Genetic transformation of Platymonas (Tetraselmis) subcordiformis (Prasinophyceae, Chlorophyta) using particle bombardment and glass-bead agitation

Platymonas (Tetraselmis) subcordiformis is a unicellular marine green alga. It was found to be very sensitive to the herbicide Basta through a sensitivity test indicating it could be employed as a selective agent. The bar gene is a practicable and selectable marker gene. The vector containing the expression cassette of the bar gene was transferred to P. subcordiformis by both particle bombardment and glass-bead agitation and transformants were then selected using Basta. Finally, Southern blotting analysis indicated that the bar gene had been successfully integrated into the nuclear genome of P. subcordiformis using both of the transgenic techniques, with the transformation efficiency of the glass-bead method being slightly higher than that of particle bombardment. This is the first report on stable transformation of P. subcordiformis, and will improve fundamental research and enlarge application of this alga.

STUDY ON PHASE-SEPARATION OF PMMA/SAN BLENDS INDUCED BY GLASS BEADS THROUGH DYNAMIC RHEOLOGICAL MEASUREMENTS

Based on the premise that the addition of glass beads(GB)could hardly influence the linear viscoelasticity in low frequency(ω)region for homogeneous polymer systems,the dynamic rheological behaviors of unfilled and filled poly(methyl methyacrylate)(PMMA)/poly(styrene-co-acrylonitrile)(SAN)blends were studied in order to explore the effect of GB on the phase-separation of binary polymer matrix.Results show that GB has an induced effect on the phase-separation, which embodies that the phase-separation temperature(T_s)of PMMA/SAN blend filled with GB is lower than that of the unfilled system.The higher content of GB,the higher is the“secondary plateau”of ω in the terminal region of storage modulus(G')versus ω plot.The“secondary plateau”appearing in the terminal region is attributed to the phase-separation of PMMA/SAN blends and it becomes more flat for filled polymer blends under the same conditions.However,it is suggested that this kind of“induced effect”is related to the GB content;the higher content of GB particles might enhance the interaction between the particles and polymer matrix.Moreover,it is found that the addition of GB also has an influence more or less on the morphology and domain size of polymer matrix.It is believed that the plot of dynamic viscosity(η') versus the loss viscosity(η')is sensitive to examine the effect induced by GB on the phase-separation of binary polymer matrix.

Effect of surface treatment on rheological behaviors of glass bead/hydroxyl terminated polybutadiene suspensions

Surface treatment of glass bead(GB) was carried out by using γ-glycidoxypropyltrimethoxy silane(GPTES) and γ-methacryloxypropyltrimethoxy silane(MPTMS) as coupling agents,respectively.The steady viscosity and yield stress of the GB/hydroxyl terminated polybutadiene(HTPB) suspensions were determined by Brookfield R/S rheometer.The effect of surface treatment on the viscosity and yield stress of GB/HTPB suspension was investigated.The results indicate that the viscosity of the pristine GB/HTPB suspension increases with increasing GB,and the relationship between its viscosity and volume fraction of GB depends on the shear rate.The modification of GB by MPTMS changes the viscosity of the MPTMS@GB/HTPB suspension,and its viscosity is the minimum at the MPTMS dosage of 0.3 g per 1 g GB.Additionally,the modification of GB by MPTMS increases the yield stress of the GB/HTPB suspension,and its yield stress is the maximum at the MPTMS dosage of 0.1 g per 1 g GB.The GPTES modified GB/HTPB suspension behaves lower viscosity and weaker shear thinning than the MPTMS modified GB/HTPB suspension within the range of experimental shear rate.

EFFECT 0F INTERFACIAL ADHESION ON CRYSTALLIZATION AND MECHANICAL PROPERTIES OF POLY (ETHYLENE TEREPHTHALATE)/GLASS BEAD COMPOSITES

The interfacial adhesion between poly (ethylene terephthalate) (PET) and glass beadwas investigated by scanning electron microscope and parallel-plate rheometer. Effect ofinterfacial adhesion on the crystallization and mechenical properties of PET/glass beadcomposites was also studied by differential scanning calorimeter and mechanical testers.The results obtained indicate that the glass bead has a heterogeneous nucleation effecton the PET crystallization. Although better interfacial adhesion is advantageous to theincrease of the tensile strength of the composite, yet it is unfavorable to the crystallizationof PET. It should be pointed out that the crystallization rate of filled PET is always higherthan that of pure PET, regardless of the state of interfacial adhesion.

Triaxial test on glass beads simulating coarse-grained soil

It is feasible to study the mechanical characteristics of coarse-grained soil by simulated granular materials such as glass beads.In this paper,3 mm diameter glass beads are used to conduct drained and undrained triaxial tests under different confining pressures to explore their strength,deformation and critical state characteristics.Specifically,the influence of drainage and confining pressure on the stick-slip phenomenon of glass beads is reported.The experimental findings from triaxial tests show that the stress-strain relationship of glass beads softens when the confining pressure is high.Under the undrained condition,the initial modulus increases with the increase in the confining pressure.In contrast,it is not significantly affected by the confining pressure in the drained condition.It is quite evident that the glass beads hardly contract during the shearing process,and their stress path is approximately a segmented straight line.The slope of the critical state line under the undrained condition is greater than that under the drained condition,and the friction angle of the glass beads under the undrained and drained conditions is calculated to be 28.1and 29.5,respectively.The phenomenon of stick-slip has been depicted for the different test conditions,and the stick-slip amplitude linearly increases with the confining pressure,especially in the undrained condition.It is also found that the maximum energy released from the phenomenon of stick-slip increases linearly with the confining pressure.

Effect of Fe_(2)O_(3) on the Formation of Micro Glass Beads under Air Staged Combustion

The effect of Fe_(2)O_(3) on the formation of micro glass beads(MGBs)under air staged combustion was studied.The experimental temperature was 1450℃,and Hegang bituminous coal was used as the experimental object.X⁃ray diffractometer(XRD),ash fusion tester,viscosity formula and scanning electron microscopy(SEM)were used to analyze the fly ash.Nano Measurer 1.2 software was used to measure the diameter of MGBs.The results showed that with the increase of Fe_(2)O_(3) in Hegang coal,the glass phase in fly ash first increased and then decreased.When the amount of Fe_(2)O_(3) was 15%,the content of the glass phase was the highest,which was 51.26%.The ash melting point first decreased and then increased,while the viscosity gradually decreased and the particles gradually became spherical.With the increase of Fe_(2)O_(3),the proportion of MGBs with particle size less than 10μm increased gradually.From the above results,it can be concluded that the addition of Fe_(2)O_(3) is conducive to the formation of MGBs and the reduction of particle size.

Preparation and Properties of Ni-plated Glass Beads/PVC Composite

Ni-plated glass beads(GB) was obtained by electroless plating, based on PVC adhesive, Niplated GB/PVC composite was prepared. Temperature insulation, fi re retardation and microwave absorption properties were tested, the results showed that the nickel coating was compact and continuous, Ni-plated GB/ PVC composite is a kind of excellent temperature insulated, fi re retardate and light-weight material, and especially for microwave absorption well; Refl ectivity was lower than-2 dB in the frequency range of 11-17 GHz.

PRELIMINARY STUDY ON RETRO-REFLECTIVE COATED PAPER BASED ON MICROGLASS BEADS

High-reflectivity micro-glass bead, as a kind of retro-reflective material, is widely used in reflective fabric or film and other reflective coatings. But it is rarely used in coated paper. The retro-reflective theory of micro-bead is described. Also the effect of size of micro-bead, dosage of binder and different color layers on reflective properties of coated paper are discussed in this article. The results show that its retro-reflective efficiency is good, equally to reflective fabric or film when the micro-glass bead is used in coated paper.

Study on Surface Modification of Glass Bead by a Block Copolymer Coupling Agent

A tri-block copolymer coupling agent polystyrene-block-poly(n-butyl-acrylate)-block-poly(γ-methacryloxypropylt rimethoxysilane)(PS-b-PnBA-b-PMPS)was synthesizedby atom transfer radical polymerization(ATRP),and its molecular structure was characterized by fourier-transform infrared spectra,hydrogen nuclear magnetic resonance and gel permeation chromatography.The glass bead was treated with the block copolymer coupling agent,and then studied by transmission electron microscopy.The result showed that strong interaction was formed between the block copolymer coupling agent and the surface of glass bead,and then the block of poly(n-butylacrylate)formed a layer of film on the surface.

汗液老化对玻璃微珠反光材料性能的影响

反光材料具有良好的夜间可视性,在夜间及视线较差的环境下给人们提供有效可靠的安全保障,被广泛应用于特殊作业服装等领域。为了科学评估反光布的安全防护作用,探讨汗液对玻璃微珠反光材料性能的影响,对反光材料分别进行1、5、10、20、25、30、40、50次酸碱汗液老化实验,对试样外观特征、色差、微观结构、逆反射系数进行实验与分析。结果表明:老化后试样有不同程度的玻璃微珠脱落、铝层溶出、表面盐结晶析出等现象,导致反光材料性能下降;试样的反光性能随酸碱汗液老化次数的增加先提升后下降,汗液老化次数大于5次,逆反射系数呈下降趋势,其中酸性汗液相比于碱性汗液对反光材料性能的影响更显著;经过酸性汗液老化50次,试样的逆反射系数下降了2.97%~12.86%。

表面活性剂对玻璃微珠镀银微观结构及性能影响

利用硅烷偶联剂KH792对小粒径玻璃微珠(GMs)表面进行修饰改性,以葡萄糖为还原剂,通过化学镀法制得玻璃微珠镀银(GMs@Ag)复合粒子,探讨了不同类型表面活性剂对样品物相、微观结构、外观及电性能的影响。将该复合粒子作为导电填料,制备柔性电磁屏蔽织物,对样品的电磁屏蔽性能进行了测试。结果表明:添加聚乙烯吡咯烷酮(PVP)和阿拉伯树胶(AG)复合表面活性剂制备的GMs@Ag镀层致密、均匀、连续,粉末电阻率值为12.4mΩ·cm,在其添加量为70%,在电磁波频率为30~1500MHz下,涂层的电磁屏蔽效能可达到40dB以上,有一定的应用前景。

乌兹别克斯坦拜松市拉巴特墓地出土珠饰的分析研究

2017年—2018年度,中乌联合考古队在乌兹别克斯坦共和国拜松市拉巴特墓地进行了考古发掘,发掘墓葬94座,出土了丰富的遗迹遗物。考古学初步研究表明,该墓地为公元前2世纪末到公元2世纪的一处月氏文化墓地,文化因素丰富,为古代月氏文化面貌研究及北巴克特里亚地区公元前2世纪至公元2世纪的古代文化研究提供了重要的考古新资料。拉巴特墓地发掘中出土各类材质珠饰1 500余件,选取了其中典型人造硅酸盐质珠饰残样13件,采用超景深三维显微系统(OM)、能量色散型X射线荧光光谱(EDXRF)、扫描电子显微镜能谱分析(SEM-EDS)、激光拉曼光谱(Raman)等方法对其进行了科技分析,确定了这些人造硅酸盐质珠饰的材质属性和部分制作工艺相关信息,结合材质和工艺特点探讨了拉巴特墓地人造硅酸盐质珠饰可能的产地。结果表明,该遗址人造硅酸盐质珠饰包括富钠费昂斯、泡碱型钠钙玻璃、植物灰型钠钙玻璃、高镁钠钙玻璃、矿物碱型钠铝玻璃、植物灰型钠铝玻璃和钾玻璃等多种材质。其中,富钠费昂斯的产地与西亚有关;已分析出的六类玻璃产地涉及西亚、地中海周边、印度、巴基斯坦、中亚等多个地区。研究表明拉巴特墓地所处区域在公元前2世纪末期到公元2世纪文化面貌丰富,与西亚、地中海、南亚等地的经济贸易往来频繁、人群间文化互动丰富。

有机硅/改性空心玻璃微珠复合材料的制备与性能研究

以缩合型有机硅为有机树脂基体,以改性空心玻璃微珠为无机填料,基于物理复合法制备出不同空心玻璃微珠含量的有机硅/改性空心玻璃微珠复合隔热材料。系统性研究其隔热机理、隔热性能、力学性能和热稳定性能,实现对复合隔热材料孔隙率和隔热性能的精准调控。研究结果表明,所制得的复合隔热材料的压缩强度最大值达到13.28 MPa,是纯有机硅材料的1.49倍,热导率最低为0.113 W/(m·K),比纯有机硅材料减小了37.91%。

低吸水率水性隔热保温涂料的制备及性能

[目的]随着水性隔热保温涂料在工业涂装领域的广泛应用,其吸水率较高引发的涂层隔热性能下降问题亟需解决。[方法]以苯丙乳液作为主要成膜物,以偶联剂表面改性的中空玻璃微珠作为隔热填料,以涂层的导热系数和吸水率作为主要性能指标,制备了一种低吸水率的水性隔热保温涂料。通过傅里叶变换红外光谱仪(FT-IR)对不同偶联剂处理的中空玻璃微珠进行了表征,通过扫描电子显微镜(SEM)考察了涂层的微观结构和形貌,测试了浸水前后涂层的导热系数、力学性能和粘结强度。[结果]铝酸酯偶联剂的改性效果比硅烷偶联剂好。当铝酸酯偶联剂改性中空玻璃微珠添加量为25%(质量分数)时,涂层的综合性能最优,24 h吸水率为9.32%,浸水168 h后的导热系数为0.1228 W/(m·K),拉伸强度为2.45 MPa,断裂伸长率为28.37%,拉拔法粘结强度为2.32 MPa。[结论]采用合适的偶联剂对中空玻璃微珠进行表面改性可有效改善隔热保温涂料体系中有机-无机界面的相容性,从而降低其吸水率,增强其力学性能。

广西越州故城遗址玻璃珠饰的科学研究

本研究利用能量色散型X射线荧光光谱分析、共聚焦激光拉曼光谱分析、光学相干层析成像、超景深光学显微观测等多种方法对广西越州故城遗址出土的印度-太平洋玻璃珠饰进行科技分析,获取了玻璃珠的化学成分、物相结构、内部物理结构、表面显微形貌等综合物理化学信息,确定了玻璃珠的玻璃体系、制作工艺(着色工艺、成形工艺)和产地来源,探讨了以丝绸之路为主线的国内发现魏晋南北朝时期印度-太平洋玻璃珠可能的输入路线。广西越州故城遗址发现的印度-太平洋玻璃珠为中外文明交流提供了新实物证据,对深入研究我国南北朝时期中外文明交流具有十分重要的学术价值和研究意义。

水性反射隔热型涂料的制备及性能影响因素探究

研究了反射隔热涂料中重要组分对其性能的影响规律。以纯丙乳胶作为成膜物,空心玻璃微珠和金红石型二氧化钛作为功能填料,在基本配方体系基础上,通过单一变量控制法研究了空心玻璃微珠、金红石型二氧化钛的尺寸及添加量等因素对反射隔热涂料透水及耐沾污性、太阳光反射性能和隔热性能的影响规律,并制备得到综合性能优异的水性反射隔热涂料。研究结果表明,反射隔热填料不仅影响涂层的太阳光反射和隔热性能,对于涂层的耐水和耐沾污性也有显著影响。

机器人喷涂用低密度聚氯乙烯焊缝密封胶的制备与性能研究

本文制备了一种机器人喷涂用低密度聚氯乙烯焊缝密封胶,分别研究了玻璃微珠种类、组分、加入量、生产工艺对试样密度、流淌性、黏度、抗压性能等的影响。结果表明:试样的密度与玻璃微珠性能有关;玻璃微珠的抗压性能影响现场施工喷涂后试样的最终密度。随玻璃微珠质量分数的增加,试样稳定性提高,密度逐渐变小,但拉伸强度和弯曲试验结果均会下降,流淌性也会受影响。批量生产时,高速分散和三辊研磨会影响玻璃微珠的降低密度效果,采用预混合及低速循环搅拌方式使玻璃微珠和物料分散均匀。

氨基-磷酸改性铁基空心玻璃微珠催化剂用于天然气湿法氧化脱硫

目的为了避免常规天然气湿法氧化脱硫工艺中硫磺沉积引发的设备堵塞问题,开发了一种氨基-磷酸双官能团改性的铁基空心玻璃微珠(HGB)催化剂,用于脱硫-再生分步进行方案中脱硫富液的非均相催化氧化再生。方法采用红外光谱表征催化剂的结构。通过静态脱硫实验研究了硅烷偶联剂KH-550的配比、焙烧温度、FeCl 3投加量等因素对脱硫剂再生及脱硫效果的影响,并考查了催化剂的重复使用性能。结果氨基-磷酸改性铁基HGB催化剂可实现脱硫富液的有效再生,且能在酸性的脱硫液中保持稳定,在温度为300℃下焙烧6 h、HGB与KH-550质量比为1∶8、HGB与FeCl_(3)·6H_(2)O质量比为1∶5的条件下制备的铁基HGB催化剂具有最佳催化性能,对脱硫液重复再生3次后,脱硫液性能基本保持稳定。红外光谱分析结果表明催化剂结构保持完好。结论氨基-磷酸改性铁基HGB催化剂在天然气湿法氧化脱硫领域中对脱硫富液的再生具有较好的效果,可为目前脱硫富液的再生提供新的选择。

低密度高导热CF/EP复合材料的制备及性能

将碳纳米管(CNT)和空心玻璃微珠(HGS)添加到环氧树脂(EP)中,利用模压工艺制备碳纤维(CF)/EP复合材料。结果表明:同时添加CNT和HGS可以有效降低CF/EP复合材料的密度,改善复合材料的力学性能,提高复合材料的导热性能,且当CNT和HGS质量比为1∶4时,复合材料综合性能最优,与不添加CNT和HGS的CF/EP复合材料相比,该复合材料的密度下降了8.8%,弯曲强度和弯曲模量分别提高了22.0%和30.1%,拉伸强度提高了8.9%,导热系数提高了87.1%。

实时荧光定量PCR检测不同结核标本及其联合玻璃珠磨菌法检测的价值

目的研究实时荧光定量聚合酶链式反应(qRT-PCR)与玻璃珠磨菌法联合用于不同结核标本检测中的价值。方法以回顾性分析为法,收集并分析2021年1月至2022年6月在上海交通大学医学院附属仁济医院住院与门诊诊治的疑似结核病患者1200份不同临床标本的qRT-PCR测定结果,其中血液样本469份,胸腔积液标本322份,心包积液标本16份,尿液标本25份,气管(支气管)肺泡灌洗液标本8份,腹腔积液标本34份,脑脊液标本143份,脓液标本31份,痰液标本152份;同时,对41份痰液标本予以玻璃珠振荡磨菌前后qRT-PCR定量检测效果分析。结果1200份不同结核标本的总检测阳性率为15.83%(190/1200),其中检出率最高的为气管(支气管)肺泡灌洗液标本,占比为37.50%(3/8),且门诊患者阳性率最高,占比为40.00%(2/5);脓液标本检出率第二,占比为35.48%(11/31),且住院患者阳性率最高,占比为38.46%(10/26);痰液标本检出率第三,占比为30.26%(46/152)。41份痰液标本经玻璃珠磨菌处理5 min之后,qRT-PCR检测核酸浓度明显高于处理前,差异有统计学意义(P<0.05);其中,14份痰液标本提升了菌株数量级,且11份含菌量为10^(2)拷贝/mL痰液标本于振荡研磨处理之后,7份痰液标本提升至了10^(3)拷贝/mL菌量数量级,磨菌处理后阳性检出率明显高于磨菌处理前,差异有统计学意义(P<0.05)。结论气管(支气管)肺泡灌洗液标本、脓液标本、痰液标本检测中qRT-PCR的检出率较高,而qRT-PCR在其他结核标本检测中的检出率较低,qRT-PCR联合玻璃珠磨菌法检测可有效提升临床结核标本阳性检出率。