期刊文献+
共找到23,417篇文章
< 1 2 250 >
每页显示 20 50 100
Investigation of bubbles escape behavior from low basicity mold flux for high-Mn high-Al steels using 3D X-ray microscope
1
作者 Qiang Liu Xiang Li +3 位作者 Shen Du Ming Gao Yanbin Yin Jiongming Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期102-110,共9页
During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a rest... During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels. 展开更多
关键词 mold flux low basicity BUBBLES three-dimensional X-ray microscope VISCOSITY
在线阅读 下载PDF
Application of Motic Digital Microscope Mutual System in the Experimental Teaching of Medicinal Plants
2
作者 Hailin LU Min GUO +3 位作者 Shenggao YIN Bin LI Yonghua LI Haicheng WEN 《Medicinal Plant》 2025年第2期88-90,共3页
In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly effi... In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly efficacious approach to enhance the teaching level of experimental courses in medicinal botany.The implementation of a digital microscope mutual system in experimental teaching not only enhances students practical skills in laboratory operations but also increases classroom efficiency.Furthermore,it supports personalized development among students while fostering innovative thinking,independent learning capabilities,and analysis and problem-solving skills.Additionally,this approach contributes to the enhancement of students scientific literacy. 展开更多
关键词 microscope Medicinal plants Mutual system Experimental teaching
在线阅读 下载PDF
An investigation of single-phased metallic solidification process using high-temperature confocal laser scanning microscope combined with differential scanning colorimetry
3
作者 Xing-zhi Zhou De-yong Wang +6 位作者 Tian-peng Qu Dong Hou Shao-yan Hu Jun Tian Xiang-long Li Lei Fan Zhi-xiao Zhang 《Journal of Iron and Steel Research International》 2025年第2期437-451,共15页
To investigate the nucleation behavior during the single-phased metallic solidification process,the commercial ultrapure ferritic stainless steels with no(Initial steel)and various melt treatments(R1,MR1,Y2,MY1,and M1... To investigate the nucleation behavior during the single-phased metallic solidification process,the commercial ultrapure ferritic stainless steels with no(Initial steel)and various melt treatments(R1,MR1,Y2,MY1,and M1 steels)were used to carry out the differential scanning colorimetry(DSC)and high-temperature confocal laser scanning microscope(HT-CLSM)experiments.Based on the results of DSC experiments,the equilibrium solidification process as well as the relationship among the critical undercooling degree(△T_(c)^(DSC)),latent heat of fusion/crystallization(△H_(f)/△H_(c)),equiaxed grain ratio(ER),and average grain size(△_(ave)^(ingot))was revealed.ER is increased with the decreasing△T_(c)^(DSC)and increasing△H_(f)/△H_(c);however,△_(ave)^(ingot)is decreased with them.Referring to the results of HT-CLSM experiments,the average sizes of micro-/macrostructures(d_(ave)/D_(ave)/)are decreased with the increasing cooling rate,as well as the difference between and apparent critical undercooling degree(△T_(c)^(CLSM))was revealed.The heterogeneous nucleation of the crystal nuclei occurs only if△T_(c)^(CLSM)>△T_(c)^(DSC).Combining with the interfacial wetting-lattice mismatch heterogeneous nucleation model,the dynamic mechanism of the metallic solidification was revealed.The as-cast grains of the melt-treated samples were obviously refined,owing to the much higher actual heterogeneous nucleation rates(I_(heter.,i))obtained through melt treatments,and the heterogeneous nucleation rates(I_(heter.,ij))for all samples are increased with the cooling rates,firmly confirming that the as-cast grains of each sample could be refined by the increasing cooling rates. 展开更多
关键词 NUCLEATION Metallic solidification process Differential scanning colorimetry High-temperature confocal laser scanning microscope Interfacial wetting-lattice mismatch heterogeneous nucleation model
原文传递
基于流式细胞摄像技术(FlowCAM)的赤潮藻类识别分析初探 被引量:3
4
作者 余肖翰 曾松福 +3 位作者 曹宇峰 陈瑶 谢杰镇 郑少平 《海洋科学进展》 CAS CSCD 北大核心 2013年第4期515-526,共12页
采用流式细胞摄像系统(Flow Cytometer And Microscope,FlowCAM)技术,构建了福建南部海域的赤潮生物图谱数据库,并利用该数据库分别用VisualSpread软件自动识别法和描述子分析算法(MATLAB)来鉴定样品,对两种方法的识别精确度进行了比较... 采用流式细胞摄像系统(Flow Cytometer And Microscope,FlowCAM)技术,构建了福建南部海域的赤潮生物图谱数据库,并利用该数据库分别用VisualSpread软件自动识别法和描述子分析算法(MATLAB)来鉴定样品,对两种方法的识别精确度进行了比较。VisualSpreadsheet专业软件分析能力达到98.2%的平均精度,自主开发的特征描述子分类器达到94.1%的平均精度,拓展了实验设备的应用范围。 展开更多
关键词 flowcam 图谱数据库 VisualSpread 形状特征描述子
在线阅读 下载PDF
Observation for Leaf Epidermal Characteristics of Four Different Pomegranate Cultivars under Scanning Electron Microscope 被引量:5
5
作者 徐迎碧 丁之恩 《Agricultural Science & Technology》 CAS 2008年第3期99-102,共4页
[Objective] The research aimed to provide reference for classification of pomegranate cultivars and studies of genetic relationship among pomegranate cultivars.[Method] The electron microscope scanning was used to com... [Objective] The research aimed to provide reference for classification of pomegranate cultivars and studies of genetic relationship among pomegranate cultivars.[Method] The electron microscope scanning was used to comparatively observe leaf epidermal structures of 4 pomegranate cultivars.[Result] The upper epidermal structures of 4 pomegranate cultivars were similar and showed reticular structure .However, the differences existed in lower epidermis,such as cell shape,cell size and arrangement mode of cell as well as stomatal density,while the structures of leaf vein in lower epidermis of 4 pomegranate cultivars were similar.[Conclusion] The research provided morphological references for studying heterosis of pomegranate to some extent. 展开更多
关键词 POMEGRANATE CULTIVAR LEAF EPIDERMIS Electron microscope scanning
在线阅读 下载PDF
Solidification process of conventional superalloy by confocal scanning laser microscope 被引量:6
6
作者 缪竹骏 单爱党 +3 位作者 王威 卢俊 徐文亮 宋洪伟 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第2期236-242,共7页
The solidification process of a conventional superalloy, IN718, was investigated by confocal scanning laser microscope (CSLM). The liquid fraction during solidification was obtained as a function of real time and te... The solidification process of a conventional superalloy, IN718, was investigated by confocal scanning laser microscope (CSLM). The liquid fraction during solidification was obtained as a function of real time and temperature in reference with the in-situ observation. The characteristics of L→γ transformation were analyzed and the γ growing rate of each stage was also calculated. Scheil equation was employed to predict the segregation behavior, and the predict results are in consistence with the experimental results. As a result, the confocal scanning laser microscope shows a great potential for solidification process research. 展开更多
关键词 IN718 alloy SOLIDIFICATION IN-SITU confocal scanning laser microscope SEGREGATION
在线阅读 下载PDF
Changes of Calmodulin Distribution in the Embryo Sac of Oryza sativa Before and After Fertilization: an Immunogold Electron Microscope Study 被引量:4
7
作者 杨军 赵洁 +1 位作者 梁世平 杨弘远 《Acta Botanica Sinica》 CSCD 2002年第3期264-272,共9页
Changes of calmodulin (CaM) distribution in the embryo sac of rice (Oryza sativa subsp. Japonica) at various stages before and after fertilization have been investigated by using immunogold electron microscopy. Before... Changes of calmodulin (CaM) distribution in the embryo sac of rice (Oryza sativa subsp. Japonica) at various stages before and after fertilization have been investigated by using immunogold electron microscopy. Before pollination, both cytoplasm and vacuoles of the egg cell, synergids and central cell were labeled by gold particles. A small amount of gold particles were localized in the nucleus, endoplasmic reticulum, mitochondria and dictyosomes. From pollination to fertilization, CaM amount increased in these cells, especially rich in the starch of amyloplasts. Increase of gold particles in the central cell began about 2 h earlier than that in the egg cell. There was no distinct difference of CaM amount between the degenerated and the persistent synergids. It is interesting to observe an obvious change of CaM distribution form during pollination and fertilization from scattered single particles to clustered particles, and back again to single particles after the fertilization finished. CaM was also localized extracellularly in the embryo sac wall as well as in the wall and intercellular space of nucellus cells. The extracellular CaM also changes in its amount and form after pollination. These results suggest that CaM, either intra- or extra-cellular, may play important roles in fertilization and zygote formation. 展开更多
关键词 CALMODULIN POLLINATION FERTILIZATION rice embryo sac immunogold electron microscope localization
在线阅读 下载PDF
用IM Microscope方法计算无源互调产物
8
作者 王海宁 梁建刚 +1 位作者 王积勤 张晨新 《空军工程大学学报(自然科学版)》 CSCD 北大核心 2005年第3期47-49,共3页
在微波与射频无源互调的研究中,预测无源互调产物的电平是非常重要的。在IM Micro-scope方法的基础上进行了改进,在预测过程中直接引入输入信号经过非线性器件后输出信号的幅度和相位变化模型,给出了详细的数学模型,并实例验证了该方法... 在微波与射频无源互调的研究中,预测无源互调产物的电平是非常重要的。在IM Micro-scope方法的基础上进行了改进,在预测过程中直接引入输入信号经过非线性器件后输出信号的幅度和相位变化模型,给出了详细的数学模型,并实例验证了该方法的正确性。 展开更多
关键词 无源互调(PIM) 无源互调产物(PIMP) IM microscope RF
在线阅读 下载PDF
用IM Microscope方法计算无源互调产物
9
作者 王海宁 梁建刚 +1 位作者 王积勤 张晨新 《弹箭与制导学报》 CSCD 北大核心 2005年第S4期458-460,共3页
在微波与射频无源互调的研究中,预测无源互调产物的电平是非常重要的,因为这样可以直观的看出无源互调噪声对于器件或者系统的影响。在众多的预测方法中,IM Microscope 方法具有很多优点。文中在IM Microscope 方法的基础上进行了改进,... 在微波与射频无源互调的研究中,预测无源互调产物的电平是非常重要的,因为这样可以直观的看出无源互调噪声对于器件或者系统的影响。在众多的预测方法中,IM Microscope 方法具有很多优点。文中在IM Microscope 方法的基础上进行了改进,在预测过程中直接引入输入信号经过非线性器件后输出信号的幅度和相位变化模型,给出了详细的数学模型,这样可以大大减少很多的测量工作。 展开更多
关键词 无源互调(PIM) 无源互调产物(PIMP) IM microscope RF
在线阅读 下载PDF
Obsevation for Epidermal Ultrastructure of Nostoc sphaeroides Kutzing under Scanning Electron Microscope 被引量:1
10
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
在线阅读 下载PDF
基于深度学习的致密砂岩显微图像识别
11
作者 李盼盼 李洋冰 +6 位作者 税蕾蕾 胡维强 马立涛 李晨晨 刘再振 曹地 陈建奇 《岩矿测试》 北大核心 2026年第1期220-230,共11页
以岩石薄片鉴定为代表的传统地质实验,具有人工依赖性强、实验周期性长、鉴定内容复杂的特点,对该实验进行智能化提升是地质实验数字化转型的关键。致密砂岩岩石矿物类型以石英、斜长石、钾长石、变质岩岩屑和火成岩岩屑为主。致密砂岩... 以岩石薄片鉴定为代表的传统地质实验,具有人工依赖性强、实验周期性长、鉴定内容复杂的特点,对该实验进行智能化提升是地质实验数字化转型的关键。致密砂岩岩石矿物类型以石英、斜长石、钾长石、变质岩岩屑和火成岩岩屑为主。致密砂岩铸体薄片鉴定可进行组分结构、孔隙喉道和填隙物类型的定性定量分析,为微观储层特征研究和评价提供重要实验支持。因致密砂岩具有颗粒粒径细、成岩作用强和储集空间复杂的特点,进行智能识别难点主要有三个方面:细粒颗粒分割、易混淆矿物识别及微孔隙定量分析。本文阐述了一种基于深度学习的致密砂岩薄片显微图像组构智能识别方法。首先,建立致密砂岩铸体薄片单偏光和正交偏光的显微图像库,利用语义分割、SAM(Segment Anything Model)算法对图像中的矿物颗粒边界进行分割,再利用深度卷积神经网络自动提取薄片显微图像中矿物的单偏光和正交偏光下完整消光周期的光性特征和结构特征,对致密砂岩薄片显微图像颗粒的矿物识别、矿物定量及分选磨圆结构分析,同时实现面孔率分类和孔隙定量分析。对鄂尔多斯盆地临兴—神府区块的致密砂岩铸体薄片测试图像集进行验证,矿物颗粒分割准确率可以达到95%,石英、斜长石和钾长石等主要矿物的识别准确率达到91%。该研究避免了人工繁琐重复性矿物鉴定及定量统计工作,为致密砂岩薄片显微图像智能化提供技术支撑。 展开更多
关键词 致密砂岩 铸体薄片 显微图像 颗粒分割 深度学习 智能识别
在线阅读 下载PDF
MicroScope高分辨率成像测井技术及应用
12
作者 夏竹君 张兰江 +2 位作者 张贺举 杨坚 付琛 《海洋石油》 CAS 2019年第1期54-60,共7页
MicroScope随钻高分辨率成像测井技术是斯伦贝谢公司最新推出,能记录超高分辨率电阻率图像UHRI和多个探测深度深钮电阻率成像图,介绍了超高分辨率电阻率成像图UHRI识别岩性及地层结构、识别沉积构造、划分沉积微相、分析古水流与砂体展... MicroScope随钻高分辨率成像测井技术是斯伦贝谢公司最新推出,能记录超高分辨率电阻率图像UHRI和多个探测深度深钮电阻率成像图,介绍了超高分辨率电阻率成像图UHRI识别岩性及地层结构、识别沉积构造、划分沉积微相、分析古水流与砂体展布等的方法,在南海西部沉积相研究方面发挥了重要作用,是值得推广的新型成像测井技术。 展开更多
关键词 microscope 成像测井 沉积相 测井技术 南海西部
在线阅读 下载PDF
Observation of Helicotylenchus digonicus by Scanning Electron Microscope
13
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
在线阅读 下载PDF
Ultrastructure and key identification points of fossilized Os Draconis in traditional Chinese medicine
14
作者 Dong-Han Bai Zi Xing +5 位作者 Zi-Hao Zhang Zhi-Jie Zhang Da-Jun Lu Nan-Xi Huang Qiao-Chu Wang Lu Luo 《Traditional Medicine Research》 2026年第1期39-46,共8页
Background:The medicinal material known as Os Draconis(Longgu)originates from fossilized remains of ancient mammals and is widely used in treating emotional and mental conditions.However,fossil resources are nonrenewa... Background:The medicinal material known as Os Draconis(Longgu)originates from fossilized remains of ancient mammals and is widely used in treating emotional and mental conditions.However,fossil resources are nonrenewable,and clinical demand is increasingly difficult to meet,leading to a proliferation of counterfeit products.During prolonged geological burial,static pressure from the surrounding strata severely compromises the microstructural integrity of osteons in Os Draconis,but Os Draconis still largely retains the structural features of mammalian bone.Methods:Using verified authentic Os Draconis samples over 10,000 years old as a baseline,this study summarizes the ultrastructural characteristics of genuine Os Draconis.Employing electron probe microanalysis and optical polarized light microscopy,we examined 28 batches of authentic Os Draconis and 31 batches of counterfeits to identify their ultrastructural differences.Key points for ultrastructural identification of Os Draconis were compiled,and a new identification approach was proposed based on these differences.Results:Authentic Os Draconis exhibited distinct ultrastructural markers:irregularly shaped osteons with traversing fissures,deformed/displaced Haversian canals,and secondary mineral infill(predominantly calcium carbonate).Counterfeits showed regular osteon arrangements,absent traversal fissures,and homogeneous hydroxyapatite composition.Lab-simulated samples lacked structural degradation features.EPMA confirmed calcium carbonate infill in fossilized Haversian canals,while elemental profiles differentiated lacunae types(void vs.mineral-packed).Conclusion:The study established ultrastructural criteria for authentic Os Draconis identification:osteon deformation,geological fissures penetrating bone units,and heterogenous mineral deposition.These features,unattainable in counterfeits or modern processed bones,provide a cost-effective,accurate identification method.This approach bridges gaps in TCM material standardization and supports quality control for clinical applications. 展开更多
关键词 Os Draconis ULTRASTRUCTURE identification points electron probe polarized light microscope
暂未订购
四川盆地海相页岩固体沥青与沥青包裹体成熟度对比分析及地质 意义
15
作者 周志鹏 吴娟 +7 位作者 罗超 梁静怡 陈钰 谢金旭 王恒 蒋前前 邓宾 焦堃 《岩矿测试》 北大核心 2026年第1期14-30,共17页
有机质成熟度是评价烃源岩生烃潜力与页岩气保存条件的重要指标。近年来,激光拉曼光谱技术因其非破坏性和高分辨率特性,在古老海相页岩有机质成熟度研究中得到广泛应用。已有学者通过页岩固体沥青的拉曼光谱特征建立了热演化程度的定量... 有机质成熟度是评价烃源岩生烃潜力与页岩气保存条件的重要指标。近年来,激光拉曼光谱技术因其非破坏性和高分辨率特性,在古老海相页岩有机质成熟度研究中得到广泛应用。已有学者通过页岩固体沥青的拉曼光谱特征建立了热演化程度的定量模型,但页岩固体沥青与沥青包裹体成熟度的定量差异及适用边界尚缺乏系统厘定,成为制约高—过成熟页岩热史精确重建与烃源岩精细评价的难点。本文以四川盆地下寒武统筇竹寺组页岩及其裂缝脉体矿物中的沥青包裹体为研究对象,通过显微激光拉曼光谱技术结合分峰拟合,系统对比了页岩固体沥青与沥青包裹体的成熟度差异,为海相页岩有机质成熟度评价提供新视角。研究结果表明:基于峰高比参数(ID1/IG)计算的页岩固体沥青成熟度范围为3.32%~3.64%,沥青包裹体为3.51%~3.71%,数据离散性较低;同一深度样品中,沥青包裹体成熟度普遍高于页岩固体沥青,其绝对值相差0.02%~0.22%,表明封闭体系更有利于保存有机质的热演化信息。同时考虑到开放体系中环境引起的次生变化亦会对烃源岩生烃能力产生影响,本文认为沥青包裹体适用于有机质埋藏-热演化历史重建,而页岩固体沥青成熟度更宜作为烃源岩评价指标。 展开更多
关键词 海相页岩 页岩固体沥青 沥青包裹体 成熟度 有机质热演化历史重建 烃源岩评价指标 显微激光拉曼光谱
在线阅读 下载PDF
Investigation into the Effect and Microscopic Mechanism of Retarders on Two-component Backfilling Grout in Shield Engineering
16
作者 CAI Hongwei MIN Fanlu +5 位作者 YUAN Rui LI Zhen ZHANG Jianfeng WANG Dengfeng ZHANG Yazhou YAO Zhanhu 《Journal of Wuhan University of Technology(Materials Science)》 2026年第1期84-95,共12页
To address the issues of short setting time and high bleeding rate of A component,which easily cause pipe plugging and poor grouting performance when a two-component grout is injected synchronously behind the Segmenta... To address the issues of short setting time and high bleeding rate of A component,which easily cause pipe plugging and poor grouting performance when a two-component grout is injected synchronously behind the Segmental Lining,the inorganic retarder sodium pyrophosphate(TSPP)and three organic retarders were added to the A component:sodium citrate(SC),sodium tartrate(ST)and glycerol(GLY).The effect law and microscopic mechanism of viscosity,bleeding rate,setting time,gelling time,compressive strength,and stone rate were investigated.The results revealed that the addition of retarders could enhance the stability and setting time of the A component and increase the gelling time,stone rate,and compressive strength of two-component grout.Among them,the performance of the grout with an SC dosage of 0.1% was superior.The bleeding rate of this grout was reduced to 3.5%,the stone rate of the two-component grout was more than 99%,and the early compressive strength and late compressive strength of this grout were increased by approximately 35% and 7%,respectively.The initial and final setting time of the A component with a TSPP dosage of 0.3% was the longest,which was prolonged to 17 and 26 h,respectively.Microscopic analysis revealed that the four retarders hindered the hydration process of cement through complexation and adsorption,and inhibited the hydration of C_(3)S and the crystallisation of CH.Moreover,they reduced the defects caused by the rapid reaction of water glass and CH on the solid phase structure,enabled the microstructure of the stone body to be denser,and subsequently,enhanced the compressive strength. 展开更多
关键词 backfilling grout two-component grout RETARDER working performance gelling performance microscopic mechanism
原文传递
基于黄原胶+木质素磺酸钙复合改良分散土的机理研究
17
作者 郭佳慧 米博阳 +2 位作者 王奕琛 王辉鑫 王帅 《山西建筑》 2026年第2期16-20,共5页
中国东北和西北季冻区广泛分布分散土,其抗侵蚀、抗剪和抗渗性差,工程稳定性低,在冻融循环、干湿交替下易破坏。针对此,文中聚焦黄原胶与木质素磺酸钙对分散土强度的改良。经直剪和SEM试验发现,随二者掺量变化,改性土力学性能增强,木质... 中国东北和西北季冻区广泛分布分散土,其抗侵蚀、抗剪和抗渗性差,工程稳定性低,在冻融循环、干湿交替下易破坏。针对此,文中聚焦黄原胶与木质素磺酸钙对分散土强度的改良。经直剪和SEM试验发现,随二者掺量变化,改性土力学性能增强,木质素磺酸钙对强度提升作用显著。当黄原胶掺量5%、木质素磺酸钙掺量1%时,复合改性土改良效果最佳,抗剪强度等指标达峰值。SEM分析表明,二者协同使土体孔隙降低、胶结物增多,土颗粒聚集成致密结构,增强咬合力与黏聚力,从而提升土体强度和稳定性。 展开更多
关键词 黄原胶 木质素磺酸钙 分散土 抗剪强度 微观孔隙结构
在线阅读 下载PDF
A Highly Stable Electrochemical Scanning Tunneling Microscope 被引量:1
18
作者 夏志刚 王纪浩 +1 位作者 侯玉斌 陆轻铀 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2015年第1期70-72,I0002,共4页
We demonstrate a home-built electrochemical scanning tunneling microscope (ECSTM). The ECSTM exhibits highly stable performance. The drifting rates in XY and Z directions of the ECSTM are about 67 and 55.6 pm/min, r... We demonstrate a home-built electrochemical scanning tunneling microscope (ECSTM). The ECSTM exhibits highly stable performance. The drifting rates in XY and Z directions of the ECSTM are about 67 and 55.6 pm/min, respectively. Moreover, a specially designed scanner unit successfully solves the well-known problem of large leakage current in high humidity atmosphere. The mechanical structure of the ECSTM is described in detail. The excellent performances of the system are demonstrated by the measured STM images (in copper sulfate solution), including clean and well-ordered large area morphology of Au(111) and the atomically resolved image of highly oriented pyrolytic graphite. 展开更多
关键词 Scanning tunneling microscope ELECTROCHEMISTRY Highly stable
在线阅读 下载PDF
依据历史数据发现三种抗凝剂均依赖性血小板聚集1例
19
作者 张新宏 卢中 谷建春 《首都食品与医药》 2026年第2期75-77,共3页
血常规检测作为临床诊断与治疗中不可或缺的三大常规检验项目之一,其结果的准确性直接关系到临床医生对患者病情的判断与诊疗方案的制定,更是临床评估出血风险、诊断血液系统疾病(如血小板减少性紫癜、再生障碍性贫血等)及监测抗凝治疗... 血常规检测作为临床诊断与治疗中不可或缺的三大常规检验项目之一,其结果的准确性直接关系到临床医生对患者病情的判断与诊疗方案的制定,更是临床评估出血风险、诊断血液系统疾病(如血小板减少性紫癜、再生障碍性贫血等)及监测抗凝治疗效果的重要依据。在临床常规检验工作中,最常见的血小板假性减少包括采血操作不规范(如采血不畅、反复穿刺导致组织液混入)、标本采集后未及时充分混匀、采血量超出抗凝管容量导致抗凝剂浓度不足等,这些因素均可能引发血液标本中血小板发生凝集,进而导致仪器检测的血小板计数出现假性降低。其中,乙二胺四乙酸盐(EDTA)依赖性假性血小板减少(EDTA-PTCP)是临床检验中较为特殊的一类假性血小板减少现象,其发生机制为血液标本经EDTA-K2抗凝处理后,可诱导血小板发生聚集,最终导致血小板计数减少。据相关文献报道,EDTA-PTCP在临床检验中的发生概率约为0.09%-0.21%。对EDTA、枸橼酸钠和肝素钠三种抗凝剂均产生依赖性血小板聚集的假性血小板减少病例较为罕见,其发生机制复杂,涉及免疫反应、抗凝剂特性及血小板自身特性等多重因素。本文报道1例对三种抗凝剂均产生依赖性血小板聚集导致假性血小板减少的临床案例。 展开更多
关键词 历史数据 镜检 抗凝剂 假性血小板减少
暂未订购
基于FlowCam影像和YOLOv3深度学习模型的多纹膝沟藻检测
20
作者 刘扬 孔凡洲 +1 位作者 于仁成 初永宝 《海洋科学》 CAS CSCD 北大核心 2024年第2期15-23,共9页
海洋中的有害藻华,包括微藻形成的赤潮和褐潮以及大型藻类形成的绿潮和金潮,已成为一类突出的海洋生态灾害问题。2021年11—12月,山东半岛东北部海域发生多纹膝沟藻(Gonyaulax polygramma)形成的大规模赤潮,导致海带养殖严重受损,亟待... 海洋中的有害藻华,包括微藻形成的赤潮和褐潮以及大型藻类形成的绿潮和金潮,已成为一类突出的海洋生态灾害问题。2021年11—12月,山东半岛东北部海域发生多纹膝沟藻(Gonyaulax polygramma)形成的大规模赤潮,导致海带养殖严重受损,亟待构建有针对性的赤潮监测预警体系。本文以多纹膝沟藻为对象,尝试应用流式影像仪(FlowCam)结合卷积神经网络模型YOLOv3,分别对含有多纹膝沟藻的浓缩海水样品、含有多纹膝沟藻和链状亚历山大藻(Alexandrium catenella)的浓缩海水样品,以及含有多纹膝沟藻活细胞及空壳的浓缩海水样品进行了检测实验,探究了基于藻种影像的深度学习模型在赤潮原因种检测方面的应用潜力。结果表明,在以FlowCam获取的影像数据集训练3万次后,YOLOv3对多纹膝沟藻表现出较好的识别能力,对浓缩海水样品中目标藻种识别的平均精度为88.2%;当样品中存在与多纹膝沟藻形态相似的链状亚历山大藻时,模型对多纹膝沟藻识别的平均精度下降为76.6%,对两种微藻同时进行训练和检测,可将对多纹膝沟藻识别的平均精度提高至84.6%。对于低温下出现脱壳现象的多纹膝沟藻,模型对海水中活细胞识别的平均精度为86.7%,对空壳识别的平均精度87.8%,将多纹膝沟藻活细胞与空壳分别识别的平均精度均值(87.3%)高于将两者统一作为多纹膝沟藻进行检测的识别精度(84.2%),整体识别精度提升3.1%。综合相关结果可以看出,FlowCam与深度学习模型相结合在赤潮监测和研究中具有重要应用潜力。 展开更多
关键词 深度学习 flowcam 有害藻华 多纹膝沟藻 微藻检测
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部