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Effects of thiocyanate anions on switching and structure of poly(N-isopropylacrylamide) brushes

Chinese Physics B 2019年第6期28卷 262-269页

作者： Xin-Jun Zhao zhi-fu gao Xinjiang Laboratory of Phase Transitions and Microstructures of Condensed Matter Physics Yili Normal UniversityYining 835000China Laboratory of Micro-Nano Electro Biosensors and Bionic Devices Yili Normal UniversityYining 835000China Xinjiang Astronomical Observatory Chinese Academy of Sciences150Science 1-StreetUrumqi 830011China

In this work, we investigate the effects of thiocyanate anions on the switching and the structure of poly(Nisopropylacrylamide)(PNIPAM) brushes using a molecular theory. Our model takes into consideration the PNIPAM–anion bonds, the electrostatic effects and their explicit coupling to the PNIPAM conformations. It is found that at low thiocyanate anion concentration, as the anion concentration of thiocyanate increases, thiocyanate anions are more associated with PNIPAM chains through the PNIPAM–anion bonds, which contributes to stronger electrostatic repulsion and leads to an increase of lower critical solution temperature(LCST). By analyzing the average volume fractions of PNIPAM brushes,it is found that the PNIPAM brush presents a plateau structure. Our results show that the thiocyanate anions promote phase segregation due to the PNIPAM–anion bonds and the electrostatic effect. According to our model, the reduction of LCST can be explained as follows: at high thiocyanate anion concentration, with the increase of thiocyanate concentration, more ion bindings occurring between thiocyanate anions and PNIPAM chains will result in the increase of the hydrophobicity of PNIPAM chains;when the increase of electrostatic repulsion is insufficient to overcome the hydrophobic interaction of PNIPAM chains, it will lead to the reduction of brush height and LCST at high thiocyanate anion concentration. Our theoretical results are consistent with the experimental observations, and provide a fundamental understanding of the effects of thiocyanate on the LCST of PNIPAM brushes.

关键词： molecular theory PNIPAM brushes effect of thiocyanate anions

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Time-resolved Spectral Properties of Fermi-GBM Bright Long Gamma-Ray Bursts

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Research in Astronomy and Astrophysics 2024年第2期24卷 58-73页

作者： Wan-Kai Wang Wei Xie zhi-fu gao Shuo Xiao Ai-Jun Dong Bin Zhang Qi-Jun zhi Department of Astronomy School of Physics and Electronic ScienceGuizhou Normal UniversityGuiyang 550001China Guizhou Provincial Key Laboratory of Radio Astronomy Data Processing Guizhou Normal UniversityGuiyang 550001China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China

The prompt emission mechanism of gamma-ray bursts(GRBs)is still unclear,and the time-resolved spectral analysis of GRBs is a powerful tool for studying their underlying physical *** performed a detailed time-resolved spectral analysis of 78 bright long GRB samples detected by Fermi/Gamma-ray Burst Monitor.A total of 1490 spectra were obtained and their properties were studied using a typical Band-shape ***,the parameter distributions of the time-resolved spectrum are given as follows:the low-energy spectral indexα~-0.72,high-energy spectral indexβ~2.42,the peak energy E_(p)~221.69 keV,and the energy flux F~7.49×10^(-6)erg cm^(-2)s^(-1).More than 80%of the bursts exhibit the hardest low-energy spectral indexα_(max),exceeding the synchrotron limit(-2/3).Second,the evolution patterns of a and E_(p)were statistically *** results show that for multi-pulse GRBs the intensity-tracking pattern is more common than the hard-to-soft pattern in the evolution of both E_(p)andα.The hard-to-soft pattern is generally shown in single-pulse GRBs or in the initial pulse of multi-pulse ***,we found a significant positive correlation between F and E_(p),with half of the samples exhibiting a positive correlation between F andα.We discussed the spectral evolution of different radiation *** diversity of spectral evolution patterns indicates that there may be more than one radiation mechanism occurring in the GRB radiation process,including photo spheric radiation and synchrotron ***,it may also involve only one radiation mechanism,but more complicated physical details need to be considered.

关键词： (stars:)gamma-ray burst general-methods statistical-methods data analysis

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Role of hydrogen bonding in solubility of poly(N-isopropylacrylamide) brushes in sodium halide solutions

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Chinese Physics B 2016年第7期25卷 277-285页

作者：赵新军高志福 Xinjiang Laboratory of Phase Transitions and Microstructures of Condensed Matter Physics Yi Li Normal University National Laboratory of Solid State Microstructures and Department of Physics Nanjing University Xinjiang Astronomical Observatory Chinese Academy of Sciences

By employing molecular theory, we systematically investigate the shift of solubility of poly（N-isopropylacrylamide）（PNIPAM） brushes in sodium halide solutions. After considering PNIPAM–water hydrogen bonds, water–anion hydrogen bonds, and PNIPAM–anion bonds and their explicit coupling to the PNIPAM conformations, we find that increasing temperature lowers the solubility of PNIPAM, and results in a collapse of the layer at high enough temperatures. The combination of the three types of bonds would yield a decrease in the solubility of PNIPAM following the Hofmeister series： Na Cl＆gt;Na Br＆gt;Na I. PNIPAM–water hydrogen bonds are affected by water–anion hydrogen bonds and PNIPAM–anion bonds. The coupling of polymer conformations and the competition among the three types of bonds are essential for describing correctly a decrease in the solubility of PNIPAM brushes, which is determined by the free energy associated with the formation of the three types of bonds. Our results agree well with the experimental observations, and would be very important for understanding the shift of the lower critical solution temperature of PNIPAM brushes following the Hofmeister series.

关键词： molecular theory PNIPAM brushes anion effect hydrogen bonds

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Structure and switching of single-stranded DNA tethered to a charged nanoparticle surface

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Chinese Physics B 2016年第7期25卷 269-276页

作者：赵新军高志福 Xinjiang Laboratory of Phase Transitions and Microstructures of Condensed Matter Physics Yi Li Normal University Yining 835000 China National Laboratory of Solid State Microstructures and Department of Physics Nanjing University Nanjing 210093 China Xinjiang Astronomical Observatory Chinese Academy of Sciences Urumqi 830011 China

Using a molecular theory, we investigate the temperature-dependent self-assembly of single-stranded DNA（ss DNA）tethered to a charged nanoparticle surface. Here the size, conformations, and charge properties of ss DNA are taken into account. The main results are as follows： i） when the temperature is lower than the critical switching temperature, the ss DNA will collapse due to the existence of electrostatic interaction between ss DNA and charged nanoparticle surface; ii）for the short ss DNA chains with the number of bases less than 10, the switching of ss DNA cannot happen, and the critical temperature does not exist; iii） when the temperature increases, the electrostatic attractive interaction between ss DNA and charged nanoparticle surface becomes weak dramatically, and ss DNA chains will stretch if the electrostatic attractive interaction is insufficient to overcome the elastic energy of ss DNA and the electrostatic repulsion energy. These findings accord well with the experimental observations. It is predicted that the switching of ss DNA will not happen if the grafting densities are too high.

关键词： molecular theory ss DNA tethered to charged nanoparticle surface temperature-dependent switching

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皮革废水痕量Cr^(3+)的快速在线检测

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北京化工大学学报（自然科学版） 2006年第4期33卷 17-20页

作者：苏海佳付志高谭天伟北京化工大学生命科学与技术学院北京100029

提出了一种简单、快速的在线检测工业废水中痕量重金属离子含量的新方法。该方法表明通过加碱测溶液pH值变化来反映溶液中痕量Cr3+离子是可行的。试验结果表明,工业废水中轻金属Ca2+,Mg2+离子的存在基本不影响溶液中pH值的变化。该方法... 详细信息

提出了一种简单、快速的在线检测工业废水中痕量重金属离子含量的新方法。该方法表明通过加碱测溶液pH值变化来反映溶液中痕量Cr3+离子是可行的。试验结果表明,工业废水中轻金属Ca2+,Mg2+离子的存在基本不影响溶液中pH值的变化。该方法可以用于简单快速的检测皮革实际废水中痕量Cr3+的浓度。与常规方法相比,该方法简单、快速、准确,易于实现在线检测和废水装置的自动化控制。

关键词：在线检测皮革废水 pH值变化 Cr^3+

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Relationship between parenting stress and behavioral and emotional problems in preschool children: A mediation effect analysis

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World Journal of Psychiatry 2025年第1期15卷 128-136页

作者： zhi-Wei fu Yue-Jing Li Ran Yu Rui-Qing Guo Li-Xia gao Sheng-Xia Zhao Department of Children's Health Shijiazhuang Maternity and Child Healthcare HospitalShijiazhuang 050000Hebei ProvinceChina

BACKGROUND Emotional reactions,such as anxiety,irritability,and aggressive behavior,have attracted clinical attention as behavioral and emotional problems in preschool-age *** To investigate the current status of family rearing,parental stress,and behavioral and emotional problems of preschool children and to analyze the mediating effect of the current status of family rearing on parental stress and behavioral/emo-tional *** We use convenience sampling to select 258 preschool children in the physical examination center of our hospital from October 2021 to September *** children and their parents were evaluated using a questionnaire ***'s correlation was used to analyze the correlation between child behavioral and emotional problems and parental stress and family rearing,and the structural equation model was constructed to test the mediating *** The score for behavioral/emotional problems of 258 preschool children was(27.54±3.63),the score for parental stress was(87.64±11.34),and the score for parental family rearing was(31.54±5.24).There was a positive correlation between the behavioral and emotional problems of the children and the“hostile/mandatory”parenting style;meanwhile,showed a negative correlation with the“support/participation”parenting style(all P<0.05).The intermediary effect value between the family upbringing of parents in parental stress and children's behavior problems was 29.89%.CONCLUSION Parental family upbringing has a mediating effect between parental stress and behavioral and emotional problems of *** paying attention to the behavioral and emotional problems of preschool-age children,clinical medical staff should provide correct and reasonable parenting advice to their parents to promote the mental health of preschool-age children.

关键词： Preschool children Parenting stress Children's behavioral and emotional problems Family rearing Mediating effect

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Real-world evidence on the efficacy and safety of vonoprazanamoxicillin dual therapy for Helicobacter pylori treatment in elderly patients

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World Journal of Gastroenterology 2025年第1期31卷 68-78页

作者： Wen gao Jing-Wen Li Hui Ye Xue-zhi Zhang Jian-Xiang Liu Hong Cheng Department of Gastroenterology Peking University First HospitalBeijing 100034China School of Medicine Tsinghua MedicineTsinghua UniversityBeijing 100034China Department of Traditional Chinese Medicine and Integrative Medicine Peking University First HospitalBeijing 100034China

BACKGROUND A dual therapy regimen containing amoxicillin is a common treatment option for the eradication of Helicobacter pylori(***).While substantial research supports the efficacy and safety of vonoprazan and amoxicillin(VA)dual therapy in the general population,there is still a lack of studies specifically focusing on its safety in elderly *** To evaluate efficacy and safety of VA dual therapy as first-line or rescue treatment for *** in elderly *** As a real-world retrospective study,data were collected from elderly patients aged 60 years and above who accepted VA dual therapy(vonoprazan 20 mg twice daily+amoxicillin 1000 mg thrice daily for 14 days)for *** eradication in the Department of Gastroenterology at Peking University First Hospital between June 2020 and January *** status was evaluated by^(13)C-urease breath test 6 weeks after *** adverse events(AEs)during treatment were *** In total,401 cases were ***-one cases were excluded due to loss to follow-up,lack of re-examination,or unwillingness to take *** total of 380 included cases comprised 250 who received VA dual therapy as first-line treatment and 130 who received VA dual therapy as rescue *** was successfully eradicated in 239 cases(95.6%)in the first-line treatment group and 116 cases(89.2%)in the rescue treatment *** overall incidence of AEs was 9.5%for both ***,9.2%of patients experienced an AE in the first-line treatment group and 10.0%in the rescue treatment *** patients discontinued treatment due to AE,with a discontinuation rate of 1.3%.No serious AE *** The VA dual therapy regimen as a first-line treatment and a rescue therapy was effective and safe for elderly patients aged 60 and older.

关键词： Helicobacter pylori Vonoprazan Amoxicillin Dual therapy Elderly

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高压隔离开关常见缺陷分析与处理

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通信电源技术 2018年第1期35卷 169-170页

作者：王志高付裕国网湖北省电力公司检修公司湖北武汉430050

针对高压隔离开关在变电站日常运行维护中的多种常见缺陷,根据运维经验进行分类原因分析,制定了相关处理对策,对电力高压隔离开关检修工作具有实际参考意义。

关键词：高压隔离开关密封传动

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贵州大学生压力与应付方式的现状及其关系研究

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凯里学院学报 2018年第5期36卷 72-76页

作者：李玲付志高凯里学院教育科学学院贵州凯里556011

为了研究贵州大学生压力和应对方式的现状及关系,丰富心理健康教育理论,提出缓解压力的科学策略,促进大学生健康成长,研究者采用大学生压力源量表和应付方式问卷,对分层抽样的贵州省4所高校936名大学生进行了调查研究。回收问卷后,通过... 详细信息

为了研究贵州大学生压力和应对方式的现状及关系,丰富心理健康教育理论,提出缓解压力的科学策略,促进大学生健康成长,研究者采用大学生压力源量表和应付方式问卷,对分层抽样的贵州省4所高校936名大学生进行了调查研究。回收问卷后,通过数据统计分析、研究,结果表明:贵州大学生的压力和应付方式各因子得分均处于中等水平,且在性别、年级和生源地等方面存在显著差异。另外,贵州大学生压力的各因子与应付方式的自责、幻想、退避、合理化等因子显著正相关。

关键词：压力应付方式大学生

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三进三提:凯里学院特色心理健康教育模式

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凯里学院学报 2019年第5期37卷 117-120页

作者：付志高付存清马燕凯里学院心理健康教育及咨询中心/教育科学学院

凯里学院心理健康教育及心理咨询中心成立10年以来,始终围绕立德树人根本任务,坚持三进三提工作思路和目的,构建了凯里学院特色12345心理健康教育模式,基本形成了教育教学、实践活动、咨询服务、预防干预“四位一体”的心理健康教育工... 详细信息

凯里学院心理健康教育及心理咨询中心成立10年以来,始终围绕立德树人根本任务,坚持三进三提工作思路和目的,构建了凯里学院特色12345心理健康教育模式,基本形成了教育教学、实践活动、咨询服务、预防干预“四位一体”的心理健康教育工作格局,为学校内涵发展和地方社会经济发展贡献力量。

关键词：三进三提心理健康教育学生工作总结

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