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Spectrum-effect relationship between HPLC fingerprints and bioactive components of Radix Hedysari on increasing the peak bone mass of rat 被引量:6
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作者 Xin-Yue Chen San-Hu Gou +2 位作者 Zhi-Qiang Shi Zhi-Yuan Xue Shi-Lan Feng 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2019年第4期266-273,共8页
The traditional Chinese medicine of Radix Hedysari plays an important role in invigorating gas for ascending, benefiting blood for promoting production of fluid, and promoting circulation for removing obstruction in c... The traditional Chinese medicine of Radix Hedysari plays an important role in invigorating gas for ascending, benefiting blood for promoting production of fluid, and promoting circulation for removing obstruction in collaterals, which is consistent with the principle of treatment for osteoporosis. This study is designed to investigate the bioactive components on increasing peak bone mass (PBM) by exploring the spectrum-effect relationship between chromatography fingerprints and effect. Multiple indicators are selected to evaluate the pharmacological activity. In fingerprints, 21 common peaks are obtained, five of which are identified. Furthermore, gray relational analysis (GRA) is a quantitative method of gray system theory and is used to describe the correlation degree of common peaks and pharmacological activities with relational value. 21 components are then divided into three different regions, of which ononin and calycosin play an extremely significant role in increasing PBM. In addition, factor analysis and hierarchical cluster analysis (HCA) are used to screen the optimal producing area for Radix Hedysari. This provides a comprehensive and efficient method to improve the quality evaluation of Radix Hedysari, confirming the bioactive components for PBM-enhancement and further develop its medicinal value. 展开更多
关键词 Factor ANALYSIS GRAY RELATIONAL ANALYSIS Hierarchical cluster ANALYSIS PEAK BONE mass RADIX Hedysari spectrum-effect relationship
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Dependence of Decamethylcyclopentasiloxane (DMCPS) Dissociation on Ionized Energy by Using Quadrupole Mass Spectrum
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作者 张海燕 叶超 宁兆元 《Plasma Science and Technology》 SCIE EI CAS CSCD 2010年第6期677-680,共4页
Dependence of decamethylcyclopentasiloxane (DMCPS) organosilicon dissociation on ionized energy in the energy range of 25 eV to 70 eV is investigated by using a quadrupole mass spectrometry. At the ionized energy be... Dependence of decamethylcyclopentasiloxane (DMCPS) organosilicon dissociation on ionized energy in the energy range of 25 eV to 70 eV is investigated by using a quadrupole mass spectrometry. At the ionized energy below 55 eV, the dissociation of DMCPS is dominant. As the ionized energy is above 55 eV, the DMCPS dissociation achieves the maximum cross section, while the fragments from the DMCPS dissociation can further dissociate, which leads to a different ingredient of fragments. At the lower ionized energy of 25 eV, the main fragments are SiOC2H+, SiCH+, Si+, O+ and CH+ ions, which shows an important effect on the SiCOH low-k film deposition. 展开更多
关键词 quadrupole mass spectrum DISSOCIATION ionized energy DMCPS organosilicon
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Towards the understanding of 1^1 p1 meson mass spectrum
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作者 冯学超 蒋逢春 +1 位作者 常同钦 冯军兰 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第12期4472-4475,共4页
Based on the meson-meson mixing and Regge trajectory, this paper establishes the mass relations which can describe the mass spectrum of 1^1 P1 meson state. Using these mass relations, it obtains the mass of K1B, hi (... Based on the meson-meson mixing and Regge trajectory, this paper establishes the mass relations which can describe the mass spectrum of 1^1 P1 meson state. Using these mass relations, it obtains the mass of K1B, hi (1380) and hc(1P) to be 1358.5MeV, 1468 MeV and 3543.9 MeV, respectively. The results are compared with other theoretical results and should be tested by experiments in the future. 展开更多
关键词 Regge trajectory meson-meson mixing mass spectrum
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Vector Boson Mass Spectrum from Extra Dimension
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作者 Dao Vong Duc Nguyen Mong Giao 《Journal of Modern Physics》 2013年第7期991-993,共3页
Based on the mechanism for mass creation in the space-time with extradimensions proposed in our previous work, (arXiv: 1301.1405 [hep-th] 2013) we consider now the mass spectrum of vector bosons in extradimensions. It... Based on the mechanism for mass creation in the space-time with extradimensions proposed in our previous work, (arXiv: 1301.1405 [hep-th] 2013) we consider now the mass spectrum of vector bosons in extradimensions. It is shown that this spectrum is completely determined by some function of compactification length and closely related to the metric of extradimensions. 展开更多
关键词 BOSON mass spectrum EXTRA DIMENSIONS
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Mass Spectrum of Dirac Equation with Local Parabolic Potential
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作者 Yingqiu Gu 《Journal of High Energy Physics, Gravitation and Cosmology》 2020年第1期20-33,共14页
In this paper, we solve the eigen solutions to the Dirac equation with local parabolic potential which is approximately equal to the short distance potential generated by spinor itself. The energy spectrum is quite di... In this paper, we solve the eigen solutions to the Dirac equation with local parabolic potential which is approximately equal to the short distance potential generated by spinor itself. The energy spectrum is quite different from that with Coulomb potential. The mass spectrum of some bary-ons is similar to this one. The angular momentum-mass relation is quite similar to the Regge trajectories. The parabolic potential has a structure of asymptotic freedom near the center and confinement at a large distance. So, the results imply that, the local parabolic potential may be more suitable for describing the nuclear potential. The procedure of solving can also be used for some other cases of Dirac equation with complicated potential. 展开更多
关键词 Regge TRAJECTORY PARABOLIC POTENTIAL mass spectrum BARYON Short DISTANCE POTENTIAL
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基于MassARRAY平台的人血小板抗原基因分型的质谱检测方法 被引量:2
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作者 周春 吕红 +7 位作者 张若洋 陈蓉 蔡莉 刘太香 石宇鹏 洪轲 刘成成 梁文飚 《南京医科大学学报(自然科学版)》 CAS CSCD 北大核心 2021年第3期361-368,共8页
目的:建立基于MassARRAY质谱iPLEX分析技术的人血小板抗原(human platelet antigen,HPA)基因分型方法。方法:通过文献检索HPA1-29W系统的单核苷酸多态性突变或缺失位点的信息,确定35个目的基因突变位点,按MassARRAY突变位点标示方法、... 目的:建立基于MassARRAY质谱iPLEX分析技术的人血小板抗原(human platelet antigen,HPA)基因分型方法。方法:通过文献检索HPA1-29W系统的单核苷酸多态性突变或缺失位点的信息,确定35个目的基因突变位点,按MassARRAY突变位点标示方法、引物设计固定格式和引物设计软件在线设计90条引物(正、反向扩增引物和延伸引物各30条),以12个插入HPA1-29W野生型和突变型序列的合成质粒以及50例已知HPA分型的献血者样本进行扩增和质谱检测,分析灵敏度、特异度和重复性,随机抽取15例样本的一代测序和质谱分型结果进行对比验证,建立检测方法。结果:基于MassARRAY平台的HPA基因分型的质谱检测方法与测序法检测结果相符合,灵敏度为100%,特异度为100%,重复性为100%。结论:成功建立基于MassARRAY平台的HPA1-29W系统的质谱分型方法,适合中国人群HPA分型,具有临床应用前景。 展开更多
关键词 massARRAY 人血小板抗原 单核苷酸多态性 基因分型 质谱分析
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用MassLynx 4.1软件提取液相色谱质谱联用部分重叠色谱峰的质谱图 被引量:1
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作者 梁乾德 刘琳 +1 位作者 黄荣清 高月 《解放军药学学报》 CAS 2011年第5期389-394,共6页
目的两个化合物A和X采用液相色谱质谱联用法实现部分分离,并形成部分重叠峰。尝试在不改变分离条件的情况下获得化合物X的"较纯的"质谱图。方法运用MassLynx 4.1软件的"谱图合并(Combine Spectra process)"功能,扣... 目的两个化合物A和X采用液相色谱质谱联用法实现部分分离,并形成部分重叠峰。尝试在不改变分离条件的情况下获得化合物X的"较纯的"质谱图。方法运用MassLynx 4.1软件的"谱图合并(Combine Spectra process)"功能,扣除化合物A的信号。结果与预期相符,所获得的质谱图明晰,提示X可能是A的脱氢类似物,后经验证,与A脱氢类似物纯品的质谱图一致。结论 Masslynx 4.1软件的"谱图合并"功能可以帮助分析者更容易地获得清晰的质谱信息,并有可能节省传统方法中优化色谱条件所花费的时间,是液相色谱质谱联用分析的有力工具。 展开更多
关键词 液相色谱质谱联用 重叠 色谱峰 质谱 massLynx
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CNKSR2 interactome analysis indicates its association with the centrosome/microtubule system
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作者 Lin Yin Yalan Xu +9 位作者 Jie Mu Yu Leng Lei Ma Yu Zheng Ruizhi Li Yin Wang Peifeng Li Hai Zhu Dong Wang Jing Li 《Neural Regeneration Research》 SCIE CAS 2025年第8期2420-2432,共13页
The protein connector enhancer of kinase suppressor of Ras 2(CNKSR2),present in both the postsynaptic density and cytoplasm of neurons,is a scaffolding protein with several protein-binding domains.Variants of the CNKS... The protein connector enhancer of kinase suppressor of Ras 2(CNKSR2),present in both the postsynaptic density and cytoplasm of neurons,is a scaffolding protein with several protein-binding domains.Variants of the CNKSR2 gene have been implicated in neurodevelopmental disorders,particularly intellectual disability,although the precise mechanism involved has not yet been fully understood.Research has demonstrated that CNKSR2 plays a role in facilitating the localization of postsynaptic density protein complexes to the membrane,thereby influencing synaptic signaling and the morphogenesis of dendritic spines.However,the function of CNKSR2 in the cytoplasm remains to be elucidated.In this study,we used immunoprecipitation and high-resolution liquid chromatography-mass spectrometry to identify the interactors of CNKSR2.Through a combination of bioinformatic analysis and cytological experiments,we found that the CNKSR2 interactors were significantly enriched in the proteome of the centrosome.We also showed that CNKSR2 interacted with the microtubule protein DYNC1H1 and with the centrosome marker CEP290.Subsequent colocalization analysis confirmed the centrosomal localization of CNKSR2.When we downregulated CNKSR2 expression in mouse neuroblastoma cells(Neuro 2A),we observed significant changes in the expression of numerous centrosomal genes.This manipulation also affected centrosome-related functions,including cell size and shape,cell proliferation,and motility.Furthermore,we found that CNKSR2 interactors were highly enriched in de novo variants associated with intellectual disability and autism spectrum disorder.Our findings establish a connection between CNKSR2 and the centrosome,and offer new insights into the underlying mechanisms of neurodevelopmental disorders. 展开更多
关键词 autism spectrum disorder CENTROSOME CNKSR2 intellectual disability INTERACTOME mass spectrometry MICROTUBULE neurodevelopmental disease protein complexes protein-protein interactions
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Establishing a protein expression profile database for the normal human pituitary gland using two-dimensional high-performance liquid chromatography combined with LTQ-Orbitrap mass spectrometry 被引量:2
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作者 Rong Xie Wei Xu +4 位作者 Weimin Bao Hang Liu Luping Chen Yiwen Shen Jianhong Zhu 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第36期2922-2928,共7页
In this study, we selected adult normal pituitary gland tissues from six patients during operations for pituitary microadenomas via the transsphenoidal approach for extended normal pituitary tissue resection around th... In this study, we selected adult normal pituitary gland tissues from six patients during operations for pituitary microadenomas via the transsphenoidal approach for extended normal pituitary tissue resection around the tumor, and analyzed the protein expression of human normal pituitary using two-dimensional high-performance liquid chromatography combined with LTQ-Orbitrap mass spectrometry proteomics technology. The ten most highly expressed proteins in normal human pituitary were: alpha 3 type VI collagen isoform 5 precursor (abundance among tall pituitary proteins 1.30%), fibrinogen beta chain preproprotein (0.99%), vimentin (0.73%), prolactin (0.69%), ATP synthase, H~ transporting and mitochondrial F1 complex beta subunit precursor (0.52%), keratin I (0.49%), growth hormone (0.45%), carbonic anhydrase I (0.40%), heat shock protein 90 kDa I (0.31%), and annexin V (0.30%). Based on the biological function classifications of these proteins, the top three categories by content were neuroendocrine proteins (abundance among all pituitary proteins, 40.1%), catalytic and metabolic proteins (28.3%), and cell signal transduction proteins (9.8%). Based on cell positioning classification, the top three categories were cell organelle (24.5%) membrane (20.8%), and cytoplasm (13.0%). Based on biological process classification, the top three categories of proteins are involved in physiological processes (42.9%), cellular processes (40.4%), and regulation of biological processes (9.1%). Our experimental findings indicate that a protein expression profile database of normal human pituitary can be precisely and efficiently established by proteomics technology. 展开更多
关键词 two-dimensional high-performance liquid chromatography mass spectrum pituitary gland PROTEINS PROTEOMICS hypophyseal tumor physiological function pathological mechanism
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Study of Galaxy Distributions with SDSS DR14 Data and Measurement of Neutrino Masses 被引量:1
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作者 B. Hoeneisen 《International Journal of Astronomy and Astrophysics》 2018年第3期230-257,共28页
We study galaxy distributions with Sloan Digital Sky Survey SDSS DR14 data and with simulations searching for variables that can constrain neutrino masses. To be specific, we consider the scenario of three active neut... We study galaxy distributions with Sloan Digital Sky Survey SDSS DR14 data and with simulations searching for variables that can constrain neutrino masses. To be specific, we consider the scenario of three active neutrino eigenstates with approximately the same mass, so &Sigma;mv=3mv. Fitting the predictions of the ΛCDM model to the Sachs-Wolfe effect, &sigma;8, the galaxy power spectrum Pga1(k) , fluctuations of galaxy counts in spheres of radii ranging from 16/h to 128/h Mpc, Baryon Acoustic Oscillation (BAO) measurements, and h=0.678&plusmn;0.009, in various combinations, with free spectral index n, and free galaxy bias and galaxy bias slope, we obtain consistent measurements of &Sigma;mv. The results depend on h, so we have presented confidence contours in the (&Sigma;mv, h) plane. A global fit with h=0.678&plusmn;0.009 obtains eV, and the amplitude and spectral index of the power spectrum of linear density fluctuations P(k): , and n=1.021&plusmn;0.075. The fit also returns the galaxy bias b including its scale dependence. 展开更多
关键词 NEUTRINO mass GALAXY Power spectrum
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Dynamic Promotional Resource Allocation for Segment Specific and Spectrum Effect of Promotion for a Product Line Incorporating Repeat Purchase Behavior 被引量:1
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作者 Prakash Chandra Jha Prerna Manik Anshu Gupta 《American Journal of Operations Research》 2013年第3期350-362,共13页
Promotion is an essential element in the marketing mix. It is used by businesses to inform, influence and persuade customers to adopt the products and services they offer. Without promotion, business would be stagnant... Promotion is an essential element in the marketing mix. It is used by businesses to inform, influence and persuade customers to adopt the products and services they offer. Without promotion, business would be stagnant and lack substantial growth because the brands would have low visibility in the market. Moreover, today’s vast and assorted markets comprise of customers with different needs and varied behavior. So it is rarely possible for companies to satisfy all customers by treating them alike. Thus there arises a need to divide the market into segments having customers with similar traits/characteristics. After identifying appropriate market segments, firms can design differentiated promotional campaigns for each segment. At the same time there can be a mass market promotional campaign that reaches different segments with a fixed spectrum. Also since promotional effort resources are limited, one must use them judiciously. In this paper, we formulate mathematical programming problem under repeat purchase scenario, which optimally allocates mass promotional effort resources and differentiated promotional effort resources across the segments dynamically in order to maximize the overall sales obtained from multiple products of a product line under budgetary and minimum sales aspiration level constraint on each product under consideration in each segment. The planning horizon is divided into multi periods, the adoption pattern of each product in each segment is observed in every subinterval and accordingly promotional effort allocations are determined for the next period till we reach the end of planning period. The optimization model has been further extended to incorporate minimum aspiration level constraints on total sales for each product under consideration from all the segments taken together. The non linear programming problem so formulated is solved using differential evolution approach. A numerical example has been discussed to illustrate applicability of the model. 展开更多
关键词 MARKET Segmentation DIFFERENTIATED MARKET PROMOTION mass MARKET PROMOTION spectrum EFFECT Promotional Effort Allocation REPEAT Purchase Product Line Non Linear Programming Problem Differential Evolution
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Simulation of experimental spectra for medium-heavy nuclides in accelerator mass spectrometry 被引量:1
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作者 WANG Hui-Juan GUAN Yong-Jin +6 位作者 HE Ming RUAN Xiang-Dong DONG Ke-Jun LI Guo-Qiang Wu Shao-Yong WU Wei-Ming JIANG Shan 《Nuclear Science and Techniques》 SCIE CAS CSCD 2005年第5期273-277,共5页
Some interferences are often encountered in accelerator mass spectrometry (AMS) measurements, espe-cially for medium-heavy nuclide measurement. It is difficult for online discrimination of the nuclide of interest from... Some interferences are often encountered in accelerator mass spectrometry (AMS) measurements, espe-cially for medium-heavy nuclide measurement. It is difficult for online discrimination of the nuclide of interest from the interfering ones. In order to solve this problem, we developed a method to simulate the experimental spectra of medium-heavy nuclides in AMS measurements. The results obtained from this method are in good agreement with experimental values. 展开更多
关键词 核素 加速器 光谱分析 AMS 灵敏度
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New lumped-mass-stick model based on modal characteristics of structures: development and application to a nuclear containment building 被引量:8
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作者 Hwasung Roh Huseok Lee Jong Seh Lee 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2013年第2期307-317,共11页
In this study, a new lumped-mass-stick model (LMSM) is developed based on the modal characteristics of a structure such as eigenvalues and eigenvectors. The simplified model, named the "frequency adaptive lumped-ma... In this study, a new lumped-mass-stick model (LMSM) is developed based on the modal characteristics of a structure such as eigenvalues and eigenvectors. The simplified model, named the "frequency adaptive lumped-massstick model," hasonly a small number of stick elements and nodes to provide the same natural frequencies of the structure and is applied to a nuclear containment building. To investigate the numerical performance of the LMSM, a time history analysis is carried out on both the LMSM and the finite element model (FEM) for a nuclear containment building. A comparison of the results shows that the dynamic responses of the LMSM in terms of displacement and acceleration are almost identical to those of the FEM. In addition, the results in terms of floor response spectra at certain elevations are also in good agreement. 展开更多
关键词 new lumped-mass-stick model frequency adaptive nuclear containment buildings seismic response floor response spectrum
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A DATA ACQUISITION SYSTEM FOR ACCELERATOR MASS SPECTROMETRY
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作者 张如菊 刘洪涛 +1 位作者 郭之虞 李坤 《Nuclear Science and Techniques》 SCIE CAS CSCD 1990年第3期149-155,共7页
A single and dual parameter data acquisition, ion beam measurements and control system for accelerator mass spectrometry is described. The system hardware has been constructed with the advantage of the lower cost and ... A single and dual parameter data acquisition, ion beam measurements and control system for accelerator mass spectrometry is described. The system hardware has been constructed with the advantage of the lower cost and higher reliability. It is provided with varieties of functions such as selecting acquisition mode carrying out the multiple display, analyzing data and especially viewing isometric spectrum at different directions. It can also be used for ordinary nuclear spectrum system. 展开更多
关键词 ACCELERATOR mass SPECTROMETRY (AMS) Single and dual parameter DATA ACQUISITION Nuclear spectrum ISOMETRIC display DATA analysis
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Quantitative energy-dispersive X-ray fluorescence analysis for unknown samples using full-spectrum least-squares regression 被引量:6
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作者 Yong-Li Liu Qing-Xian Zhang +2 位作者 Jian Zhang Hai-Tao Bai Liang-Quan Ge 《Nuclear Science and Techniques》 SCIE CAS CSCD 2019年第3期149-159,共11页
The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectr... The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectrum evaluation method is able to obtain the background-corrected and interference-free net peaks, which is significant for quantization analyses. A variety of analytical parameters and functions to describe the features of the fluorescence spectra of pure elements are used and established, such as the mass absorption coefficient, the Gi factor, and fundamental fluorescence formulas. The FSLS iterative program was compiled in the C language. The content of each component should reach the convergence criterion at the end of the calculations. After a basic theory analysis and experimental preparation, 13 national standard soil samples were detected using a spectrometer to test the feasibility of using the algorithm. The results show that the calculated contents of Ti, Fe, Ni, Cu, and Zn have the same changing tendency as the corresponding standard content in the 13 reference samples. Accuracies of 0.35% and 14.03% are obtained, respectively, for Fe and Ti, whose standard concentrations are 8.82% and 0.578%, respectively. However, the calculated results of trace elements (only tens of lg/g) deviate from the standard values. This may be because of measurement accuracy and mutual effects between the elements. 展开更多
关键词 Energy-dispersive X-ray fluorescence analysis Full-spectrum LEAST-SQUARES METHOD Effective atomic number mass attenuation coefficient Fundamental parameter METHOD
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Investigation of Spectra (NMR,Mass) of Some Fe_3S_3 Cluster Compounds
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作者 刘平 王艰 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2000年第5期352-358,共7页
The chemical shifts of 1H-NMR of five Fe_3S_3 cluster compounds were assigned. The main chemical shift values are: δ_ CH_3=1.095-1.946, δ_ CH_2=2.882-3\^803, δ_ C_6H_n=7.547-7.172. In comparison with those of... The chemical shifts of 1H-NMR of five Fe_3S_3 cluster compounds were assigned. The main chemical shift values are: δ_ CH_3=1.095-1.946, δ_ CH_2=2.882-3\^803, δ_ C_6H_n=7.547-7.172. In comparison with those of pure (CH_3CH_2)_3N and thiophenol, these values are moved to high position, and the width of these peaks is obviously increased. These characteristics conformed to NMR spectra of paramagnetic compounds and their molecular structures. The paramagnetic property of these compounds was also studied with ESR spectrum. Mass spectra of three compounds were determined. The main fragments were observed, for example, m/z: 130〔(C_2H_5)_4N〕+, 264〔Fe_3S_3〕+, 144〔Fe-S-Fe〕+, 120〔S-Fe-S〕+, 88〔Fe-S〕+, 136〔FeBr〕+, 91〔FeCl〕+ etc. These supported structural characteristics of the anion skeleton and molecules strongly. The possible mechanism of fragmentation was discussed. 展开更多
关键词 Fe_3S_3 cluster compounds NMR spectrum mass spectrum
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Studies on Electron Impact Mass Spectra of Some Anhydro-sugars
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作者 YU Jian xin LIU Yu ting +3 位作者 WANG Yong fu O YANG Li DONG Ying CAI Meng shen 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1997年第4期39-43,共5页
The fragmentation patterns of anhydro sugars 1—6 in electron impact mass spectrometry have been proposed, and verified by means of metastable ions scanning method.
关键词 Anhydro sugar Anormeric isomers Electron impact mass spectrum
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Direct Mass Spectroscopy Analysis and Comparison of Middle Eastern and Texas Crude Oils
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作者 Gamze Kaya Necati Kaya +3 位作者 Mahmood Amani Abul H. M. J. Rahman Alexandre A. Kolomenskii Hans A. Schuessler 《International Journal of Organic Chemistry》 2017年第4期312-318,共7页
We analyzed two types of crude oil samples: Middle Eastern crude oil and Texas crude oil by using a residual gas analyzer (RGA) based on the linear quadrupole principle. This portable mass analyzer is capable of measu... We analyzed two types of crude oil samples: Middle Eastern crude oil and Texas crude oil by using a residual gas analyzer (RGA) based on the linear quadrupole principle. This portable mass analyzer is capable of measuring hydrocarbons with masses of up to 300 atomic mass units (amu) as well as low mass targets, such as methane and carbon dioxide at ppm level concentrations. The generated mass spectra revealed differences in the composition and signal intensity of hydrocarbons of Middle Eastern and Texas crude oil samples. Even if RGA 300 is manufactured to be served as a detailed gas analysis of vacuum systems, we have shown that it is sensitively capable of detection of hydrocarbons and it enables one to qualitative and quantitative analysis of the composition of the crude oils. 展开更多
关键词 OIL COMPOSITION mass spectrum Analysis Hydrocarbons Content
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Improvement of the Mass Spectrometry Process on an Ion Implantation
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作者 José Lopes Jorge Rocha +1 位作者 Luís Redondo Francisco Alegria 《Open Journal of Optimization》 2016年第1期31-34,共4页
Mass spectrometry is an essential part of ion implantation. Therefore, in order to guarantee beam purity avoiding contamination of the implanted samples, a system was developed for the high current implanter at the La... Mass spectrometry is an essential part of ion implantation. Therefore, in order to guarantee beam purity avoiding contamination of the implanted samples, a system was developed for the high current implanter at the Laboratory of Accelerators and Radiation Technologies (LATR) at the Instituto Superior Técnico. The system presented and discussed in this paper was developed using a LabVIEW code and uses a PC to control and display the mass spectrum. It also permits to save all data acquired for posterior analysis. In order to show some capabilities of this system, some experimental results are presented. 展开更多
关键词 Ion Implanter LABVIEW mass spectrum
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Mass-Spectrometric Method of Measurement of Isotopic Content of Nitrogen in Organic Compounds
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作者 Lamzira Parulava Levani Eliashvili +1 位作者 Vakhtang Betlemidze Natia Mzareulishvili 《American Journal of Analytical Chemistry》 2022年第5期186-194,共9页
Nitrogen-15 isotope-modified compounds are widely used in medicine, pharmacology, agriculture and various fields of science and their nomenclature is gradually increasing. Their widespread use depends on the availabil... Nitrogen-15 isotope-modified compounds are widely used in medicine, pharmacology, agriculture and various fields of science and their nomenclature is gradually increasing. Their widespread use depends on the availability of inexpensive and simple isotope analysis methods. The present article is an attempt to determine the nitrogen-15 isotope content directly in organic compounds without their conversion. The general principle of possibility of determination of the isotopes of nitrogen directly in organic compounds is proposed. Based on the study of mass-spectra of Carbamide Carbonyldiamide, isocyanic acid and nitrobenzene the mass peaks are selected, by which it is possible to determine the atomic fraction of the isotopes of nitrogen. The respective formulas are proposed. 展开更多
关键词 Atomic Fraction ISOTOPE NITROGEN Molecular Ions mass Spectrometer mass spectrum Monoisotopic Forms Carbamide Carbonyldiamide (Urea) Isocyanic Acid NITROBENZENE Isotope Analysis Isotope-Modified Compound Nitrogen Center Monoisotopic Form Two Different Nitrogen Centers
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