Facile and controllable synthesis of nitrogen self-doped chitosan-derived carbon for high-performance Li-ion batteries

Xia Wentao,Cheng Miao,Hu Jing,Liu Qianqian,Wei Tao,Wang Ruirui,Li Wanfei,Liu Bo 한국탄소학회 2024 Carbon Letters Vol.34 No.1

N-doping content and configurations have a significant effect on the electrochemical performance of carbon anodes. Herein, we proposed a simple method to synthesize highly N self-doped chitosan-derived carbon with controllable N-doping types by introducing 2ZnCO3·3Zn(OH)2 into the precursor. The as-synthesized NC-CS/2ZnCO3·3Zn(OH)2 electrode exhibited more than twice the reversible capacity (518 mAh g−1 after 100 cycles at 200 mA g−1) compared to the NC-CS electrode, superior rate performance and outstanding cycling stability. The remarkable improvement should be mainly attributed to the increase of N-doping content (particularly the pyrrolic-N content), which provided more active sites and favored Li+ diffusion kinetics. This study develops a cost-effective and facile synthesis route to fabricate high-performance N self-doped carbon with tunable doping sites for rechargeable battery applications.

Impacts of CEO Incentives and Power on Employee Wages

Qianqian Li(Qianqian Li),Yong Jae Shin(Yong Jae Shin),Unyong Pyo(Unyong Pyo) The International Academy of Global Business and T 2022 The International Academy of Global Business and T Vol.18 No.6

Purpose - This study investigates the impact of CEO incentive compensation and power on employee wages. While CEO compensation negatively affects employee wages, powerful CEOs may care for employees, and their compensation can have positive impacts on employee wages. Design/Methodology/Approach - Using data from US capital markets during 1992 - 2017, we employ pay-performance sensitivity to measure incentive compensation and CEO pay slices to proxy CEO power. We also examined the potential interaction effects between CEO compensation and CEO power. We conduct a Heckman two-step analysis to address potential sample bias and two-stage regression to address potential endogeneity. Findings - While incentive compensation negatively affects employee wages, CEO power positively affects employee wages. When examining the interaction effect between incentive compensation and CEO power, we note that the incentive effect is negative on employee wages only when the CEO is less powerful. However, when the CEO is more powerful, the incentive effect is positive on employee wages. Research Implications - When firms grant incentive compensation to CEOs for firm performance, they must also consider CEO power. Our results imply that CEO incentive compensation has a positive impact on employee wages when a CEO becomes more powerful. More incentive compensation to less-powerful CEOs could suppress employee wages and hurt firm performance in the long run.

Fabrication of dual-coated graphene oxide nanosheets by polypyrrole and poly(ionic liquid) and their enhanced electrorheological responses

Chen, Panpan,Cheng, Qianqian,Wang, Li-Min,Liu, Ying Dan,Choi, Hyoung Jin Elsevier 2019 Journal of industrial and engineering chemistry Vol.69 No.-

<P><B>Abstract</B></P> <P>A two-dimensional composite material, poly(ionic liquid)-modified graphene oxide/polypyrrole (GO/PPy/PIL) multilayered nanosheets, was fabricated and applied as a new electrorheological (ER) material. The morphological differences between the single- and dual-coated nanosheets were confirmed using scanning electron microscopy and transmission electron microscopy. Rheological properties measured using a rotational rheometer indicated that the GO/PPy/PIL composite nanosheets exhibited relatively high ER effect under a certain electric field strength than the GO/PPy nanosheets because of the universal PIL second coating. The dual-coated nanosheets also showed a higher applicable electric field strength due to the semiconductive properties of the thick PIL layer.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Dual-coated composite GO/PPy/PIL nanosheets were fabricated. </LI> <LI> The PIL second coating significantly enhanced the ER effect of the nanosheets. </LI> <LI> GO/PPy/PIL exhibited higher available electric field strength than GO/PPy. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Utilization of waste cation exchange resin to prepare carbon/iron composites for the adsorption of contaminants in water

Qianqian Shi,Aimin Li,Qing Zhou,Chendong Shuang,Yan Li,Yan Ma 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

Carbon/iron composites were prepared from waste cation exchange resin by NaOH activation. The BETsurface areas were over 1200 m2 g-1. The presence of iron led to the formation of new mesopores andmacropores. Activation temperature had a significant impact on the pore size distributions, crystalstructures, and magnetic properties of the carbon composites, and the magnetic properties of thecomposites were related to their crystal structures. The composite synthesized at 800 8C (800ACS-1)could effectively remove diethyl phthalate, bisphenol A, and malachite green from aqueous solutions. 800ACS-1 also exhibited high stability over a wide pH range of 4–11.5.

Oxidative degradation of Orange G by persulfate activated with iron-immobilized resin chars

Qianqian Shi,Aimin Li,Zhou Qing,Yan Li 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.25 No.-

Advanced oxidation processes based on persulfate activation are promising techniques for the removal of organic compounds in aqueous solutions. In the study, iron-immobilized resin chars were prepared by different methods and used as persulfate activators for the degradation of Orange G. The results showed that iron immobilization method had a significant effect on the reactivity of activator, which might be related to the distribution and chemical states of iron and sulfur elements in the sample. The activator prepared by doping method could be used over wide pH and temperature ranges and reused char still exhibited good performance for persulfate activation.

Inhibition of chromosomal region maintenance 1 suppresses the migration and invasion of glioma cells via inactivation of the STAT3/MMP2 signaling pathway

Qianqian Shan,Shengsheng Li,Qiyu Cao,Chenglong Yue,Mingshan Niu,Xiangyu Chen,Lin Shi,Huan Li,Shangfeng Gao,Jun Liang,Rutong Yu,Xuejiao Liu 대한생리학회-대한약리학회 2020 The Korean Journal of Physiology & Pharmacology Vol.24 No.3

Chromosomal region maintenance 1 (CRM1) is associated with an adverse prognosis in glioma. We previously reported that CRM1 inhibition suppressed glioma cell proliferation both in vitro and in vivo. In this study, we investigated the role of CRM1 in the migration and invasion of glioma cells. S109, a novel reversible selective inhibitor of CRM1, was used to treat Human glioma U87 and U251 cells. Cell migration and invasion were evaluated by wound-healing and transwell invasion assays. The results showed that S109 significantly inhibited the migration and invasion of U87 and U251 cells. However, mutation of Cys528 in CRM1 abolished the inhibitory activity of S109 in glioma cells. Furthermore, we found that S109 treatment decreased the expression level and activity of MMP2 and reduced the level of phosphorylated STAT3 but not total STAT3. Therefore, the inhibition of migration and invasion induced by S109 may be associated with the downregulation of MMP2 activity and expression, and inactivation of the STAT3 signaling pathway. These results support our previous conclusion that inhibition of CRM1 is an attractive strategy for the treatment of glioma.

Protective effect and mechanism of ginsenoside Rg2 on atherosclerosis

Qianqian Xue,Tao Yu,Zhibin Wang,Xiuxiu Fu,Xiaoxin Li,Lu Zou,Min Li,Jae Youl Cho,Yanyan Yang The Korean Society of Ginseng 2023 Journal of Ginseng Research Vol.47 No.2

Background: Ginsenoside Rg2 (Rg2) has a variety of pharmacological activities and provides benefits during inflammation, cancer, and other diseases. However, there are no reports about the relationship between Rg2 and atherosclerosis. Methods: We used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) to detect the cell viability of Rg2 in vascular smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (HUVECs). The expression of inflammatory factors in HUVECs and the expression of phenotypic transformation-related marker in VSMCs were detected at mRNA levels. Western blot method was used to detect the expression of inflammation pathways and the expression of phenotypic transformation at the protein levels. The rat carotid balloon injury model was performed to explore the effect of Rg2 on inflammation and phenotypic transformation in vivo. Results: Rg2 decreased the expression of inflammatory factors induced by lipopolysaccharide in HUVECs-without affecting cell viability. These events depend on the blocking regulation of NF-κB and p-ERK signaling pathway. In VSMCs, Rg2 can inhibit the proliferation, migration, and phenotypic transformation of VSMCs induced by platelet derived growth factor-BB (PDGF-BB)-which may contribute to its anti-atherosclerotic role. In rats with carotid balloon injury, Rg2 can reduce intimal proliferation after injury, regulate the inflammatory pathway to reduce inflammatory response, and also suppress the phenotypic transformation of VSMCs. Conclusion: These results suggest that Rg2 can exert its anti-atherosclerotic effect at the cellular level and animal level, which provides a more sufficient basis for ginseng as a functional dietary regulator.

Venture Capital Backing and Issuance of Seasoned Equity Offerings: Evidence from China

Juncheng Li,Songling Yang,Hemei Li,Qiuyue Zhang,Qianqian Shi 한국증권학회 2020 Asia-Pacific Journal of Financial Studies Vol.49 No.6

We analyze how venture capital (VC) affects the timing of seasoned equity offering (SEO) issuance and the post-SEO performance of Chinese companies during the 2006–2018 period. Empirical analysis confirms that VC “accelerates” SEO issuance because of greater financing demands. Thus, VC-backed firms prefer to issue their first SEOs earlier than non-VC-backed firms. Moreover, quick SEOs promoted by venture capitalists are more underpriced because of information asymmetry.

Flight and Hover Control System Design for a Mini-quadrotor Based on Multi-sensors

Zhongli Ma,Huixin Li,Yanming Gu,Zuoyong Li,Qianqian Li 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.2

Mini-quadrotor is difficult to control in the air due to its small size and light weight. This paper presentsthe flight and hover control system for a mini-quadrotor, including design and simulation of calculations and controllers. Firstly, the attitude and position of the mini-quadrotor are obtained by distributed multi-sensors. Since attitudecalculation of aircraft needs a number of combined rotations and vectors transformed by rotation, quaternionsare applied to express the attitude model. About error compensation of gyroscope and accelerometer, IMU_Updataalgorithm of Mahony filter are applied and improved to realize data fusion [1]. In order to realize accurate hoveringat certain position, UWB (UltraWideband) are applied to gain positional information of mini-quadrotor and correctthe antenna delay caused sensor error by base station positioning. The discrete Kalman filter of original data is usedto achieve the optimized estimation of the airborne position. Px4flow optical flow sensor is able to gets velocityinformation and avoid the noise problem, which is caused by differential of position data. Then, the mathematicalmodel of a mini-quadrotor’s flight and hover control system can be established. Herein, integral items are solved bythe integral separation and integral limiting to mitigate the serious overshoot and oscillation of the system caused bythe cascade PID. Finally, the simulation of the attitude controller and position controller are applied with the MATLABSimulink library. The simulation result shows that the designed attitude controller and position controller canenable the mini-quadrotor to fly smoothly, move in all directions and hover.

The Moderated Mediation Roles of Motivational Systems in the Interaction Effects of Distinct Self-discrepancy and Implicit Theories on Compensatory Consumption

Li Wang(왕려),QIANQIAN ZHU(주천천),Nak Hwan Choi(최낙환) 한국산업경제학회 2021 산업경제연구 Vol.34 No.3

이 연구는 보상소비 유형에 대한 자아격차의 유형과 사고의 틀의 상호작용 효과에서 접근 및 회피동기의 매개역할을 탐색 하였다. 로컬 자아격차와 글로벌 자아격차 간의 차이로 집단 간의 실험을 설계하고 사고의 틀을 집단내부변수로 사용하여, 설문조사로 자료를 수집하였다. 분산분석과Process macro 7로 가설을 검증하였다. 검증 결과에서, 글로벌 자아격차 보다 로컬 자아격차를 경험 하는 경우에 실체적 사고를 하는 소비자 보다 점증적 사고를 하는 소비자가 접근동기를 갖게 되고 영역 외 보상 소비보다 영역 내 보상 소비를 하였다. 그리고 로컬 자아격차 보다 글로벌 자아격차를 경험 하는 경우에 점증적 사고를 하는 소비자 보다 실체적 사고를 하는 소비자가 회피동기를 갖게 되고 영역 내 보상 소비 보다 영역 외 보상 소비를 하였다. 이 연구는 자아 격차의 유형과 사고의 틀이 보상소비 유형에 상호작용 하는 과정에서 동기유형의 매개역할을 분석하여 보상소비이론의 발전에 기여한다. 그리고 마케터가 소비자의 사고의 틀과 지각하는 자아격차의 유형에 기초하여 내부동기를 파악하고 전략을 개발하여 실행해야 함을 관리적으로 시사한다. This study explored the interaction effect of distinct self-discrepancy and implicit theory on compensatory consumption type and mediation roles of avoidance/approach motivations in the interaction effect. 2 (local self-discrepancy vs. global self-discrepancy) between-subjects design with implicit theory as within-subject was used to collect data for testing the hypotheses. The results indicate that approach motivations are highly aroused to incremental (vs. entity) theorists which leads to within-domain (vs. across-domain) compensatory consumptions when they experience local self-discrepancy (vs. global self-discrepancy). And avoidance motivations are highly activated to entity theorists which results in across-domain (vs. within-domain) consumption when they experience global self-discrepancy (vs. local self-discrepancy). This paper contributes to the development of compensatory consumption behavior theory via highlighting the mediation roles of motivation type in the interactive effects of self-discrepancy type and implicit theory on the compensatory consumption, and suggests that marketers should develop and conduct strategies by grasping consumers’ distinct internal motivations based on consumers’ implicit theory and self-discrepancy type.