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Tough Semi-interpenetrating Polyvinylpyrrolidone/Polyacrylamide Hydrogels Enabled by Bioinspired Hydrogen-bonding Induced Phase Separation

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Chinese Journal of Polymer Science 2024年第5期42卷 591-603,I0006页

作者： Qiong-Jun Xu zhao-Yang yuan Chang-Cheng Wang Hao Liang yu Shi Hai-Tao Wu Hu Xu Jing zheng Jin-Rong Wu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China

Semi-interpenetrating(semi-IPN)hydrogels formed by the continuous interpenetration of cross-linked polymer network and linear non-crosslinked polymer with multifunctionality are widely used in biomedical and other ***,the negative impact of linear polymer on the homogeneity of the cross-linked network often leads to a decrease in the mechanical properties of semi-IPN hydrogels and severely limits their ***,a bioinspired hydrogen-bonding induced phase separation strategy is presented to construct the tough semi-IPN polyvinylpyrrolidone/polyacrylamide hydrogels(named PVP/PAM hydrogels),including the linear polymer polyvinylpyrrolidone(PVP)and cross-linked polyacrylamide(PAM)*** resultant PVPx/PAM hydrogels exhibit unique phase separation induced by the hydrogen bonding between PVP and PAM and affected by the amount of substance of ***,the phase separation of PVPx/PAM hydrogels results in excellent mechanical properties with a strain of 2590%,tensile strength of 0.28 MPa and toughness of 2.17 MJ/m^(3).More importantly,the hydrogen bonding between PVP and PAM firstly disrupts to dissipate energy under external forces,so the PVPx/PAM hydrogels exhibit good self-recovery properties and outperform chemically cross-linked PAM hydrogels in impact resistance and damping *** is believed that the PVPx/PAM hydrogels with hydrogen-bonding induced phase separation possess more potential application prospects.

关键词： Tough Semi-interpenetrating networks Polyvinylpyrrolidone/polyacrylamide Hydrogels Phase separation

Evolution of inner wall wrinkle defects in the sinking zone of a thick-walled steel tube during radial forging

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Advances in Manufacturing 2024年第2期12卷 396-408页

作者： yu-zhao Yang Cheng Xu Li-Xia Fan School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094People’s Republic of China

An axial wrinkle defect was observed in the inner wall of the sinking zone of a thick-wall steel tube processed by cold radial *** can evolve into *** present study focuses on the evolution of wrinkles and the effects of process parameters on them using a three-dimensional radial forging process finite element model,radial forging experiments,and surface morphology *** results indicated that the vertical section angle of the hammer die and the size of the tube blank significantly affect the evolution of *** height-to-width ratioλwas introduced to describe the morphology of *** had an approximately linear relationship with the radius reduction in the sinking *** was a linear correlation between the growth slope ofλand the axial to circumferential strain ratio|εr/εθ|,which can predict theλunder few process *** the 30SiMn2MoVA steel,at the junction of the forging and sinking zones,the threshold ofλof the wrinkle that can evolve into a fissure is approximately 1.123.

关键词： Radial forging Inner wall Wrinkle defects Evolution Sinking zone

A flat-foldable equiangular spiral folding pattern inspired by sunflowers for deployable structures

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Chinese Journal of Aeronautics 2024年第6期37卷 425-438页

作者： Shuangqing yu Jinguo LIU Pengyuan zhao Yingying TANG State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169China University of Chinese Academy of Sciences Beijing 100049China

Flasher origami pattern has been widely utilized to improve the stowage efficiency of deployable ***,flasher origami cannot be folded fully flat,and they still have great potential for optimization in terms of storage volume and folding *** this paper,a flat foldable equiangular spiral folding pattern inspired by the sunflower disk is ***,a parametric design method for this equiangular spiral crease diagram is introduced in ***,a kinematic model of the equiangular spiral folding pattern is established based on the kinematic equivalence between rigid origami and spherical linkages.A simulation of the developed model demonstrates that the equiangular spiral folding pattern can be folded *** the folded ratio as an evaluation index,the calculated results and experiments show that the equiangular spiral crease pattern can yield fewer creases and improve stowage efficiency in comparison to flasher origami *** spiral folding pattern can save a considerable amount of space and provide a new approach to spatially deployable structures.

关键词： Flasher origami Sunflower-inspired Deployable structures Flat-foldability Equiangular spiral folding pattern

Rosiglitazone could improve clinical outcomes after coronary stent implantation in nondiabetic patients with metabolic syndrome

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Chinese Medical Journal 2006年第14期119卷 1171-1175页

作者： CAO zheng ZHOU yu-jie zhao Ying-xin LIU yu-yang GUO Yong-he CHENG Wan-jun Department of Cardiology Beijing Anzhen Hospital Affiliated of Capital University of Medical Sciences Beijing 100029 China

Background Recent studies have shown that thiazolidinediones （TZDs） could reduce in-stent restenosis and improve clinical outcomes in patients with type 2 diabetes after coronary stent implantation. It remains unclear whether nondiabetic patients with metabolic syndrome after stenting could also benefit from the treatment with TZDs. Methods Three hundred and sixty patients with metabolic syndrome who underwent coronary stent implantation were randomly assigned to a rosiglitazone group （n= 180） or a control group （n= 180）. Patients in the rosiglitazone treatment group were treated with rosiglitazone 1 day before coronary stenting （4 mg once daily） and treatment was continued until the 9 months follow-up; while in the control group, patients were treated with placebo 1 day before the procedure and until the 9 months follow-up. Adverse events were death, myocardial infarction and urgent target vessel revascularization within 9 months after coronary stenting. Results One hundred and fifty two patients in the rosiglitazone group and 145 patients in the control group survived during the follow-up. Baseline characteristics among patients in the two groups were well balanced. There was no significant difference in target vessels or the procedure of stent implantation. Compared with the control group, treatment with rosiglitazone was associated with a lower rate of death, myocardial infarction and urgent target vessel revascularization （7.2% vs 14.5%, P=0.044）. Conclusion Rosiglitazone could reduce the risk of the adverse cardiovascular event and improve clinical outcomes in nondiabetic patients with metabolic syndrome after coronary stent implantation.

关键词： stents thiazolidinediones coronary disease metabolic syndrome

Strength and ductility optimization of HPDC AlSi8MgCuZn2 alloys by modifying pre-aging treatment

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China Foundry 2024年第4期21卷 343-351页

作者： yuan-hang Jiang Hui-ting zheng Fei Liu Hai-dong zhao National Engineering Research Center of Near-net Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510641China

Considering the components produced by high pressure die casting(HPDC)process usually with ultra-large sizes and complex morphologies,high temperature solid solution treatment is not a suitable method to further improve their mechanical *** this study,two-stage aging treatment with different pre-aging times was designed and employed to further improve the mechanical properties of HPDC Al8SiMgCuZn *** characteristics of precipitates were evaluated by a transmission electron microscope(TEM),and the precipitation strengthening mechanism was *** results reveal that the strengthening is mainly contributed by the precipitation ofβ″phase after two-stage aging,and the number density and size of the precipitates are significantly depended on the pre-aging *** number density of precipitates is increased with the pre-aging time prolonged from 0 h to 4 h,and then decreases with the further increase of pre-aging time from 4 h to 6 *** precipitates with the highest density and smallest size are observed after pre-aging for 4 *** pre-aged at 100℃for 4 h and then artificial aged at 200℃for 30 min,the yield strength of 207 MPa,ultimate tensile strength of 325 MPa and elongation of 7.6%are achieved.

关键词： high pressure die cast aluminum alloy microstructural heterogeneity mechanical properties precipitation strengthening two-stage aging

Assessing the Performance of CMIP6 Models in Simulating Droughts across Global Drylands

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Advances in Atmospheric Sciences 2024年第2期41卷 193-208页

作者： Xiaojing yu Lixia ZHANG Tianjun ZHOU Jianghua zheng LASG Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044China University of Chinese Academy of Sciences Beijing 100049China College of Geography&Remote Sensing Sciences Xinjiang UniversityUrumqi 830046China

Both the attribution of historical change and future projections of droughts rely heavily on climate modeling. However,reasonable drought simulations have remained a challenge, and the related performances of the current state-of-the-art Coupled Model Intercomparison Project phase 6(CMIP6) models remain unknown. Here, both the strengths and weaknesses of CMIP6 models in simulating droughts and corresponding hydrothermal conditions in drylands are *** the general patterns of simulated meteorological elements in drylands resemble the observations, the annual precipitation is overestimated by ~33%(with a model spread of 2.3%–77.2%), along with an underestimation of potential evapotranspiration(PET) by ~32%(17.5%–47.2%). The water deficit condition, measured by the difference between precipitation and PET, is 50%(29.1%–71.7%) weaker than observations. The CMIP6 models show weaknesses in capturing the climate mean drought characteristics in drylands, particularly with the occurrence and duration largely underestimated in the hyperarid Afro-Asian areas. Nonetheless, the drought-associated meteorological anomalies, including reduced precipitation, warmer temperatures, higher evaporative demand, and increased water deficit conditions, are reasonably reproduced. The simulated magnitude of precipitation(water deficit) associated with dryland droughts is overestimated by 28%(24%) compared to observations. The observed increasing trends in drought fractional area,occurrence, and corresponding meteorological anomalies during 1980–2014 are reasonably reproduced. Still, the increase in drought characteristics, associated precipitation and water deficit are obviously underestimated after the late 1990s,especially for mild and moderate droughts, indicative of a weaker response of dryland drought changes to global warming in CMIP6 models. Our results suggest that it is imperative to employ bias correction approaches in drought-related studies over drylands by using CMIP6 o

关键词： droughts hydrothermal conditions drylands CMIP6 model evaluation

π-conjugated chromophore functionalized high-nuclearity titanium-oxo clusters containing structural unit of anatase for photocatalytic selective oxidation of sulfides

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Rare Metals 2024年第4期43卷 1736-1746页

作者： Ling-Rong Liao Dong-Chun zheng Pin-Xi Ou Qi-Xin zhao Wei-Min Xuan Qi zheng State Key Laboratory for Modification of Chemical Fibers and Polymer Materials&College of Materials Science and Engineering Donghua UniversityShanghai201620China State Key Laboratory for Modification of Chemical Fibers and Polymer Materials and College of Chemistry and Chemical Engineering Donghua UniversityShanghai 201620China

N-doping has significant influence in manipulating the properties of TiO_(2),and this has stimulated the development of N-donor-functionalized titanium-oxo clusters(TOCs)as molecular models to study the structure-property ***,the structural type and photoresponsive application are still limited for such TOCs,especially regarding the high-nuclearity TOCs that contain structure unit of TiO_(2)for ***,we showed the synthesis of a series of high-nuclearity TOCs 1-3 compounds usingπ-conjugated 1,10-phenanthroline(phen)as chromophore and N-donor functional *** 1 features cocrystal structure composed of one[Ti_(26)]~(2+)and half[Ti_(22)]~(2+),which renders it as the first cocrystallized TOC containing two positively charged species and phen-functionalized TOC showing the highest nuclearity up to 37 Ti *** adjusting the synthetic conditions,the individual{Ti_(22)}and{Ti_(26)}clusters can also be isolated as Compounds 2 and 3,*** core structure of{Ti_(22)}is mainly constructed from four lacunary{Ti_(4)}derived from pentagonal{Ti(Ti)_5}unit,while{Ti_(26)}is built from four complete{Ti(Ti)_5}***,a{Ti_8O_(14)}structure unit of anatase TiO_(2)can be identified in{Ti_(26)}.Based on the unique structural features and proper photophysical and photochemical properties of Compounds 1-3,they are applied for photocatalytic *** to the presence of anatase structure unit in{Ti_(26)}and the synergistic effect from{Ti_(22)}and{Ti_(26)},the catalytic performance presents in the order of Compound 1>Compound 3>Compound *** work provides excellent models to understand the structureproperty relationship from the perspective of cocrystallization and Ti-O binding model and will further promote the application of TOCs as functional catalysts for organic transformation.

关键词： Titanium-oxo cluster Molecular model of anatase TiO_(2) High nuclearity π-conjugated chromophore Photocatalytic sulfoxidation

Author correction to‘Co-delivery of nigericin and decitabine using hexahistidine-metal nanocarriers for pyroptosis-induced immunotherapeutics’[Acta Pharm Sin B 12(2022)4458–4471]

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Acta Pharmaceutica Sinica B 2024年第5期14卷 2359-2360页

作者： Qiang Niu yu Liu yujing zheng Ziwei Tang yuna Qian Ruogu Qi Jianliang Shen Ping zhao School of Chemistry and Chemical Engineering Guangdong Pharmaceutical UniversityGuangzhou 510006China State Key Laboratory of Ophthalmology Optometry and Vision ScienceSchool of Ophthalmology and OptometrySchool of Biomedical EngineeringWenzhou Medical UniversityWenzhou 325027China Wenzhou Institute University of Chinese Academy of SciencesWenzhou 325001China School of Medicine&Holistic Integrative Medicine Nanjing University of Chinese MedicineNanjing 210023China

The authors regret that there is an error in Fig.6 in the article due to the mistake of copying and pasting in the process of assemblingﬁgures and negligence in the *** it does not affect the conclusion,it is an obvio... 详细信息

关键词： journal correction conclusion

Spherical Confinement Generates Entropic Force to Accelerate Polymer Chain Detachment

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Chinese Journal of Polymer Science 2024年第3期42卷 407-416,I0010页

作者： yu-Shan zheng Jian-Ping Zhou Yan Xu Kai Li Mechanical Engineering Xinjiang UniversityUrumqi 830002China

To understand the dynamic process of polymer detachment, it is necessary to determine the mean detachment time of a single breakable link, which is modeled as a spring. Normally, this time can be viewed as the escape of a Brownian particle from the potential well of the spring. However, as the free dangling length of the polymer chain increases, the conformational entropy of the chain is affected by geometric confinement. It means that the wall exerts a repulsive force on the chain, resulting in accelerated link detachment from a macroscopic perspective. In this work, we investigate the effect of entropy on the detachment rate in the case where the substrate is spherical. We demonstrate that spherical confinement accelerates chain detachment both inside and outside the sphere. An analytical expression for the mean detachment time of breakable links is given, which includes an additional pre-factor that is related to the partition function. Additionally, we analyze the expressions for entropic forces inside the sphere, outside the sphere, and on a flat wall, comparing their magnitudes to explain the difference in mean detachment time.

关键词： Polymer detachment Breakable link Entropic force Mean first passage time