目的探讨加温输液与环境加温联合干预对剖宫产低温产妇心理和妊娠结局的影响,为选择使用最佳的保温措施提供理论依据,从而预防低温对剖宫产产妇造成危害。方法选取2019年8月-2020年8月期间该院收治的符合入组标准的80例剖宫产低温产妇...目的探讨加温输液与环境加温联合干预对剖宫产低温产妇心理和妊娠结局的影响,为选择使用最佳的保温措施提供理论依据,从而预防低温对剖宫产产妇造成危害。方法选取2019年8月-2020年8月期间该院收治的符合入组标准的80例剖宫产低温产妇作为研究对象。将80例产妇根据随机数字表划分为对照组和观察组,每组各40例。对照组产妇剖宫产术中给予常规护理,观察组产妇在常规护理的基础上给予加温输液和环境加热联合干预,分别比较对照组和观察组产妇的心理情况(焦虑程度、满意度)、术中寒战发生率及不良妊娠结局。结果术前对照组和观察组低温产妇的SAS得分差异无统计学意义(57.6±5.86 vs. 58.3±6.03,t=0.527,P>0.05)。术中观察组低温产妇的焦虑自评量表(SAS)得分显著低于对照组(52.17±6.18 vs. 63.49±6.35,t=8.08,P<0.05)。同时,观察组低温产妇的手术整体满意度显著高于对照组(97.5%vs. 65.0%,χ^(2)=13.867,P<0.05),且术中出现寒战和不良新生儿结局的概率明显低于对照组(2.5%vs. 30.0%,χ^(2)=11.114,P<0.05)。结论加温输液与环境加温联合干预应用于低温产妇剖宫术,能够有效避免患者产生焦虑心理,显著提高患者的满意度,同时能够有效避免低温产妇在术中出现寒战和不良妊娠结局。展开更多
Performic acid (PFA) is an oxidant used in chemical processing, synthesis and bleaching. The macro kinetic models of synthesis, hydrolysis and decomposition of PFA were investigated via formic acid-autocatalyzed rea...Performic acid (PFA) is an oxidant used in chemical processing, synthesis and bleaching. The macro kinetic models of synthesis, hydrolysis and decomposition of PFA were investigated via formic acid-autocatalyzed reaction. It was found that the intrinsic activation energies of PFA synthesis and hydrolysis were 75.2 kJ·mol^-1 and 40.4 kJ·mol^-1 respectively. The observed activation energy of PFA decomposition was 95.4 kJ·mol^-1. The experi-mental results indicated that the decomposition of PFA was liable to occur even at the ambient temperature. Both the spontaneous decomposition and the radical-introduced decomposition contributed to the decomposition of PFA.展开更多
The adsorption of CO2can be enhanced through loading amines on adsorbents,therefore,the separation of CO2from other gases is promoted.Water plays an important role in this process.Water increases both the adsorption a...The adsorption of CO2can be enhanced through loading amines on adsorbents,therefore,the separation of CO2from other gases is promoted.Water plays an important role in this process.Water increases both the adsorption amount of CO2and the separation coefficient with N2for all amines loaded.However,the effect of loading trialkylamines is not remarkable in the absence of water.The effect of loading dialkylamine does not depend on water,but the adsorbent cannot be regenerated at ambient temperature.In comparison,an adsorbent loading trialkylamine can be regenerated at ambient temperature even in the presence of water with fairly good stability.展开更多
In cryogenic wind tunnel tests,piezoelectric stacks are adopted to realize the vibration control of the cantilever sting.However,the free stroke and blocking force of the piezoelectric stack would decrease dramaticall...In cryogenic wind tunnel tests,piezoelectric stacks are adopted to realize the vibration control of the cantilever sting.However,the free stroke and blocking force of the piezoelectric stack would decrease dramatically as the temperature decreases.This paper proposes a convenient and effective warming structure for the piezoelectric stack,which could keep it working at operating temperatures when the ambient temperature drops.The piezoelectric stack actuator is wrapped with the heating film,and this resulting assembly is then wrapped with the aerogel material for thermal insulation.Both ends of the piezoelectric stack actuator make direct contact with the payload structure.Both one-dimensional and two-dimensional theoretical analyses of the heating conduction problem of the piezoelectric stack actuator are conducted.These analyses results are compared with those of the finite element simulation analysis.The finite element method results show a good consistency with the two-dimensional theoretical results,and a slight deviation of only 0.91 K is observed,indicating its potential for protecting piezoelectric stacks at low temperatures.展开更多
The hydrogenation at various temperatures of the (6√3 ×6√3)R30° reconstruction of SIC(0001), the so-called buffer layer graphene (BLG), is investigated. For the BLG, a significant concentration of re...The hydrogenation at various temperatures of the (6√3 ×6√3)R30° reconstruction of SIC(0001), the so-called buffer layer graphene (BLG), is investigated. For the BLG, a significant concentration of remaining dangling bonds related to unsaturated Si atoms of the outermost SiC bilayer is evidenced in the inverse photoemission spectra. These dangling bonds give rise to a peak around 1 eV above the Fermi level, associated with the upper single-electron states of a Mott-Hubbard insulator, which vanishes upon hydrogenation. Hydrogen atoms adsorbed at ambient temperature remain covalently bound to BLG (H-BLG) up to temperatures of -500℃. They induce additional C-Si bonds at the BLG/SiC interface that saturate the remaining Si dangling bonds, as evidenced in both IPES and Auger electron spectra. The H-BLG further shows a large energy gap and an excess n-type doping in comparison to the pristine BLG. Upon hydrogen exposure at higher temperature (〉 700 ℃), hydrogen atoms intercalate at the BLG/SiC interface, inducing the formation of a single layer of quasi-free- standing graphene (QFSG) lying on top of a hydrogenated (√3×√3)R30° reconstruction as supported by IPES. We suggest that the high-stability and the distinct electronic structure of both BLG-derived structures, H-BLG and QFSG, may open a route for the engineering of graphene-based devices.展开更多
文摘目的探讨加温输液与环境加温联合干预对剖宫产低温产妇心理和妊娠结局的影响,为选择使用最佳的保温措施提供理论依据,从而预防低温对剖宫产产妇造成危害。方法选取2019年8月-2020年8月期间该院收治的符合入组标准的80例剖宫产低温产妇作为研究对象。将80例产妇根据随机数字表划分为对照组和观察组,每组各40例。对照组产妇剖宫产术中给予常规护理,观察组产妇在常规护理的基础上给予加温输液和环境加热联合干预,分别比较对照组和观察组产妇的心理情况(焦虑程度、满意度)、术中寒战发生率及不良妊娠结局。结果术前对照组和观察组低温产妇的SAS得分差异无统计学意义(57.6±5.86 vs. 58.3±6.03,t=0.527,P>0.05)。术中观察组低温产妇的焦虑自评量表(SAS)得分显著低于对照组(52.17±6.18 vs. 63.49±6.35,t=8.08,P<0.05)。同时,观察组低温产妇的手术整体满意度显著高于对照组(97.5%vs. 65.0%,χ^(2)=13.867,P<0.05),且术中出现寒战和不良新生儿结局的概率明显低于对照组(2.5%vs. 30.0%,χ^(2)=11.114,P<0.05)。结论加温输液与环境加温联合干预应用于低温产妇剖宫术,能够有效避免患者产生焦虑心理,显著提高患者的满意度,同时能够有效避免低温产妇在术中出现寒战和不良妊娠结局。
基金Supported by the International Cooperation Project of the Ministry of Science and Technology of China (2010DFB40170)the National Basic Research Program of China (973 Program) (2011CB707406)
文摘Performic acid (PFA) is an oxidant used in chemical processing, synthesis and bleaching. The macro kinetic models of synthesis, hydrolysis and decomposition of PFA were investigated via formic acid-autocatalyzed reaction. It was found that the intrinsic activation energies of PFA synthesis and hydrolysis were 75.2 kJ·mol^-1 and 40.4 kJ·mol^-1 respectively. The observed activation energy of PFA decomposition was 95.4 kJ·mol^-1. The experi-mental results indicated that the decomposition of PFA was liable to occur even at the ambient temperature. Both the spontaneous decomposition and the radical-introduced decomposition contributed to the decomposition of PFA.
基金Supported by National Natural Science Foundation of China(No.20876114)
文摘The adsorption of CO2can be enhanced through loading amines on adsorbents,therefore,the separation of CO2from other gases is promoted.Water plays an important role in this process.Water increases both the adsorption amount of CO2and the separation coefficient with N2for all amines loaded.However,the effect of loading trialkylamines is not remarkable in the absence of water.The effect of loading dialkylamine does not depend on water,but the adsorbent cannot be regenerated at ambient temperature.In comparison,an adsorbent loading trialkylamine can be regenerated at ambient temperature even in the presence of water with fairly good stability.
基金the National Natural Science Foundation of China(No.11872207)Aeronautical Science Foundation of China(No.20180952007)+2 种基金Foundation of National Key Laboratory on Ship Vibration and Noise(No.614220400307)Natural Science Foundation of Jiangsu Province(No.BK20200413)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘In cryogenic wind tunnel tests,piezoelectric stacks are adopted to realize the vibration control of the cantilever sting.However,the free stroke and blocking force of the piezoelectric stack would decrease dramatically as the temperature decreases.This paper proposes a convenient and effective warming structure for the piezoelectric stack,which could keep it working at operating temperatures when the ambient temperature drops.The piezoelectric stack actuator is wrapped with the heating film,and this resulting assembly is then wrapped with the aerogel material for thermal insulation.Both ends of the piezoelectric stack actuator make direct contact with the payload structure.Both one-dimensional and two-dimensional theoretical analyses of the heating conduction problem of the piezoelectric stack actuator are conducted.These analyses results are compared with those of the finite element simulation analysis.The finite element method results show a good consistency with the two-dimensional theoretical results,and a slight deviation of only 0.91 K is observed,indicating its potential for protecting piezoelectric stacks at low temperatures.
文摘The hydrogenation at various temperatures of the (6√3 ×6√3)R30° reconstruction of SIC(0001), the so-called buffer layer graphene (BLG), is investigated. For the BLG, a significant concentration of remaining dangling bonds related to unsaturated Si atoms of the outermost SiC bilayer is evidenced in the inverse photoemission spectra. These dangling bonds give rise to a peak around 1 eV above the Fermi level, associated with the upper single-electron states of a Mott-Hubbard insulator, which vanishes upon hydrogenation. Hydrogen atoms adsorbed at ambient temperature remain covalently bound to BLG (H-BLG) up to temperatures of -500℃. They induce additional C-Si bonds at the BLG/SiC interface that saturate the remaining Si dangling bonds, as evidenced in both IPES and Auger electron spectra. The H-BLG further shows a large energy gap and an excess n-type doping in comparison to the pristine BLG. Upon hydrogen exposure at higher temperature (〉 700 ℃), hydrogen atoms intercalate at the BLG/SiC interface, inducing the formation of a single layer of quasi-free- standing graphene (QFSG) lying on top of a hydrogenated (√3×√3)R30° reconstruction as supported by IPES. We suggest that the high-stability and the distinct electronic structure of both BLG-derived structures, H-BLG and QFSG, may open a route for the engineering of graphene-based devices.