扫描

Based on the theory proposed by Alkhalifah, that is the reflection wave is determined by normal moveout velocity V of short-spread and anisotropic parameter η under the condition of long-spread data of vertical and lateral isotropic media and non-hyperbolic curve, a method for long-spread data velocity analysis is studied. A 2 step scanning method is used for the hyperbolic and dual parameter scanning of long-spread data.

根据Alkhalifah提出的垂直横向各向同性介质长排列情况下反射波走时由短排列的正常时差速度v和各向异性参数η确定，并具有非双曲线形式的理论，研究了针对长排列数据的速度分析方法，通过2步扫描方法实现了长排列数据的非双曲线双参数扫描。

It consists of four: parts: the program of automatic Z-scan control and data processing, multi-function data acquisition and control board, motorized translation stage, and joulemeter/-powermeter. Based on the Windows98 system, the program of automatic Z-scan control and data processing is programmed in LabWindows/CVI environment. The experiment error can be eliminated by Automatic Z-scan system through dual channel scan. The multi-function data acquisition and control board, motorized translation stage are made in our lab. The joulemeter/powermeter is EPM2000 of Molectron Detector Inc..

其中，Z扫描控制及数据采集软件是在Windows98操作系统下，利用LabWindows/CVI开发出来的，利用该软件进行双通道扫描可以很方便的消除由于功率波动引起的实验误差；多功能数据采集卡是我们自行开发的，它可以同时控制电动导轨和进行数据采集；电动导轨是由光学精密导轨和步进电机等组装成的；功率能量系统采用的是Molectron Detector Inc。

Increasing the kilovolt peak or milliamperes used during scanning can reduce noise and improve scan quality, but this is not generally necessary to obtain diagnostic scans.

增加扫描时的管电压和电流能够减少噪声，改善图象质量，但是这不是获得诊断扫描图象的必要条件。

The patent paraumbilical vein is echo free tubular structure and continuous with the left portal vein, it also can be enhanced as a vascular structure in CT scan though it revealing a hypodense structure before contrast injection and simulating a hepatic tumor.

当门静脉压增高时，脐旁静脉变粗形成一侧枝循环，上述结构以超音波扫描时为一管状无回音之结构；以电脑断层扫描时，在注射对比剂前似一低密度之病灶，但在注射对比剂后其密度增高非常明显，可高达100Hu，显示其为血管构造。

In order to improve the application of SPM lithography, SPM oxidation and its overlay lithography were studied.

为加强基于扫描探针显微镜的微细加工技术的应用，本文对扫描探针显微镜的阳极氧化加工及套刻对准进行研究。

Results Cavernous hemangiomas had a enhancement from edge to inside after contrast enhancement scan,and had equal-density with spleen in plain scan. Cystic focus of spleen had not enhanced in contrast scan with lubricous border. Lymphangioma enhanced in contrast scan with multiple round focus.

结果 海绵状血管瘤增强扫描呈边缘强化并向中心充填，延期扫描病灶可完全弥合与脾成等密度；脾囊肿呈圆形或椭圆形囊状占位，水样密度，边缘光滑，不强化为其特点；淋巴管瘤的典型表现是多发低密度灶，可有间隔状强化。

Results all of the 20 x-ray cases demonstrated the trabeculae bone hazy with pathy high density in the weight-supporting zone .all of the ct cases demonstrated the collapse of the femoral head. and the 4 cases demonstrated the high density, fragment of the femoral head and cystic lucency zone in the high density area and mixed density could be seen in 3 cases. the 4 mri cases demonstrated cystic hypointensity in t1wi and hyperintensity in t2wi. the 3 mri cases demonstrated mixed intensity in t1wi and t2wi,the 3 mri cases demonstrated irregular hypointensity with collapse of the femoral head in t1wi and t2wi.

结果 x线平片20 例，均表现为股骨头持重区骨小梁增粗且模糊不清，持重部位呈斑片状或斑点状密度增高影，本组均可见（占100%）。ct扫描20 例，平扫均表现为股骨头形态塌陷，其中显示高密度硬化4 例（占20%），股骨头碎裂，显示高密度区内有不规则透亮区，呈高低混杂密度改变有3 例（占15%）。mri扫描10 例， t1wi呈斑点状或小囊状低信号，t2wi为高信号，本组4 例，t1wi与t2wi均为不规则低、等、高混杂信号，本组3 例，股骨头塌陷、变形，t1wi与t2wi均为不规则形低信号3 例。

This paper divided the mix type virus into the mail-virus and worm virus, and then analyzed thoroughly the essential characteristics and spreading means of these three kinds of different viruses. According to characteristic of these viruses, this thesis put out a project of "Intelligent Macro Code Scanning Technique" to macro-virus, a project of "Base of Command Code Scanning Technique" for mail virus and a project of "File Head Check-Up Method" for worm virus to protect file of PE type.

根据这些病毒的不同特征和传播手段等特点，对宏病毒提出了一种"智能宏代码扫描技术"的方案，对邮件病毒提出了一种"基于命令式的代码扫描技术"的解决方案，对蠕虫病毒的解决则是以保护PE格式文件为重点提出了一种"文件头检测法"的解决方案。

Results One case with infantile onset had macrocephaly. The CT scan and MRI showedprominent low-density white matter throughout the cerebral hemispheres. MRI showed prominent also increased T2 signal in the periventricular whitematter. Another patient had an onset at school-age. The CT scan demonstrated brain atrophy. Histological examination on brain biopsy revealed diffuse demyelination and fibrous gliosis.

结果1例婴儿期起病者头颅大，CT扫描示前额明显的广泛性脑白质密度减低特征，MRI示脑室旁白质T2高信号；另1例学龄期起病，CT扫描显示脑萎缩，脑活检光镜下发现脱髓鞘和胶质细胞增生，电镜下观察到大量Rosenthal纤维及不规则的颗粒状沉积物。

In chapter five, it is founded in measuring the magnetic hysteresis loops withvarious field sweep rates that the penetration field of the high temperaturesuperconducting sample depends on the field sweep rate.

在第五章中，我们在实验中发现，在高温超导体样品变磁场扫描速率磁滞回线测量时，样品的完全穿透场与磁场扫描速率相关，这也是高温超导体磁弛豫的另一表现。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。