溶胶-凝胶法制备含锶生物玻璃及其溶解性

采用溶胶-凝胶法制备不同锶含量改性的生物玻璃(CaO-P2O5-SiO2-SrO),分别采用X射线衍射仪和扫描电子显微镜对样品的相成分和形貌进行分析,采用浸泡法研究不同锶含量的生物玻璃在三羟甲基氨基甲烷(Tris)和模拟体液(SBF)中的溶解行为和生物矿化。结果表明:锶取代部分钙制备的锶改性生物玻璃为非晶结构,锶掺杂没有改变生物玻璃的微观结构;含锶生物玻璃与纯生物玻璃一样,在Tris和SBF溶液中均表现出良好的生物活性,但含锶生物玻璃表现出更缓的溶解速率,并且随Sr含量增加溶解速率下降;同时,矿化生成的羟基磷灰石(HA)结晶性变差,表明Sr的加入可以有效地调控生物玻璃的溶解速率,使设计与制备一定溶解速率的生物玻璃成为可能。     

锌掺杂锗酸锶纳米棒及其光催化特性

以乙酸锶、氧化锗及乙酸锶作为原料,通过水热法制备出了锌掺杂锗酸锶纳米棒。通过X-射线衍射、扫描电子显微镜及固体紫外—可见光漫反射光谱分析了锌掺杂锗酸锶纳米棒的结构、形貌及光学特性。X-射线衍射分析表明所得锌掺杂锗酸锶纳米棒由六方Sr Ge O3和三方Zn Ge O3晶相。不同含量锌掺杂的锗酸锶纳米棒的禁带宽度为3.67 e V到2.88 e V。在紫外光照射下,分析了锌掺杂锗酸锶纳米棒光催化降解亚甲基蓝的光催化活性。光催化分析结果显示锌掺杂锗酸锶纳米棒比未掺杂的锗酸锶具有更高的光催化活性。     

氨化改性Sr2Ta2O7/SrTa4O11光催化剂用于光电催化性能研究

以钽酸锶同素异质结Sr2Ta2O7/SrTa4O11(STO)为原始材料,采用高温氨化法对原始材料做氮掺杂改性处理,得到了新型氮掺杂钽酸锶同素异质结材料Sr2Ta2O7?xNx/SrTa4O11?xNx(STO-N),并对其光电催化性能进行研究.结果显示,对比改性前的STO,STO-N具有更强的可见光吸收能力.紫外可见...     

溶胶-凝胶自燃烧法制备镧取代锶铁氧体

采用溶胶-凝胶自燃烧法制备了镧取代锶铁氧体(Sr1-xLaxFe12O19),用X射线衍射仪(XRD)、扫描电镜(SEM)和HB8510网络矢量分析仪研究了镧取代对锶铁氧体的结构、形貌和电磁性能的影响。结果表明,经900℃煅烧后,纯六角晶系磁铅石结构的锶铁氧体晶相生成。La3+取代摩尔数为0.1和0.2时,锶铁氧体的结构没有变化,未出现杂相。La3+具有抑制铁氧体晶粒生长的作用。当La3+取代量为0.1时,可使锶铁氧体的复介电常数和复磁导率的值升高,但当La3+取代量增加到0.2时,又使复介电常数和复磁导率的值降低。Sr0.9La0.1Fe12O19的样品具有最大的介电损耗角正切tanδε值和磁损耗角正切tanδμ值,分别为0.01和0.26。     

锶铝中间合金研制成功

南京特种合金厂与上海工业大学合作,采用盐电解法成功地制取了含Sr量为8—12％的锶铝中间合金。该工艺特点为流程短、易操作、投资少、能耗低、成本低。近年来,国内外均在研究新的铝硅系铸造合金变质剂,试验有Sr、Ba、Te、Sb、S、Ca、As、Y、Ce、Nb和Pr等元素。     

稀土掺杂Sr2MgSi2O7长余辉发光材料的研究进展

硅酸镁锶(Sr2MgSi2O7)作为目前常用的一种长余辉发光材料基质,性能稳定,耐酸碱性能良好。本文介绍了长余辉发光材料的发光原理,综述了近年来Sr2MgSi2O7长余辉发光材料的主要制备方法以及稀土掺杂Sr2MgSi2O7材料的研究进展,并对该材料的发展做出了展望。制备Sr2MgSi2O7长余辉发光材料的方法主要包括高温固相法,溶胶-凝胶法,化学沉淀法和燃烧合成法,其中最常用的为高温固相法。通过掺杂稀土离子可以形成具有不同发光特性的长余辉发光材料。稀土掺杂Sr2MgSi2O7材料作为一种储能、节能的长余辉发光材料,展现出了广阔的发展和应用前景。     

重晶石矿中硫酸钡含量测定方法的优化

重晶石在工业上有广泛用途,一般以测定硫酸钡的含量来表明它的纯度,但是其通常会伴生有锶、铅、银的硫酸盐。传统的重晶石分析方法,因其分离较困难,容易使测定结果偏高。本文优化了实验条件,利用碳酸钠-氧化锌半熔法分解试样,以重量法测定重晶石中Ba、Sr、Pb、Ag的硫酸盐含量,用酸分解半熔浸取后的沉淀,以ICP-OES法测定沉淀中的Sr、Pb、Ag含量,从而间接测定重晶石中硫酸钡的含量。此法适用于一般重晶石矿石中硫酸钡含量在15%—90%的准确测定。     

接触阴极法制取金属锶

本文用接触阴极在 SrCl_2-KCl 熔盐中进行了金属锶的电解。在电解试验的基础上,确定了在 SrCl_2-KCl 盐系中,用接触阴极制取锶的最佳工艺条件和锶电解的技术经济指标。从阴极上取下被熔盐结壳覆盖的锶棒,经在密闭充氩的容器中重熔铸锭,其纯度接近99％Sr。     

La1-xSrxMnO3薄膜的热辐射特性研究

利用溶胶凝胶-丝网印刷法在氧化铝基底上制备了La1-x Sr x MnO3(x=0.3、0.4和0.5)薄膜,研究了薄膜通电发热后的热辐射特性。不同掺锶量的薄膜发热温度在90℃~360℃范围内时,红外辐射波长主要集中在4000 nm~5000 nm,发热温度越高,最大辐射波长越短,而掺锶量对红外辐射光谱影响较小;掺锶量x=0.4的薄膜可实现800℃以上的加热温度,控制电压使发热温度保持在500℃时,可实现长时间稳定加热。     

稀土掺杂铝酸锶长余辉薄膜制备方法的研究现状

稀土掺杂铝酸锶薄膜在长余辉夜视照明、无损实时可视化探测、机械应力传感器、纳米光电子器件、二维温度传感器以及薄膜太阳能电池等领域具有极为广阔、诱人的应用前景.要实现以上应用,首要条件是制备出质量高、性能优良的薄膜.因此制备稀土掺杂铝酸锶薄膜成为当今研究的热点.综述了国内外制备稀土掺杂铝酸锶薄膜的主要方法,包括射频磁控溅射法、溶胶—凝胶法、脉冲激光沉积法和激光熔蒸法,并重点介绍了射频磁控溅射法;另外对各种方法的优缺点进行了阐述.     

Contribution of endogenous opioids to gonadal hormones-induced temporomandibular joint antinociception.

The authors have recently demonstrated that the high serum estradiol level during the proestrus phase of the estrous cycle and that the administration of estradiol or progesterone in ovariectomized female and of testosterone in orchiectomized male rats significantly decrease formalin-induced temporomandibular joint (TMJ) nociception. In this study, the authors investigate the contribution of endogenous opioids to this antinociceptive effect of gonadal hormones in the TMJ formalin test. The opioid receptor antagonist naloxone was administrated either in the surrounding of the trigeminal sensory complex or in the TMJ region. The antinociceptive effect induced by endogenous estradiol in proestrus females and by exogenous estradiol in ovariectomized females was blocked by the administration of naloxone in the surrounding of the trigeminal sensory complex, but not in the TMJ region. The antinociceptive effect induced by the administration of progesterone in ovariectomized females and of testosterone in orchiectomized males was blocked by the administration of naloxone either in the surrounding of the trigeminal sensory complex or in the TMJ region. The authors conclude that central and peripheral opioid mechanisms mediate the antinociceptive effect of progesterone and testosterone, and central opioid mechanisms mediate the antinociceptive effect of estradiol. These findings suggest that the enhanced pain perception during low gonadal hormone periods in women and animals may be mediated by a decrease in endogenous opioid activity. This suggestion helps explain the higher severity of some pain conditions, such as temporomandibular dysfunctions in women than in men, that have no hormonal fluctuations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Introduction to the special section on cognitive processes and psychotherapy.

Theoretical models featuring cognitive processes have played a fundamental role in advancing knowledge of psychopathology and its treatment and have emphasized the importance of cognition in psychotherapy. Recognition of the importance of cognition in psychotherapy has led to a number of questions that are addressed by the articles in this special section of the Journal of Consulting and Clinical Psychology. Cognitive therapy is well represented in the articles in this special section, but therapeutic procedures that do not represent typical cognitive therapy are also examined. The articles in this special section focus on homework in the modification of cognition, cognition in the treatment of anxiety in adults and in children, change in depressive cognitions in children, cognition and rapid change in the treatment of depression, and the role of cognition in the treatment and prevention of depression that is recurrent. Examination of these types of questions holds the possibility of advances in existing treatments and the possibility of innovations in new treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impacts of Obstacles in East Asian Cross-Border Construction

In the light of the rapidly growing investment in infrastructure over the past 10 years, East Asia has developed into one of the most dynamic construction markets in the world. Despite progress in market-oriented reforms in some countries of this region, considerable obstacles in the form of varying technical standards and local preference policies still can lead to significant cost increases. Five categories of obstacles are identified in this paper: business environment risk, regulatory restrictions, contractual arrangements and differences in standards and in culture. The likelihood of occurrence of these obstacles as well as their impact on the profitability of cross-border construction are uncertain. The degree of their effect also varies across East Asian countries. Through an industry survey of top international construction firms based in Singapore, the significant obstacles or cost growth factors and their impact on cost growth in tendering, construction, and overheads are determined. In particular, the risk situations in China and Singapore are compared.     

Case Study: Delayed Sedimentation Response to Inflow and Operations at Sanmenxia Dam

This paper presents a study on the reservoir sedimentation processes in response to changes in incoming flow at the upstream and changes in the pool level at the downstream for Sanmenxia Reservoir, which is located on the middle reach of the Yellow River in China and has experienced serious sedimentation problems even since its impoundment in 1960. The hysteresis effect in reservoir sedimentation was used as the basis for analysis and its behavior was fully investigated throughout this study. The research found that the rise in the elevation of Tongguan, which is located in the backwater region at a distance of 113.5?km upstream of the Sanmenxia Dam, had a time delay of about 2?years compared with the sediment deposition in the reservoir area downstream of Tongguan. Moreover the accumulated sediment deposition in the reservoir area was closely related not only to the current year’s flow and dam operational conditions, but also to the preceding 3–4?years’ flow and dam operational conditions. Likewise the variation of Tongguan’s elevation was a function of 6?years’ linearly superimposed runoff, and the channel bed slope in the vicinity of Tongguan was determined by a moving average pool level over a 7?year period. The research results are of practical importance in particular for optimizing the operation of Sanmenxia Dam, and the finding of the hysteresis phenomenon in the sedimentation process of the reservoir is of merit to the advancement of sedimentation science.     

Imperfection Sensitivity of Laminated Cylindrical Shells According to Different Shell Theories

The imperfection sensitivity of laminated cylindrical shells is considered—via the initial postbuckling analysis—on the basis of three different shell theories: Donnell in 1933; Sanders in 1963; and Timoshenko in 1961. The procedure involves nonlinear partial differential equations, which are converted into a sequence of three linear sets. The equations are solved with the variables expanded in Fourier series in the circumferential direction and in finite differences in the axial directions. A general code is developed and used in studying the effect of higher exactness of the shell theory on the sensitivity behavior, and in a parametric study of the sensitivity of anisotropic angle-ply cylindrical shells.     

钢水夹杂物研究与控制技术的最新进展

介绍了国外钢中夹杂物研究与控制技术的最新进展,包括:浦项采用计算流体力学模型研究钢水中的夹杂物、埃及开罗大学控制钙的添加量提高钢水的洁净度、神户制钢CaO系夹杂物的分析方法、JFE单个中间包热周转降低头坯裂纹、住友金属改进水口套管减少板坯内宏观夹杂物等。总结了浦项宽板坯连铸机改造采用的先进技术,以及镭目公司的RAMON功能结晶器全面优化技术,提高铸坯质量。     

Vulnerability of Fully Glazed High-Rise Buildings in Tropical Cyclones

This paper examines some of the features of the built environment that are most likely to be related to the potential for damage causation in the event of a tropical cyclone strike in a densely populated urban area. The common incidence of fully glazed buildings, vulnerable as they are to wind-borne debris, forms a central feature of this consideration. The problem of loss estimation from both direct and indirect losses is considered. Use is made in the paper of information available from instances in which this scenario has been played out. While the most common episode in the minds of most research workers is probably the damage caused by Hurricane Alicia in Houston in 1983, the most recent occurrence of this damage mechanism has been in Hong Kong, in September 1999, when Typhoon York caused significant damage to the central business district including Central Plaza, one of Asia’s tallest buildings. The paper indicates a relationship of building damage to wind speed. This relationship, when taken with the uncertainty surrounding the estimation of the magnitude of long return-period wind speeds, results in considerable uncertainty in the estimation of the value of losses in extreme meteorological events. The influence of this level of uncertainty on insurance premiums and reinsurance rates is noted.     

河北省中南部农田孢粉组合特征

The study on 82 surface soil pollen samples from different types of cultivated vegetations in central and southern parts of Hebei Province indicates that the pollen assem-blages from farmlands in the plain have not only their own plant types, but also the pollen components from the nearby mountains. Arboreal pollen percentages and concentrations (dominated by Pinus)from farmlands in mountain area are higher than those in the plain, and it reduces gradually with the increasing distance away from the mountains. Taking Pinus pollen in Taihang Mountains as an example, its content is 20%-30%, 10%-20%, 20%-30% and below 16% respectively for the samples from the area of 0-50, 50-100, 100-150 and more than 150 km away from the east Taihang Mountains. The increase of Pinus pollen proportion in the central plain is probably related to the fohn effect. The spatial variation of AP from mountains to the plain in Hebei Province may be similar to the forests clearance by human activities in the early historical period. Shrubby pollen proportion is small both in mountains and in the plain, but their major components are different. Elaeagnaceae, Corylus,Ostryopsis and Oleaceae are common in mountain areas, while there are relatively high contents of Rosaceae and Vitaceae in the plain. Herbs content in the plain(about 60%)is 15% higher than that in mountains, among which the Cereals and Cruciferae pollen per-centages are 5% and 2% higher respectively. Artemisia pollen percentage in the plain is lower than that in mountains. Since the human activities are weaker in mountains compared with that in the plain, the general trend is that Chenopodiaceae pollen increases from mountains to the plain gradually, reflecting the raising intensity of human activities. The fern spores of Se-laginella sinensis in mountains are higher than that in the plain, but it still reaches to about 7% in the plain. The fern spores of Selaginella sinensis are not prone to be spread by wind, in-dicating that those in the surface soil of the plain may be carried by river water from moun-tains during the deposition of the plain.     

球团链箅机回转窑工艺中氯和硫元素迁移规律

摘要：对链箅机回转窑工艺中各段球团样品进行实验分析,研究了氯元素和硫元素在链箅机回转窑工艺中的迁移规律,明晰了烟气中HCl的生成机制。结果表明,球团原料中的氯元素主要是以NaCl的形式存在,氯元素有一部分在链箅机抽风干燥段会转变成HCl气体并进入烟气,一部分在链箅机预热Ⅱ段之后以NaCl的形式汽化进入烟气,剩余的氯元素仍以NaCl的形式存在于成品球团矿中。烟气中的HCl气体是在抽风干燥段,由富含SO2的烟气与含水球团料层中的NaCl发生反应生成的,烟气中SO2转变成Na2SO4重新固定于料层中。在预热Ⅰ段和预热Ⅱ段,烟气中的SO2与原料中碳酸钙分解生成的游离CaO反应生成CaSO4,也会重新固定烟气中的SO2。     

民营企业电工钢生产高质量发展的思考

为了加快中国电工钢产业高质量发展的进程,探讨民营企业电工钢生产高质量发展的思路,通过对民营企业电工钢生产现状的深入了解,找到电工钢产业高质量发展的关键,重点对民营企业电工钢生产的主要问题进行剖析,并提出民营企业发展可借鉴的思考。研究表明,提高中国民营企业电工钢生产技术水平是改进和提升中国电工钢产业整体水平的重要策略之一;高质量发展必须国有企业、民营企业共同科技进步,才能提高中国电工钢产业整体水平、实现电工钢强国的目标。