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Search Results: 1 - 10 of 11307 matches for " CAI Zengxuan "
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Simultaneous determination of 7 female sex hormones in essential oil by high performance liquid chromatography- tandem mass spectrometry with isotope dilution
同位素稀释-超高效液相色谱-串联质谱法同时测定精油中的7种雌性激素

HUANG Baifen,HAN Zheng,XU Xiaomin,CAI Zengxuan,JIANG Wei,REN Yiping,
黄百芬
,韩铮,徐小民,蔡增轩,姜维,任一平

色谱 , 2011,
Abstract: A reliable ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous determination of 7 female sex hormones (estriol, estradiol, estrone, ethinyloestradiol, dienestrol, hexestrol, diethylstilbestrol) in essential oil was developed. The sample was extracted by ethylacetate-normal hexane solution (2:98, v/v) and the extract was purified by a silica solid phase extraction-based clean-up column. Then, the analytes were separated on an ACQUITY UPLC BEH SHELD RP18 column (100 mm×2.1 mm, 1.7 μm) in gradient elution with the mobile phases of water and acetonitrile. The separated compounds were detected with a Waters Xevo TQ MS tandem quadrupole mass spectrometer operated in negative electro-spray ionization using multiple reaction monitoring mode. Estriol-D3, estradiol-D3 and diethylstilbestrol-D6 were used as the internal standards to reduce the matrix effects. The limits of detection and quantitation for the 7 female sex hormones in essential oil were 0.3~7 μg/kg and 1~20 μg/kg, respectively. Good linear relationships and high correlation coefficients (r2≥0.997) were obtained in the mass concentration range of 20~500 μg/L. The average recoveries were 88.5%~114.8% and the intra-assay relative standard deviations were 4.8%~18.9% at the spiked levels of 20~500 μg/kg. Finally, a total of 12 samples randomly collected from different supermarkets in Zhejiang Province were screened for the 7 female sex hormones by the proposed method. The results showed that only one sample contained estradiol and estrone.
Curriculum Design, Linguistic Competence and Self-Actualization: A Case Study on English Curriculum Design for Chinese Non-English Major Postgraduates  [PDF]
Shangzhi Cai
Creative Education (CE) , 2010, DOI: 10.4236/ce.2010.13028
Abstract: Studies conducted hitherto on English education for Chinese non-English major postgraduates have preponderantly focused on themes such as learning motivations, teaching or learning strategies, and various examinations. Yet little attention has been paid to the issue of curriculum design. In order to explore the correlations amongst curriculum design, linguistic competence and self-actualization, the author has carried out a survey on the English curriculum design for non-English major postgraduates in Yunnan Normal University by applying Maslow’s theory of self-actualization. The survey reveals that postgraduates’ reading abilities hold low correlation with self-actualization, thus priority should be given to improve their speaking proficiency as well as listening abilities. Besides, as a basic requirement for all postgraduates, academic writing receives the most attention since the quality of their graduate dissertation is considered as the ultimate indication of their self-actualization. Apart from providing concerning suggestions on the curriculum design according to the above findings, the author also holds that curriculum design is an autonomous, flexible and dynamic process. Hence, instead of sticking to the long-adopted uniform English curriculum for all non-English major postgraduates in China, more flexible curricula and requirements should be introduced in order to fulfill the self–actualization of postgraduates from different universities, different majors, and different regions.
The Existence and Multiplicity of Solutions for Singular Boundary Value Systems with p-Laplacian  [PDF]
Zengxia Cai
Journal of Applied Mathematics and Physics (JAMP) , 2015, DOI: 10.4236/jamp.2015.34052
Abstract:

This paper presents sufficient conditions for the existence of positive solutions for the fourth-order boundary value problem system with p-Laplacian operator. The existence of single or multiple positive solutions for the system is showed through the fixed point index theory in cones under some assumptions.

On the Relation of Grain Orientation and Opening Crack of an Al-Cu-Mg Sheet  [PDF]
Cai Hu
Engineering (ENG) , 2017, DOI: 10.4236/eng.2017.95031
Abstract: In this paper, the orientation of grains which adjacent to a developed opening crack was investigated by EBSD. A definition of θ has been came up with which represents the angle between the principal stress plane and each plane of the grains. Smaller θ means easier to crack. It gave a good explanation of the crack propagation throughout the grains. It also revealed that propagation path is along with the plane. This finding will give a prediction of tear properties and help us understanding the cracking mechanism and the behavior of tearing.
Traditional Chinese Herbal Medicine for Epilepsy Treatment Should Be Administered According to the Seizure Type and Epileptic Syndrome  [PDF]
Lun Cai
Health (Health) , 2017, DOI: 10.4236/health.2017.98087
Abstract: Traditional Chinese herbal medicine (TCHM) has long been used to treat epilepsy. Although many clinical trials and animal studies have seemingly demonstrated its effect, the question of whether TCHM is efficacious in epileptic patients has not been certified because of insufficient supportive evidence. This insufficient supportive evidence stems from the fact that most of the current studies regarding TCHM for epilepsy treatment are not designed according to the different seizure types and epileptic syndromes (STESs). Here, we explore the reasons why many studies have not considered the various STESs and explain how to treat epilepsy according to the pharmacological mechanism for different STESs and exploit the advantage of TCHM for epilepsy treatment. Then, we explain how we treat epilepsy using TCHM according to the different STESs and Bian Zheng Lun Zi.
Research on Internet Consumer Financial Products Usage Intention—Taking College Students as an Example  [PDF]
Yexin Cai
Journal of Financial Risk Management (JFRM) , 2017, DOI: 10.4236/jfrm.2017.64027
Abstract: With the rise of Internet consumer finance, it has greatly promoted the prosperity of the stage consumption market, and the college students group is a market with great development space and untapped market. In this research background, this article combines the technology acceptance model and the rational acceptance model, and introduces consumer innovation and perceived risk to explore the influence of consumers on the willingness of e-commerce Internet consumer financial products. The study found that perceived usefulness and willingness to use had a significant positive correlation, and that perceived risk and willingness to use had a significant negative correlation. Perceived ease of use and subjective norms have a significant positive effect on perceived usefulness; Consumer innovation and perceived ease of use have significant positive impact, and consumers’ innovation and perceived risk have significant negative impact. The conclusions of this study enrich the study of willingness to use, and put forward relevant marketing strategies for enterprises to promote and occupy market share.
Effects of Short-Term International Capital Flows on China’s Real Estate Prices  [PDF]
Xiaoxiong Cai
Modern Economy (ME) , 2018, DOI: 10.4236/me.2018.91002
Abstract: Nowadays, the real estate prices in China have shown a continuous upward trend. Prices in the first-tier cities such as the north and the Guangzhou-Shenzhen are getting higher and higher, and ordinary people are becoming increasingly unaffordable. High housing prices have not only put pressure on people’s lives but also have had many adverse effects on China’s economic development. Many scholars at home and abroad think that the continuous rise of house prices is closely related to the flow of international short-term capital. International short-term capital when entering the Chinese market, because of its speculative easy to create a bubble, bringing huge risks. Through theoretical and empirical research, this paper analyzes whether the international short-term capital flows have an impact on house prices. Finally, it concludes that the inflow of international short-term funds to the real estate market in China has a positive impact on the real estate market in China, and to a certain extent, has promoted the real estate prices. The entry and exit of hot money have a great volatility effect on the real estate market, which has a great impact on the long-term, healthy and stable development of China’s real estate market.
The Evolution of Distribution of Technology Transfer in China: Evidence from Patent Licensing  [PDF]
Yuqing Cai
American Journal of Industrial and Business Management (AJIBM) , 2018, DOI: 10.4236/ajibm.2018.85084
Abstract: This study explores the temporal and spatial distribution of technology transfer in China by analyzing the licensing activities from the perspective of supplier and demander of the technology transfer chain, using the data obtained from the State Intellectual Property Office of China (SIPO). We find that the overall number of licensed technologies has increased dramatically during 10 years and different types of technology show diverse trends. And the technology age is declining year by year, among which the age of invention patents is the oldest. As licensors, individuals and firms provide the vast majority of outward technologies and most of their technologies are utility models. However, only firms take the vast majority as licensee. And most inward technologies come from foreign organizations before 2008, while domestic sources provide the majority of inward technologies after 2008. We also provide suggestions for policy-makers and firms.
Differential Integrals of Curves and Inversion of Magnetic Source Morphology  [PDF]
Jiaxiong Cai
Journal of Applied Mathematics and Physics (JAMP) , 2018, DOI: 10.4236/jamp.2018.66098
Abstract: In this paper, the problem of magnetic source shape determination is simplified into iterative inversion after symbol recognition. Based on the theory of differentiating different forms of magnetic sources by integral magnetic anomaly curves, a unified expression for calculating magnetic fields of different magnetic sources under undulating terrain conditions is given, and the triangular system plate interpretation method is used to identify the magnetic fields of different magnetic sources. The calculus parameter basis for the classification of unknown magnetic source morphology and the method technology for determining the magnetic source spatial morphology are confirmed. The example shows that the application of the calculus triangulation method to the magnetic source morphological system inversion has a good prospect.
The Mechanism for Introduction of Strategic Talents to Less-Developed Areas: An Analysis from the Perspective of Collaborative Governance Theory  [PDF]
Yihe Cai
Open Journal of Business and Management (OJBM) , 2018, DOI: 10.4236/ojbm.2018.64071
Abstract:
In the era of knowledge economy, the introduction of strategic talents plays an important role in achieving rapid economic development of less-developed areas. However, due to the “Matthew effect”, there is high degree of polarization in the field of strategic talent introduction which is riddled with many other issues as well, and it is difficult to solve so many problems simply by relying on the government and the self-developed solutions of the companies. The collaborative governance which emerged as a new social theory in response to the needs of modern society can be used as a theoretical basis for the participation of government, market and the society. From the perspective of collective governance, this paper aims to identify through case study the main problems in the strategic talent introduction mechanism of less-developed areas, explore the collaborative governance model of the same and draw some inspiration from such a model so as to propose possible solutions.
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