Common Correlated Effects Estimation of Unbalanced Panel Data Models with Cross-Sectional Dependence

Qian kun Zhou,Yong hui Zhang 한국계량경제학회 2016 JOURNAL OF ECONOMIC THEORY AND ECONOMETRICS Vol.27 No.4

We consider the estimation and inference of unbalanced panel data models with cross-sectional dependence with a large number of individual units in a relatively short time period. By following the common correlated effects (CCE) approach of Pesaran (2006), we propose a CCE estimator for unbalanced panels (CCE-UB). The asymptotics of the CCE-UB estimator is developed in the paper. Small scale Monte Carlo simulation is conducted to examine the finite sample properties of the proposed estimator.

High-temperature steam oxidation behaviors of a ZrO₂/CrAlSi composite coating on Zr-2 alloy deposited by PEO duplex FCVA treatments

Qian Zhou,Yizhao Liao,Hui Li,Hu Chen,Chi Xu,Xiaoyue Jin,Wenbin Xue 한국표면공학회 2023 한국표면공학회 학술발표회 초록집 Vol.2023 No.11-1

Enrichment of iron element from sulfur-containing iron tailings by S-HGMS technology

Zhou, Ya-qian,Yang, Rui-ming,Guo, Peng-hui,Li, Su-qin,Xing, Yi The Korean Society of Superconductivity and Cryoge 2021 한국초전도저온공학회논문지 Vol.23 No.3

Comprehensive utilization of sulfur-containing iron tailings (SIT) not only solves environmental problems but also creates certain economic value. The iron element from SIT was enriched by the superconducting high gradient magnetic separation (S-HGMS) technology in this study. In the experiments, the total iron content (TFe) was increased from 26.3% to 60.5% with the total sulfur content (TS) of 5.9% under the optimal parameters, i.e., a magnetic flux density of 0.4 T, a slurry flow rate of 1500 mL/min. The high-quality sulfur-containing material with TFe of more than 60% was obtained, which can be used for preparing high-sulfur free cutting steel. The S-HGMS technology can realize the resource utilization of iron tailings with high added value.

A HYBRID METHOD FOR NCP WITH P_0 FUNCTIONS

Qian Zhou,Yi-Gui Ou 한국전산응용수학회 2011 Journal of applied mathematics & informatics Vol.29 No.3

This paper presents a new hybrid method for solving nonlinear complementarity problems with P_0-functions. It can be regarded as a combination of smoothing trust region method with ODE-based method and line search technique. A feature of the proposed method is that at each iteration, a linear system is only solved once to obtain a trial step, thus avoiding solving a trust region subproblem. Another is that when a trial step is not accepted, the method does not resolve the linear system but generates an iterative point whose step-length is defined by a line search. Under some conditions, the method is proven to be globally and superlinearly convergent. Preliminary numerical results indicate that the proposed method is promising.

A Novel Mutant of Human Papillomavirus Type 18 E6E7 Fusion Gene and its Transforming Activity

Zhou, Zhi-Xiang,Zhao, Chen,Li, Qian-Qian,Zeng, Yi Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.17

Background: Persistent human papillomavirus (HPV) infection, especially with high-risk types such as HPV16 and HPV18, has been identified as the primary cause of cervical cancer. E6 and E7 are the major onco-proteins of high-risk HPVs, which are consistently expressed in HPV infected tissues but absent in normal tissues and represent ideal therapeutic targets for immunotherapy of cervical cancer. Materials and Methods: In this study, the optimized fusion gene HPV18 E6E7 (HPV18 ofE6E7) was constructed according to genetic codon usage for human genes. At the same time, for safety future clinical application, a mutant of HPV18 ofE6E7 fusion gene was generated by site-directed mutagenesis at L52G for the E6 protein and C98G for the E7 protein. Results: HPV18-E6E7 mutant (HPV18 ofmE6E7) constructed in this work not only lost the transformation capability for NIH 3T3 cells and tumorigenicity in BALB/c nude mice, but also maintained very good stability and antigenicity. Conclusion: These results suggest that the mutant should undergo further study for application as a safe antigenspecific therapeutic vaccine for HPV18-associated tumors.

A HYBRID METHOD FOR NCP WITH $P_0$ FUNCTIONS

Zhou, Qian,Ou, Yi-Gui The Korean Society for Computational and Applied M 2011 Journal of applied mathematics & informatics Vol.29 No.3

This paper presents a new hybrid method for solving nonlinear complementarity problems with $P_0$-functions. It can be regarded as a combination of smoothing trust region method with ODE-based method and line search technique. A feature of the proposed method is that at each iteration, a linear system is only solved once to obtain a trial step, thus avoiding solving a trust region subproblem. Another is that when a trial step is not accepted, the method does not resolve the linear system but generates an iterative point whose step-length is defined by a line search. Under some conditions, the method is proven to be globally and superlinearly convergent. Preliminary numerical results indicate that the proposed method is promising.

Enrichment of iron element from sulfur-containing iron tailings by S-HGMS technology

Ya-qian Zhou,Rui-ming Yang,Peng-hui Guo,Su-qin Li,Yi Xing 한국초전도저온공학회 2021 초전도와 저온공학 Vol.23 No.3

Comprehensive utilization of sulfur-containing iron tailings (SIT) not only solves environmental problems but also creates certain economic value. The iron element from SIT was enriched by the superconducting high gradient magnetic separation (S-HGMS) technology in this study. In the experiments, the total iron content (TFe) was increased from 26.3% to 60.5% with the total sulfur content (TS) of 5.9% under the optimal parameters, i.e., a magnetic flux density of 0.4 T, a slurry flow rate of 1500 mL/min. The high-quality sulfur-containing material with TFe of more than 60% was obtained, which can be used for preparing high-sulfur free cutting steel. The S-HGMS technology can realize the resource utilization of iron tailings with high added value.

중국 중산층의 해외여행과 소셜미디어에서의 자아 구축

저우치엔(Qian Zhou) 서울대학교 아시아연구소 2016 아시아리뷰 Vol.6 No.1

이 연구는 중국 중산층의 해외여행에 대한 해외 매체의 보도 현상에 주목하고, 먼저 중국 중산층은 무엇인가에서 시작하여 기존 중산층 연구를 개관했다. 그리고 매체에서 ‘주관적 중산층’의 출현과 그 영향으로부터 독창적인 ‘중산층 이해 모형’을 설립했다. 그리고 이 모형에 근거하여 중산층과 인구통계학적 특성이 비교적 일치하는 웨이보(微博) 이용자를 분석 대상으로 삼아 중국 중산층의 해외여행이 어떠한 특성이 있는지, 매체를 이용하여 해외여행이라는 소비 행위를 통해 자신의 계층 의식과 이미지를 어떻게 형성하는지 알아보았다. 아울러 중국 중산층의 해외여행과 소셜미디어에서의 자아 형성이 중국 사회와 기타 계층에 미치는 영향에 대해서도 살펴보았다. 이 연구는 웨이보의 글과 그림의 분석, 인터넷 가상 커뮤니티에서의 상호작용 관찰을 통해 다음과 같은 사실을 발견했다. 중국 중산층의 해외여행 동기는 경험과 휴식, 그리고 사회 교류로 복합적이다. 여행 방식은 자가용 이용과 자유여행이 주를 이룬다. 여행 특징은 “깊이와 품위의 표현, 합리적인 기호의 소비, 개성화와 다양화”로 요약할 수 있다. 중국 중산층 여행자는 웨이보에 글과 사진을 결합하는 전략을 사용함으로써 ‘현실적인 자아’를 구축한다. 그리고 이러한 자아 구축은 ‘관람과 공연’에서 서로 주고 받는 관계(授受)다. 요컨대, 현재 중국 중산층의 해외여행은 중국 사회의 안정과 소비 견인 작용을 한다. 그들의 여행 소비 활동 중의 문명화된 행위 또한 중국의 대중적 여행자의 관념에 영향을 미치고 있다. 중국 중산층의 해외여행 중 과시적 소비가 중국의 일반 대중에게 어느 정도 부정적인 영향을 미칠 수 있지만 이러한 부작용이 분명 주된 것은 아니다. 결론적으로, 이 연구는 중국 중산층의 해외여행과 소셜미디어에서의 자아 구축이라는 주제를 시도해 봄으로써 기존 사회학의 여행과 계층에 대한 연구, 여행과 소셜미디어 사용에 대한 연구, 중국 웨이보 관련 연구의 부족한 부분을 보충하고자 한다. This study focuses on the foreign media’s coverage of the foreign travels by the Chinese middle class. Starting from examining the Chinese middle class, this article reviews previous studies on the middle class. It proposes a “three-fold model for understanding the middle class,” and applies it to analyze the Weibo users, who, as a group, have the same demographic characteristics of the middle class. This model analyzes the characteristics of the foreign trips of the Chinese middle class, their use of the media, and their consumption behavior while on the trip. The aim is to examine their impact on the formation of class identity of the Chinese middle class, and how such identity formation, in turn, affects other parts of the Chinese society. By examining the texts and pictures on the micro-blogs and the interactions within the virtual communities on the internet, the findings were: the Chinese middle class has complex motives for traveling abroad – gaining experiences, leisure, and cultural interchange. The mode of travel was dominated by car and leisurely travel. The characteristics of the travels can be summarized as “expressing of culturedness and social statue, rational consumption, individualization and social diversification.” Chinese middle class travelers establish “realistic selves” by posting a combination of texts and pictures on micro-blogs. Currently, the trips abroad by the Chinese middle class have the function of stabilizing the Chinese society and promoting consumption. Their civility while traveling positively affects the mindset of the popular travelers. The negative effects of the conspicuous consumption of the Chinese middle class are not the dominant aspect of their travels. In conclusion, by examining the foreign travels of the Chinese middle class and their construction of the self on the social media, this study attempts to complement previous sociological studies on traveling and class, traveling and social media, as well as on the Chinese micro-blog.

Increased brain uptake of venlafaxine loaded solid lipid nanoparticles by overcoming the efflux function and expression of P-gp

Yan Zhou,Xin’an Wu,Guo-Qiang Zhang,Zhi Rao,Yang Yang,Qian Zhou,Hongyan Qin,Yuhui Wei 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.7

Venlafaxine (VLX) could be pumped out of the brain by P-glycoprotein (P-gp). Moreover, the expression of P-gp distributed in blood–brain barrier could be significantly induced by VLX. Thus, P-gp could be considered as the nature barrier for delivering of VLX to the brain. The aim of this study was to investigate whether the efflux function and increased expression of P-gp could be reversed by utilizing solid lipid nanoparticles (SLN). VLX solid lipid nanoparticles (VLX - SLN) were prepared and evaluated. Pharmacokinetics and brain distribution of VLX in different formulations were conducted after oral or intravenous administration. P-gp efflux function to VLX was evaluated by the brain uptake amount of VLX, while P-gp expression was investigated by Western blotting. Results indicated that the entrapment, mean size and zata potential of VLX - SLN was 74.9 ± 3.0 %, 186.3 ± 69.26 nm and -22.8 ± 7.78 mv, respectively. After vein injection of VLX formulations, the brain uptake amount of VLX from VLX - SLN was significantly higher than that of VLX solution, VLX solution with empty SLN (VLX? empty SLN) and VLX solution with Verapamil (VLX ? Ver), respectively. Furthermore, the protein mass of P-gp in VLX - SLN treated group was the lowest among all the investigated groups. These results indicated that SLN could overcome P-gp and achieve brain target by intravenous administration.

Layered double hydroxide nanosheets embedded β-cyclodextrin composite membranes with enhanced chiral separation performance

Zhengzhong Zhou,Lingli Zhou,Yi Liu,Qian Wang,Xiaoshan Meng,Qigang Wu,Taoli Huhe 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

The technologies for enantiomeric resolution are essential to the development of pharmaceutical industry. The membrane technology has great potential in chiral separation owing to its low cost and highthroughput; however, the enantioselective of membrane is limited by the thickness of the active layer,which is closely related to the number of theoretical separation plates. In this work, the layered doublehydroxides (LDH) are synthesized by hydrothermal process and then vacuum filtrated with bcyclodextrin(b-CD) and polyvinyl alcohol (PVA) on a porous substrate to fabricate chiral selective membranes. 2D channels with increased number of separation stages are formed in the selective layer afterheat post-treatment. The enantiomeric excesses value is enhanced from 10.95% to 24.32% for racemicL/D- tryptophan resolution. This work provides a new approach for designing high performance chiralseparation membranes from the aspect of increasing the transport path.