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51.
Salman Majeed Muhammad Zafar Mushtaq Ahmad Omer Kilic Shazia Sultana Jamil Raza Ghulam Yaseen Hina Gul Sehrosh Mir Lubna Munazza Jabeen 《Microscopy research and technique》2020,83(7):767-777
The family Cactaceae is the diversified group of angiosperm plants whose pollen statistics has been used for taxonomic identification. In this article, we present the pollen morphology of eight species belong to seven taxonomically complex genera of Cactaceae including Astrophytum, Cylindropuntia, Echinocereus, Echinopsis, Mammillaria, Opuntia, and Thelocactus using light and scanning electron microscopy. The pollen grains were acetolyzed, measured, described, and electron photomicrographs were taken. Cactaceae can be characterized by presenting different palynomorphological features including pollen type, sculpturing, polar and equatorial diameter, aperture orientation, exine thickness, P/E ratio, and echini features. Four types of pollen shapes, that is, prolate spheroidal (three species), subprolate (two species), prolate (two species), and oblate spheroidal in Echinocereus reichenbachii were observed. The polar and equatorial diameter observed maximum in O. ficus indica 116.95 and 112.27 μm while minimum in M. compressa 38.42 and 21.05 μm. Pollen of two types, tricolpate in members of subfamily Cactioideae and pantoporate in the Opuntioideae were examined. The fertility percentage has been observed maximum in Opuntia macrocentra (83.84%) and minimum in Opuntia ficus‐indica (57.89%). Exine sculpturing showing great variations such as granulate, reticulate, granulate perforate and micro‐echinate foveolate ornamentation was examined only in Echinopsis eyriesii. A key to species, based on pollen micromorphological attributes, has been constructed for correct identification of complex cactus species. 相似文献
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《International Journal of Hydrogen Energy》2020,45(24):13353-13364
In response to the energy crisis, molybdenum-based catalyst has been proposed as a high-performance electrocatalytic material due to its low price and excellent HER performance. However, in contrast with its excellent HER performance, its poor OER performance often limits practical application as a high-performance overall water splitting catalyst. In this study, Prussian blue analogue (PBA) is grown in-situ on molybdenum-based nanosheet spheres by a simple and ingenious method and then subjected to phosphorization. The resulting composite catalyst exhibits highly efficient overall water splitting performance, overpotentials at current densities of 10 mA cm−2 and 100 mA cm−2 for the HER and OER are −61 mV and 268 mV, respectively. Moreover, an alkaline electrolyzer makes up by the catalyst both as positive and negative can reach a cell voltage 1.494 V at 10 mA cm−2 for the overall water splitting. This method has provided a new strategy to effective combine PBA and molybdenum-based catalyst. 相似文献
54.
近年来,“自动矿物学”(或“定量矿物学”)的概念和相关技术得到了显著的发展和广泛的应用,使矿物学研究,尤其是工艺矿物学研究从人工测试走向自动化测试、从定性研究走向定量研究。本文评述了自动矿物学的技术进展与应用,主要包括:①矿物分析技术发展阶段;②自动矿物学技术国际研究进展与国内研究现状;③自动矿物学的应用领域及发展趋势。在此基础上,总结了基于扫描电镜的自动矿物学技术的基本原理以及选矿产品环氧树脂抛光片制备过程中需要注意的一些问题。以期为固体地球科学研究和矿产资源开发利用过程中遇到的一些瓶颈问题提供新的研究途径和新的思路。 相似文献
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《International Journal of Hydrogen Energy》2019,44(51):28007-28030
The effect of hydrogen in AHSS material (automobile and structural component) was discussed. Dual Phase steels were highly susceptible to hydrogen-related failure when working on hydrogen environment. The influence of hydrogen on TRIP steel was seen during fractographic examination where the brittle transgranular fracture was presented. TWIP steels results were inconsistent. The mechanisms which were responsible for crack growth are discussed. LIST and SSRT testing were performed for mechanical properties evaluation and SEM and TEM were used for microstructural examination of fractured samples. Simultaneous preventing methods to reduce hydrogen embrittlement such as coating, alloying and providing diffusion layer were discussed. 相似文献
58.
Prof. li Xiao-Juan Li li Prof. zhang Xian-Chun Prof. li Jian-Xiu 《Microscopy research and technique》2022,85(2):533-537
In this article, we explored systematically the spore morphology of Pteridaceae by observation of the species distributed in Shandong Province using scanning electron microscopy (SEM). The results showed that the spore morphology of all the species in the family is tetrahedral and trilete. The characters of spore ornamentation are intraspecies stable, but significantly different among species and genera. Spore morphology is significant in exploring the phylogenetic relationships of Pteridaceae as well as in generic and specific delimitations. 相似文献
59.
M. Basiaga W. Walke M. Antonowicz M. Szindler D. Nakonieczny W. Kajzer A. Dubiel K. Matus 《Materialwissenschaft und Werkstofftechnik》2020,51(5):569-578
The presence of a biofilm can lead to the disappearance of the surrounding bone tissue and, as a result, disturb the osseointegration process. Unfortunately, both in the case of instability of the implant and long-term bacterial infections, there is often a need for reoperation as well as replacement of the implant, which in turn is associated with huge costs, but most of all discomfort for the patient associated with long-term hospitalization. In order to limit this unfavorable process, the physicochemical properties of the surface layer of implants are indicated. Therefore, the paper proposes applying a layer with antibacterial effect on the surface of 316LVM steel used in bone surgery. As part of the work, the ZnO layer was applied using the atomic layer deposition method with different parameters of the application process (different number of cycles at constant temperature). In the first stage, pitting corrosion resistance tests were carried out using the potentiodynamic method and studies using electrochemical impedance spectroscopy. The surface morphology tests using a scanning electron microscope were also complemented. Obtained results may form the basis for the development of more detailed criteria for the assessment of the final quality of medical devices used in the skeletal system. 相似文献
60.
In the ultra-precision manufacturing of large optics, industrial robots have the potential to become an intelligent and economical choice of surface polishing. However, the transport of the workpieces between the polishing platform and the measurement instrument seriously limits the manufacturing efficiency. Therefore, an in-situ measurement system based on the monoscopic deflectometry is developed to determine the form quality of the optical lenses during rough polishing. Stray light reflected from the lower surface of transparent lenses may degrade the measuring quality, thus an effective absolute phase retrieval algorithm is developed to decouple the superposed fringes associated with the upper and lower surfaces. Then, the form of the upper surface under polishing can be reconstructed to guide the subsequent polishing. Experimental results demonstrate that the accuracy of the method is comparable to that of the coordinate measuring machine, consequently the manufacturing efficiency and reliability of large optical workpieces can be greatly improved. 相似文献