基于CCT模型的基底式胶结疏松砂岩声波速度修正模型

针对CCT(contact cement theory)模型中胶结物中心厚度为0的假设与基底式胶结疏松砂岩的地质特征不符合的问题,重新推导得到基底式胶结疏松砂岩的胶结半径表达式,给出基于CCT模型的基底式胶结疏松砂岩声波速度修正模型及其统计近似式,并将人造基底式胶结疏松砂岩的纵、横波速度的修正模型及近似式预测结果与试验测量值进行比较。结果表明:利用新推导的胶结半径表达式修正的CCT模型可应用于基底式胶结的疏松砂岩;修正模型统计近似式有效地提高了计算效率;修正模型及其近似式相对原CCT模型能够更好地预测基底式胶结的疏松砂岩声波速度。

连续胶结声速理论胶结半径表达式的一般性推广及应用

针对Dvorkin和Nur(1996)提出的连续胶结声速理论(CCT)中的胶结半径表达式仅适用于孔隙式胶结疏松砂岩的局限性,通过胶结物与颗粒之间的空间几何关系,在胶结物中心厚度不为零的前提下,推导了胶结物胶结半径的一般表达式,并考察了胶结物中心厚度对疏松砂岩声波速度的影响,探讨了该表达式在基底式胶结疏松砂岩纵横波速度预测中的应用.结果表明:随胶结物中心厚度变大,纵、横波速度均减小,且孔隙度越大,胶结物含量越少,速度下降越快;孔隙度或胶结物含量不变时,纵横波速比随胶结物中心厚度的增大而增大;纵横波速比随孔隙度的变化规律与胶结物中心厚度有关,当胶结物中心厚度较小时,孔隙度增大,纵横波速比略微减小,而当胶结物中心厚度较大时,孔隙度的增大会引起纵横波速比略微增大;对于基底式胶结疏松砂岩,使用推广后表达式修正的CCT模型相对原CCT模型能够更好地预测其声波速度,同时发现,利用其纵横波速比无法预测由孔隙度或胶结物含量变化引起的疏松砂岩软硬的变化,但是在胶结物含量或孔隙度不变的情况下,纵横波速比可指示由胶结物中心厚度变化引起的疏松砂岩软硬的变化.

Treatment of Hodgkin＇s Disease with Chemotherapy Based- Regimens： Long-term Follow-up Results with 295 Patients

OBJECTIVE Hodgkin's disease (HD) is a chemo and radio-sensitive hematologic malignancy. At the present time, improvement of its cure rate, reduction of its long-term detrimental effects, and maintenance of a good quality of life are the major concerns in the treatment of HD. In this study the results of a long -term follow-up from our cancer center was analyzed retrospectively in terms of efficacy and collateral side effects. METHODS The results were analyzed for 295 patients with histologicallyverified HD who were treated from 1970 to 2000, especially 182 patients treated from 1980 to 2000. Multivariant analysis (COX model ) was employed to elucidate the prognostic determinants. RESULTS The 5, 10 and 20-year survival for 295 patients with HD were 63.5%, 55.8% and 47.1% respectively with a median survival time of 172 months (28-352 months ). The median follow-up time was 43 months (17-352 months). The 5, 10 and 20 years overall survival and disease-free survival were 79.6%, 74.5%, 66.8% and 74.5% ,69.4%, 69.4% respectively for patients treated by regular chemotherapy and radiotherapy from 1980 to 2000. The incidence of late toxicities was low. An age of≥45 years, B symptoms and stage Ⅲ / Ⅳ were the main prognostic determinants (P=0.000, P=0.035 and P=0.047) in this clinical study. Stage Ⅰ/Ⅱ and nodularsclerosis were favorable factors in comparison with stages Ⅲ/Ⅳ and other histologic subtypes. CONCLUSIONS A chemotherapy-predominant modality plays an important role in the treatment of HD with promising long-term survival and fewer late toxicities. Further investigation for this simplified convenient comprehensive therapy is warranted.

Fundus Analysis and Visual Prognosis of Macular Hemorrhage in Pathological Myopia without Choroidal Neovasculopathy

Purpose:To analysis and evaluate the fundus characteristics and visual prognosis of macular hemorrhage in pathological myopia without choroidal neovasculopathy. Methods:Thirty-seven patients (38 eyes) of pathological myopia with macular hemorrhage and without choroidal neovascularization (CNV) underwent color photograph and fundus fluorescein angiography (FFA) examinations. Indocyanine green angiography (ICGA) was also performed on 11 patients (11 eyes). Follow-up ranged from 3 to 21 months. Results:The macular hemorrhage in pathological myopia without CNV demonstrated oval, less than 1PD, without edema and exudation. Lacquer cracks appeared at the site of previous subretinal bleeding in 84.2% of the eyes. The visual acuities were improved in 81.6% of eyes during the follow-up period. ICGA revealed linear hypofluorescence in 7 of 11 eyes (63.6%), indicating a ruptured Bruch’s membrance at the onset of subretinal bleeding. Conclusion:A rupture of choriocapillaris complex and Bruch’s membrane causes macular hemorrhage of pathological myopia without CNV, leading to the formation of a new lacquer crack. Its prognosis is favorable. Eye Science 2004;20:57-62.

人类感染疯牛病的识别

今年以来,关于英国流行疯牛病的报道引人注目。疯牛病会不会传入中国,怎样诊断与识别,是大家所关心的问题。本文简述如下: 疯牛病病牛的脑和眼组织中含有慢性病毒,人们误食被感染后初期毫无症状,潜伏期长达数年。该病毒侵入大、小脑,基底结和脊髓等部位,造成弥漫非炎症变性,即慢或亚急性海绵样脑(亦称克——贾氏)病。 早期,患者有记忆、智力。

Fabrication of porous g-C_3N_4 and supported porous g-C_3N_4 by a simple precursor pretreatment strategy and their efficient visible-light photocatalytic activity

Porous g-C_3N_4 and supported porous g-C_3N_4 were fabricated for the first time by a simple strategy using pretreated melamine as a raw material and pretreated quartz rod as a substrate.The formation of a richly porous microstructure can be attributed to the co-existence of different pore-fabricating units in the preparation system for porous g-C_3N_4.The richly porous microstructure endowed the as-prepared porous g-C_3N_4 with an excellent photocatalytic activity.The as-prepared supported porous g-C_3N_4 exhibited considerable stability because of the existence of chemical interaction between porous g-C_3N_4 and the quartz rod substrate.The photocatalytic activity of the supported porous g-C_3N_4 was competitive with that of porous g-C_3N_4 in powder form because neither the surface migration of photogenerated electrons nor the diffusion of the target organic pollutant were affected by the construction of the quartz rod reactor.The photocatalytic activity of the as-prepared porous g-C_3N_4 and supported porous g-C_3N_4 was preliminarily evaluated by the treatment of single-component organic wastewater under visible-light irradiation.Subsequently,the as-prepared porous g-C_3N_4 was further applied in conventional hydrogen evolution and a new system for simultaneous hydrogen evolution with organic-pollutant degradation.The hydrogen yield and degradation efficiency both increased with increasing photocatalytic activity of the as-prepared materials in the system for simultaneous hydrogen evolution with organic-pollutant degradation.

Microstructures and magnetic properties of [SiO_2/FePt]_5/Ag thin films

[SiO2/FePt]5/Ag thin films were deposited by RF magnetron sputtering on the glass substrates and post annealing at 550 ℃ for 30 min in vacuum. Vibrating sample magnetometer and X-ray diffraction analyser were applied to study the magnetic properties and microstructures of the films. The results show that without Ag underlayer [SiO2/FePt]5 films deposited onto the glass are FCC disordered; with the addition of Ag underlayer [SiO]FePt]5/Ag films are changed into L10 and （111） mixed texture. The variation of the SiO2 nonmagnetic layer thickness in [SiO2/FePt]5/Ag films indicates that SiO2-doping plays an important role in improving the order parameter and the perpendicular magnetic anisotropy, and reducing the grain size and intergrain interactions. By controlling SiO2 thickness the highly perpendicular magnetic anisotropy can be obtained in the [SiO2 （0.6 nm）/FePt （3 nm）]5/Ag （50 nm） films and highly （001）-oriented films can be obtained in the [SiO2 （2 nm）/FePt （3 nm）]5/Ag （50 nm） films.

Subepithelial basement membrane thickness in patients with normal colonic mucosal appearance in colonoscopy: Results from southern Turkey

AIM: Our aims were to determine the normal limits of subepithelial basement membrane (SEBM) thickness in order to more accurately diagnose collagenous colitis in the population from southern Turkey and to investigate into links between SEBM thickness and age, and sex. METHODS: The study included 100 patients (mean age 50.0±13.3 years; male, 34; female, 66) with miscellaneous gastrointestinal symptoms, and normal colonic mucosal appearance in colonoscopic evaluation. Biopsies were taken from five different regions of the colon. SEBM was measured with a calibrated eyepiece on specimens prepared with specific stains for collagen. Intensity of inflammatory cells was graded semiquantitatively. Differences in SEBM thickness among the different colon regions, and relationships between SEBM thickness and age, sex, and density of inflammatory cells were statistically evaluated. RESULTS: The cecum and rectum showed the largest amounts of infiltrate. None of the specimens showed histologic findings of collagenous colitis. The SEBM thicknesses measured for each case ranged from 3-20 μm. The biggest thickness was observed in rectal mucosa (median value: 10 μm). Cecum and ascending colon showed similar SEBM thickness (median value: 5 μm). SEBM thickness was not correlated with patient age or sex, but was positively correlated with the intensity of inflammatory cells in each colon segment. CONCLUSION: In this patient group from southern Turkey, SEBM was thickest in the rectum. Our results indicate that, in this population, SEBM thickness is not correlated with age or sex, but is positively correlated with severity of inflammation. The findings also support the concept that measuring SEBM thickness at one segment in the colon is inadequate and may be misleading.

Hollow and substrate-supported Prussian blue,its analogs,and their derivatives for green water splitting

To meet the current energy needs of society,the highly efficient and continuous production of clean energy is required.One of the key issues facing the green hydrogen evolution is the construction of efficient,low-cost electrocatalysts.Prussian blue(PB),Prussian blue analogs(PBAs),and their derivatives have tunable metal centers and have attracted significant interest as novel photo-and electrochemical catalysts.In this review,recent research progress into PB/PBA-based hollow structures,substrate-supported nanostructures,and their derivatives for green water splitting is discussed and summarized.First,several remarkable examples of nanostructured PB/PBAs supported on substrates(copper foil,carbon cloth,and nickel foam)and hollow structures(such as single-shelled hollow boxes,open hollow cages,and intricate hollow structures(multi-shell and yolk-shell))are discussed in detail,including their synthesis and formation mechanisms.Subsequently,the applications of PB/PBA derivatives((hydr)oxides,phosphides,chalcogenides,and carbides)for water splitting are discussed.Finally,the limitations in this research area and the most urgent challenges are summarized.We hope that this review will stimulate more researchers to develop technologies based on these intricate PB/PBA structures and their derivatives for highly efficient,green water splitting.

Effect of substrate rotation speed on structure and properties of Al-doped ZnO thin films prepared by rf-sputtering

Al-doped ZnO(AZO)thin films were deposited on glass substrates by rf-sputtering at room temperature.The effects of substrate rotation speed(ωS)on the morphological,structural,optical and electrical properties were investigated.SEM transversal images show that the substrate rotation produces dense columnar structures which were found to be better defined under substrate rotation.AFM images show that the surface particles of the samples formed under substrate rotation are smaller and denser than those of a stationary one,leading to smaller grain sizes.XRD results show that all films have hexagonal wurtzite structure and preferred c-axis orientation with a tensile stress along the c-axis.The average optical transmittance was above90%in UV-Vis region.The lowest resistivity value(8.5×10?3Ω·cm)was achieved atωS=0r/min,with a carrier concentration of1.8×1020cm?3,and a Hall mobility of4.19cm2/(V·s).For all other samples,the substrate rotation induced changes in the carrier concentration and Hall mobility which resulted in the increasing of electrical resistivity.These results indicate that the morphology,structure,optical and electrical properties of the AZO thin films are strongly affected by the substrate rotation speed.

碎屑岩中的碳酸盐胶结特征——以鄂尔多斯盆地南部富县地区延长组长6砂体为例

致密化储层是困扰和制约低孔、特低渗储层油气勘探的重要因素.鄂尔多斯盆地南部富县地区上三叠统延长组长6三角洲前缘水下分流河道砂体中碳酸盐胶结作用较为发育,是影响储层质量的主要因素之一.本文通过岩石学、地球化学等综合研究,系统地探讨了碳酸盐致密化储层的成因,首次将碳酸盐胶结作用划分为内源碳酸盐胶结和外源碳酸盐胶结两个成岩阶段与类型,指出这两种成岩作用的本质区别是碳酸盐流体的来源和成岩作用的时期不同.借助各种薄片鉴定、电子探针、微量元素及碳氧同位素等分析结果,进一步明确了内源碳酸盐胶结的流体源自岩石内部,其胶结物形成于成岩作用早期,故矿物颗粒自形程度较好,且存在后期被溶蚀现象,使储层孔隙度提高3%～8%,从而改善了储层物性;而外源碳酸盐胶结的流体源自富含有机质的泥岩中释放出的大量二氧化碳与水的结合,由于物化条件的变化,在砂体中溶蚀、扩散、运移,并充填剩余孔隙,因此,属成岩晚期产物,且多呈基底式胶结,使岩石孔隙度骤然降低,严重地破坏了储层物性,导致该区长6储层的局部致密化,影响了油气的富集.而部分形成于砂体顶部的致密层可构成碳酸盐成岩圈闭,是油气勘探的有利区带.本文在对碎屑岩中致密化储层成因机理探讨的基础上,指出了碳酸盐致密化储层的空间分布特征,明确了该区石油勘探的方向和有利区带,对碎屑岩致密化储层油气藏的勘探开发具有重要的理论和实际指导意义.

Hierarchical TiO2 photocatalysts with a one-dimensional heterojunction for improved photocatalytic activities

Hierarchical TiO2 photocatalysts with a one-dimensional heterojunction were synthesized via a facile template-free hydrothermal method. The TiO2 photo- catalysts were flower-like microspheres with a 3 μm diameter. The base structure of the flower-like microspheres was a uniform nanowire with a 10 nm diameter. Anatase films were evenly coated onto the surface of the rutile TiO2 nanowires to form a one-dimensional core--shell base structure. This kind of one-dimensional heterojunction is conducive to the separation of charge carriers. In addition, the hierarchical TiO2 microspheres possessed a good mesoporous structure with a high specific surface area of 260 m2/g. Thus, the light scattering and utilization efficiency were improved in this structure. The photocatalysts exhibited better performance in both photocatalytic oxidation and reduction reactions. Moreover, the novel TiO2 photocatalysts displayed excellent stability in these reactions. This kind of hierarchical TiO2 structure has never been reported in the literature. The hierarchical structure and one-dimensional heterojunction were vital to the increase in quantum efficiency. Therefore, these hierarchical TiO2 photocatalysts have potential applications in the environmental and energy fields, such as in photocatalytic degradation, hydrogen production, Li-ion batteries, and dye-sensitized solar cells.

Salt-related structure and deformation mechanism of the Middle-Lower Cambrian in the middle-west parts of the Central Uplift and adjacent areas of the Tarim Basin

The salt beds of the Middle-Lower Cambrian are widespread in the middle-west parts of the Central Uplift and adjacent areas, the Tarim Basin. This paper presents the results of seismic interpretation and drilling data analysis, which discovered that the salt beds were formed in an old geologic age, deeply buried, with relatively small scaled flowing and gathering and uneven distribution. As the regional detachment layers, the salt sequences considerably control the structural deformation of the up-salt Paleozoic, forming a series of hydrocarbon traps. In due course, the salt beds of the Middle-Lower Cambrian provide excellent cap rocks and trap conditions; thus the value of exploring hydrocabon reservoir in the target strata of the sub-salt Sinian- Cambrian is greatly increased. Research has shown that the salt-related structures of the Middle-Lower Cambrian in the area mainly exist in the form of salt pillow, salt roller, up-salt anticline, salt diapir, assemblage of the salt arch and up-salt fault-block, assemblage of basement fault and salt anticline, assemblage of the basement fault-block and salt dome, assemblage of salt detachment and fault-related fold, and assemblage of basement fault-block, salt arch and up-salt imbricated thrusts. The evolution and deformation mechanisms of the salt-related structures are controlled largely by basement faulting, compressional shortening, plastic flowing and gathering, superstratum gravitation, and up-salt faulting and detaching. They are distributed in rows or belts along basement faults or fault block belts.

Influences of Fractal Substrate Structures on Dynamic Scaling Behaviors of Etching Model

The Etching model on various fractal substrates embedded in two dimensions was investigated by means of kinetic Mento Carlo method in order to determine the relationship between dynamic scaling exponents and fractal parameters. The fractal dimensions are from 1.465 to 1.893, and the random walk exponents are from 2.101 to 2.578.It is found that the dynamic behaviors on fractal lattices are more complex than those on integer dimensions. The roughness exponent increases with the increasing of the random walk exponent on the fractal substrates but shows a non-monotonic relation with respect to the fractal dimension. No monotonic change is observed in the growth exponent.