http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Shijie Qu (검색결과 5 건)
- 무료
- 기관 내 무료
- 유료
-
Shuwei Qu,Ruiqin Li,Shaoping Bai,Shijie Liang 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.10
A unified model is proposed for the output accuracy of open-chain manipulators in consideration of joint clearance and structural parameters. First, the operator of the finite-displacement screw matrix and the combination operation are presented. Second, the joint clearance and structural parameters are described and analyzed with screw theory. A virtual screw is established for the joint clearance and structural parameter errors. Third, a unified model is built through the adjoint transformation of Lie groups in consideration of the two effectors of the virtual screw. The error pose is decomposed into orientation and position errors, which are obtained through the virtual screw. Finally, an open-chain manipulator with six degrees of freedom is analyzed based on the proposed model. The position and orientation errors are obtained with the trajectory that provided an intuitive geometric insight into the accuracy and exact maximal position and orientation errors.
-
Wu Dongzhe,Shen Yulin,Qu Chaoyi,Huang Peng,Geng Xue,Zhang Jianhong,Rao Zhijian,Wei Qiangman,Liu Shijie,Zhao Jiexiu 한국역학회 2024 Epidemiology and Health Vol.46 No.-
OBJECTIVES In light of the rise in the global aging population, this study investigated the potential of the oxidative balance score (OBS) as an indicator of phenotypic age acceleration (PhenoAgeAccel) to better understand and potentially slow down aging. METHODS Utilizing data from the National Health and Nutrition Examination Survey collected between 2001 and 2010, including 13,142 United States adults (48.7% female and 51.2% male) aged 20 and above, OBS and PhenoAgeAccel were calculated. Weighted generalized linear regression models were employed to explore the associations between OBS and PhenoAgeAccel, including a sex-specific analysis. RESULTS The OBS demonstrated significant variability across various demographic and health-related factors. There was a clear negative correlation observed between the higher OBS quartiles and PhenoAgeAccel, which presented sex-specific results: the negative association between OBS and PhenoAgeAccel was more pronounced in male than in female. An analysis using restricted cubic splines revealed no significant non-linear relationships. Interaction effects were noted solely in the context of sex and hyperlipidemia. CONCLUSIONS A higher OBS was significantly associated with a slower aging process, as measured by lower PhenoAgeAccel. These findings underscore the importance of OBS as a biomarker in the study of aging and point to sex and hyperlipidemia as variables that may affect this association. Additional research is required to confirm these results and to investigate the biological underpinnings of this relationship.
-
Jiang Wei,Ni Guosong,Zuo Pingping,Qu Shijie,Li Yunmei,Niu Hongxian,Shen Wenzhong 한국탄소학회 2019 Carbon Letters Vol.29 No.5
Isotropic pitch-based carbon fiber was successfully prepared from tetrahydrofuran-soluble fraction of coal tar pitch co-carbonization with petrolatum by air-blowing. The effects of reaction temperature and time, amount of petrolatum added on the composition and spinning properties of resultant pitches were investigated. It indicated that petrolatum could effectively improve the softening point, aromaticity, hydrogen content and molecular weight of the resultant pitches by promoting cross-linking and dehydrogenation polymerization reactions at low air-blowing temperature. Moreover, more aliphatic and naphthenic structures had been introduced into resultant pitches as addition of petrolatum and also inhibited the generation of quinoline-insoluble particles. The obtained green fibers were facile to be stabilized and carbonized and the resultant carbon fibers showed fully isotropic and finer, uniform diameter with smooth surface and higher tensile strength of up to 0.92 GPa. It provided a facile chemical modification method for isotropic pitch-based carbon fiber production.
-
Wei Jiang,Guosong Ni,Pingping Zuo,Shijie Qu,Yunmei Li,Hongxian Niu,Wenzhong Shen 한국탄소학회 2019 Carbon Letters Vol.29 No.5
Isotropic pitch-based carbon fiber was successfully prepared from tetrahydrofuran-soluble fraction of coal tar pitch cocarbonization with petrolatum by air-blowing. The effects of reaction temperature and time, amount of petrolatum added on the composition and spinning properties of resultant pitches were investigated. It indicated that petrolatum could effectively improve the softening point, aromaticity, hydrogen content and molecular weight of the resultant pitches by promoting cross-linking and dehydrogenation polymerization reactions at low air-blowing temperature. Moreover, more aliphatic and naphthenic structures had been introduced into resultant pitches as addition of petrolatum and also inhibited the generation of quinoline-insoluble particles. The obtained green fibers were facile to be stabilized and carbonized and the resultant carbon fibers showed fully isotropic and finer, uniform diameter with smooth surface and higher tensile strength of up to 0.92 GPa. It provided a facile chemical modification method for isotropic pitch-based carbon fiber production.
-
Nitrogen-doped carbon nanosheets from polyurethane foams and removal of Cr(VI)
Jiaqi Duan,Baohua Zhang,Huailin Fan,Wenzhong Shen,Shijie Qu 한국탄소학회 2017 Carbon Letters Vol.22 No.-
Nitrogen-doped carbon nanosheets with a developed porous structure were prepared from polyurethane foams by hydrothermal carbonization following ZnCl2 chemical activation. Scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, solid state 13C nuclear magnetic resonance (NMR) spectra and X-ray photoelectron spectroscopy were used to characterize the nitrogen-doped carbon nanosheet structure and composition. The removal of Cr(VI) by the N-doped carbon nanosheets was investigated. The results showed that the maximum removal capacity for chromium of 188 mg/g was found at pH=2.0 with PHC-Z-3. pH had an important effect on Cr(VI) removal and the optimal pH was 2.0. Moreover, amino groups and carboxyl groups in the nitrogen-doped carbon nanosheet played important roles in Cr(VI) removal, and promoted the reduction of Cr(VI) to Cr(III).
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
