Discrimination of Geographical Origin of Asian Garlic Using Isotopic and Chemical Datasets under Stepwise Principal Component Analysis

Isotopic compositions of δ²H, δ¹⁸O, δ¹³C, and δ¹⁵N and concentrations of 22 trace elements from garlic samples were analyzed and processed with stepwise principal component analysis (PCA) to discriminate garlic's country of origin among Asian regions including South Korea, Vietnam, Taiwan, and China. Results indicate that there is no single trace‐element concentration or isotopic composition that can accomplish the study's purpose and the stepwise PCA approach proposed does allow for discrimination between countries on a regional basis. Sequentially, Step‐1 PCA distinguishes garlic's country of origin among Taiwanese, South Korean, and Vietnamese samples; Step‐2 PCA discriminates Chinese garlic from South Korean garlic; and Step‐3 and Step‐4 PCA, Chinese garlic from Vietnamese garlic. In model tests, countries of origin of all audit samples were correctly discriminated by stepwise PCA. Consequently, this study demonstrates that stepwise PCA as applied is a simple and effective approach to discriminating country of origin among Asian garlics.     

超声辅助固相萃取-HPLC法测定不同地区缴获鸦片样品中生物碱

目的本文建立了超声辅助固相萃取-HPLC法定量测定缴获鸦片样品中吗啡、可待因、蒂巴因、罂粟碱、那可汀5种生物碱并同时检出6种未知化合物的方法。采用主成分分析法区分不同地区缴获的鸦片样品。方法采用超声辅助固相萃取法提取生物碱,XDB-C18（5μm×4.6mm×250mm）色谱柱,流动相为10mM的1-庚烷磺酸钠（pH 3.2）和乙腈,梯度洗脱,紫外检测器检测。结果该方法的定量限为0.58~2.78 mg/kg。添加水平在0.2～1.5mg/mL范围内,平均加标回收率为81.0%～99.2%,相对标准偏差为1.6%～5.0%。结论本方法重现性好、定量准确,满足定量检测鸦片中生物碱含量并对不同产地鸦片进行分类的需要。     

增强领导干部忧患意识的四个维度

党的十八大报告指出,面对人民的信任和重托,面对新的历史条件和考验,全党必须增强忧患意识,谦虚谨慎,戒骄戒躁,始终保持清醒头脑。作为党的领导干部更要有强烈的忧患意识,常怀忧党之心,恪尽兴党之责。     

主体地位变迁与契约合意基础的辩证关系简

契约法是债法的主要组成部分,契约的成立建立在当事人合意的基础之上.伴随着人类社会的发展,人的主体性地位经历了不同的展现阶段,人的意志自由也有着不同的表现程度,而意志自由恰恰是作为契约的合意基础而存在的,从而对于契约法的发达程度造成了重要影响;同时契约的运用空间反映着商品经济的发展状态,并对人的主体性的动态需求产生作用.     

PAG圆盘电泳同步检测人血清Hp、Gc、Tf表型

本文采用不连续ＰＡＧ圆盘电泳法，以邻联甲苯胺和氨基黑染液取代有强致癌作用的联苯胺试剂用于染色，同时检测出Ｈｐ、Ｇｃ、Ｔｆ表型。该法简便快速，安全可靠，经济实用，用于法医学检察实际，可使检案质量和办案效率大为提高。     

公众安全感指标体系的构建与评价方法研究——以社会治安秩序为视角

公众安全感是指居民对社会治安状况的主观感受和评价,它反映了公众对犯罪的恐惧程度,也成为衡量和谐社会建设的一个重要指标。建立了我国公众安全感的评价指标体系,包括四个层次和四个系统。并为该指标的理论分析提出了主成分分析和聚类分析相结合的评价方法。     

Classification and individualization of black ballpoint pen inks using principal component analysis of UV-vis absorption spectra

The technique of principal component analysis has been applied to the UV-vis spectra of inks obtained from a wide range of black ballpoint pens available in the UK market. Both the pen ink and material extracted from the ink line on paper have been examined. Here, principal component analysis characterised each spectrum within a group through the numerical loadings attached to the first few principal components. Analysis of the spectra from multiple measurements on the same brand of pen showed excellent reproducibility and clear discrimination between inks that was supported by statistical analysis. Indeed it was possible to discriminate between the pen ink and the ink line from all brands examined in this way, suggesting that the solvent extraction process may have an influence on these results. For the complete set of 25 pens, interpretation of the loadings for the first few principal components showed that both the pen inks and the extracted ink lines may be classified in an objective manner and in agreement with the results of parallel thin layer chromatography studies. Within each class almost all inks could be individualised. Further work has shown that principal component analysis may be used to identify a particular ink from a database of reference UV-vis spectra and a strategy for developing this approach is suggested.     

诉利息未诉本金之诉讼时效如何认定

起诉时,只请求被告归还借款的利息,没有请求归还本金,不应视为原告放弃本金权利。利息诉讼时效的中断,自然及于本金,因为利息是依附本金而生的孳息。     

试析巨额财产来源不明罪

巨额财产来源不明罪自其创设起就是一个颇有争议的罪名 ,通过分析该罪的构成要件 ,认为“司法机关无法查清巨额财产的真实来源”不是本罪客观要件的内容。分析了本罪在现实中出现的尴尬境况 ,认为前置制度的缺乏是导致其尴尬境况的深层次原因 ,并对本罪的完善提出了建议