烧结铁矿中FeO含量对其在富氢高炉中还原行为的影响

Japan started the national project “COURSE 50” for CO₂ reduction in the 2000s. This project aimed to establish novel technologies to reduce CO₂ emissions with partially utilization of hydrogen in blast furnace-based ironmaking by 30% by around 2030 and use it for practical applications by 2050. The idea is that instead of coke, hydrogen is used as the reducing agent, leading to lower fossil fuel consumption in the process. It has been reported that the reduction behavior of hematite, magnetite, calcium ferrite, and slag in the sinter is different, and it is also considerably influenced by the sinter morphology. This study aimed to investigate the reduction behavior of sinters in hydrogen enriched blast furnace with different mineral morphologies in CO–CO₂–H₂ mixed gas. As an experimental sample, two sinter samples with significantly different hematite and magnetite ratios were prepared to compare their reduction behaviors. The reduction of wustite to iron was carried out at 1000, 900, and 800°C in a CO–CO₂–H₂ atmosphere for the mineral morphology-controlled sinter, and the following findings were obtained. The reduction rate of smaller amount of FeO led to faster increase of the reduction rate curve at the initial stage of reduction. Macro-observations of reduced samples showed that the reaction proceeded from the outer periphery of the sample toward the inside, and a reaction interface was observed where reduced iron and wustite coexisted. Micro-observations revealed three layers, namely, wustite single phase in the center zone of the sample, iron single phase in the outer periphery zone of the sample, and iron oxide-derived wustite FeO and iron, or calcium ferrite-derived wustite 'FeO' and iron in the reaction interface zone. A two-interface unreacted core model was successfully applied for the kinetic analysis of the reduction reaction, and obtained temperature dependent expressions of the chemical reaction coefficients from each mineral phases.     

Mg和La对Ca–Ti 处理钢中夹杂物演变和组织的影响

The evolution of inclusions and the formation of acicular ferrite (AF) in Ca–Ti treated steel was systematically investigated after Mg and La addition. The inclusions in the molten steel were Ca–Al–O, Ca–Al–Mg–O, and La–Mg–Ca–Al–O after Ca, Mg, and La addition, respectively. The type of oxide inclusion in the final quenched samples was the same as that in the molten steel. However, unlike those in molten steel, the inclusions were Ca–Al–Ti–O + MnS, Ca–Mg–Al–Ti–O + MnS, and La–Ca–Mg–Al–Ti–O + MnS in Mg-free, Mg-containing, and La-containing samples, respectively. The inclusions distributed dispersedly in the La-containing sample. In addition, the average size of the inclusions in the La-containing sample was the smallest, while the number density of inclusions was the highest. The size of effective inclusions (nucleus of AF formation) was mainly in the range of 1–3 μm. In addition, the content of ferrite side plates (FSP) decreased, while the percentage of AF increased by 16.2% due to the increase in the number of effective inclusions in the La-containing sample in this study.     

若干蛇毒蛋白的结构生物学研究

以本研究组较有研究特色的五种蛇毒蛋白家族为线索,简要综述了蛇毒金属蛋白酶、蛇毒丝氨酸蛋白酶、蛇毒crisp蛋白、蛇毒磷脂酶A2及蛇毒神经毒素等蛋白家族有关结构生物学研究的结果、现状及进展.强调了蛇毒蛋白研究中蛇毒糖蛋白的结构生物学研究、超高分辨率晶体学研究及与蛇毒蛋白相关的复合物结构生物学研究的重要性.     

细胞动力学研究进展与展望

细胞是生命活动的最小单元,其功能可塑性及动力学特征是维系生命个体健康及物种繁衍的重要保证.在分子水平,细胞可塑性与动力学特征受遗传学及表观遗传学的调控.随着基因组计划的顺利完成及我们对细胞增殖重要蛋白质作用网络生物化学特征研究的成功实施,表示细胞重要生命活动过程中功能分子的动力学特征及其调控机制显得日益重要.组建中国科学技术大学细胞动力学实验室旨在纳米尺度揭示细胞重要生命活动全过程的详尽全息分子调控机制.在过去的几年中,已取得了动点蛋白质网络研究的阶段性进展,动点蛋白复合物组分剖析、功能评估、蛋白质作用动力学及可塑性研究等方面均取得了具有特色的成绩.目前,拟在纳米尺度评估动点组装的时空动力学调控机制.相信在未来的日子里,细胞动力学实验室的创新性成果能够综合集成,并为人口与健康领域的重大命题提供相关的解答方案与技术平台.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

非整倍体和人类生殖健康

非整倍体即染色体数目异常,发生于生殖细胞则可能导致不育不孕、自发流产和先天出生缺陷.精子非整倍体发生率为5%～7%,卵子非整倍体发生率为22%～90%;在早期自然流产中,非整倍体率高达50%.绝大多数临床上常见的非整倍体患儿的异常染色体来自卵子(母亲),而且母亲减数分裂I同源染色体不分离是除13和18号染色体以外的各种常见染色体非整倍体的主要原因.母亲的年龄是迄今唯一被证实的与生殖细胞非整倍体发生密切相关的流行病学因素,减数分裂遗传重组(频率和位点分布)异常可能是导致减数分裂I同源染色体不分离的主要细胞学和遗传学因素,减数分裂前最后一次DNA复制时cohesin复合体的加载及其之后的维持异常则可能是引起减数分裂染色体不分离的分子生物学因素.减数分裂遗传重组和cohesin复合体的加载均发生于女性胚胎发育的8～30周,而非整倍体卵子的形成多发生在35岁以上的女性,因此我们认为导致非整倍体卵子形成的\"罪恶种子\"早在35年前即已埋下,随着女性年龄增大,其体内保障染色体精确分离的保护机制如纺锤体聚合检验点被\"磨损\"削弱,而最终导致减数分裂时染色体分离异常.未来的研究应着重探讨遗传重组改变的原因、机理及如何导致减数分裂染色体不分离,了解卵母细胞中cohesin复合体、纺锤体聚合检验点的功能是否随女性年龄增大而减弱及其生物学机制,从而为有效防止非整倍体的发生、减少人类生殖相关非整倍体疾病的发生提供理论基础.     

核磁共振波谱研究蛋白质三维结构及功能

文中总结了中国科学技术大学生命科学学院核磁共振波谱实验室十多年来的工作.我们的研究主要集中于研究人和其他真核生物基因表达调控相关蛋白质以及细胞连接处相关蛋白质.在这两个体系中许多蛋白质与人类健康及疾病相关,有的可能是潜在的药物作用靶标.我们主要关注用核磁共振波谱方法研究蛋白质-蛋白质相互作用的结构基础.核磁共振适合研究在接近生理条件下的分子相互作用,特别是适合研究低亲和力的瞬态的复合物.它可以提供蛋白质相互作用界面,复合物结构,以及蛋白质相互识别过程动力学的信息.文中给出了一些例子.我们也研究蛋白质内部动力学,包括皮秒-纳秒时间尺度,与毫秒-微秒时间尺度的动力学.与圆二色谱及荧光光谱结合,核磁共振可以详细表征蛋白质的折叠与去折叠.文中给出的核磁共振应用的最后一个例子是用计算机虚拟筛选,核磁筛选,我们发现了一个人的双功能的磷酸酶的一种新类型的抑制剂,并研究了该抑制剂对细胞功能的影响.这一策略有可能用于早期药物的发现.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.