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81.
过程分析化学的新进展 总被引:4,自引:0,他引:4
综述了国外过程分析化学(PAC)的最新进展,内容包括过程量测、传感器、化学计量学等,并展望了PAC的发展趋势。引用文献62篇。 相似文献
82.
Matthias Otto Gerhard Stingeder Kurt Piplits Manfred Grasserbauer Michael Heinrich 《Mikrochimica acta》1992,106(3-6):163-173
Automated quantitative comparison of depth-profiles recorded by SIMS based on a fuzzy difference measure has been used to characterize Sb and B implantation profiles in a marker experiment to study the diffusion of As in silicon. The variations of the concentration (intensity) measurements are described by a fuzzy set that is specified by smoothing the data with a polynomial digital filter. For each depth an individual spread as the size of variation is defined. Applications of the method enabled the influence of As-concentration and of annealing conditions on the implantation profiles of Sb and B to be quantified. 相似文献
83.
该文回顾了科学研究范式的形成并讨论了化学与分析测试科学的相关发展历程。实验科学向理论科学演进实际是现代科学的形成过程,对化学而言是一个困难的数学化进程,直到第三即计算科学范式形成,化学的现代科学地位才得以确定。分析化学或分析测试科学发展过程中遇到类似的问题,化学计量学/信息学在助推其完善分析化学“数学化”进程的同时,也能够挖掘更多有效信息。随着现代分析仪器的快速发展和数据海啸的到来,化学计量学/信息学作为成熟的化学学科分支和有力“武器”,正在协助并推动化学和分析测试科学步入第四即“数据密集型”的科学新范式。该文以作者实验室的研究工作为基础,论述了化学计量学/信息学助力推动化学与分析测试科学研究范式的转换过程中的相关进展,并对未来的研究动向进行了展望。 相似文献
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Mathias Sawall Christian Fischer Detlef Heller Klaus Neymeyr 《Journal of Chemometrics》2012,26(10):526-537
Multivariate curve resolution techniques allow to uncover from a series of spectra (of a chemical reaction system) the underlying spectra of the pure components and the associated concentration profiles along the time axis. Usually, a range of feasible solutions exists because of the so‐called rotational ambiguity. Any additional information on the system should be utilized to reduce this ambiguity. Sometimes the pure component spectra of certain reactants or products are known, or the concentration profiles of the same or other species are available. This valuable information should be used in the computational procedure of a multivariate curve resolution technique. The aim of this paper is to show how such supplemental information on the components can be exploited. The knowledge of spectra leads to linear restrictions on the concentration profiles of the complementary species and vice versa. Further, affine–linear restrictions can be applied to pairs of a concentration profile and the associated spectrum of a species. These (affine) linear constraints can also be combined with the usual non‐negativity restrictions. These arguments can reduce the rotational ambiguity considerably. In special cases, it is possible to determine the unknown concentration profile or the spectrum of a species only from these constraints. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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88.
Yogita Deshmukh Puja Khare Altafhusain B. Nadaf Dharnidhar Patra 《Journal of Chemometrics》2015,29(12):648-658
2‐Acetyl‐1‐pyrroline (2AP) is known as a principal basmati aroma compound. The present study aims at discriminating rhizobacteria isolated from soils cultivated with basmati and non‐basmati rice for long duration. Volatile profiling was used as marker to discriminate the rhizobacterial isolates. Quantification of 2AP and other volatile compounds (VCs) produced by rhizobacteria was undertaken using HS‐SPME coupled with GC‐MS. Chemometrics tools such as hierarchical cluster analysis (HCA), principle component analysis (PCA) and multi dimensional scaling (MDS) were applied for volatile profiling of different isolates. Results showed significant discrimination of all 2AP producing (AP‐P) and non‐producing rhizobacterial isolates (AP‐NP) on the basis of their VC profile. This was validated by bacterial identification data as well. The frequency distribution for 2AP levels indicates that basmati isolates had higher frequency for 2AP production as compared to non‐basmati control. AP‐P and AP‐NP isolates have different VC profiling pattern irrespective of their origin. These isolates were found belonging to different groups when identified using 16S rDNA sequencing data. Chemometric analysis (PCA, HCA and MDS) helped to identify volatiles, which could be used as biomarker in discriminating the AP‐P and AP‐NP isolates. VC pattern of rhizobacteria could be used as volatile markers to distinguish between AP‐P and AP‐NP rhizobacterial isolates. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
89.
《Journal of separation science》2017,40(22):4377-4384
A potential method for the discrimination and prediction of honey samples of various botanical origins was developed based on the non‐targeted volatile profiles obtained by solid‐phase microextraction with gas chromatography and mass spectrometry combined with chemometrics. The blind analysis of non‐targeted volatile profiles was carried out using solid‐phase microextraction with gas chromatography and mass spectrometry for 87 authentic honey samples from four botanical origins (acacia, linden, vitex, and rape). The number of variables was reduced from 2734 to 70 by using a series of filters. Based on the optimized 70 variables, 79.12% of the variance was explained by the first four principal components. Partial least squares discriminant analysis, naïve Bayes analysis, and back‐propagation artificial neural network were used to develop the classification and prediction models. The 100% accuracy revealed a perfect classification of the botanical origins. In addition, the reliability and practicability of the models were validated by an independent set of additional 20 authentic honey samples. All 20 samples were accurately classified. The confidence measures indicated that the performance of the naïve Bayes model was better than the other two models. Finally, the characteristic volatile compounds of linden honey were tentatively identified. The proposed method is reliable and accurate for the classification of honey of various botanical origins. 相似文献
90.
Elena Piacenza Delia Francesca Chillura Martino Luciano Cinquanta Pellegrino Conte Paolo Lo Meo 《Magnetic resonance in chemistry : MRC》2022,60(3):369-385
A set of commercial milk and Sicilian cheeses was analysed by a combination of fast field cycling (FFC) nuclear magnetic resonance (NMR) relaxometry and chemometrics. The NMR dispersion (NMRD) curves were successfully analysed with a mathematical model applied on Parmigiano–Reggiano (PR) cheese. Regression parameters were led back to the molecular components of cheeses (water trapped in casein micelles, proteins and fats) and milk samples (water belonging to hydration shells around dispersed colloidal particles of different sizes and bulk water). The application of chemometric analysis on relaxometric data enabled differentiating milk from cheeses and revealing differences within the two sample groups of either cheeses or milk samples. Marked differences among cheeses were evidenced by statistical analysis of the sole quadrupolar peaks parameters, suggesting that these contain information on the nature of the milk used during cheese production. Hence, combination of FFC NMR and chemometrics represents a powerful tool to investigate alterations in dairy products. 相似文献