化脓性脊柱炎影像学诊断（附23例分析）

笔者报告了２３例化脓性脊柱炎。本文着重分析对比了Ｘ线平片和ＣＴ检查结果，通过分析对比，发现ＣＴ检查优于Ｘ线平片，并有助于对化脓性脊柱炎早期作出诊断。主要影像学表现：早期，软组织肿胀和脓肿形成，骨质呈虫蚀状破坏，随之破坏区周围出现增生硬化。ＣＴ还能发现炎块中的气块，晚期骨修复占优势，即骨质增生硬化，骨桥形成，最后可产生骨性融合。     

冻土蠕变过程中结构的CT分析

ＣＴ为非破坏的持续检测和定量描述不同实验条件下试样的内部结构提供了可能，本文利用这一手段观测分析了冻土蠕变过程结构的变化情况，认为冻土蠕变过程中所进行的发育微裂隙、颗粒集合体的破坏以及其它结构缺陷的增生与扩展，制约着土结构的强化与弱化作用，控制着蠕变过程的形态特征，同时还给出了ＣＴ值与物密度和含水量之间的定量关系。     

脊椎结核的CT诊断

本文报告了经ＣＴ检查确诊的３０例脊椎结核．ＣＴ表现为椎体前２／３为主的骨质破坏，破坏区伴有死骨、椎旁软组织肿大和脓肿形成向纵向延伸．死骨为ＣＴ发现脊椎结核的新征象。     

肝脏肺吸虫病的CT诊断

作者认为肺吸虫病发生在肝脏系少见病例，以ＣＴ认识和诊断上有待进一步提高，特别与肝结核、肝脓肿、肝包虫囊肿等鉴别诊断，仍存在一定的困难。临床上肺吸虫病多见脑部，肺，及皮下组织，我院病理科近十余年在肝脏发现肺吸虫病也是仅有一例，上述疾病ＣＴ表现均可出现低密度坏死区，有规则环状增强，斑点状钙化灶，单房及改变及大小不等的结节。组织学上的改变，肝细胞混浊肿胀，液化，变性，坏死，钙化，所不同处寄生虫病的病理组     

正常小儿颅内不同组织CT值

正常小儿脑组织ＣＴ值国内尚我报告；作者选择１０岁以内正常小儿子１２０例，分三人年龄组进行颅内不同脑组织ＣＴ值测定，并将小儿与成人的脑绰组织值ＣＴ比较，收结果看出；小儿灰质、白质及小脑ＣＴ值明显低于成人的，随年龄增长ＣＴ值递增；新生儿脑组织ＣＴ值明显低于儿童；儿童丘脑莫过基底节ＣＴ值近似成人。     

CT定位用于眼面部异物诊断治疗

本文报告２６例由于外力作用致使眼面部广泛异物存留。临床应用Ｘ线的归咎常见漏诊及定位困难，因此采取ＣＴ定位达到异物诊断治疗目的。     

论γ射线的点放射源和非点放射源的辐射研究

本文讨论点放射源和非点放射源的辐射，为简化理论模型，暂不考虑二次γ射线，只讨论点源和线源和柱状源的辐射，本文的讨论有助于工业ＣＴ的设计及系统的优化。     

Low latitude airglow

Tropical airglow work during the last few years is reviewed. Airglow instrumentation is becoming more complex. Some of these sophisticated airglow experiments giving important information about the upper atmosphere such as ionospheric F region electron density, height of maximum electron density, dynamics of and irregularities in the F region, mesospheric neutral temperature and its variation, dynamics of mesospheric, etc. are mentioned. At the end some problems which could be tackled in near future with airglow techniques have been suggested. Invited Review paper, Commission 21, IAU, Patras, Greece, August, 1982.     

Oxygen deficient perovskites in the system CaSiO3–CaAlO2.5 and implications for the Earth’s interior

Oxygen deficient perovskites of the system CaSiO₃–CaAlO_2.5 have been synthesised at high-pressure and -temperature conditions relevant to the Earth’s transition zone in order to investigate their stabilities in the Earth’s mantle and determine structural properties associated with vacancy incorporation. Two polysomes of thermodynamically stable defect perovskites with Ca(Al_0.4Si_0.6)O_2.8 and Ca(Al_0.5Si_0.5)O_2.75 stoichiometry have been identified. The ordering of oxygen defects into pseudo-cubic (111) layers results in well-ordered ten- or eightfold superstructures, respectively. At all other compositions examined, a metastable formation of perovskites has been observed instead, which are assumed to grow initially disordered. These are now characterised by tiny domains, formed due to subsequent ordering of vacancies along various pseudo-cubic {111} layers. Both ordered defect perovskites show a large P–T stability field ranging from about 9–18 GPa and 4–12 GPa, respectively. Microstructural TEM analyses revealed the presence of growth and ferroelastic twins, which indicate a phase transition from rhombohedral to monoclinic symmetry during quenching. Electron energy loss spectroscopy of Si and Al K edges point at the presence of tetrahedral, octahedral and maybe some pentacoordinated silicon, whereas aluminium is predominantly octahedrally coordinated with minor fractions in lower coordination. Observed properties are interpreted in terms of a new structural model, explaining the observed phase transition and formation of different twin laws as well as giving reasons for the development of such large superstructures. With respect to phase relations of the transition zone, the potential occurrence of such defect perovskites in the Earth’s interior is discussed.     

Wave propagation in a general anisotropic poroelastic medium: Biot’s theories and homogenisation theory

Anisotropic wave propagation is studied in a fluid-saturated porous medium, using two different approaches. One is the dynamic approach of Biot’s theories. The other approach known as homogenisation theory, is based on the averaging process to derive macroscopic equations from the microscopic equations of motion. The medium considered is a general anisotropic poroelastic (APE) solid with a viscous fluid saturating its pores of anisotropic permeability. The wave propagation phenomenon in a saturated porous medium is explained through two relations. One defines modified Christoffel equations for the propagation of plane harmonic waves in the medium. The other defines a matrix to relate the relative displacement of fluid particles to the displacement of solid particles. The modified Christoffel equations are solved further to get a quartic equation whose roots represent complex velocities of the four attenuating quasi-waves in the medium. These complex velocities define the phase velocities of propagation and quality factors for attenuation of all the quasi-waves propagating along a given phase direction in three-dimensional space. The derivations in the mathematical models from different theories are compared in order to work out the equivalence between them. The variations of phase velocities and attenuation factors with the direction of phase propagation are computed, for a realistic numerical model. Differences between the velocities and attenuations of quasi-waves from the two approaches are exhibited numerically.