. 相似文献
117.
SrO对Al2O3载体的改性及MnOx/SrO-Al2O3催化剂的甲烷燃烧活性 总被引:3,自引:0,他引:3
以Mn(CH3COO)2为前驱体,制备了MnOx/Al2O3,MnOx/SrO-Al2O3系列催化剂,考察了SrO对Al2O3热稳定性的影响及MnOx/SrO-Al2O3催化甲烷燃烧的活性,并用X-射线衍射(XRD),程序升温还原(TPR)对其进行了表征,结果表明,随SrO加入量的增加复合载体SrO-Al2O3的比表面发生明显变化,高温焙烧过程中生成SrAl2O4,SrO.6Al2O3,SrO的加入抑制了Al2O3的α相变,SrO-Al2O3(1000℃焙烧)负载的MnOx催化剂,其还原性能有较大提高,对甲烷燃烧的催化活性明显增强。 相似文献
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