暴雨衰减指数在中小流域雨型设计中的运用探讨

求得设计雨量后,还需拟定设计暴雨时程分配过程,简称“雨型”设计,现今通常采用典型暴雨过程同频率放大而得.鉴于实测典型雨型偶然性较大,通过引入暴雨衰减指数(np)这个量化指标来进行雨型设计.并根据浙江省中小流域特点,分析时段为1h、3h、6h的暴雨衰减指数、区间暴雨衰减指数来提高雨型设计的计算精度,并应用于工程实际.     

Wrinkle modeling based on shape control functions and adaptive subdivision

Realistic wrinkles are an extremely important contribution for enhancing the realism of three dimensional (3D) face model.For different shapes of the wrinkle in three views, this paper proposes three shape control functions for each view, namely, cross-sectional shape control function (CSCF), depth attenuation function (DAF) and width attenuation function (WAF).CSCF is used to realistically and naturally express the furrows and bulges of wrinkles. Depth attenuation function and width attenuation function are applied to control the attenuation variations of the depth and width. Users can create various wrinkles just defining several intuitive parameters. Meanwhile, an image matching technique based on feature is employed to obtain three dimensional wrinkle lines. And a simple adaptive subdivision approach is proposed in the predefined influence region to adjust the resolution around the wrinkle mesh for better results and enhance the efficiency of wrinkle modeling simultaneously. Comparing experiment results with the corresponding image demonstrates that our method can generate realistic and natural wrinkles and can greatly improve the similarity of face model.     

Triple phase computed tomography of the pancreas in healthy cats

While the availability and use of computed tomography (CT) continues to grow, no study has described the size and multiphase CT appearance of the normal feline pancreas. This information is important to not only allow more accurate identification and differentiation of disease, but it may also be useful in assessing pancreatic function. In this prospective analytical study, we described a triple phase CT protocol of the pancreas for use in sedated cats and the attenuation, enhancement pattern, size, and volume of the pancreas for a group of healthy cats. Fifteen healthy cats were enrolled in the study and a standardized protocol for acquiring arterial, portal, and delayed phase CT images of the pancreas was developed and described. The pancreas was hypo to isoattenuating to both the liver and spleen in all phases in the majority of cats with a homogenous enhancement pattern noted in all 15. Mean pancreatic attenuation was 48, 79, 166, and 126 Hounsfield units (HU) respectively on precontrast, arterial, portal, and delayed phase images. In addition, mean height, length, and width of the left lobe of the pancreas were larger than the right lobe in all 15 cats. There were no associations between volume and volume: body weight ratio with age (P = 0.6518, P = 0.6968) or sex (P = 0.7013, P = 0.2043). This baseline information may be beneficial for use in future studies characterizing pancreatic disease in cats as well as future research studies evaluating pancreatic endocrine function.     

减毒鼠伤寒沙门菌活疫苗载体研究进展

活载体疫苗技术的发展促使产生了更多的疫苗设计新思路.沙门菌是一种肠道细菌,目前已通过基因突变的方法构建了许多种减毒株,如GID101、GID105、X4064、ZJⅢ、Ty800、X4632、X4550、X4072和X3730等,这些减毒株被突变掉了两个或两个以上的基因,然而其基因型和血清型仍很稳定,所以人们常将其用作基因疫苗的表达载体或运送载体.现在已有许多种细菌、病毒和寄生虫的减毒沙门菌活载体疫苗被研制成功.文章对沙门菌的减毒方法,减毒沙门菌的免疫机理以及其用途和作为疫苗载体的优缺点做了简述.     

阻尼减振降噪结构几何参数特性分析

分析了阻尼减振降噪结构模型中几何参数的特性及其对结构损耗因子的影响。对采用非间隔式阻尼层结构和间隔阻尼层结构几何参数进行了研究,最后对大型履带式拖拉机行走系进行了阻尼减振降噪结构的实际应用和性能对比试验分析。     

草鱼出血病病毒减毒的研究

草鱼出血病病毒ＧＣＨＶ－８２９野毒株在ＰＳＦ细胞连续传代过程,于培养液中加入一定浓度的桉液,传至１９代已达减毒目的,继续传至２９代其减毒效果保持稳定,２７代后不再加入桉液,继续传至３７代其减毒效果仍然保持稳定不变。致弱病毒对草鱼的安全性好,免疫原性强,用该弱毒株制备的弱毒疫苗免疫草鱼后,草鱼的成活率和免疫保护率均达１００％,表明桉液的草鱼出血病病毒的一种良好减毒剂,经桉液减毒的ＧＣＨＡＶ－８９２是     

THE EFFECT OF BODY WALL ON VIDEO SIGNAL ANALYSIS MEASUREMENTS

Rectangular body wall specimens were extracted from 16 juvenile swine and 9 adult beagle hounds after euthanasia. The body wall specimen included the epidermis to parietal membrane, with falciform fat removed. Ten images of a reference phantom with known attenuation and 10 additional images of the phantom with the specimen placed between the transducer and phantom surface were collected with a 5-MHz ultrasound system and computer with frame grabber board. Mean pixel values were converted to relative echogenicities. Echogenicity versus depth yielded an estimate of attenuation. An unpaired t test was applied to compare reference attenuation values with and without body wall, and a Pearson correlation was applied to body wall parameters versus measured attenuation through body wall. Measured attenuation through body wall increased significantly in dogs (P = 0.0016) and swine (P < 0.0001) when compared with phantom material alone. Increased attenuation positively correlated to body wall thickness (r = 0.6442) and mean gray level within body wall (r = 0.5069) for swine but not in canine. The presence of body wall in images used for video signal analysis significantly increases the measured attenuation in a phantom. This increase does not correlate with a measurable body wall parameter in dogs.     

SCINTIGRAPHY OF THE SACROILIAC JOINT REGION IN ASYMPTOMATIC RIDING HORSES: SCINTIGRAPHIC APPEARANCE AND EVALUATION OF METHOD

The sacroiliac region in 33 clinically normal riding horses was examined with scintigraphy to determine the normal scintigraphic appearance, to evaluate a semiquantitative method used to calculate a sacroiliac joint (SI joint) ratio, and to identify factors that affect the scintigraphic appearance of the pelvis. The scintigraphic examination included dorsal views of each SI joint region and one lateral view of the urinary bladder. Two predefined areas (the SI joint and the area between the tuber sacrale and the SI joint) were evaluated subjectively by comparing the intensity in each area to the intensity in the tuber sacrale, and a semiquantitative method was applied on the images to calculate an SI joint ratio. The thickness of the muscle mass overlying each SI joint was measured by using ultrasound. A corrected ratio was calculated based on a corrected pixel count for each SI joint. Of 29 evaluated horses, 28 had normal radiotracer uptake in the SI joints and 10 horses had symmetric normal radiotracer uptake in the area between the tuber sacrale and the SI joint. The mean SI joint ratio was 0.53 on both the left and right sides, and the mean corrected SI joint ratio was 2.15 on the left side and 2.13 on the right side. Factors that affect the scintigraphic appearance of the pelvis were identified and included attenuation, radioactive urine, and muscle symmetry. The muscle thickness ranged from 8-11 cm, causing 71-82% attenuation. Radioactive urine in the urinary bladder was located ventral to the SI joint region in 16 horses, and four of these were excluded from further evaluation because of risk of misinterpretation. A visual assessment of symmetry of the horses' gluteal muscle mass was compared with the ultrasound measurements. Fourteen horses (14/33) were regarded symmetric by both techniques. Soft tissue attenuation was found to severely compromise the result and indicated that only lesions in the SI joint with severely increased radiotracer uptake can be detected with scintigraphy. Knowledge about presence of radioactive urine ventral to the SI joint region and assessment of muscle symmetry is essential for a correct subjective evaluation. Any situation with difference in muscle mass between the left and right side of the pelvis will give a false impression of increased radiotracer uptake on the side with lesser muscle mass.     

用静力触探原位测试参数估算群桩基础最终沉降量

《高层建筑岩土工程勘察规程》(JGJ72-2004)提出用原位测试参数估算群桩基础最终沉降量的规定,这比用传统的土工试验压缩模量计算沉降量既快又经济节省,很值得推广应用。     

陕北黄土高原牧草生产潜力及其提高畜牧业发展能力对策建议

采用光合衰减法,计算陕北6县1970~2000年各年度牧草的生产潜力,对影响该区域牧草生产力的主要因素加以分析。结果表明,气候条件中的降水因子直接影响着牧草的生产力,加之人文因素的干扰作用,导致牧草生产力水平下降。并通过对该区域自然、经济和社会条件的综合分析,探讨草场资源合理利用的有效途径。