云南鹤庆深钻揭示的区域气候轨道尺度演化

IEECAS SKLLQG

SFC轴向注入系统和中心区的研究和设计

介绍了在ＨＩＲＦＬ注入器ＳＦＣ上进行的中心区、聚束器系统和轴向注入 束运线的设计、加工和调试结果．中心区的设计采用了两种注入半径及相应的 两套螺旋式静电偏转镜，解决了高频电压在某些工作区域偏低及三次谐波加速 时轴向注入线上空间电荷效应较为严重的问题．新的锯齿波聚束器系统不仅可 以提高聚束效率，而且还提出了采用半频聚束模式以提高ＳＦＣ与主加速器ＳＳＣ 的纵向匹配效率．新设计的轴向注入束运线配备了两台在线 ＥＣＲ离子源，提高 了电荷态分辨能力和注入相空间匹配能力，在提高注入效率的同时还改善了离 子源及束运线的工作环境和调束手段．

Defect production in silicon carbide irradiated with Ne and Xe ions with energy of 2.3 MeV/amu

In the present work specimens of mono-crystalline silicon carbide (4H polytype) were irradiated to three successively increasing ion fluences ranging from 7.2 x 10(14) to 6.0 x 10(16) ions/cm(2) (corresponding to the peak displacement damage of 1, 4 and 13 dpa) with Ne and Xe ions respectively with the energy of 2.3 MeV/amu. The irradiated specimens were subsequently annealed at temperatures of 1173 and 1273 K. Defect structure was investigated with transmission electron microscopy (TEM) using a cross-sectional specimen preparation technique. The typical microstructures of the annealed specimens irradiated with Ne or Xe ions to high fluences are characterized by small gas bubbles in high concentration in the peak damage region and black dots and dislocation loops (located in the basal plane) in a shallower and broader depth region. Larger dislocation loops were observed in the Xe-ion irradiated specimen than in the Ne-ion irradiated specimen at the same peak damage level. The enhanced formation of dislocation loops in the case of Xe-ion irradiation is understandable by assuming stronger inclination of heavier inert-gas atoms to occupy substitute site in the peak damage region.

Novel catalysis of TiO2 for the catalytic alcohols synthesis from CO and H2O

Direct synthesis of alcohols from CO and H2O was investigated using TiO2 catalyst. MeOH (about 24 mg g(-1) h(-1)) and EtOH (about 8 mg g(-1) h(-1)) could be produced under the reaction conditions of T= 573 K, P= 0.5 MPa, CO flow rate of 30 ml min(-1) and CO/H2O = 3/2 during the period of 12 to 44 h time-on-stream. Compared with PbO, TiO2 could preserve stable catalytic activity during a long time of reaction. For the same catalyst TiO2, the reaction performance of alkali carbonates increased with their solubility (K2CO3>Na2CO3>Li2CO3). The corresponding catalytic activity was found to increase with the alkalescence of solvent. The formation mechanism of alcohols was proposed as well. (C) 2004 Elsevier B.V. All rights reserved.

辽宁省昌图烟区植烟土壤养分肥力状况及评价

通过田间采样室内分析的方法,对辽宁省昌图烟区145个土壤样品的肥力指标进行分析测定。根据昌图地区植烟土壤养分状况和作物生长特性提出肥力分级标准,并利用测定数据对昌图地区植烟土壤肥力状况进行评价。结果表明:昌图烟区宝力、金家子、付家、长发、古榆树、七家子等6个乡镇中分别有75%、90%、95%、100%、100%、100%的植烟土壤的有机质含量低于当地的适宜值范围;七家子、古榆树、付家、金家子、长发等5个乡镇中分别有80%、100%、90%、90%、80%的植烟土壤处于缺氮状态;有效磷含量都处于适宜值范围之内;昌图地区植烟土壤的有效钾含量普遍处于缺乏状态。

侵蚀环境国际合作研究取得新进展

<正> 中国科学院水利部水土保持研究所贺秀斌博士在主持的国家自然科学基金项目“人为开垦加速侵蚀与土壤质量演变机理及其调控”研究的同时,获得英国皇家学会博士后奖学金资助,与英国Swansea(斯旺西)大学地理系J.A.Matthews(马弗休斯)教授合作研究“全球变化与人为活动的侵蚀响应区域对比研究”。经过1年多的努力,该项目研究取得了很大的进展。贺秀斌博士所著的研究报告“中国西部与挪威南部人为活动及环境变化的侵蚀响应对比研究”被英国皇家学会选入4年一度的皇家学会科技展。

土壤抑真菌作用与细菌群落结构的关系

自然清洁土壤所具有的抑真菌作用,是健康土壤的一种自然属性,也是土壤质量的重要指标之一,对控制农作物土传病原真菌的爆发具有积极的生态学意义.本试验以中国科学院沈阳生态实验站近10年未受农药和肥料影响的撂荒地土壤作为自然清洁土壤样品,通过高温(对照、100℃、110℃、121℃)处理得到具有不同抑真菌作用的土壤模型,采用PCR-DGGE(变性梯度凝胶电泳)方法对上述土壤样品的细菌群落结构进行分析.结果表明:土壤抑真菌作用与土壤细菌群落结构紧密相关;对照清洁土壤抑真菌作用最强,处理后土壤细菌群落结构偏离自然清洁土壤愈远,土壤抑真菌能力愈差;DGGE特异性条带切胶测序结果表明,Sphingomonas asaccharolytica、Nitrospira sp.、Hyphomicrobiaceae sp.、Bacillus megaterium和Micro-coccus sp.可能与土壤抑真菌作用密切相关.

卡通化图像和视频的毛发纹理生成与替换

低成本卡通制作中的图像和视频通常缺乏对动物角色毛发效果的表现,为了能对已有图像及视频中的动物角色进行处理,为其增添具备真实感的毛发效果,提出一种毛发风格化算法——卡通化毛发纹理算法.针对卡通中的动物角色合成毛发纹理并进行替换,分为图像应用及视频应用2个部分.在图像替换时,对要进行风格化处理的目标区域进行图像结构分析,以获取覆盖目标区域的三角网格,再生成毛发纹元并映射于网格之上,通过绘制纹元来生成具备真实感的毛发效果;在进行视频替换时,提取视频关键帧并基于图像应用算法生成相应的卡通化毛发纹理进行图像替换,之后根据关键帧的替换结果指导整个视频的替换.为了获取随时间变化的图像关键帧目标区域,采用SIFT算法计算特征点在时间轴上的匹配;为了快速合成卡通化毛发纹理,采用基于GPU的光线行进算法加速毛发纹元的体绘制过程.实验结果表明,文中算法可成功地对已有图像及视频的动物角色添加具备真实感的毛发效果.

Crystal structure and charge transfer energy of the vaterite-type orthoborate YBO3:Eu

Ligand-to-metal charge transfer energies of YBO3:Eu have been investigated from the chemical bond viewpoint. The chemical bond parameters, such as the covalency, the polarizability of the chemical bond volume, and the presented charge of the ligands in the chemical bond have been quantitatively determined based on the dielectric theory of complex crystal. We calculated the environmental factor (h(e)), which is the major factor influencing the charge transfer energy in the compounds. The calculated results show that the suitable group space of YBO3 is C2/c. The method provides us with a supplementary tool to judge the proper structure when the structure of the crystal has many uncertain space groups.

Hot-corrosion behaviors of overlay-clad yttria-stabilized zirconia coatings in contact with vanadate-sulfate salts

A dense clad overlay with chemical inertness was achieved on top of the plasma-sprayed YSZ thermal barrier coatings by laser in order to protect them from hot-corrosion attack. The Al2O3-clad YSZ coating exhibited good hot-corrosion behavior in contact with salt mixture of vanadium pentoxide (V2O5) and sodium sulfate (Na2SO4) for a longtime of 100 h at 1173 K. The LaPO4-clad YSZ coating showed corrosion resistance inferior to the Al2O3-clad one. Yttria was leached from YSZ by reaction between Y2O3 and V2O5, which caused progressive destabilization transformation of YSZ from tetragonal (t) to monoclinic (m) phase. The chemical inertness of the clad layers and the restrained infiltration of the molten corrosive salts by the dense clad layers were primary contributions to improvement of the hot-corrosion resistances.

Feasibility of biodegradable PLGA common bile duct stents: An in vitro and in vivo study

The current study investigates the feasibility of using a biodegradable polymeric stent in common bile duct (CBD) repair and reconstruction. Here, poly(l-lactide-co-glycolide) (PLGA, molar ratio LA/GA = 80/20) was processed into a circular tube- and dumbbell-shaped specimens to determine the in vitro degradation behavior in bile. The morphology, weight loss, and molecular weight changes were then investigated in conjunction with evaluations of the mechanical properties of the specimen. Circular tube-shaped PLGA stents with X-ray opacity were subsequently used in common bile duct exploration (CBDE) and primary suturing in canine models. Next, X-ray images of CBD stents in vivo were compared and levels of serum liver enzymes and a histological analysis were conducted after stent transplantation. The results showed that the PLGA stents exhibited the required biomedical properties and spontaneously disappeared from CBDs in 4-5 weeks. The degradation period and function match the requirements in repair and reconstruction of CBDs to support the duct, guide bile drainage, and reduce T-tube-related complications.