Zeolite-catalyzed Isomerization of 1-Hexene to trans-2-Hexene: An ONIOM Study

Yan-Feng Li,Ji-Qin Zhu,Peng He,Peng Wang,Hui-Ping Tian,Hui Liu 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.6

Details of the double-bond isomerization of 1-hexene over H-ZSM-5 were clarified using density functional theory. It is found that the reaction proceeds by a mechanism which involves the Brønsted acid part of the zeolite solely. According to this mechanism, 1-hexene is first physically adsorbed on the acidic site, and then,the acidic proton transfers to one carbon atom of the double bond, while the other carbon atom of the double bond bonds with the Brønsted host oxygen, yielding a stable alkoxy intermediate. Thereafter, the Brønsted host oxygen abstracts a hydrogen atom from the C_6H_13 fragment and the C.O bond is broken, restoring the acidic site and yielding trans-2-hexene. The calculated activation barrier is 12.65 kcal/mol, which is in good agreement with the experimental value. These results well explain the energetic aspects during the course of double-bond isomerization and extend the understanding of the nature of the zeolite active sites.

From Self-Innovation to International Standardization: A Case Study of TD-SCDMA in China

Yan Hui 서울대학교 경제연구소 2013 Seoul journal of economics Vol.26 No.1

Time Division Synchronous Address (TD-SCDMA ) is one of three 3G standards in China, the two others being Wideband Code Division Synchronous Address (WCDMA) from Europe and Code Division Synchronous Address (CDMA2000) from the US. TD-SCDMA is a Chinese-developed standard currently applied only in the Chinese market. From the very beginning, TD-SCDMA has caught tremendous attention. As a government-led standardization, it demands continuous technical progress, industry accumulation, and national confidence. At the time of its inception, China was not yet the second largest economy in the world; furthermore, as a developing country and technology latecomer, it faced many difficulties and challenges. Thus, it is interesting to note how the Chinese government reached the decision to apply standardization and prepare the relevant conditions to fully commercialize TD-SCDMA in China. After five years of TD-SCDMA application, more information has become available to help answer the questions above. Thus, in the current paper, we introduce the evolution of TD-SCDMA, from its very early stage technology to a standard approved by the International Telecommunication Union (ITU), until its first launch during the 2008 Beijing Olympic Games. The paper provides arguments and evidence to show that TD-SCDMA is a successful case because it has been selected by the ITU as one of the 3G standards for commercial application, even though it is a standard used only domestically in a country, which is considered a technology latecomer with low technological capabilities.

Implementation of Non-Local Multi-Qubit CNOT Operation with Multi-Qubit GHZ States

Yan-Hui Zhou,Xiao-Qiang Shao,Chun-Jiao Yang,Shou Zhang,연규황 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.2

A scheme is proposed to implement a non-local controlled-not (CNOT) operation with two control qubits and two target qubits, where two three-particle Greenberger-Horne-Zeilinger (GHZ) states and eight cbits (bits of classical communication) are needed. The scheme can also be generalized straightforwardly to implement a non-local multi-qubit operation with M control qubits and N target qubits.

Prevalence, Risk Factors, and Psychological Effects of Primary Nocturnal Enuresis in Chinese Young Adults

Hui Jie Hu,Zhen Wei Zhang,Yu Liang,Yan Yan Luo,Qi Feng Dou,Cui Ping Song,Hui Min Zhang,Ying Zhao,Guang Run Tian,Ke Zhang,Qiu Fang Mao,Jing Gui Song,Soren Rittig,Jian Guo Wen 대한배뇨장애요실금학회 2021 International Neurourology Journal Vol.25 No.1

Purpose: This study aimed to investigate the prevalence, risk factors, and effects of primary nocturnal enuresis (PNE) on physical and mental health in young adults in mainland China. Methods: An anonymous questionnaire was used to collect information including the sociodemographic characteristics, history of PNE, family history, daytime voiding symptoms, Pittsburgh Sleep Quality Index (PSQI) scores, Self-Esteem Scale (SES), and Self-Rating Depression Scale (SDS). A total of 22,500 university students from 23 provinces and 368 cities in mainland China were included. Results: In total, 21,082 questionnaires were collected, and 20,345 of them qualified for statistical analysis. The PNE prevalence was 1.17%, and the distribution of monosymptomatic nocturnal enuresis (MNE) and nonmonosymptomatic nocturnal enuresis (NMNE) was 66.1% and 33.9%, respectively. In total, 28% of respondents with PNE reported bedwetting daily, 31.6% between 1 and 7 times weekly, and 40.4% between 1 and 4 times monthly; 80% of PNE cases had no history of treatment. The prevalence of PNE in patients with a family history, frequency, urgency, urinary incontinence, and recurrent urinary tract infections was significantly higher than in those without these conditions (P<0.001). PNE was significantly correlated with the PSQI total score (sleep quality) (P=0.011). The SES score was lower and the SDS was higher (P<0.001) in the PNE group than in those without PNE. Conclusions: In mainland China, the PNE prevalence among young adults was found to be high, and PNE had significant effects on physical and mental health. Risk factors included a family history, daytime voiding symptoms, and lack of treatment.

Analysis of The Coupling Behavior of a Thin Layer of a Temperature-pH Dual Sensitive Hydrogel for an Inhomogeneous Large Deformation

Hui-Xian Yan,Hai-Lian Hong,Lian-Hui Zheng,Heng-Di Su 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.73 No.7

Due to ionic migration and adsorption, an electrical double layer with a thickness scaled by the Debye length is formed at the hydrogel-solution interface. For a thin temperature-pH dual sensitive hydrogel whose chickness is comparable to the Debye length, its mechanical behavior may be affected by the electrical double layer. In this paper, by incorporating electromagnetic field theory into thermodynamic theory, we develop a coupled field theory for a temperature-pH dual sensitive hydrogel, and we take into account the electrical double layer. The proposed model can be used to analyze the in uences of the size effect, ionic concentration, ambient temperature and solution pH value on the swelling of a thin layer of the temperature-pH sensitive hydrogel.

Salivary Pepsin as an Intrinsic Marker for Diagnosis of Sub-types of Gastroesophageal Reflux Disease and Gastroesophageal Reflux Disease-related Disorders

( Yan-jun Wang ),( Xiu-qiong Lang ),( Dan Wu ),( Yu-qin He ),( Chun-hui Lan ),( Xiao-xiao ),( Bin Wang ),( Duo-wu Zou ),( Ji-min Wu ),( Yong-bin Zhao ),( Peter W Dettmar ),( Dong-feng Chen ),( Min Yan 대한소화기 기능성질환·운동학회 2020 Journal of Neurogastroenterology and Motility (JNM Vol.26 No.1

Background/Aims To determine the value of salivary pepsin in discriminating sub-types of gastroesophageal reflux disease (GERD) and GERD-related disorders. Methods Overall, 322 patients with different sub-types of GERD and 45 healthy controls (HC) were studied. All patients took Gastroesophageal Reflux Disease Questionnaire (GerdQ) and underwent endoscopy and 24-hour esophageal pH monitoring and manometry. Salivary pepsin concentration (SPC) was detected by using colloidal gold double-antibody immunological sandwich assay. Oral esomeprazole treatment was administrated in the patients with non-erosive reflux disease (NERD) and extra-esophageal symptoms (EES). Results Compared to HC, patients with erosive esophagitis, NERD, EES, EES plus typical GERD symptoms, or Barrett’s esophagus had a higher prevalence of saliva and SPC (all P < 0.001). There was no significant difference in the positive rate for pepsin in patients with functional heartburn or GERD with anxiety and depression, compared to HC. After esomeprazole treatment, the positive rate and SPC were significantly reduced in NERD (both P < 0.001) and in EES (P = 0.001 and P = 0.002, respectively). Of the 64 NERD patients, 71.9% (n = 46) were positive for salivary pepsin, which was significantly higher than the rate (43.8%, n = 28) of pathological acid reflux as detected by 24-hour esophageal pH monitoring (P = 0.002). Conclusions Salivary pepsin has an important significance for the diagnosis of GERD and GERD-related disorders. Salivary pepsin and 24-hour esophageal pH monitoring may complement with each other to improve the diagnostic efficiency.

Energy Management of Household Microgrid with Multiple Energy Resources for Rural Area

Hui Yan,Nian Lv,Fang Zhuo,Hao Yi,Zhenxiong Wang 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

The rural villages situated in the loess plateau of China often face with intermittency or even no electricity supply due to inconvenient geometrical location and enormous initial investment. However, renewable resources like solar energy are rich in such area, where microgrid with multiple energy resources is efficient for dealing with the power shortage. This paper proposes a scheme about hybrid household microgrid with multiple resources suitable for both islanded and grid-connected situations. The microgrid integrates photovoltaic, batteries and gasoline generator in source side and constructs AC and DC buses for different load requirements. The possible operation modes are analyzed and energy management strategies are proposed correspondingly. Finally, the microgrid platform has been established in laboratory. Several cases have been tested in experiment and energy management strategies in both islanded and grid-connected situations show good performance. Experimental results verify effectivity of this microgrid scheme and validation of proposed energy management strategies.

Cucumber Growth and Nitrogen Uptake as Affected by Solution Temperature and NO₃^-:NH₄⁺ Ratios during the Seedling

Yan, Qiu-Yan,Duan, Zeng-Qiang,Li, Jun-Hui,Li, Xun,Dong, Jin-Long Korean Society of Horticultural Science 2013 원예과학기술지 Vol.31 No.4

The effect of solution temperature and nitrogen form on cucumber (Cucumis sativus L.) growth, photosynthesis and nitrogen metabolism was investigated in hydroponic culture. Cucumber plants were grown for 35 days in a greenhouse at three constant solution temperatures ($15^{\circ}C$, $20^{\circ}C$, and $25^{\circ}C$) within a natural aerial temperature ($15-30^{\circ}C$). Four nitrate:ammonium ($NO{_3}^-:NH{_4}^+$) ratios (10:0, 8:2, 5:5, and 2:8 $mmol{\cdot}L^{-1}$) at constant nitrogen (N) concentration of $10mmol{\cdot}L^{-1}$ were applied within each solution temperature treatment. Results showed an increasing solution temperature enhanced plant growth (height, dry weight, and leaf area) in most N treatments. Dry weight accumulation was greatest at the 10:0 $NO{_3}^-:NH{_4}^+$ ratio in the $15^{\circ}C$ solution, the 5:5 ratio in the $20^{\circ}C$ solution and the 8:2 ratio in the $25^{\circ}C$ solution. Photosynthetic rate (Pn) response to solution temperature and $NO{_3}^-:NH{_4}^+$ ratio was similar to that of plant growth. Probably, the photosynthate shortage played a role in the reduced biomass formation. Increasing solution temperature enhanced the nitrate reductase (NR) activity, and further reduced shoots nitrate content. Our results indicate that the optimal ratio of nitrate to ammonium that promotes growth in hydroponic cucumber varies with solution temperature.

Monosaccharide as a Central Scaffold Toward the Construction of Salicylate-Based Bidentate PTP1B Inhibitors via Click Chemistry

Yan-Hui Tang,Min Hu,Xiao-Peng He,Sando Fahnbulleh,Cui Li,Li-Xin Gao,Li Sheng,Yun Tang,Jia Li,Guo-Rong Chen 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.3

The discovery of carbohydrate-based bioactive compounds has recently received considerable interest in the drug development. This paper stresses on the application of 1-methoxy-O-glucoside as the central scaffold,whereas salicylic pharmacophores were introduced with diverse spatial orientations probing into the structural preference of an enzymatic target, i.e. protein tyrosine phosphatase 1B (PTP1B). By employing regioselective protection and deprotection strategy, 2,6-, 3,4-, 4,6- and 2,3-di-O-propynyl 1-methoxy-O-glucosides were previously synthesized and then coupled with azido salicylate via click chemistry in forming the desired bidentate salicylic glucosides with high yields. The inhibitory assay of the obtained triazolyl derivatives leads to the identification of the 2,3-disubstituted salicylic 1-methoxy-O-glucoside as the structurally privileged PTP1B inhibitor among this bidentate compound series with micromole-ranged IC50 value and reasonable selectivity over other homologous PTPs tested. In addition, docking simulation was conducted to propose a plausible binding mode of this authorized inhibitor with PTP1B. This research might furnish new insight toward the construction of structurally different bioactive compounds based on the monosaccharide scaffold.

A Study of English Writing and Domain-Specific Motivation and Self-Efficacy of Chinese EFL Learners

( Yan Yan Zhang ),( Hui Guo ) 범태평양응용언어학회 2012 범태평양응용언어학회지 Vol.16 No.2

This paper aims to analyze the relationships between English writing and domain-specific motivation and self-efficacy of Chinese EFL learners. 66 English major students from two grades were invited as participants to complete a writing task and two self-designed questionnaires on English writing motivation and self-efficacy, respectively. It was found that the students were largely not self-efficacious with respect to English writing although they had a relatively high motivation for English writing. The results of correlation analyses indicated that English writing motivation, self-efficacy and English writing proficiency positively and significantly correlated with each other for English major freshmen, but not for sophomores. Moreover, the two groups of students differed significantly in terms of English writing proficiency, English writing self-efficacy and intrinsic motivation. These results are partially consistent with those of the previous research and have important implications for the teaching of English writing in EFL countries.