期刊文献+
共找到102篇文章
< 1 2 6 >
每页显示 20 50 100
Obsevation for Epidermal Ultrastructure of Nostoc sphaeroides Kutzing under Scanning Electron Microscope 被引量:1
1
作者 李莉 《Agricultural Science & Technology》 CAS 2009年第1期1-3,共3页
[Objective]The experiment aimed to explore a new way for observing surface structure of Nostoc sphaeroides Kutzing. [Method] The scanning electron microscope was used to observe the epidermal ultrastructure of wild an... [Objective]The experiment aimed to explore a new way for observing surface structure of Nostoc sphaeroides Kutzing. [Method] The scanning electron microscope was used to observe the epidermal ultrastructure of wild and cultured Nostoc sphaeroides Kutzing. [ Result] The epidermis of wild and cultured Nostoc sphaeroides Kutzing showed mixture structure of fibril colloid which was reticular arranged. The difference between wild and cultured Nostoc sphaeroides Kutzing was that the outer epidermis of cultured Nostoc sphaeroides Kutzing had trichome distribution but the wild Nostoc sphaeroides Kutzing did not has such distribution. The obsevation results of under smaller than 10 μm by scanning electron microscope was touched thick and showed many folds and distortions. [ Conclusion] The scanning electron microscope was an effective way to study development of Nostoc sphaeroides Kutzing colony and it was worth popularizing. 展开更多
关键词 Nostoc sphaeroides Kutzing Epidermal ultrastructure scanning electron microscope
下载PDF
Observation of Helicotylenchus digonicus by Scanning Electron Microscope
2
作者 郑炜 《Plant Diseases and Pests》 CAS 2011年第5期32-33,37,共3页
[ Objective] The paper was to observe Helicotylenchus digonicus by scanning electron microscope (SEM). [ Method ] H. digonicus collected from Changxing of Zhejiang Province was observed under scanning electron micro... [ Objective] The paper was to observe Helicotylenchus digonicus by scanning electron microscope (SEM). [ Method ] H. digonicus collected from Changxing of Zhejiang Province was observed under scanning electron microscope, and its morphological structure was confmned under optical microscope. [ Resuit]The nematode specimens fixed by glutaraldehyde and osmium tetroxide and prepared by critical point drying were unmodified and unshrinkable with clear mor- phological structure, which could be scanned very well by scanning electron microscope. [ Conclusion ] The study provided reference for study and control of H. digonicus. 展开更多
关键词 Helicotylenchus d^gonicus Morphological structure scanning electron microscope China
下载PDF
Chalkiness Characters and Scanning Electron Microscope Observation of Rice Grain Endosperm of Japonica Varieties in Southern Henan 被引量:5
3
作者 Bo PENG Yanfang SUN +8 位作者 Dongyan KONG Ruihua PANG Xiaohua SONG Huilong LI Jintao LI Qiying ZHOU Qiu HAN Shizhi SONG Hongyu YUAN 《Asian Agricultural Research》 2017年第3期80-85,共6页
Chalkiness characters affect not only the grain appearance,milling,eating and cooking qualities but also the grain nutritional quality in rice,thus it is one of the most important traits in rice. It is very important ... Chalkiness characters affect not only the grain appearance,milling,eating and cooking qualities but also the grain nutritional quality in rice,thus it is one of the most important traits in rice. It is very important for us to investigate the relation of the chalkiness formation and the development of endosperm structure and starch granule of different rice varieties. Here,we have investigated the chalkiness characters such as chalkiness rate,chalkiness degree and chalkiness area in 15 japonica rice varieties from southern Henan. Furthermore,the endosperm structure and starch granules of rice grain were also observed with scanning electron microscope. The results showed that the 15 japonica varieties have a significantly linear relationship between the chalkiness rate and chalkiness degree. Among the varieties,the biggest difference is the chalkiness rate,the second is the chalkiness area,and the last is the chalkiness degree. Moreover,there is a certain correlation between the distribution of starch granules,the arrangement of endosperm cells and the occurrence of grain chalkiness in the different rice varieties. For the same variety,the starch granules of chalky and non-chalky grains have obvious difference,while the starch granules from the transparent part of chalky rice and non-chalky rice do not have significant difference. The results would provide useful references for the improvement of grain quality in rice. 展开更多
关键词 CHALKINESS scanning electron microscope Japonica rice Starch granule ENDOSPERM
下载PDF
Retrieving analog images from a scanning electron microscopewith a synchronous data acquisition method 被引量:1
4
作者 BAI Jiang-hua 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2019年第4期329-334,共6页
In this work,an old scanning electron microscope(SEM)is refurbished to enhance its image processing capability.How to digitally sample and process an analog image is also presented.An NI PCI-6259 multiple input/output... In this work,an old scanning electron microscope(SEM)is refurbished to enhance its image processing capability.How to digitally sample and process an analog image is also presented.An NI PCI-6259 multiple input/output data acquisition(DAQ)board is used to acquire signals originally being sent to an analog display,and then convert the signals into a digital image.Two output channels are used for raster scan of the horizontal and verticle axes of the image buffer,while one input channel is used to read the brightness signals at various coordinate points.Synchronous method is used to maximize the DAQ speed.Finally,the digitally buffered images are read out to display and saved in a hard drive.The hardware and software designs of this work are explained in great detail,which can serve as a very good example for fast synchronous DAQ,advanced virtual instrument design and structural driver programming with LabVIEW. 展开更多
关键词 scanning electron microscope analog image display raster scan synchronous data acquisiotion(DAQ) LABVIEW
下载PDF
Gill surface architecture of mullet, Mugil soiuy (Basilewsky) : A scanning electron microscope study
5
作者 Wang LiangchenDepartment of Biology Nankai University, Tianjin, ChinaGuo ShuhuaTest and Computation Centre Nankai University, Tianjing, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1989年第4期606-609,共4页
Specimens of Mugil soiuy were collected from the coastal waters of Bohai Sea in Tianjin. The gillfilaments were cut with fine scissors and soaked for 24h in a fixative consisting of 2.5% glutaralde-hyde in 0.1 mol lph... Specimens of Mugil soiuy were collected from the coastal waters of Bohai Sea in Tianjin. The gillfilaments were cut with fine scissors and soaked for 24h in a fixative consisting of 2.5% glutaralde-hyde in 0.1 mol lphosporic acid buffer. After three washes in a buffer solution the tissue was fixedin a mixture of 1% osmium tetraoxide at 4℃ for 1h. The tissue was dehydrated in graded ethandethanols and dried. The tissue was examined and photographed with an SEM at an accelerating voltage 展开更多
关键词 A scanning electron microscope study Basilewsky Gill surface architecture of mullet
下载PDF
Scanning Electron Microscopic Observation on Morphologic Characteristics of Sperms in Uremic Patients
6
作者 Long-gen XU Shi-fang SHI +6 位作者 Hai-zhen ZHONG Xiao-feng HUANG Xiao-ping QI Qi-zhe SONG Xin-hong WANG Li YAN Zong-fu SHAO 《Journal of Reproduction and Contraception》 CAS 2004年第4期227-232,共6页
To observe the morphologic characteristics of spermatozoon ultramicroscopic structure in uremic subjects.Method Semen sample from lO patients with uremia and 5 healthy men were observed under light microscope and scan... To observe the morphologic characteristics of spermatozoon ultramicroscopic structure in uremic subjects.Method Semen sample from lO patients with uremia and 5 healthy men were observed under light microscope and scanning electronic microscope.Results Abnormalities were found in sperms of uremic patients either in the sperm head (acrosome, acrosomic deficit, nuclear abnormality, pointed head, headless and double head of spermatozoon), neck (rupture, separation and enlargement), or tail (mitochondrial swelling, mitochondrial deficit, tailless, double tail, short tail and curled tail); whereas none of the above-mentioned abnormalities was observed in healthy men. Conclusion Sperms of uremic patients had many morphologic and structural abnormalities in the head, neck and tail. 展开更多
关键词 UREMIA SPERMATOZOON scanning electronic microscope
下载PDF
Electronic Scanning of Uterine Endometrium in Postpartum Cow
7
作者 TIANWen-ru HEJian-bin 《Journal of Northeast Agricultural University(English Edition)》 CAS 2000年第2期118-124,共7页
Two postpartum cows were used to study the ultrastructural changes of uterine endometrium by using scanning electron microscope.The results showed that the process of repair of uterine endometrium after calving was de... Two postpartum cows were used to study the ultrastructural changes of uterine endometrium by using scanning electron microscope.The results showed that the process of repair of uterine endometrium after calving was demonstrated by scanning electron microscope through a series of endometrium biopsy.Some part of the endometrium was damaged after calving and its adjacent endometrium cells became necrosis and exfoliated during the first 7 days post-partum;the cilium and microvillus of the epithelial cell in the undamaged area of the endometrium disappeared.By 26 days postpartum the damaged area reduced and the cilium and microvillus increased in their numbers.The damaged tissues were all repaired by day 60 postpartum. 展开更多
关键词 postpartum cow uterine involution scanning electron microscope
下载PDF
Scanning Electron Microscopically Study of Sesame Seeds Infected with Macrophomina phaseolina
8
作者 D. A. El-Wakil A. M. Mahdy R. Z. El-Menshawy 《Journal of Agricultural Science and Technology(A)》 2011年第1X期96-99,共4页
The direct impact of seed-borne fungi on seed is considerable. Many fungi are serious parasites of seed primordial and maturing seeds and reduce yield of seed both quantitatively and qualitatively. Other fungi, includ... The direct impact of seed-borne fungi on seed is considerable. Many fungi are serious parasites of seed primordial and maturing seeds and reduce yield of seed both quantitatively and qualitatively. Other fungi, including saprophytes and very weak parasites, may lower the quality of seeds by causing discoloration which may seriously depreciate the commercial value of seeds, particularly of grain when graded for consumption. Studies by using scanning electron microscopy (SEM) confirmed the importance of the seed coat, and seed cells as infection sites as well as location of the mycelium of the investigated fungus. Macrophominaphaseolina The present investigation is undertaken to study the colonization, infection and fungal establishment on different sesame seed parts by (SEM). A successful colonization of M. phaseolina to seed tissues was also detected. Different forms of pycnidial shapes were also observed. 展开更多
关键词 scanning electron microscope Macrophomina phaseolina sesame seed
下载PDF
COEXISTENCE OF OSTEOARTHRITIS AND OSTEOPOROSIS IN FEMORAL HEAD: A SCANNING ELECTRON MICROSCOPIC STUDY
9
作者 柴本甫 汤雪明 李慧 《Medical Bulletin of Shanghai Jiaotong University》 CAS 2000年第2期71-76,共6页
Objective To ascertain the coexistence of osteoarthritis and osteoporosis in the femoral head. Methods During total hip replacement for osteoarthritis of hip joint in 12 female patients with an average age of 56 years... Objective To ascertain the coexistence of osteoarthritis and osteoporosis in the femoral head. Methods During total hip replacement for osteoarthritis of hip joint in 12 female patients with an average age of 56 years, the femoral heads were procured. After processing the femoral had, specimens were studied under scanning electron microscope. Results Different degrees of osteoarthritic lesions (characterized by degeneration of articular cartilage and hyperplasia of subchondral bone tissues) could coexust with osteoporotic lesions (characterized by icicle-like trabeculae ) in the femoral had. The hyperplas- tic bone tissues of osteoarthritis lay in the vicinity of icicle-like trabeculae. However, they did not care into contact, nor did they exert influence on each other. Coexistence of these two different lesions covered a brood territory extending from the deep surface of subchondral bone plate to the head-neck junction of femoral head. Conclusion The results suggest that osteoarthritis and osteoporosis do coexist in the femoral head. 展开更多
关键词 osteoarthritis osteoporosis coexistence scanning electron microscope
下载PDF
Microstructure and water-swelling mechanism of red-bed mudstone in the Xining region,Northeastern Tibetan Plateau
10
作者 Huan Guan Yong Ren +5 位作者 Sixiang Ling Xiyong Wu Tao Yu Xian Li Sen Wang Chunwei Sun 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第7期2537-2551,共15页
This paper examines the effect of the microstructure and electrical conductivity(EC)on the swelling ratio and pressure in red-bed mudstone sampled from arid areas in the Xining region in the northeastern Tibetan Plate... This paper examines the effect of the microstructure and electrical conductivity(EC)on the swelling ratio and pressure in red-bed mudstone sampled from arid areas in the Xining region in the northeastern Tibetan Plateau.A series of laboratory tests,including swelling experiments,X-ray diffraction(XRD),and scanning electron microscope(SEM),was carried out for mechanical and microstructural analysis.The coupled influence of the EC and microstructural parameters on the expansion ratio and pressure was investigated,and the weight coefficients were discussed by the entropy weight method.The results revealed an increasing exponential trend in EC,and the maximum swelling speed occurred at an EC of approximately 10 μS/cm.In addition,a method for predicting the expansion potential is proposed based on the microstructure,and its reliability is verified by comparing with swelling experimental results.In addition,according to the image analysis results,the ranges of the change in the clay minerals content(CMC),the fractal dimension(FD),the average diameter(AD)of pores,and the plane porosity(PP)are 23.75%-53%,1.08-1.17,7.53-22.45 mm,and 0.62%-1.25%,respectively.Moreover,mudstone swelling is negatively correlated with the plane porosity,fractal dimension and average diameter and is linearly correlated with the clay mineral content.Furthermore,the weight values prove that the microstructural characteristics,including FD,AD,and PP,are the main factors influencing the expansion properties of red-bed mudstones in the Xining region.Based on the combination of macro and micro-analyses,a quantitative analysis of the swelling process of mudstones can provide a better reference for understanding the mechanism of expansion behavior. 展开更多
关键词 MUDSTONES MICROSTRUCTURE Swelling characteristics Electrical conductivity(EC) scanning electron microscope Water-swelling
下载PDF
Acoustical properties of a 3D printed honeycomb structure filled with nanofillers:Experimental analysis and optimization for emerging applications
11
作者 Jeyanthi Subramanian Vinoth kumar Selvaraj +3 位作者 Rohan Singh Ilangovan S Naresh Kakur Ruban Whenish 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第5期248-258,共11页
The novelty of this research lies in the successful fabrication of a 3D-printed honeycomb structure filled with nanofillers for acoustic properties,utilizing an impedance tube setup in accordance with ASTM standard E ... The novelty of this research lies in the successful fabrication of a 3D-printed honeycomb structure filled with nanofillers for acoustic properties,utilizing an impedance tube setup in accordance with ASTM standard E 1050-12.The Creality Ender-3,a 3D printer,was used for printing the honeycomb structures,and polylactic acid(PLA)material was employed for their construction.The organic,inorganic,and polymeric compounds within the composites were identified using fourier transformation infrared(FTIR)spectroscopy.The structure and homogeneity of the samples were examined using a field emission scanning electron microscope(FESEM).To determine the sound absorption coefficient of the 3D printed honeycomb structure,numerous samples were systematically developed using central composite design(CCD)and analysed using response surface methodology(RSM).The RSM mathematical model was established to predict the optimum values of each factor and noise reduction coefficient(NRC).The optimum values for an NRC of 0.377 were found to be 1.116 wt% carbon black,1.025 wt% aluminium powder,and 3.151 mm distance between parallel edges.Overall,the results demonstrate that a 3Dprinted honeycomb structure filled with nanofillers is an excellent material that can be utilized in various fields,including defence and aviation,where lightweight and acoustic properties are of great importance. 展开更多
关键词 3D printing Honeycomb structure ACOUSTICS Field emission scanning electron microscope Response surface methodology
下载PDF
Significance of including lid thickness and particle shape factor in numerical modeling for prediction of particle trap efficiency of invert trap
12
作者 Salman Beg Deo Raj Kaushal 《Water Science and Engineering》 EI CAS CSCD 2024年第2期166-176,共11页
Sediment accumulation on the bed of open sewers and drains reduces hydraulic efficiency and can cause localized flooding.Slotted invert traps installed underneath the bed of open sewers and drains can eliminate sedime... Sediment accumulation on the bed of open sewers and drains reduces hydraulic efficiency and can cause localized flooding.Slotted invert traps installed underneath the bed of open sewers and drains can eliminate sediment build-up by catching sediment load.Previous three-dimensional(3D)computational studies have examined the particle trapping performance of invert traps of different shapes and depths under varied sediment and flow conditions,considering particles as spheres.For two-dimensional and 3D numerical modeling,researchers assumed the lid geometry to be a thin line and a plane,respectively.In this 3D numerical study,the particle trapping efficiency of a slotted irregular hexagonal invert trap fitted at the flume bottom was examined by incorporating the particle shape factor of non-spherical sewage solid particles and the thicknesses of upstream and downstream lids over the trap in the discrete phase model of the ANSYS Fluent 2020 R1 software.The volume of fluid(VOF)and the realizable k-turbulence models were used to predict the velocity field.The two-dimensional particle image velocimetry(PIV)was used to measure the velocity field inside the invert trap.The results showed that the thicknesses of upstream and downstream lids affected the velocity field and turbulent kinetic energy at all flow depths.The joint impact of the particle shape factor and lid thickness on the trap efficiency was significant.When both the lid thickness and particle shape factor were considered in the numerical modeling,trap efficiencies were underestimated,with relative errors of-8.66%to-0.65%in comparison to the experimental values of Mohsin and Kaushal(2017).They were also lower than the values predicted by Mohsin and Kaushal(2017),which showed an overall overestimation with errors of-2.3%to 17.4%. 展开更多
关键词 Invert trap Lid thickness Particle image velocimetry Particle shape factor Turbulent kinetic energy scanning electron microscope
下载PDF
Detection of Bisphenol A (BPA) in Plastic Bottles Using Vertical Cultivation at Various Temperatures
13
作者 Karwan Alkaradaghi Tara Ali +2 位作者 Nadhir Al-Ansari Polla Khanaqa Jan Laue 《Journal of Environmental Protection》 2024年第6期656-671,共16页
Polycarbonate plastics containing bisphenol A (BPA) used to manufacture drinking water bottles. Kurdistan region in northern Iraq is a developed area with increased pollution from plastic bottles. Trace amounts of BPA... Polycarbonate plastics containing bisphenol A (BPA) used to manufacture drinking water bottles. Kurdistan region in northern Iraq is a developed area with increased pollution from plastic bottles. Trace amounts of BPA have been detected in bottled water samples. The absorption of BPA was measured with HPLC using a vertical cultivation system with Bulbs of the Allium Cepa plant planted in these plastic bottles with monitored growth. Vertical cultivation was found to have a low level of BPA in the plant cells, making it a safe cultivation method under specific climate conditions. The mean concentration of BPA in vertical cultivation is 0.19 ug/ml (3.8 ng for a 20 uL injection), and the Limit of Quantification (LOQ) is 0.63 ug/ml (12.7 ng for 20 uL injection). While Scanning Electron Microscope (SEM) shows that the concentrations are relatively low in water samples stored at room temperature compared to those exposed to direct sunlight (40°C) and water bottle samples stored at (-4°C), The correlation coefficients were found to be good (0.9992). SEM is used for plastic bottle samples stored at different temperatures. The images identify compound decay and explore the morphology of BPA in manufactured plastic materials. 展开更多
关键词 Vertical Cultivation ALLIUM Bisphenol A Plastic Bottles scanning electron microscope (SEM)
下载PDF
A Pioneering Approach to the Synthesis of Silver Nanoparticles
14
作者 Wasan A. Al-Dulaimi Zeena M. Al-Azzawi Emad K. Al-Shakarchi 《Journal of Materials Science and Chemical Engineering》 2024年第7期14-22,共9页
Our research introduces a groundbreaking chemical reduction method for synthesizing silver nanoparticles, marking a significant advancement in the field. The nanoparticles were meticulously characterized using various... Our research introduces a groundbreaking chemical reduction method for synthesizing silver nanoparticles, marking a significant advancement in the field. The nanoparticles were meticulously characterized using various techniques, including optical analysis, structural analysis, transmission electron microscopy (TEM), and field-emission scanning electron microscope (FESEM). This thorough process instills confidence in the accuracy of our findings. The results unveiled that the silver nanoparticles had a diameter of less than 20 nm, a finding of great importance. The absorption spectrum decreased in the peak wavelength range (405 - 394 mm) with increasing concentrations of Ag nanoparticles in the range (1 - 5%). The XRD results indicated a cubic crystal structure for silver nanoparticles with the lattice constant (a = 4.0855 Å), and Miller indices were (111), (002), (002), and (113). The simulation on the XRD pattern showed a face center cubic phase with space group Fm-3m, providing valuable insights into the structure of the nanoparticles. 展开更多
关键词 Chemical Reduction Method UV-VIS Absorption Spectrometer Field-Emission scanning electron microscope (FESEM) Transmission electron Microscopy (TEM)
下载PDF
Visualization of Methamphetamine-Contaminated Fingermarks on Glass Surfaces by Field Emission Scanning Electron Microscope for Forensic Investigation
15
作者 Sarah Aliah Amir Sarifudin Kah Haw Chang +1 位作者 Bee Ee Khoo Ahmad Fahmi Lim Abdullah 《Journal of Forensic Science and Medicine》 2023年第1期6-11,共6页
Background:Fingermark is an individual’s primary identification source.It is helpful in determining individuals involved in illegal activities and is frequently encountered in clandestine laboratories.During forensic... Background:Fingermark is an individual’s primary identification source.It is helpful in determining individuals involved in illegal activities and is frequently encountered in clandestine laboratories.During forensic investigation,the critical question to be answered is whether a fingermark was left on a surface before or after the initiation of an unlawful activity.Aims and Objectives:This study aimed to investigate the visualization of methamphetamine-contaminated fingermarks on glass surfaces and estimate the immediacy of their depositions.Materials and Methods:In this study,the prior-deposition contaminated fingermarks,i.e.,fingermarks deposited a surface priorly contaminated by methamphetamine,and the postdeposition contaminated fingermarks,i.e.,fingermarks deposited on a clean surface but subsequently contaminated with methamphetamine were visualized and compared using Field Emission Scanning Electron Microscope(FESEM).Results:Under FESEM,the latent fingermarks and the crystalline structure of methamphetamine were clearly visualized.The postdeposition contaminated fingermarks appeared in smudge conditions in all the three replicate samples,where the ridge and nonridge areas could not be well-distinguished.On the contrary,the prior-deposition contaminated fingermark demonstrated distinct separations between ridges and nonridges.However,the application of fingerprint powders reduced the possibility to determine the immediacy of deposition.Conclusion:To conclude,both prior-deposition contaminated fingermarks and postdeposition contaminated fingermarks can be discriminated,providing information on the instance when a fingermark was left on a surface. 展开更多
关键词 FINGERMARK METHAMPHETAMINE scanning electron microscope VISUALIZATION POWDER
原文传递
Bacteriological and electron microscopic examination of primary intrahepatic stones 被引量:17
16
作者 Shuo-Dong Wu, Hong Yu and Ji-Mei Sun Department of General Surgery Department of Microbiology Center Second Affiliated Hos- pital China Medical University, Shenyang 110004, China 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2006年第2期228-231,共4页
BACKGROUND: Primary intrahepatic cholelithiasis is usually combined with biliary tract infection. This research was undertaken to investigate the relationship between intrahepatic stones and biliary tract infection. M... BACKGROUND: Primary intrahepatic cholelithiasis is usually combined with biliary tract infection. This research was undertaken to investigate the relationship between intrahepatic stones and biliary tract infection. METHODS: Thirty-five bile samples and 30 stones specimens were cultured for bacteria and 12 stones specimens were examined with a scan electron microscope (SEM) or a transmission electron microscope (TEM). RESULT: 94.2% bile samples and 96.7% stones specimens were positive in bacteria culture. Bacteria were found in stones under SEM and TEM. CONCLUSION: Bacteria in stones are associated with the infection of the biliary tract. 展开更多
关键词 CHOLELITHIASIS BACTERIA scan electron microscope transmission electron microscope BIOFILM
下载PDF
Secondary electron emission yield from vertical graphene nanosheets by helicon plasma deposition
17
作者 Xue-Lian Jin Pei-Yu Ji +2 位作者 Lan-Jian Zhuge Xue-Mei Wu Cheng-Gang Jin 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第2期613-617,共5页
The secondary electron emission yields of materials depend on the geometries of their surface structures.In this paper,a method of depositing vertical graphene nanosheet(VGN)on the surface of the material is proposed,... The secondary electron emission yields of materials depend on the geometries of their surface structures.In this paper,a method of depositing vertical graphene nanosheet(VGN)on the surface of the material is proposed,and the secondary electron emission(SEE)characteristics for the VGN structure are studied.The COMSOL simulation and the scanning electron microscope(SEM)image analysis are carried out to study the secondary electron yield(SEY).The effect of aspect ratio and packing density of VGN on SEY under normal incident condition are studied.The results show that the VGN structure has a good effect on suppressing SEE. 展开更多
关键词 secondary electron emission secondary electron yield vertical graphene nanosheets scanning electron microscope
下载PDF
Monte Carlo Simulation of the Coaxial Electrons Backscattering from Thin Films
18
作者 Hu Da-ping School of Management, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China 《Wuhan University Journal of Natural Sciences》 CAS 2002年第2期203-206,共4页
By using the Monte Carlo method, we simulated the trajectories of coaxial backscattering electrons corresponding to a new type of scanning electron microscope. From the calculated results, we obtain a universal expres... By using the Monte Carlo method, we simulated the trajectories of coaxial backscattering electrons corresponding to a new type of scanning electron microscope. From the calculated results, we obtain a universal expression, which describes with good accuracy the backscattering coefficient versus film thickness under all conditions used. By measuring the coaxial backscattering coefficient and using this universal formula, the thickness of thin films can be determined if the composition is known. 展开更多
关键词 Monte Carlo simulation coaxial backscattered electrons thin film scanning electron microscope
下载PDF
钢渣粉/聚酯纤维沥青混合料水稳定性研究 被引量:4
19
作者 张抒幻 吴金荣 张涛 《科学技术与工程》 北大核心 2023年第2期785-793,共9页
为了实现钢渣粉在沥青路面中的可持续利用,同时结合河南省冬季冰雪天气下路面的除冰情况,研究了掺有聚酯纤维与钢渣粉沥青混合料的水稳定性。制备4种聚酯纤维掺量(0、0.3%、0.4%、0.5%)AC-13沥青混合料开展复盐(掺量配比为NaCl∶CaCl2∶... 为了实现钢渣粉在沥青路面中的可持续利用,同时结合河南省冬季冰雪天气下路面的除冰情况,研究了掺有聚酯纤维与钢渣粉沥青混合料的水稳定性。制备4种聚酯纤维掺量(0、0.3%、0.4%、0.5%)AC-13沥青混合料开展复盐(掺量配比为NaCl∶CaCl2∶CH2COONa=1∶1∶2)冻融循环劈裂试验,结果表明聚酯纤维掺量为0.4%时,沥青混合料水稳定最好;在最佳纤维掺量下制备5种替代率(0、25%、50%、75%、100%)钢渣粉沥青混合料,采用冻融劈裂抗拉强度比(freeze-thaw splitting tensile strength ratio,TSR)确定最佳钢渣粉替代率为75%,混合料水稳定性最佳;通过冻融腐蚀因子K评价沥青混合料的抗侵蚀性能,结果表明:聚酯纤维/钢渣粉沥青混合料的抗侵蚀性能最强,聚酯纤维沥青混合料次之,普通石灰岩沥青混合料最弱。通过电镜扫描(scanning electron microscope,SEM)、X射线衍射(X-ray diffraction,XRD)技术探索钢渣粉/聚酯纤维沥青混合料界面黏附作用的改性机理。微观分析表明:掺量为0.4%的聚酯纤维形成的纤维网状结构以及沥青、钢渣粉(75%的替代率)和矿粉三者存在界面能量作用可以很好地改善沥青混合料的水稳定性。 展开更多
关键词 聚酯纤维 钢渣粉 水稳定性 电镜扫描(scanning electron microscope SEM) X射线衍射(X-ray diffraction XRD)
下载PDF
New and interesting diatoms from the Shimen Wetwalls,Yunnan Province,China.Ⅱ.The diatom genus Nupela Vyverman&Compère(Bacillariophyceae)
20
作者 Qi LIU Xi LUO +1 位作者 Shulian XIE John Patrick KOCIOLEK 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第1期327-341,共15页
We detailed the valve morphology of five new species of diatom genus Nupela from wetwall communities in Yunnan Province,China,with light and scanning electron microscope.The five new species demonstrate great variabil... We detailed the valve morphology of five new species of diatom genus Nupela from wetwall communities in Yunnan Province,China,with light and scanning electron microscope.The five new species demonstrate great variability within the genus,as three of them are biraphid and two are monoraphid.In addition,variation was noted in the structure of internal proximal raphe ends,with some species having anchor-shaped ends and other species have hooked ends.The genus Nupela has grown considerably in 30years since it was first proposed,going from a monotypic genus to over 85 taxa.Diagnosis of the genus is based on the presence of an external covering over the areolae.We discussed the systematic placement of Nupela within the naviculoid diatoms.Yunnan Province appears to harbor many endemic diatom taxa,and many regions of the province have yet to be studied. 展开更多
关键词 Nupela scanning electron microscope(SEM) Yunnan new species morphology China BACILLARIOPHYCEAE
下载PDF
上一页 1 2 6 下一页 到第
使用帮助 返回顶部