Systematics study through scanning electron microscopy; a tool for the authentication of herbal drug Mentha suaveolens Ehrh

In all over the world, herbal drugs are usually adulterated with similar species or varieties due to incorrect identification. Most of herbal products devoid purity and quality, therefore an attempt was carried out to identify plant species and authenticate its herbal drug products from Mentha suaveolens. Microscopy tools provide an excellent platform to identify plants at species level. In this study, microscopic and pharmacokinetic parameters of M. suaveolens were observed. Plant species were collected from high diverse areas of Northern Pakistan. Macro and micro‐morphology including palynology and anatomical features were analyzed to study M. suaveolens. Species characteristics were studied, while implementing microscopic techniques for the delimitation and identification of the species. Traditionally Mentha species are used to cure several diseases that is, digestive disorders, respiratory disorders. Micromorphology (stem, leaves, flowers structure, length etc.), palynology (shape, size of pollen etc.), and anatomical characters (types of stomata, epidermal cell shape, and trichomes) were studied. Micromorphology and anatomical characters were of great interest and significance to discuss the taxonomy of the species. Taxonomic characters were studied to characterize and authenticate the species. The aim of the present study is to observe in detail the taxonomic identification of the species in term of morphology, palynology, and foliar epidermal anatomy for the correct identification along with their medicinal uses in the area.     

Nb5+掺杂对(Ca0.97Ba0.03)Cu3Ti4O12陶瓷结构与电性能的影响

该文利用固相反应法制备了(Ca0.97Ba0.03)Cu3Ti4-xNbxO12 (x=0,0.01,0.03,0.05,0.07,0.10,0.15,0.20， 摩尔分数)陶瓷。借助X线衍射仪及扫描电子显微镜研究了Nb5+的摩尔分数对(Ca0.97Ba0.03)Cu3Ti4O12陶瓷的相结构及表面微观形貌的影响，借助高低温介电测试系统和阻抗测试仪获得了(Ca0.97Ba0.03)Cu3Ti4-xNbxO12陶瓷电性能变化规律。结果表明，各组分(Ca0.97Ba0.03)Cu3Ti4-xNbxO12陶瓷均为单相立方钙钛矿结构；Nb5+摩尔分数的增加可抑制(Ca0.97Ba0.03)Cu3Ti4-xNbxO12陶瓷晶粒的生长并消除其晶粒异常长大；适量掺杂 Nb+能够有效提高(Ca0.97Ba0.03)Cu3Ti4-xNbxO12陶瓷的晶界电阻，从而降低其介电损耗，且可提高(Ca0.97Ba0.03)Cu3Ti4-xNbxO12陶瓷相对介电常数的温度稳定性。     

Leaf and stem micromorphology of Byrsonima sericea DC. by light and scanning electron microscopy

Micromorphological studies were carried out using multiple microscopic techniques on the leaves and stem bark of Byrsonima sericea DC. (Malpighiaceae), a species popularly known as “murici” and used medicinally, in order to identify both qualitative and quantitative features of leaf and stem anatomy and histochemistry as differential parameters to support both the quality control of its ethnodrugs and the taxonomy of the genus. The study was conducted using traditional techniques of plant anatomy, histochemical tests, and the stomatal index (SI). Byrsonima sericea has hypostomatic leaves, anomocytic stomata, and its epidermal walls are anticlinal and straight on the adaxial and curved on the abaxial faces. T‐shaped trichomes were observed mainly on the abaxial surface. The leaf epidermis showed waxes syntopism on both surfaces, with the occurrence of different crystalloid forms on a single phylloplane. The mesophyll is dorsiventral, with 3‐4 collateral vascular bundles. Phenolic compounds, starch, and proteins were identified in the petiole and stem. The SI was 14.5 ± 0.53% (p < .05), but did not showed significant variations. A set of characters were found to be distinctive for the studied species, however, constituting parameters that could be used to separate B. sericea from other species of the genus.     

增容高抗冲聚苯乙烯/高乙烯基聚丁二烯橡胶热塑性硫化胶的Mullins效应及其可逆性

采用动态硫化法制备了苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)增容高抗冲聚苯乙烯(HIPS)/高乙烯基聚丁二烯橡胶(HVPBR)热塑性硫化胶(TPV),考察了SBS用量对TPV物理机械性能的影响,表征了TPV的微观形貌,并研究了TPV的Mullins效应及其可逆性。结果表明,SBS可显著改善HIPS/HVPBR体系的相容性,其用量为12份时,TPV的物理机械性能较好;SBS增容TPV的断面平整、结构致密,界面相互作用明显增强;SBS增容TPV在循环单轴拉伸过程中出现明显的Mullins效应,提高应变速率时,TPV的最大应力和内耗呈增大趋势,瞬时残余形变则减小;当拉伸比相同时,TPV经第1次拉伸热处理后,第2次单轴拉伸中TPV的最大应力和内耗均增大,瞬时残余形变则减小。     

Soil micromorphology of clayey hill slopes, central Italy

Thirty-one undisturbed samples were collected from depths of 1.5 to 3.0 m on clayey hill slopes in the Pliocene and Allochthonous geological formations of Tuscany and Abruzzi in central Italy. Thin sections were made from each of the samples and the micromorphological aspects described semi-quantitatively using both microscopic and image analyses. The results were compared with the three, broad hill slope profiles – straight, convex and concave. The study showed that hill slope evolution by both creeping and surface and subsurface runoff has changed the conditions within the clay fabric and that linear voids due to tension and shear processes have formed in the soil. The data suggest that clayey hill slope form evolves from convex to concave via a linear shape. Electronic Publication     

Ru籽晶层对CoCrPt-SiO_2垂直记录层形貌及结构的影响

采用磁控溅射方法,制备了以不同厚度Ru薄膜为籽晶层的CoCrPt-SiO2垂直磁记录薄膜。利用原子力显微镜(AFM)、透射电镜(TEM)分析Ru薄膜的结构和形貌,并研究了其结构对CoCrPt-SiO2薄膜表面形貌、粗糙度及结构的影响。结果表明,CoCrPt-SiO2记录层的晶粒尺寸和粗糙度均随着Ru籽晶层厚度的增加而增加,薄而粗糙的籽晶层适合于高密度磁记录介质。对于CoCrPt-SiO2记录层晶粒的优化,厚度为70nm的Ru籽晶层有利于记录层薄膜晶粒的完全隔离,从而提高了磁记录性能。     

超声磁粒复合研磨对石英玻璃管内表面的光整研究

目的探究超声磁粒复合研磨对石英玻璃管内表面管研磨的可能性,分析有无辅助磁极及不同粒径的研磨粒子对内表面的影响。方法在石英玻璃管内表面添加辅助磁极并辅助超声磁粒复合研磨装置,加快磨粒的翻滚,提高抛光质量和效率。结果采用超声磁粒复合研磨装置,选用150、250、350μm三种粒径的研磨粒子分别进行研磨实验,研磨40 min后,150μm的研磨粒子表面粗糙度值从原始4.4μm下降到1.2μm,250μm的研磨粒子表面粗糙度值下降到0.2μm,350μm的研磨粒子表面粗糙度值下降到0.6μm。对比传统磁粒研磨装置与超声磁粒复合研磨装置,保持研磨粒子粒径为250μm,经40 min研磨,在传统磁粒研磨装置上未添加辅助磁极,石英玻璃管内表面粗糙度值从原始4.4μm下降到2.8μm;在传统磁粒研磨装置上添加辅助磁极,粗糙度值从原始4.4μm下降到1.1μm;在超声磁粒复合研磨装置上添加辅助磁极,粗糙度值从原始4.4μm下降到0.2μm。结论在石英玻璃管内表面添加辅助磁极后,表面粗糙度值得到下降。采用超声磁粒研磨装置使石英玻璃管内表面粗糙度值在原有基础上进一步下降,且选用粒径为250μm的研磨粒子最佳。加工后,工件内表面的加工均匀性显著提升,原始缺陷和原始波峰基本去除。     

Water‐absorption characteristics of organic–inorganic composite superabsorbent polymers and its effect on summer maize root growth

Adding inorganic materials in SAPs to synthesize organic–inorganic composite superabsorbent polymers (OICSAPs) can effectively improve salt‐tolerance, gel strength, thermal stability, and water retention. However, most researches mainly focus on synthesizing process optimization and new multifunctional products, lacking reports on how ions affected water‐absorption characteristics and mechanism of OICSAPs and its influence on summer maize root growth. On the basis of these, we set up laboratory experiments and field cultivation experiment, using environmental scanning electron microscopy (ESEM) and fractal theory to study the questions above. Results show that OICSAPs have better salt‐tolerance, while cations and concentration affected its water‐absorption characteristics significantly. With higher cation valence, larger ionic radius, and concentration, its water‐absorption rate reduced remarkably as Na⁺ < K⁺ < Mg²⁺ < Ca²⁺ < Fe²⁺ < Fe³⁺ < Al³⁺ < Cu²⁺, while the effects of anions could be neglected. The OICSAPs presented typical honeycomb membrane‐like 3D crosslinked network structure, but Ca²⁺, Mg²⁺, Fe²⁺, Fe³⁺, Al³⁺, and Cu²⁺ would damage the structure (Cu²⁺ with the most significant effect) in local microdomain, and changed the complexity of pores. In the experiment, higher concentration could reduce water‐absorption rate without changing micromorphological characteristics. Applying OICSAPs will reduce total length, surface area, and volume of summer maize root, while promoting absorbing and transmitting ability by larger root diameter and the proportion of root <0.5 cm. All these results will provide a theoretical basis on application, marketing, and product development of OICSAPs. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Investigation on Microcrystalline Wax Doped Asphalts by Temperature Control Mode of Atomic Force Microscopy

Because of its economical and environmentally friendly characteristics, the warm mix asphalt(WMA) is widely used in pavement engineering. However, the lack of microscopic study of WMA brings difficulties in understanding of its mechanical behavior and mechanisms at macroscopic scale which finally hinders the enhancement of WMA's performance. Therefore, this article aims to use atomic force microscopy(AFM), a promising microscopic technique, to investigate the effects of wax-based warm mix agents on asphalt microstructures and micromechanical properties at different temperatures. For simplicity's sake, microcrystalline waxes are selected as an alternative of these wax-based additives. It is shown that the sample preparation method has a vital impact on the morphology of asphalt samples. The effects of microcrystalline wax on asphalt's mechanical properties can be well captured by AFM tests. Results show that the blending of #70, #80 and #90 microcrystalline waxes lowers the modulus(20—60 MPa) of Pen70 asphalt at 25 ℃ while increasing its adhesion force(5—20 n N). The results of this study may shed some light on the comprehension of the effects of wax-based additives on asphalt materials at macroscopic level which can help estimate and predict its actual performance.     

选区电化学沉积镍镀层的微观形貌及耐磨性

利用选区电化学沉积技术在45钢基体上沉积镍镀层,并对其进行形貌观察、能谱分析探寻选区电化学沉积镍镀层组织生长规律,并将镀层和基体耐磨性进行了试验对比。结果表明,选区电化学沉积生长过程为由小型颗粒逐步生长堆叠成为致密镀层;晶粒生长呈螺旋式上升堆叠形态,球状晶粒内部和表面存在微裂纹;晶粒间隙处存在氧元素,氧化反应对于小型晶粒之间的相互融合起抑制作用;选区电化学沉积镍镀层结构组织更加致密,镀层组织与基体组织间存在明显的分界线,镀层组织相较于基体材料耐磨性更好。