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71.
72.
In this present research, a spectroscopic method based on UV–Vis spectroscopy is utilized to quantify the level of corn adulteration in peaberry ground roasted coffee by chemometrics. Peaberry coffee with two types of bean processing of wet and dry-processed methods was used and intentionally adulterated by corn with a 10–50% level of adulteration. UV–Vis spectral data are obtained for aqueous samples in the range between 250 and 400 nm with a 1 nm interval. Three multivariate regression methods, including partial least squares regression (PLSR), multiple linear regression (MLR), and principal component regression (PCR), are used to predict the level of corn adulteration. The result shows that all individual regression models using individual wet and dry samples are better than that of global regression models using combined wet and dry samples. The best calibration model for individual wet and dry and combined samples is obtained for the PLSR model with a coefficient of determination in the range of 0.83–0.93 and RMSE below 6% (w/w) for calibration and validation. However, the error prediction in terms of RMSEP and bias were highly increased when the individual regression model was used to predict the level of corn adulteration with differences in the bean processing method. The obtained results demonstrate that the use of the global PLSR model is better in predicting the level of corn adulteration. The error prediction for this global model is acceptable with low RMSEP and bias for both individual and combined prediction samples. The obtained RPDp and RERp in prediction for the global PLSR model are more than two and five for individual and combined samples, respectively. The proposed method using UV–Vis spectroscopy with a global PLSR model can be applied to quantify the level of corn adulteration in peaberry ground roasted coffee with different bean processing methods. 相似文献
73.
Limited literature is available concerning the phenolic biosynthesis and antioxidative potential of common bean sprouts induced by ultrasound elicitation. In this study, common bean seeds were treated with ultrasound at different power (0, 180 and 360 W) and time (0, 30, 45 and 60 min) levels, before they were subjected to sprouting (24, 48, 72 and 96 h). Stress markers (H2O2, catalase and guaiacol peroxidase), activities of defense phenolic triggering enzymes (phenylalanine ammonia-lyase and tyrosine ammonia-lyase), phenolic contents (total phenolic acids, total flavonoids and anthocyanins) and antioxidant capacities (DPPH, ABTS and Fe2+ scavenging) were monitored. Results showed that, ultrasound elicitation (especially 360 W, 60 min) significantly increased accumulation of stress markers at 96 h of sprouting, leading to elevated activities of defense phenolic triggering enzymes, and final accumulation of phenolics and antioxidant capacities at significant levels compared to control. Ultrasound treatment at 360 W and 60 min reduced sprouting time by 60 h, compared to control. Results from principal component analysis clearly differentiated latter stages of sprouting and high ultrasound levels from other sprouting conditions as distinct treatments for the production of phenolic-rich common bean sprouts. Overall, results from this study indicated that elicitation with ultrasound can be a green and novel approach for producing phenolic-enriched common bean sprouts as an organic nutraceutical vegetable. 相似文献
74.
An improved enzyme-linked immunosorbent assay (ELISA) for the determination of southern bean mosaic virus (SBMV) with linear sweep voltammetry based on a new system of p-aminophenol (PAP)-H2O2-horseradish peroxidase (HRP) has firstly been developed. The enzymatic product 3-[(4-hydrox-yphenyl) amino]-4-(2-amino-5-hydroxyphenyl)-6-[ (4-hydrox-yphenyl)imino]-2,4-cyclohexadiene-l-one, produced from the oxidation of PAP with H2O2 catalyzed by HRP, yielded a sensitive linear sweep voltammetric response at - 0.45 V ( vs. SCE) in Britton-Robinson (BR) buffer solution. Based on the voltammetric peak, HRP can be measured with a detection limit of 0.4 mU/L and a linear range of 1.0-1.0 × 102 mU/ L. The detection limit for the SBMV is 8.0 ng/mL and the highest dilution ratio for the detection of infected leaf sap is 1: 1.5×105. 相似文献
75.
基于锥形束CT下颌骨外轮廓提取的研究 总被引:1,自引:0,他引:1
目的:在法医学鉴定中,采用单一的自适应阈值分割方法对锥形束CT下颌骨图像进行轮廓的提取,常产生区域断裂现象。因此需要对单一的分割方法进行改进,从而提高下颌骨外轮廓提取的精度。方法:腐蚀-重构和膨胀-重构等数学形态学的方法与阈值分割方法的组合使用可以明显克服上述缺陷。结果:通过单一的分割方法与组合改进方法分别对300幅锥形束CT下颌骨图像进行阈值分割并对比分割效果,直接采用自适应闽值分割方法有228幅图像获取下颌骨外轮廓失败,而改进的方法仅有53幅图像无法扶得下颌骨外轮廓。结论:改进方法能够明湿抑制锥形束CT下颌骨图像在分割过程中出现的局部区域断裂观象。 相似文献
76.
Muhammad Ateeq Muhammad Muzammal Adeel Ayesha Kanwal Muhammad Tahir ul Qamar Ahsan Saeed Binish Khaliq Qamar Saeed Muhammad Nauman Atiq Muhammad Bilal Metab Alharbi Abdulrahman Alshammari Ahmed Akrem 《Molecules (Basel, Switzerland)》2022,27(10)
Vicilin has nutraceutical potential and different noteworthy medicative health-promoting biotic diversions, and it is remarkable against pathogenic microorganisms and insects. In this study, Vigna aconitifolia vicilin (VacV) has been identified and characterized from the seed of Vigna aconitifolia (Jacq.) Marechal (Moth beans). LC-MS/MS analysis of VacV provided seven random fragmented sequences comprising 238 residues, showing significant homology with already reported Vigna radiata vicilin (VraV). VacV was purified using ammonium sulfate precipitation (60%) followed by size exclusion chromatography on Hi-Load 16/60 Superdex 200 pg column and anion-exchange chromatography (Hi trap Q FF column). Purified VacV showed a major ~50 kDa band and multiple lower bands on 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) under both reduced and non-reduced conditions. After all, a three-dimensional molecular structure of VacV was predicted, which showed β-sheeted molecular conformation similar to crystallographic structure of VraV. All Vicilins from V. aconitifolia and other plants were divided into six sub-groups by phylogenetic analysis, and VacV shared a high degree of similarity with vicilins of Vigna radiata, Pisum sativum, Lupinus albus, Cicer arietinum and Glycine max. Additionally, VacV (20 μg) has significant growth inhibition against different pathogenic bacteria along strong antifungal activity (50 μg). Likewise, VacV (3.0 mg) produced significant growth reduction in Rice Weevil Sitophilus oryzae larvae after 9 days compared with control. Furthermore, by using MMT assay, the cytotoxicity effect of VacV on the growth of HepG2 liver cancerous cells was tested. VacV showed cytotoxicity against the HepG-2 line and the acquired value was 180 µg after 48 h. Finally, we performed molecular docking against caspase-3 protein (PDB ID: 3DEI) for VacV bioactive receptor interface residues. Hence, our results reveal that VacV, has nutraceutical potential and moth beans can be used as a rich resource of functional foods. 相似文献
77.
78.
Feifei Wei Kazuo Furihata Fangyu Hu Takuya Miyakawa Masaru Tanokura 《Magnetic resonance in chemistry : MRC》2010,48(11):857-865
A complex mixture analysis by one‐ and two‐dimensional nuclear magnetic resonance (NMR) spectroscopy was carried out for the first time for the identification and quantification of organic compounds in green coffee bean extract (GCBE). A combination of 1H? 1H DQF‐COSY, 1H? 13C HSQC, and 1H? 13C CT‐HMBC two‐dimensional sequences was used, and 16 compounds were identified. In particular, three isomers of caffeoylquinic acid were identified in the complex mixture without any separation. In addition, GCBE components were quantified by the integration of carbon signals by use of a relaxation reagent and an inverse‐gated decoupling method without a nuclear Overhauser effect. This NMR methodology provides detailed information about the kinds and amounts of GCBE components, and in our study, the chemical makeup of GCBE was clarified by the NMR results. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
79.
We developed a simplified nanofabrication process for imprint templates by fast speed electron beam lithography (EBL) and a dry etch technique on a SiNx substrate, intended for large area manufacturing. To this end,the highly sensitive chemically amplified resist (CAR), NEB-22, with negative tone was used. The EBL process first defines the template pattern in NEB-22, which is then directly used as an etching mask in the subsequent reactive ion etching (RIE) on the SiNx to form the desired templates. The properties of both e-beam lithography and dry etch of NEB-22 were carefully studied, indicating significant advantages of this process with some drawbacks compared to when Cr was used as an etching mask. Nevertheless, our results open up a good opportunity to fabricate high resolution imprint templates with the prospect of wafer scale manufacturing. 相似文献
80.
To utilize the wasted coat resources, which are usually discarded in the process of mung bean derived food, and understand the traditional use of mung bean, nuclear magnetic resonance-based metabolic fingerprinting approach was used to compare the chemical composition between the coat and kernel. The results showed that the flavonoids, isovitexin and vitexin, were only present in the coat, while the kernel contained higher levels of amino acids and sugars. In addition, the coat showed much stronger 2,2-diphenyl-1-picrylhydrazyl scavenging activity than the kernel, which was in accordance with the analysis result from the biplot of partial least squares. 相似文献