OCT系统对单层散射组织的有效探测深度

为了研究光学相干层析术(OCT)系统在细直光束下对高散射生物组织的深度探测能力,介绍并应用了一种基于蒙特卡罗仿真方法的OCT模型.通过对蒙特卡罗仿真结果的统计分析,提出了OCT系统有效探测深度的评估方法,并分析了生物组织的光学特性参数对有效探测深度的影响.研究表明,生物组织的散射系数越小,越有利于提高OCT系统的有效探测深度.     

网格计点法测待定相占百分数的计算公式的修正

研究钢材的不同组织对其性能的影响一般采用网格计点法测再结晶百分数或测待定相百分数.文章给出如下公式Vv=Pa/(m-1)(n-1)×100%并分析以往公式 Vv=Pa/(m·n)×100% 存在的误差.     

细菌纤维素生物医学材料的性能改进

针对细菌纤维素(BC)生物医学材料的需要,研究改进其柔软度、柔韧性、吸水性、拉伸强度和抑菌性能的措施.BC湿膜在ε-聚赖氨酸溶液中浸泡后干燥,可获得满意的抑菌效果.BC湿膜被ε-聚赖氨酸溶液处理后在一定浓度的丙三醇溶液中浸泡并干燥,可获得满意的吸水性、柔软度、柔韧性和拉伸强度.经100%丙三醇处理的BC干膜,在相对湿度为(92.31±0.60)%的空气中,吸水质量达到自身质量的14倍;处理后BC干膜的柔软度为A级卫生纸的柔软度的5.5倍:拉伸强度增加了56%,断裂伸长率大幅增加,从原始的1.01%增加到19.29%,BC干膜的柔韧性得到改善.     

SiCp/FVS1012薄板微观结构及高温性能的研究

利用OM,XRD和TEM等方法研究了喷射沉积-挤压-轧制SiC颗粒增强FVS1012(SiCP/FVS1012)薄板的微观结构以及退火对该复合材料硬度的影响.结果表明,本工艺制备的SiCP/FVS1012薄板具有优异的高温力学性能,在315℃时,σb=308 MPa,σ0.2=290 MPa,δ=5.69%;在415℃时,σb=201 MPa,σ0.2=182 MPa,δ=3.65%.微观组织分析表明:类球状细小弥散的Al12(Fe,V)3Si相的生成是该复合材料具有优异高温力学性能的主要原因,此外,SiC颗粒的加入对提高该复合材料的高温力学性能也有重要作用.     

基于OCT图像的组织散射系数提取方法及其应用

采用自制频域光学相干层析（OCT）系统对大鼠的正常和疮伤皮肤进行成像,轴向分辨率为8 m,探测深度3 mm,根据组织对光的吸收特性和OCT成像系统的共聚焦特性,建立了A-scan方向图像灰度随探测深度的单次散射-点扩散函数模型. 利用模型中的散射系数作为量化皮肤疮面诊断的光学评价指标. 测量了正常与疮伤皮肤在各阶段的皮肤衰减系数,证明衰减系数能够定量区分正常与疮伤皮肤.     

Ca对AZ31镁合金CO_2激光焊接接头组织和性能的影响

采用添加填充材料的CO2激光焊接工艺对AZ31镁合金薄板进行焊接,研究了不同Ca含量对焊缝金属的显微组织和力学性能的影响.结果表明:当激光功率为1 500W,焊接速度为3 m/min时,AZ31镁合金CO2激光焊接的焊缝金属中添加一定量的σCa0.19%元素,可以得到成分相对较均匀、组织细小的焊缝.当填充带材为AZC04(焊缝中Cσa=0.19%)时,焊缝区晶粒相对细小,析出相细小弥散,此时焊接接头的力学性能最优,焊接效率基本可达到100%.     

深海钴结壳采集微地形探测技术实验研究

通过地表高程信息计算最佳采集深度是解决钴结壳开采贫化问题的关键技术之一。根据钴结壳的赋存环境和开采方法,提出了一种摆动式超声单波束微地形探测方法。为了检验该方法的可行性,成功搭建了实验台,并验证了该实验台的垂直探测精度可达到厘米级;提出了一种改进型数据加窗算法,进一步提高了高程异常值被剔除的准确性;提出了采用线性相关系数法解决支持向量线性与非线性回归的选择问题;提出并证明了高斯径向基参数σ可根据测线上的坡度、坡长信息来确定。     

热处理对ZGMn18Cr2MoRE组织和性能的影响

研究了热处理工艺对超高锰钢ZGMn18Cr2MoRE组织和力学性能的影响。试验结果表明,热处理工艺对超高锰钢组织和性能有显著影响,沉淀(弥散)强化使奥氏体晶内析出了弥散颗粒状M7C3型碳化物,强化了基体,使钢的力学性能得到提高。其中,经1100℃水韧处理后再经250℃×4h回火,ZGMn18Cr2MoRE钢的奥氏体晶粒细小,晶内颗粒状碳化物均匀、弥散分布,σb=994.51Mpa,sσ=430.98Mpa,αk=260J.cm-2,HB=227,δ=55.03%。与水韧处理后不回火相比,σb、sσ、αk、δ、HB分别提高了18.2%、7%、22%、30.3%、9.7%。     

弯拉应力作用下粉煤灰混凝土的1D和2D碳化

首先建立了弯拉应力作用下混凝土的1D和2D碳化测试方法,在此基础上系统研究了粉煤灰混凝土在弯拉应力水平分别为0.0,0.20,0.35,0.50,0.65,0.80作用下1D和2D碳化深度的依时变化规律,并探讨了粉煤灰掺量(0%,10%,20%,40%,60%,质量分数)、粉煤灰种类(Ⅰ,Ⅱ级)、水胶比(0.3,0.35,0.4,质量比)、胶凝材料用量(458,380 kg/m3)、养护龄期(28,90 d) 5个重要因素对处于弯曲应力状态下的粉煤灰混凝土1D和2D碳化深度的影响规律.另外,还将不同弯拉应力水平(σS)下的碳化试验结果与同条件下无应力状态下的碳化进行了定量比较,发现弯拉应力水平对碳化存在明显的加速作用,为量化该交互作用提出了应力加速因子(KσS)概念,研究表明KσS随σS的增加而变大,符合指数函数KσS=1 kσCS.     

混合菌种发酵生产酱油的工艺研究

利用米曲霉(Aspergillus oryzae)和黑曲霉(Aspergillus niger)混合接种,并在制曲后期混合添加嗜盐片球菌(Pediococus halophilus)和高渗酵母进行多菌种发酵生产酱油实验研究。结果表明,混合发酵的菌种最佳培养时间为36～40h,最佳发酵温度为45～48℃。米曲霉和黑曲霉的接种比为90%∶10%时,全氮利用率提高13.2%,氨基酸生成率提高6.8%。将成熟曲拌以10%的食盐水,在pH值为6.5的环境下,混合添加嗜盐片球菌和高渗酵母参与发酵可以提高酱油产品中的醇类含量和酸类含量,改进酱油的风味。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has