Electron Microscopic In－situ Observation for Preparation of Ultrafine La_2O_3 Nanophase Powder

In-situ observation in high voltage electron microscope(HVEM) was used to investigate transformation from amorphous La(OH)3 to nanophase La2O3. Electron diffraction pattern indicates that the transition temperature from La(OH)3 to nanophase La2O3 is 400 ℃. Particle sizes for nanophase La2O3 are from 20 to 50 nm.

Microscopic Observation and Stability Study on the Fe_3s_4 Nanocrystals Synthesizedunder Thermal and Humid Conditions

Fe3S4 is important magnetic mineral that widely exists in the sediments of lakes and oceans. It can not only instruct reducing environment that contains organic matter and sulfate, but also provide paleomagnetic signal for paleoenvironmet research. Simultaneously, as a new type of magnetic material, it causes attention. Because Fe3S4 generally exists as an unstable intermediate, it is stringent in preparation conditions. Although some scholars have conducted on the synthesis experiments of Fe3S4 materials, the research on its stable conditions, formation mechanism and evolution process is not yet depth. Accordingly, defining the stable conditions and revealing evolution law of Fe3S4 nanocrystals have important significance for the determination of environmental conditions and the preparation of pure Fe3S4 nanomaterials.

Corneal histomorphology and electron microscopic observation of R124L mutated corneal dystrophy in a relapsed pedigree

·AIM:To investigate the histological characteristics and ultrastructure of recurrent Chinese R124 L mutated corneal dystrophy after keratoplasty.·METHODS:The subjects were enrolled from a Chinese family of corneal dystrophy with R124 L heterozygous gene mutation and with a history of consanguineous marriage.Normal corneal samples were used as controls.·RESULTS:In this family,2 patients(3 eyes)underwent penetrating keratoplasty(PKP)and 2 patients(4 eyes)underwent lamellar keratoplasty(LKP).They had recurrence at 33.5±3.0(range 30-36)mo after keratoplasty.Among them,1 patient(1 eye)underwent PKP again and 1 patient(2 eyes)underwent LKP again.In the R124 L mutated recurrent corneal dystrophy,the corneal turbidity was mainly distributed from the upper corneal cortex to the anterior stroma;the corneal epithelium surface was rougher and more uneven;and,the corneal erosions were larger.Hematoxylin-eosin staining showed that the thickness of the corneal epithelium was uneven;the arrangement of the epithelial cells was disordered;and,some corneal epithelial cells were swollen.The results of Congo red staining,Masson’s trichrome staining and Periodic acid-Schiff staining were positive,while that of Alcian blue staining was negative.Under a transmission electron microscope,deposition of high electron density substances between epithelial and basal cells,and,apoptosis of basal cells were observed.Many high electron density depositions were observed in the sub-epithelial and anterior corneal matrix.·CONCLUSION:In the Chinese family of recurrent corneal dystrophy with R124 L gene mutation,the corneal epithelia of the recurrent cases are rougher,and the corneal depositions are extra cellular amyloid fibrin.

ELECTRON MICROSCOPIC OBSERVATION OF DIFFERENTIATION OF LEUKEMIC CELL CLONE AFTER CFU-MIX CULTURE

By scanning and transmission electron microscopy, leukemlc celb were obwrved after CFU-Mix culture. Even though granulocytlc growth factor, erythropoietin and lymphocytlc growth factor were added at vitor, acute leukemlc celb still showed defects In differentiation and maturation. These were characterized by abnormal colony which consisted of smooth cells, bizarre shape, nuclear-cytoplasmic asynchrony In development, and appearance of nuclear bleb. However, chronic myelogenous leukemlc celb were more nature than the acute ones, manifesting in normal colony with finger- like projections and ruffled membrane. Macrophages and eosinophils could be observed. It b suggested that there b a difference In differentiation between acute and chronic leukemia cells.

ELECTRON MICROSCOPIC OBSERVATION OF SIMIAN SARCOMA VIRUS TRANSFORMED NIH 3T3 CELLS IN VITRO

For electronic microscopic observation, we found SSV-transformed NIH 3T3 cells were different from non-transformed cells. In SSV-transformed NIH 3T3 cells nuclei cytoplasma ratio was increased and in cytoplasma the ribosomes (polyribosomes were attached to the swollen rough endoplasmic reticulum. It was likely that ribosomes were lined together functionally and structionally to produce specific protein (PDGF-like protein).

LIGHT AND ELECTRON MICROSCOPE OBSERVATIONS ON NEPHROSELMIS GAOAE SP.NOV.(PRASINOPHYCEAE)

Nephroselmis gaoae sp.nov.is described on the basis of light and electron microscope observations ofcultured material originally collected and isolated from seawater of Jiaozhou Bay,Qingdao,China.Theperiplasts on the cell body and flagella are covered by five types of scales,two types on the flagella andthree on the body.Among these,the morphology and the number of spines of large stellate body scalesdiffer remarkably from those of previously described species of Nephroselmis.Apart from these,the unusualfine structure of the eyespot(stigma)is very characteristic.As in the other species of Nephroselmis,theeyespot lies immediately under the two-membraned chloroplast envelope;unlike the others,however,it isnot composed of a number of osmiophilic globules,but consists of about 14 curved rod-shapedosmiophilic bodies arranged loosely and randomly.This feature distinguishes the present new species notonly from the other species of Nephroselmis but also from the other motile algal species,the eyespots

JH油田含蜡原油析蜡温度测试与分析

采用显微镜观察法、黏温曲线法、DSC法分别测试了JH油田六个不同区块的原油析蜡温度。在DSC法中,测定了降温速率5、10℃/min下的析蜡点。在黏温曲线法中,测定了剪切速率10、20、50、100 s^(-1)下的析蜡点。在显微镜观察法中,测定了降温速率0.5、5℃/min下的析蜡点。实验结果表明,不同方法测量的析蜡点有所差异,一方面与不同测试方法的原理有关,另一方面与仪器的分辨率、操作者的经验有关。若原油中的活性物质和大分子不溶物影响较大时,也会表现不同。

丽江金沙江流域烟草病毒电镜观测与宏病毒组分析

【目的】明确丽江金沙江流域烟草病毒病的病毒种类及其分布特点,为病害防控提供依据。【方法】采集烟区具有明显病毒病症状的烟株样品53份,采用宏病毒组测序技术分析各病毒属的丰度,并构建遗传进化树;进一步采用扫描电镜观测病毒形态;调查各病毒病在烟区的发生情况。【结果】宏病毒组测序分析结果表明:属水平上,华坪县(S1)样品中马铃薯Y病毒属(Potyvirus)、黄瓜花叶病毒属(Cucumovirus)和正番茄斑萎病毒属(Orthotospovirus)丰度分别为66.08%、20.83%和5.91%;玉龙纳西族自治县(S2)样品中正番茄斑萎病毒属丰度为97.20%;宁蒗彝族自治县(S3)样品中马铃薯Y病毒属和正番茄斑萎病毒属丰度分别为96.29%和2.20%。系统进化树结果显示:S1样品病原为烟草马铃薯Y病毒(potato virus Y,PVY)、烟草番茄斑萎病毒(tomato spotted wilt virus,TSWV)和烟草黄瓜花叶病毒(cucumber mosaic virus,CMV),S2样品病原为TSWV,S3样品病原为PVY和TSWV。电镜观察到样品中线状病毒粒体直径10~15 nm,长度700~900 nm;球状病毒粒体包括2种,一种为直径25~30 nm、无包膜,另一种为直径80~120 nm、表面有1层包膜。宏病毒组测序分析、系统进化树和电镜观测结果相吻合。田间调查结果表明:华坪县PVY、TSWV和CMV的发病率分别为42.34%~68.25%、12.59%~26.52%和29.27%~72.31%;玉龙县TSWV的发病率为5.66%~20.34%;宁蒗县PVY和TSWV的发病率分别为19.18%~36.27%和1.08%~4.92%。【结论】危害丽江金沙江流域烟区的烟草病毒种类主要为TSWV、PVY和CMV,其中,TSWV和PVY的检出率最高、发生最普遍。

扫描电镜下页岩微观断裂原位观测与变形表征

为定量化获取页岩微观裂纹萌生、连接过程中的变形量,从而揭示页岩微观裂纹的变形、演化规律及破裂机理。本研究探索并对比了基于页岩表面天然斑点、表面光刻处理、表面金属纳米颗粒处理的微观DIC应变表征方法,研究了微观裂纹萌生、扩展中的变形演化过程。得出结论如下:(1)3种表面处理方法均可实现DIC变形表征,利用页岩表面天然斑点较为简单、方便,但无法在高放大倍数下进行变形表征;光刻处理相对廉价,对页岩物理力学性质不产生影响,但最小散斑尺寸为2μm,且光刻胶不随页岩的微小破裂而破裂,易遮挡微观裂纹;表面金属纳米颗粒处理所形成散斑较为精细、散斑尺寸可人为控制,DIC变形表征较为准确,但页岩需经过300℃处理,可能影响页岩物理力学性质。(2)非连续裂纹的萌生、连接是微观裂纹扩展的重要形式,非连续裂纹形成前存在非连续应变集中现象。非连续裂纹具有层级展布特征,这可能是微观裂纹曲折复杂的原因;(3)相互连接的非连续裂纹形成主裂纹,未与主裂纹连接的非连续裂纹由于应力释放而闭合,形成分支裂纹。本研究为页岩微观变形演化表征提供了新的技术手段与研究思路,同时也为微观裂纹扩展规律及非连续裂纹形成演化研究提供了试验证据。

考虑真实颗粒形状的尾矿动力特性离散元研究

土体材料由大量单个颗粒组成,颗粒形态对于土体的宏细观力学性质有直接的影响。通过显微观测,考虑颗粒形态效应,对尾矿颗粒进行一系列离散元模拟。通过CT扫描与图像处理技术,研究3组不同围压下真实颗粒试样与圆颗粒试样的液化特征。研究结果表明:尾粉砂颗粒多以粒状和片状形式存在,以边边接触和面面接触为主。离散元试样在液化时会出现“连通带”现象。在不同围压下,圆颗粒试样的动孔压表现为“快—平稳”,动应变发展均呈现“喇叭状”,而真实颗粒试样的动孔压则由低围压时的“快—平稳”变为高围压时的“快—平稳—慢”发展模式,动应变发展则由低围压时的“喇叭状”变为高围压时的“号角状”。2种试样所表现出的孔隙率、配位数与能量发展变化均有所不同。

不同授粉方式对香蕉花粉萌发与花粉管生长的影响及显微观察

以可育、高结实率香蕉野生种质资源小果野蕉(AA)及粉蕉栽培品种热粉1号(ABB)为材料,观察香蕉花、子房、胚珠结构,研究不同授粉方式对花粉萌发、花粉管生长的影响。结果表明,小果野蕉自花授粉后花粉萌发率高,萌发数量随授粉时间递增,授粉3 d时达到峰值,后不再变化。花粉管生长迅速,授粉后8 h可到达花柱中部,24 h可到达子房,受精过程可持续1~3 d。不同授粉方式下,自花授粉花粉萌发数量显著高于异花授粉,达到萌发峰值比异花授粉早2 d。且异花授粉花粉管会产生畸形,如花粉管短粗、末端粗壮膨大、形状扭曲等。综上,野生香蕉种质资源自交亲和,花粉萌发、花粉管伸长、受精过程发育良好,是理想的杂交材料。异花授粉时花粉与柱头的亲和性降低、花粉管萌发异常、栽培种胚珠发育不完全等因素致使杂交育种效率低。

面向适航验证的人工造雪晶核直径实验研究及应用

为了满足国产大飞机的适航试验需求,为扬雪、降雪试验提供规定密度与含水量的雪质,开展结冰风洞造雪实验,对不同工况下的人造雪进行采样和显微观察,利用图像识别算法进行数据分析,探究环境温度、风速、成雪距离、气水比等因素对冰晶生长的影响。结果表明:较大的环境过冷度有利于冰晶的快速生长,导致冰晶平均直径的减小,小于5℃的过冷度有利于冰晶均匀稳定生长;风速的降低与成雪距离的增加均可促进冰晶的直径增大;相比于气水比为1.1时,在气水比为1.2的工况下,较高的气相比例可以促进液滴的成核,然而过低的液相水比例会限制冰晶直径的增长。

线叶蓟的性状和显微鉴别研究

目的对线叶蓟Cirsium lineare(Thunb.)Sch.-Bip进行生药学研究,为线叶蓟药材的鉴定提供依据。方法查阅有关文献,采用性状、微性状及显微鉴别方法对线叶蓟进行生药学研究。结果经性状观察,线叶蓟叶上下表面异色,茎、叶及苞片被有蛛丝毛,茎叶上还存在多细胞长节毛。根部显微可观察到具缘纹孔导管、分泌道及菊糖等特征。茎横切面可见有若干分泌道和草酸钙针晶。叶部显微可见多细胞非腺毛、分隔石细胞。花及果实粉末显微中可见花粉粒、果皮薄壁细胞等。结论通过性状、微性状及显微特征可对线叶蓟进行准确鉴别。

杨树白粉病菌鉴定及宿主叶片的生理反应

为研究山新杨白粉病的病原菌种类以及病原菌侵染后宿主叶片的生理反应,观察了山新杨白粉病菌分生孢子的形态特征及特异性入侵结构,统计不同介质分生孢子的萌发情况,测定5个不同感病时期(健康、早期、中期、晚期、末期)山新杨叶片的过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)活性和丙二醛(MDA)的质量摩尔浓度变化,应用分子生物学分析的方法鉴定山新杨白粉菌病原。结果表明:山新杨白粉病菌分生孢子萌发时产生裂瓣状附着胞,并且萌发时不受介质面影响。感病前后,山新杨叶片内的生理生化指标变化显著,其中超氧化物歧化酶、过氧化物酶以及过氧化氢酶活性均呈先升高后下降趋势,丙二醛质量摩尔浓度则呈不断上升趋势。说明侵染前期,由于白粉病菌胁迫,叶片活性氧上升,抗氧化酶活性与丙二醛质量摩尔浓度升高;随着感病程度加重,叶片清除活性氧的能力下降,抗氧化酶活性降低,丙二醛质量摩尔浓度升高。通过ITS序列比对与系统发育进化树分析,可认为山新杨白粉病病原菌为Erysiphe adunca(Wallr.)Fr.var.adunca。

赤水金钗石斛“鱼肚兰”的基因组特征

【目的】探明赤水金钗石斛“鱼肚兰”野生种与栽培种的基因组特征,为赤水金钗石斛的资源保护及品种选育提供遗传信息支撑。【方法】采用高通量测序技术、显微观察等方法研究赤水金钗石斛“鱼肚兰”的野生种与栽培种,并分析其基因组大小、数量、倍性等特征。【结果】高通量测序共获得赤水金钗石斛“鱼肚兰”野生种和栽培种有效序列长度分别53.30 Gb和60.62 Gb,k-mer分析基因组估测的基因组大小分别为1.18 Gb和1.13 Gb,重复序列比例分别为50.56%和57.59%,基因组杂合度分别为2.19%和2.76%;根尖染色体数目的显微计数显示,野生种与栽培种赤水金钗石斛均为二倍体(2n=2x=38),与基因组调研结果一致。【结论】赤水金钗石斛“鱼肚兰”的野生种与栽培种均为二倍体,从基因组特征上看,二者均属于高杂合的复杂基因组。

猪轮状病毒G9P[7]型云南株的分离鉴定及VP4和VP7基因测序分析

为确定云南省某猪场仔猪腹泻的病原,对送检腹泻病仔猪小肠组织样品进行猪急性腹泻综合征冠状病毒(SADS-CoV)、猪流行性腹泻病毒(PEDV)、猪丁型冠状病毒(PDCoV)、猪传染性胃肠炎病毒(TGEV)和猪轮状病毒(PoRV)RT-PCR检测,将PoRV检测阳性样品处理后接种至MA-104细胞进行PoRV分离;对分离毒株进行间接免疫荧光、电镜观察、胶体金检测和VP4、VP6、VP7基因测序及遗传进化分析。结果显示,仔猪肠道组织样品经终浓度20μg/mL的胰酶在37℃孵育2 h,能在MA-104细胞上增殖传代,第3代出现稳定的细胞病变,盲传20代,每隔5代进行PoRV的检测;间接免疫荧光试验可见特异性荧光,胶体金和RT-PCR检测均为PoRV阳性,电镜观察可见病毒粒子直径约为65 nm,呈车轮状,符合PoRV粒子典型形态特征,将该分离株命名为PoRV YN-A株。基因同源性比较和遗传进化树分析显示,YN-A株的VP6基因序列与国内A群GD株的同源性为99.93%,VP7与中国G9型NJ2012株的同源性为99.12%,VP4与美国P[7]型OSU株的同源性为98.91%,确定该分离株为猪A群轮状病毒G9P[7]型。YN-A株VP7序列在9个氨基酸位点存在点突变,即aa9(I→V)、aa16(V/T→I)、aa44(A→V)、aa100(D/E→N)、aa212(T/A→K)、aa221(N→S)、aa225(V→A)、aa271(I→V)、aa267(D→E)。首次从云南地区的腹泻仔猪小肠组织中成功分离到1株G9P[7]型的新基因型PoRV毒株,为PoRV的致病性、分子生物学特性研究及PoRV G9优势基因型新疫苗研发奠定了基础。

Micro-galvanic corrosion behaviour of Mg-(7,9)Al-1Fe-xNd alloys

The localized micro-galvanic corrosion process and the kinetic information of Mg-(7,9)Al-1Fe-x Nd alloys were investigated by in situ observation under electrochemical control and in situ atomic force microscopy(AFM)in an electrolyte environment.The results revealed that the formation of the Nd-rich phase in alloys resulted in a decrease in the Volta potential difference from~400 m V(AlFe3/α-Mg)to~220 mV(Nd-rich/α-Mg),reducing the corrosion products around the cathodic phase and corrosion current density of the microscale area.The addition of Nd significantly improved the corrosion resistance,mainly due to the suppression of the micro-galvanic corrosion between the second phases and substrate.Finally,the corrosion mechanism of Mg-(7,9)Al-1Fe-x Nd alloys was discussed based on in situ observations and electrochemical results.

不同入药部位干药材石蜡制片方法的改良研究

石蜡制片作为干药材显微鉴定的关键技术之一,在组织学中应用广泛.根据不同组织构造特点,选取有代表性的皮类、茎类、种子类、根类干药材为主要实验材料,主要从软化、脱水和透明等环节对传统制片方法进行改进,探索各药材专属性石蜡制片方法.结果表明,软化是制作石蜡切片的关键步骤,对不同种类干药材应区别处理.纤维、石细胞富集的皮类生药如厚朴,采用5%氢氟酸水浴浸透软化12 h;木质部纤维化严重的茎类生药如桂枝,采用甘油与氢氧化钠混合溶液软化14 h;内外硬度差异较大的种子类生药如芥子,5%甘油软化6 h;纤维性强和试剂不易渗透的根类生药如黄芪,5%盐酸软化6 h,能提高各干药材横切面的清晰度和完整度,获得组织完整、细胞结构清晰的高质量切片.经改良的石蜡切片技术专属性高,重复性好,避免了常规制片易出现的浸蜡不彻底、组织变硬变脆等问题.研究结果可为制作不同部位石蜡切片提供方法学参考.

鸭短喙与侏儒综合征病毒分离与鉴定

山东某樱桃谷鸭场出现以患鸭短喙、长舌、生长不良为主要特征的疾病,疑似感染鸭短喙与侏儒综合征病毒(duckling short beak and dwarfism syndrome virus,SBDSV)。本研究旨在分离鉴定该病毒,并检测其对樱桃谷鸭的致病性。首先,通过临床症状、病理变化、病料PCR检测,确定感染鸭短喙侏儒综合征病毒。其次,用SPF鸭胚分离培养病毒后,对病毒进行电镜观察和同源性与系统发育树分析,再检测病毒尿囊液EID_(50)。最后,动物回归试验中,给2日龄樱桃谷鸭口服病毒感染鸭胚尿囊液,观察致病特点,以及用PCR和间接免疫荧光试验检测病毒分布。结果显示:SPF鸭胚接毒后96~120 h鸭胚死亡,电镜观察病毒粒子大小为20~50 nm,尿囊液EID_(50)为10^(-4.85)·0.2 mL^(-1)。尿囊液PCR检测SBDSV为阳性,证明从鸭胚中成功分离培养SBDSV。该病例主要临床表现短喙和体重降低,感染后2周内持续排毒,VP 2片段与鸭短喙侏儒综合征病毒序列的相似性为99.8%,表明是由鸭短喙与侏儒综合征病毒感染引起,命名为SBDS-SD株。动物回归试验中,出现短喙、腹泻、体重显著降低等与自然病例相似的临床症状。本试验成功分离到一株鸭短喙与侏儒综合征病毒,并验证其对樱桃谷鸭具有致病性,为该病的进一步研究提供基础。

原子制造过程的可视化与原位检测

原子制造是指将能量直接作用于原子,对原子进行精准可控去除、增加等操作,从而调控材料结构和性质的技术。为实现原子制造的精准性和可控性,跨尺度的实时观察与检测势在必行。原位透射电子显微技术不仅能在原子尺度下实时研究纳米材料结构与性质之间的关系,而且可以构建原子级器件并实现其性能的原位检测。简要综述了原位透射电子显微技术在纳米/原子精度的加工、器件构建及原位检测方面取得的重要进展,提出了当前原位透射电子显微技术在原子制造过程的可视化与原位检测领域面临的挑战和未来的发展方向。