Preparation and Properties of Spray Polyurea Elastomer for Aquaculture Foam Floating Balls

[Objectives] This study was conducted to develop a polyurea elastomer which can be sprayed on the surface of expanded polystyrene (EPS) floating balls, so as to improve the surface strength and service life of the floating balls. [Methods] The effects of the types and amounts of isocyanate, chain extenders and polyether polyols on the gelation rate, adhesion and wear resistance of polyurea elastomer were investigated, and it was finally determined the preparation process of polyurea elastomer using liquid isophorone diisocyanate (IPDI) and amino-terminated polyether (D2000) as the main raw materials, dimethylthiotoluene diamine (E300) as the chain extender and silica as the wear resistance modifier through two-step solution polymerization of prepolymerization and chain extension. [Results] The physical properties and chemical resistance tests of spray polyurea elastomer showed that it had good physical properties and acid and alkali resistance, and could meet the requirements of spraying and protection of EPS floating ball surface in marine environment. [Conclusions] Polyurea elastomer coating can improve the aging resistance, wear resistance and acid and alkali resistance of EPS floating balls, and prevent them from being fragile and floating randomly to form marine floating garbage which results in "white pollution".

老龄化背景下智慧健康养老服务与管理专业学生专业认同现状及影响因素研究

探讨智慧健康养老服务与管理专业学生的专业认同水平及其相关影响因素,为制定提高专业认同水平的教学改革方案提供依据。

养老机构老年人灵性健康与迁移应激相关性研究

目的 了解重庆市养老机构老年人灵性健康与迁移应激现状,并分析二者的相关性。方法 2021年12月至2022年6月采用一般资料调查表、灵性健康简表、应激反应问卷便利抽取重庆市6家养老机构150名老年人进行问卷调查。结果 150名老年人平均灵性健康总分为(3.44±0.86)分,平均迁移应激总分为(2.16±0.81)分。灵性健康与迁移应激呈明显负相关,除宗教寄托维度外,灵性健康各维度与迁移应激各维度均呈明显负相关,差异均有统计学意义(P<0.05)。结论 养老机构老年人灵性健康及迁移应激均处于中等水平,二者间存在相关性。养老机构照护人员应重视老年人的灵性需求,采取措施提高其灵性健康水平,帮助老年人缓解迁移应激,进而改善其生活质量和养老服务质量。

基于压力驱动多液滴浸润状态响应调控

液液界面浸润性可控操作的实现,在界面纳米有序结构组装、液体透镜调节、航空航天等方面具有重要意义。从宏观尺度研究了以表面活性剂溶液为底液的液液界面浸润问题,进行以表面活性剂溶液为底液、正十六烷为操控对象的浸润可控调节研究,分析界面单层活性剂分子在液体动态浸润性变化过程中的内在机理,选择固定浓度的表面活性剂溶液,以此匹配最佳的正十六烷铺展状态。通过拉压驱动液面的方式改变液滴铺展状态:挡板拉伸时,每个液滴浸润面积增大,并产生液滴形变;挡板压缩后,浸润面积减小,恢复圆环形状。实现了浸润状态的动态响应。通过拉压,实现了对单液滴的铺展–收缩的控制,在单液滴的基础上实现了双液滴、三液滴浸润状态的协同。

Relevant detection indicator of prethrombotic state in patients with primary hypertension

BACKGROUND Hypertension is a common chronic disease that affects many people worldwide.Only a few reports related to the exploration of relevant indicators of the prethrombotic state in patients with primary hypertension(PH)in clinical settings were available.AIM To detect prethrombotic state-related indicators in patients with PH and analyze their differences in different patient populations to provide a laboratory basis for the clinical prevention and control of hypertensive thrombotic diseases.METHODS The general data of patients with PH who attended the Department of Cardiovascular Medicine,The First Affiliated Hospital of Jiangxi Medical College,from January 2022 to December 2022 were collected retrospectively.The patients were divided into three groups of 40 patients each according to the Grade of PH:Grade 1,Grade 2,and Grade 3 hypertension experimental group.The baseline data of 40 volunteers,who underwent physical examination in our hospital but were not diagnosed with PH during the same period,were included in the control group.The relevant indicators of prethrombotic state of the participants were compared,and mainly included inflammation-related indicators,hemorheology-related indicators,and coagulation function related indicators.The relationship between the aforementioned indicators and the progression of PH was analyzed.RESULTS No significant differences were observed in age,sex,diabetes mellitus,smoking history,drinking history,body mass index,New York Heart Association functional classification,or the course of hypertension among the four groups(P>0.05).The expressions of high-sensitivity C-reactive protein(hs-CRP),thrombomodulin(TM),hematocrit(Hct),erythrocyte sedimentation rate(ESR),P-selectin on platelet surface(CD62P),and fibrinogen(FIB)in the control group were<Grade 1 hypertension group<Grade 2 hypertension group<Grade 3 hypertension group,and the expressions of platelet(PLT),activated partial thromboplastin time(APTT),prothrombin(PT),and plasma thrombin time(TT)in the control group was>Grade 1 hypertension group>Grade 2 hypertension group>Grade 3 hypertension group,and the difference was statistically significant(P<0.05).The results of the multivariate logistic regression model showed that the expression of hs-CRP,TM,Hct,ESR,CD62P,PLT,APTT,PT,TT,and FIB in the included participants was related to the progression of PH.Among these,high expression of hs-CRP,TM,Hct,ESR,CD62P,APTT,PT,and TT,and low expression of PLT and FIB were risk factors for PH(OR>1,P<0.05).The results of the receiver operating characteristic curve analysis showed that the area under the curve of hs-CRP,TM,ESR,CD62P,APTT,PT,TT,and FIB for the prediction of PH were>0.80,and the prediction value was ideal.Linear correlation analysis with bivariate Spearman showed that hs-CRP,TM,Hct,ESR,CD62P,APTT,PT,and TT were positively correlated with each other(r>0,P<0.05);PLT and FIB were negatively correlated with hs-CRP,TM,Hct,ESR,CD62P,APTT,PT,and TT(r<0,P<0.05);and PLT and FIB were positively correlated(r>0,P<0.05).Linear correlation analysis using bivariate Spearman showed that hs-CRP,TM,Hct,ESR,CD62P,and FIB were positively correlated with each other(r>0,P<0.05),whereas PLT,APTT,PT,and TT were negatively correlated with hs-CRP,TM,Hct,ESR,CD62P,and FIB(r<0,P<0.05).There was a positive correlation between PLT,APTT,PT,and TT(r>0,P<0.05).CONCLUSION The relevant indicators of the prethrombotic state in patients with PH,such as hs-CRP,TM,Hct,ESR,CD62P,PLT,APTT,PT,TT,and FIB,showed differences.High expression of hs-CRP,TM,Hct,ESR,CD62P,and FIB,and low expression of PLT,APTT,PT,and TT are the keys to the occurrence,progression,and thrombotic state of PH.Based on the above serum indicators’expression in patients,targeted interventions can be administered to patients with abnormal expression levels to control the progression of their disease and reduce the risk of developing a prethrombotic state.

Renewable Energy Seawater Desalination Technology and Application Analysis

This paper proposed a new technology way for seawater desalination which used renewable energy(wind energy and solar energy).The effects of practical application showed that remote islands and cage culture zones in the bay that lack electricity and water are very suitable for using small seawater desalination devices that do not require consumption of conventional energy.

应用德尔菲法构建高职护生临床实践能力客观结构化考核评价指标

目的构建一套科学、可行、实用的高职护生临床实践能力客观结构化考核(OSCE)评价指标。方法在文献回顾的基础上,通过课题组讨论,初步编制高职护生临床实践能力OSCE评价指标体系,应用德尔菲法进行两轮专家函询,对函询结果进行统计学分析,最终形成高职护生临床实践能力OSCE评价指标。结果最终构建的高职护生临床实践能力OSCE评价指标包括6项一级指标(健康史采集、身心评估、技能操作、健康教育、评判性思维、职业素养),25项二级指标,权重排名前两位的一级指标分别是“技能操作”和“健康教育”。函询专家的代表性和信度均较高,两轮专家函询的权威程度分别为0.87和0.90。结论高职护生临床实践能力OSCE评价指标能用于全面评价高职护生的护理临床实践能力,为高职护理专业教学改革提供科学依据。

基板和流速对羟基磷灰石生长的影响

通过共混制备聚二甲基硅氧烷(PDMS)/羟基磷灰石(HAP)和PDMS/生物玻璃复合材料作为生长基板,研究了静止条件下不同基板上HAP的生长.设计了一套流速加载装置,观察模拟体液流速对生物玻璃基板上HAP晶体生长的影响.研究发现在静止条件下,HAP晶体在PDMS复合材料上比在生物玻璃上生长更快,尺寸更大;随着流速的增加,HAP晶体尺寸更大而且无定形沉淀数量减少.

基于Marangoni效应的液-液驱动铺展过程

液体表面的液滴运动在微流体和许多生物过程中具有广泛的应用前景.本文通过研究在液体基底上一种低表面张力液体对另一液体的驱动来理解Marangoni效应在自发驱动体系中的作用.为了研究液体驱动的液滴铺展过程,建立了以不易挥发性硅油作为驱动溶剂、正十六烷作为受驱动液滴,以及不同浓度的十二烷基硫酸钠溶液作为基底溶液的实验体系.通过对正十六烷液滴受驱动铺展动态过程的观察和研究,发现界面张力梯度对液体驱动的铺展起主导作用.实验结果表明:基底溶液浓度主要对正十六烷液滴的最大铺展半径存在影响.此外,用经典稳定性分析模型解释了正十六烷在受驱动铺展过程中由液柱破碎成小液滴的原因,同时得到了失稳特征参数最快不稳定波长与正十六烷液柱半径之间的关系.

液-液驱替动力学研究

Marangoni效应是一种液体在界面张力梯度作用下的自发流动行为.液体界面上液体的Marangoni效应在工程技术领域具有重要作用.本文使用硅油作为驱动液体,正十六烷作为被驱动液体,十二烷基硫酸钠溶液作为液体基底,通过高速相机捕捉正十六烷受驱动铺展的整个过程,研究了三相液体系统中液滴的Marangoni效应.实验发现,正十六烷在硅油的驱动下从内向外铺展,形成液体圆环.本文根据正十六烷圆环内、外边界铺展行为,分析了正十六烷内边界和外边界的铺展原理,并研究了滴入硅油体积对于铺展过程的影响.研究发现,正十六烷内边界铺展与单一液滴的铺展规律相同,正十六烷内边界前期铺展由重力主导,内边界铺展标度律在R~t^(1/4)到R~t^(1/2)范围.随后铺展由界面张力梯度主导,内边界铺展标度律为.因内边界铺展受重力影响,内边界的铺展速度与硅油体积成正相关.而正十六烷外边界在硅油驱动下,因接触角改变而产生界面张力梯度,在界面张力梯度作用下外边界铺展标度律为R~t^(3/4).

Picosecond terahertz pump-probe realized from Chinese terahertz free-electron laser

Electron energy relaxation timeτis one of the key physical parameters for electronic materials.In this study,we develop a new technique to measureτin a semiconductor via monochrome picosecond(ps)terahertz(THz)pump and probe experiment.The special THz pulse structure of Chinese THz free-electron laser(CTFEL)is utilized to realize such a technique,which can be applied to the investigation into THz dynamics of electronic and optoelectronic materials and devices.We measure the THz dynamical electronic properties of high-mobility n-GaSb wafer at 1.2 THz,1.6 THz,and 2.4 THz at room temperature and in free space.The obtained electron energy relaxation time for n-GaSb is in line with that measured via,e.g.,four-wave mixing techniques.The major advantages of monochrome ps THz pump-probe in the study of electronic and optoelectronic materials are discussed in comparison with other ultrafast optoelectronic techniques.This work is relevant to the application of pulsed THz free-electron lasers and also to the development of advanced ultrafast measurement technique for the investigation of dynamical properties of electronic and optoelectronic materials.

Dynamic microwave-assisted extraction combined with liquid phase microextraction based on the solidification of a floating drop for the analysis of organochlorine pesticides in grains followed by GC

A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides in grains including rice,maize and millet.Twelve samples can be processed simultaneously in the method.During the extraction process,10%acetonitrile-water solutions containing 110μL of n-hexadecane were used to extract organochlorine pesticides.Subsequently,1.0 g sodium chloride was placed in the extract,and then centrifuged and cooled.The n-hexadecane drops containing the analytes were solidifi ed and transferred for determination by gas chromatography-electron capture detector without any further filtration or cleaning process.Limits of detection for organochlorine pesticides were 0.97–1.01μg/kg and the RSDs were in the range of 2.6%–8.5%.The developed technology has succeeded in analyzing six real grains samples and the recoveries of the organochlorine pesticides were 72.2%–94.3%.Compared with the published extraction methods,the developed method was used to analyze organochlorine pesticides in grains,being more environmentally friendly,which is suitable for the daily determination of organochlorine pesticides.

Manipulation of Colloidal Droplets in Space and the Instability of Thermocapillary Convection in Large Prandtl Number Liquid Bridge in Microgravity

In 2016 and 2017, SJ-10 and TG-2 satellites were launched. In this short paper, we report recent progress on the studies of manipulation of colloidal droplets and instability of thermocapillary convection in large Prandtl number liquid bridge that based on the space experiments boarding SJ-10 and TG-2 satellites,separately. It was shown that the colloidal droplets can be successfully formed and manipulated in microgravity through the patterned substrates. In another aspect, the coffee-ring effect was observed at the first time in space. For the studies of the instability of thermocapillary convection in large Prandtl number liquid bridge in microgravity, our experiments in TG-2 broadened the way of such kind of study and abundant experimental results are emerging.

Frequency domain based super-resolution method for mixed-resolution multi-view images

Super-resolution (SR) techniques, which are based on single or multi-frame low-resolution (LR) images, have been extensively investigated in the last two decades. Mixed-resolution multiview video format plays an important role in three-dimensional television (3DTV) coding scheme. Previous work considers multiview or multi-camera images and videos at the same resolution, which performs well under the planar model without or with little projection error among the videos captured by different cameras. In recent years, several researchers have discussed the SR problem in mixed-resolution multi-view video format, where the superresolved image is created using the up-sampled version of the LR image and the high frequency components extracted from the warped image in the adjacent high-resolution (HR) views. Unfortunately, the output HR images suffer from artifacts caused by depth error. To obtain the detailed texture and edge information from the HR image as much as possible, while preserving the structure of the LR image, a novel SR reconstruction algorithm is proposed. The algorithm is composed of three components: the structure term, the detail information term, and the regularization term. The first term preserves the structure similarity of the LR image; the second term extracts detailed information from the adjacent HR image; and the last term ensures the uniqueness of the solution. Experimental results show the effectiveness and robustness of the proposed algorithm, which achieves high performance both subjectively and objectively. ? 2016 Beijing Institute of Aerospace Information.

Recent Progress of Microgravity Science Research in China

Microgravity science is an important branch of space science.Its major objective is to study the laws of materials movement in microgravity,as well as to reveal the influence of gravity on the movement of materials in different gravity environments.Application researches relevant to these basic studies are also important contents of microgravity science.The advanced subjects,to some extent,reflect the ability of human beings to understand nature and the R&D level in this field in various countries.In this paper,the recent progress and the latest achievements of microgravity science and application researches in China aboard space platforms such as the Core Capsule Tianhe of the China Space Station(CSS)and satellites,as well as utilizing ground-based short-term microgravity facilities such as the Drop Tower Beijing and TUFF,are summarized,which cover the following sub-disciplines:microgravity fluid physics,microgravity combustion science,space materials science,space fundamental physics,space bio-technology,and relevant space technology applications.

Relationship of depression and sleep quality,diseases and general characteristics

BACKGROUND Depression is the most common type of depressive disorder.The most common sleep disorder associated with depression is insomnia.Insomnia and depression are closely related.AIM To investigate the relationship of designed questionnaire items and depression,and analyze the related factors with depression.METHODS Questionnaire included Patient Health Questionnaire-9(PHQ-9)and Pittsburgh sleep quality index(PSQI),12 kinds of diseases,8 general characteristics,and 20 insomnia characteristics,totally 56 items were filled out by 411 patients enrolled.RESULTS All the 9 items of PHQ-9,6 components of PSQI(except sleep duration),education,living situation,exercise,years of insomnia,western medicine treatment,Chinese medicine treatment,psychotherapy,kinds of insomnia,treatment expected to treat insomnia,psychological counseling,habit of 1 h before bed,habit of lunch break,diagnosed depression,coronary heart disease,mental illness showed significant difference between without and with depression group.By univariate analysis and multivariate analysis.The odds ratio of education,exercise,kinds of insomnia,habit of 1 h before bed,diagnosed depression,coronary heart disease(P=0.01)showed significant difference.Their odds ratios were 0.71(0.55,0.93),2.09(1.32,3.31),0.76(0.63,0.91),0.89(0.81,0.98),0.32(0.17,0.60),0.43(0.23,0.79).CONCLUSION We demonstrated that education,exercise,kinds of insomnia,habit of 1 h before bed,diagnosed depression and coronary heart disease affect the depression.

中国儿童青少年近视防控的现状和思考

近视是一种常见眼病,已成为中国儿童青少年视力下降的主要原因。2020年我国儿童青少年总体近视率为52.7%,近视低龄化问题仍突出,且高度近视数量逐年增加。虽然国家将近视防控上升到战略层面,但仍没有彻底改变现状,仍有很多难点和瓶颈没有得到解决。近视的病因复杂,还无法找到一条普适的防控策略。针对近视防控的现状,笔者思考了医工交叉协助方式,从儿童青少年眼发育及近视认知理念出发,以屈光发育档案为指导,建立屈光发育档案数据采集标准体系,并建立纵向数据的精准预测,为儿童青少年眼健康的早预警、早预防提供手段。以期为突破近视防控的瓶颈提供解决方案。

Controllable Emission via Tuning the Size of Fluorescent Nano-probes Formed by Polymeric Amphiphiles

Incorporating fluorophores into polymeric nanoparticles has been testified as a feasible way to improve the emitting property and bio-compatibility of nano-emitters, which can be applied as fluorescent probes in labeling cells for imaging. Plenty of efforts have been made on the above direction. However, the size effect of nano-emitters has not been addressed yet mainly given the difficulties in controlling morphology and size of the assemblies. In our preceding study, we employed post-polymerization modification method for preparing amphiphilic copolymers, and obtained core-shell(the hydrophobic fluorophores are wrapped inside the nanoparticle to form the core) assemblies in aqueous solution. By this method, we are able to regulate the ratio of the hydrophilic/hydrophobic moieties, and thus alternate the size of the assemblies in a rather simple way. In this study, we synthesized a series of random copolymers by changing the ratio of poly(ethylene glycol) to tetraphenylethylene groups. Notably, the number of repeating units of the polymer was controlled constant for all the copolymers. The self-assembly of these copolymers resulted in different sizes of nanoparticles, and the size decreased with the decreasing fraction of poly(ethylene glycol). Interestingly, the emission of the nanoparticles showed size dependence, and smaller diameter corresponded to stronger emission. Being cultured with HeLa cells, either the large(diameter of ~300 nm) or the small(diameter of ~180 nm) nano-emitters allowed for very high cell viabilities up to 25 μg·mL-1. Both of them can be applied in cell imaging and provide high contrast fluorescent images.

Crack and size-dependence of shear modulus in a drying particulate film

We utilized controlled vertical drying deposition (CVDD) method,which can fabricate a uniform face-center-cubic (FCC) structure film,to investigate the crack formation and the size dependence of shear modulus in a drying particulate film.We found that both crack spacing and shear modulus depend on colloidal particle size.They drop with increase of particle radius (R) in a single range.Furthermore,compared with the shear modulus variation of a dry particulate film,it was found that both solid part and liquid part in a drying particulate film play equivalent roles in the film mechanical behavior.

Recent progress of quantum dots for energy storage applications

The environmental problems of global warming and fossil fuel depletion are increasingly severe,and the demand for energy conversion and storage is increasing.Ecological issues such as global warming and fossil fuel depletion are increasingly stringent,increasing energy conversion and storage needs.The rapid development of clean energy,such as solar energy,wind energy and hydrogen energy,is expected to be the key to solve the energy problem.Several excellent literature works have highlighted quantum dots in supercapacitors,lithium-sulfur batteries,and photocatalytic hydrogen production.Here,we outline the latest achievements of quantum dots and their composites materials in those energy storage applications.Moreover,we rationally analyze the shortcomings of quantum dots in energy storage and conversion,and predict the future development trend,challenges,and opportunities of quantum dots research.