[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
[ 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
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
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
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
A scanning electron microscope(SEM)provides real-time imaging with nanometer resolution and a large scanning area,which enables the development and integration of robotic nanomanipulation systems inside a vacuum chamb...A scanning electron microscope(SEM)provides real-time imaging with nanometer resolution and a large scanning area,which enables the development and integration of robotic nanomanipulation systems inside a vacuum chamber to realize simultaneous imaging and direct interactions with nanoscaled samples.Emerging techniques for nanorobotic manipulation during SEM imaging enable the characterization of nanomaterials and nanostructures and the prototyping/assembly of nanodevices.This paper presents a comprehensive survey of recent advances in nanorobotic manipulation,including the development of nanomanipulation platforms,tools,changeable toolboxes,sensing units,control strategies,electron beam-induced deposition approaches,automation techniques,and nanomanipulation-enabled applications and discoveries.The limitations of the existing technologies and prospects for new technologies are also discussed.展开更多
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
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
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
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
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
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
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
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
Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheri...Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheric particulate matter samples were collected at three different altitudes on Mount Qomolangma(Everest).Using an automated scanning electron microscope system,the composition,size,and morphology of 52,349 particles were analyzed.The average mass concentrations of PM_(1),PM_(2.5),and PM_(10)were 0.678,5.054,and 16.698μg/m^(3),respectively.Aluminosilicate particles dominated the samples,accounting for 71.5%to 82.8%of PM_(10)mass and 34.7%to 62.4%of the particle number.Quartz particles,carbonate particles,metal oxides,and sulfates were also observed at different periods.Carbonaceous particles made up a significant portion of aerosols,comprising 2.1%to 9.7%of PM_(10)mass and 10.4%to 45.4%of particle number,with their concentration showing an upward trend with altitude.Small amounts of tar ball particles and fly ash particles were also observed,providing direct evidence of anthropogenic influences on high-altitude regions,even at altitudes exceeding 6000 m.The size distribution and abundance of different particle categories were closely related to the transport trajectories of air masses.The morphology of different particle categories varied,with fly ash particles mainly spherical and carbonaceous particles exhibiting higher irregularity.展开更多
The deformation characteristics of silty soils under vibrational loads can easily change due to the wetting process,leading to the failure of roadbed structures.Commonly used methods for improving silty soils in engin...The deformation characteristics of silty soils under vibrational loads can easily change due to the wetting process,leading to the failure of roadbed structures.Commonly used methods for improving silty soils in engineering often yield unsatisfactory economic and ecological outcomes.As an environment-friendly soil improvement material,Xanthan gum has broad application prospects and is therefore considered a solidifying agent for enhancing silty soil properties in the Yellow River Basin.In this study,a series of tests is conducted using a scanning electron microscope and a dynamic triaxial testing apparatus to investigate the microstructure and dynamic deformation characteristics of unsaturated silty soil with varying xanthan gum contents during the wetting process.The results show that xanthan gum effectively fills voids between soil particles and adheres to their surfaces,forming fibrous and network structures.This modification enhances the inherent properties of the silty soil and significantly improves its stability under dynamic loading.Specifically,with increasing xanthan gum content,the dynamic shear modulus increases while the damping ratio decreases.During the wetting process,as suction decreases,the dynamic shear modulus decreases while the damping ratio increases.Xanthan gum reduces the sensitivity of the dynamic deformation characteristics of the treated silty soil to changes in suction levels.Finally,based on the modified Hardin-Drnevich hyperbolic model,a predictive model for the dynamic shear modulus and damping ratio of treated silty soil is proposed,considering the xanthan gum content.These research findings provide a theoretical basis for the construction and maintenance of water conservancy,slope stabilization,and roadbed projects in the Yellow River Basin.展开更多
[Objective] This study aimed to compare and analyse the morphological characteristics of the seed-like fruits between Salvia shandongensis J. X. Li et F. Q. Zhou and its relatives. [Method] The morphological character...[Objective] This study aimed to compare and analyse the morphological characteristics of the seed-like fruits between Salvia shandongensis J. X. Li et F. Q. Zhou and its relatives. [Method] The morphological characteristics of the mature seed-like fruits of Salvia shandongensis and its three congeners, S. miltiorrhiza, S. miltiorrhiza f. alba and S. bowleyana, were comparatively observed using both optical microscope and scanning electron microscope. [Result] The results showed that there were distinct differences in the shape, size and exine sculpture of the seed-like fruits of the four Danshen congeners： the seed-like fruits of S. shandongensis that were elliptical and had areolate sculpture with subquadrangular convex meshes as well as densely filamentous transverse lines were easy to be distinguished from those of S. miltiorrhiza Bge., which were broadly elliptical and had reticulate sculpture with subquadrate concave meshes. The seed-like fruits of S. bowleyana were fusiform and their ektexine had reticulate sculpture with polygonal meshes, which were slightly convex at the center, which are obviously different from those of S. shandongensis. [Conclusion] This study first accumulates data of the seed-like fruits of S. shandongensis, which provides important bases for establishing its taxonomical status and studying its germplasm. The morphological characteristics and reticulate sculpture on ektexine of the seed-like fruits S. miltiorrhiza Bge. are consistent with the previous report. The results in this study not only provide references for uncovering the genetic relationships between S. shandongensis and S. miltiorrhiza Bge., as well as the interspecific classification and identification. In addition, this study also provides new scientific proofs for the identification of Danshen species and their introduction and cultivation, genetics and breeding.展开更多
Nanoscale defects such as dislocations have a significant impact on the phonon thermal transport properties in non-metallic materials.To unravel these effects,an understanding of defect phonon modes is essential.Herei...Nanoscale defects such as dislocations have a significant impact on the phonon thermal transport properties in non-metallic materials.To unravel these effects,an understanding of defect phonon modes is essential.Herein,at the atomic scale,the localized phonons of individual dislocations at a Si/Ge interface are measured via monochromated electron energy loss spectroscopy in a scanning transmission electron microscope.These modes are then correlated with the local microstructure,further revealing the dislocation effects on the local thermal transport properties.The dislocation causes a phonon redshift of several milli-electron-volts within about two to four nanometers of the core,where both the strain field and Ge segregation play roles.With the presence of dislocation,the local interfacial thermal conductance can be either enhanced or reduced,depending on the complex interaction and competition between lattice disorder(dislocation)and element disorder(heterointerface mixing and Ge-segregation)at the interface.These findings provide valuable insights to improve the thermal properties of thermoelectric generators and thermal management systems through proper defect engineering.展开更多
[ Objective] The research aimed to explore the manufacturing methods of scanning electron microscope （SEM） and transmission electron microscopy （TEM） for oocyte and provide technical support for related research. ...[ Objective] The research aimed to explore the manufacturing methods of scanning electron microscope （SEM） and transmission electron microscopy （TEM） for oocyte and provide technical support for related research. [ Method] Based on GV-and MII-stage oocytes, samples of SEM and TEM were prepared respectively, then ultrastructure changes were observed. [ Result] The results showed that the method needed few samples, keep intact cell morphology and can see clear ultrastructure. [Conclusion] The method is suitable for ultrastructural observation of oocyte.展开更多
文摘[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.
文摘[ 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.
基金Supported by Key Project of Science and Technology in Henan Province(152102110100,152102110036)National Natural Science Foundation of China(U1604110,U1404319,31270727,31600992)+3 种基金Nanhu Scholars Program for Young Scholars of XYNU(2016056)Major Science and Technology Project in Henan Province(121100110200)Students Scientific Research Fund of Xinyang Normal University(2015-DXS-158)Fund of Institute for Conservation and Utilization of Agro-bioresources in Dabie Mountains(2016020)
文摘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.
文摘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.
文摘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
基金This study was supported by the Natural Sciences and Engineering Research Council of Canada,the Canada Research Chairs Program,and the Ontario Ministry of Research and Innovation via an ORF-RE grant.
文摘A scanning electron microscope(SEM)provides real-time imaging with nanometer resolution and a large scanning area,which enables the development and integration of robotic nanomanipulation systems inside a vacuum chamber to realize simultaneous imaging and direct interactions with nanoscaled samples.Emerging techniques for nanorobotic manipulation during SEM imaging enable the characterization of nanomaterials and nanostructures and the prototyping/assembly of nanodevices.This paper presents a comprehensive survey of recent advances in nanorobotic manipulation,including the development of nanomanipulation platforms,tools,changeable toolboxes,sensing units,control strategies,electron beam-induced deposition approaches,automation techniques,and nanomanipulation-enabled applications and discoveries.The limitations of the existing technologies and prospects for new technologies are also discussed.
基金Universiti Sains Malaysia RUI grant(1001/PPSK/8012236).
文摘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.
基金The projectis supported financially by Heilongjiang( C- 970 2 ) and Chinese national( 39870 572 ) natural and scientificfunds.
文摘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.
文摘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.
文摘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.
文摘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.
基金supported by the National Natural Science Foundation of China(Grant No.11975163)。
文摘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.
文摘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.
文摘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.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(No.2019QZKK0106)the Basic Research Fund of CAMS(Nos.2023Z004 and 2023Z015).
文摘Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheric particulate matter samples were collected at three different altitudes on Mount Qomolangma(Everest).Using an automated scanning electron microscope system,the composition,size,and morphology of 52,349 particles were analyzed.The average mass concentrations of PM_(1),PM_(2.5),and PM_(10)were 0.678,5.054,and 16.698μg/m^(3),respectively.Aluminosilicate particles dominated the samples,accounting for 71.5%to 82.8%of PM_(10)mass and 34.7%to 62.4%of the particle number.Quartz particles,carbonate particles,metal oxides,and sulfates were also observed at different periods.Carbonaceous particles made up a significant portion of aerosols,comprising 2.1%to 9.7%of PM_(10)mass and 10.4%to 45.4%of particle number,with their concentration showing an upward trend with altitude.Small amounts of tar ball particles and fly ash particles were also observed,providing direct evidence of anthropogenic influences on high-altitude regions,even at altitudes exceeding 6000 m.The size distribution and abundance of different particle categories were closely related to the transport trajectories of air masses.The morphology of different particle categories varied,with fly ash particles mainly spherical and carbonaceous particles exhibiting higher irregularity.
基金supported by the Postgraduate Education Reform and Quality Improvement Project of Henan Province,China(Grant No.YJS2023AL004)the Graduate Innovation Project of North China University of Water Resources and Electric Power(Grant No.NCWUYC-202315069)the China National Scholarship Fund organized by the China Scholarship Council(Grant No.202208410337).
文摘The deformation characteristics of silty soils under vibrational loads can easily change due to the wetting process,leading to the failure of roadbed structures.Commonly used methods for improving silty soils in engineering often yield unsatisfactory economic and ecological outcomes.As an environment-friendly soil improvement material,Xanthan gum has broad application prospects and is therefore considered a solidifying agent for enhancing silty soil properties in the Yellow River Basin.In this study,a series of tests is conducted using a scanning electron microscope and a dynamic triaxial testing apparatus to investigate the microstructure and dynamic deformation characteristics of unsaturated silty soil with varying xanthan gum contents during the wetting process.The results show that xanthan gum effectively fills voids between soil particles and adheres to their surfaces,forming fibrous and network structures.This modification enhances the inherent properties of the silty soil and significantly improves its stability under dynamic loading.Specifically,with increasing xanthan gum content,the dynamic shear modulus increases while the damping ratio decreases.During the wetting process,as suction decreases,the dynamic shear modulus decreases while the damping ratio increases.Xanthan gum reduces the sensitivity of the dynamic deformation characteristics of the treated silty soil to changes in suction levels.Finally,based on the modified Hardin-Drnevich hyperbolic model,a predictive model for the dynamic shear modulus and damping ratio of treated silty soil is proposed,considering the xanthan gum content.These research findings provide a theoretical basis for the construction and maintenance of water conservancy,slope stabilization,and roadbed projects in the Yellow River Basin.
基金Supported by the Scientific and Technological Development Project of Shandong Province(2008GG2NS02022)the Special Fund for Agricultural Fine Seed Project in Shandong Province(2009LZ01-03)~~
文摘[Objective] This study aimed to compare and analyse the morphological characteristics of the seed-like fruits between Salvia shandongensis J. X. Li et F. Q. Zhou and its relatives. [Method] The morphological characteristics of the mature seed-like fruits of Salvia shandongensis and its three congeners, S. miltiorrhiza, S. miltiorrhiza f. alba and S. bowleyana, were comparatively observed using both optical microscope and scanning electron microscope. [Result] The results showed that there were distinct differences in the shape, size and exine sculpture of the seed-like fruits of the four Danshen congeners： the seed-like fruits of S. shandongensis that were elliptical and had areolate sculpture with subquadrangular convex meshes as well as densely filamentous transverse lines were easy to be distinguished from those of S. miltiorrhiza Bge., which were broadly elliptical and had reticulate sculpture with subquadrate concave meshes. The seed-like fruits of S. bowleyana were fusiform and their ektexine had reticulate sculpture with polygonal meshes, which were slightly convex at the center, which are obviously different from those of S. shandongensis. [Conclusion] This study first accumulates data of the seed-like fruits of S. shandongensis, which provides important bases for establishing its taxonomical status and studying its germplasm. The morphological characteristics and reticulate sculpture on ektexine of the seed-like fruits S. miltiorrhiza Bge. are consistent with the previous report. The results in this study not only provide references for uncovering the genetic relationships between S. shandongensis and S. miltiorrhiza Bge., as well as the interspecific classification and identification. In addition, this study also provides new scientific proofs for the identification of Danshen species and their introduction and cultivation, genetics and breeding.
基金supported by the National Natural Science Foundation of China(Grant No.52125307)the National Key R&D Program of China(Grant No.2021YFB3501500)the support from the New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘Nanoscale defects such as dislocations have a significant impact on the phonon thermal transport properties in non-metallic materials.To unravel these effects,an understanding of defect phonon modes is essential.Herein,at the atomic scale,the localized phonons of individual dislocations at a Si/Ge interface are measured via monochromated electron energy loss spectroscopy in a scanning transmission electron microscope.These modes are then correlated with the local microstructure,further revealing the dislocation effects on the local thermal transport properties.The dislocation causes a phonon redshift of several milli-electron-volts within about two to four nanometers of the core,where both the strain field and Ge segregation play roles.With the presence of dislocation,the local interfacial thermal conductance can be either enhanced or reduced,depending on the complex interaction and competition between lattice disorder(dislocation)and element disorder(heterointerface mixing and Ge-segregation)at the interface.These findings provide valuable insights to improve the thermal properties of thermoelectric generators and thermal management systems through proper defect engineering.
基金Supported by Natural Science Foundation of Jiangsu Province(Grant number:BK2008589)Shanghai Committee(Grant num-ber:2003 #14-1)~~
文摘[ Objective] The research aimed to explore the manufacturing methods of scanning electron microscope （SEM） and transmission electron microscopy （TEM） for oocyte and provide technical support for related research. [ Method] Based on GV-and MII-stage oocytes, samples of SEM and TEM were prepared respectively, then ultrastructure changes were observed. [ Result] The results showed that the method needed few samples, keep intact cell morphology and can see clear ultrastructure. [Conclusion] The method is suitable for ultrastructural observation of oocyte.
