汉诺坝玄武岩中麻粒岩和辉石岩捕虏体Sr-Nd-Pb同位素五维空间特征及其地质意义

研究了汉诺坝玄武岩中麻粒岩和辉石岩捕虏体在Sr-Nd-Pb同位素五维空间中的特征 .结合捕虏体的空间分布相对位置, 认为层离作用可较好地解释不同类型捕虏体同位素之间的相互关系。published_or_final_versio

Localized-density-matrix, segment-molecular-orbitals and poly(p-phenylenevinylene) aggregates

The segment-molecular-orbital representation is developed and incorporated into the recently developed linear-scaling localized-density-matrix method. The entire system is divided into many segments, and the molecular orbitals of all segments form the basis functions of the segment-molecular-orbital representation. Introduction of different cutoff lengths for different segment-molecular-orbitals leads to a drastic reduction of the computational cost. As a result, the modified localized-density-matrix method is employed to investigate the optical responses of large Poly(p-phenylenevinylene) aggregates. In particular, the interchain excitations are studied. The complete neglect of differential overlap in spectroscopy hamiltonian is employed in the calculation. © 1999 American Institute of Physics.published_or_final_versio

Sr, Nd Pb isotopic characteristics of granulite and pyroxenite xenoliths in Hannuoba basalts, Hebei Province, and their implications for geologic processes

Rb-Sr, Sm-Nd and Pb isotopic systematics are reported for granulite and pyroxenite xenoliths in Hannuoba basalts, Hebei Province. The isotopic characteristics of xenoliths suggest t hat they might have formed recently , although there is no strict constraint on the precise age. The decoupling of low Rb/Sr and high [87]Sr/[86]Sr ratios implies the multi-stage evolution history and strong mixing processes. There are close ties between granulite and pyroxenites with different mineral assemblages on the Sr-Nd, Pb-Sr and Pb-Nd correlation figures. The granulite is the common end-member o f the three kinds o f pyroxenite. Combined with the distribution of the xenoliths in space and their isotopic relationships, It is proposed that delamination can be well used to explain the ties.系统研究了河北汉诺坝玄武岩中二辉麻粒岩和辉石岩捕虏体的Sr、Nd、Pb 同位素特征。虽然未确定捕虏体的形成时代, 但同位素特征显示它们可能为较近期( 中生代以来) 形成。低的Rb/Sr 与高 的[87]Sr/[86]Sr 比值的解耦表明捕虏体的形成经历了较强的混合作用。在二元同位素相关图上, 三类具不同矿物组成的辉石岩与二辉麻粒岩有密切关系, 即二辉麻粒岩投点位置是三类辉石岩的共同端点。综合考虑捕虏体的空间分布及其在Sr 、Nd、Pb 同位素协变图上的关系, 可以认为层离作用可较好地解释这些现象。published_or_final_versio

下地壳及壳慢过渡带化学不均一性 -- 河北汉诺坝地区深源捕虏体元素地球化学证据

河北汉诺坝玄武岩中长英质麻粒岩、镁铁质麻粒岩和辉石岩捕虏体的主量元素和微量元素特征, 反映了下地壳及壳鳗过渡带组成具有高度化学不均一性。不相容元素原始地慢标准化曲线特征的差异表明捕虏体成因复杂。MgO 与不相容元素无或仅有很弱的相关性, 与相容元素的相关性则相对较明显。这些特征反映了下地壳及壳慢过渡带存在较强和多元的混合作用。捕虏体的加权平均值比基于麻粒岩地体资料估算的下地壳平均组成偏基性, 揭示了二者可能的成因差异。The major and trace element data of granulite and pyroxenite xenoliths, which are entrained in Hannuoba basalt Hebei Province, North China, suggest the highly chemical heterogeneity in the lower crust and crust-mantle transitional zone. There is no or only POor linear correlation between MgO and incompatible elements. Whereas a bit remarked correlations are observed between MgO and most compatible elements.The geochemical characteristics suggest that the strong and multiple mixing processes may have Occurred universally both in the lower crust and crust-mantle transitional zone. The weighed average composition of xenoliths shows a more mafic composition of the lower crust than that estimated from granulite data, which may imply the difference in the genesis.published_or_final_versio

华北克拉通北缘晚中生代火山岩Sr-Nd-Pb同位素填图及其构造意义

辽宁西部广泛分布着晚中生代火山岩，横跨华北克拉通和兴> 蒙造山带两大构造单元，一般认为它们是以在这一地区发育的两条主要断裂———西拉木伦河断裂和赤峰> 开源断裂为界。这些火山作用曾被认为是中生代伊泽奈崎板块西向或西北向消减作用的结果。在岩性上它们主要以中酸性岩石为主，玄武岩等中基性岩石较少。为查明下伏岩石圈对这些岩浆作用成因的影响，对其中的SiO2 含量 开源断裂两侧为界，两侧火山岩的同位素特征存在显著区别。南区有明显的EMI 特征并具EMI-PM 混合趋势，而北区则显示了原始或略亏损的特征。南北两区之间的过渡带（介于西拉木伦河断裂和赤峰> 开源断裂之间）则表现了同位素组成上相应的过渡特征。这一地球化学观测与已有的地质和地球物理资料颇为吻合。基于新生代幔源岩石化学反演的中国东部陆下地幔化学区划研究揭示了克拉通下(subcratonic)岩石圈地幔与EMI 存在着密切关系。本研究所提供的地球化学证据说明了采用中生代中基性岩类作为类似研究途径的可行性，并进一步提出对华北克拉通边缘中生代火山作用成因另一种可能的解释，即古消减带物质的活化有可能对华北北缘火山岩源区物质组成产生重要影响。Late Mesozoic volcanic rocks are extensively spread on both sides of northern margin of the North China Craton (NCC), where is the boundary between an Archean craton to the south and a Paleozoic orogenic belt, Xing an- Mongolia Orogenic Belt (XMOB), to the north. Two major east- west trending faults, Kaiyuan- Chifeng Fault (KCF) and Xar Moron He Fault (XHF) develop in this margin zone as a boundary between two tectonic domains. The volcanism has been thought to be the magmatic response to the west- , or no...published_or_final_versio

Costs associated with febrile neutropenia in solid tumor and lymphoma patients - an observational study in Singapore.

BackgroundThe primary objective was to describe the total direct inpatient costs among solid tumor and lymphoma patients with chemotherapy-induced febrile neutropenia (FN) and the factors that were associated with higher direct cost. The secondary objective was to describe the out-of-pocket patient payments and the factors that were associated with higher out-of-pocket patient payments.MethodsThis was a single-center observational study conducted at the largest cancer center in Singapore. All of the adult cancer patients hospitalized due to FN from 2009 to 2012 were studied. The primary outcomes were the total hospital cost and the out-of-pocket patient payments (adjusted by government subsidy) per FN episode. Univariate analysis and multiple linear regression were conducted to identify the factors associated with higher FN costs.ResultsThree hundred and sixty seven adult cancer patients were documented with FN-related hospitalizations. The mean total hospital cost was US$4,193 (95$3,779-4,607) and the mean out-of-pocket patient payment was US$2,230 (95$1,976-2,484), per FN episode. The factors associated with a higher total hospital cost were longer length of stay, severe sepsis, and lymphoma as underlying cancer. The out-of-pocket patient payment was positively associated with longer length of stay, severe sepsis, lymphoma diagnosed as underlying cancer, the therapeutic use of granulocyte colony-stimulating factor (GCSF), the private ward class, and younger patients.ConclusionsThe total hospital cost and out-of-pocket patient payments of FN management in lymphoma cases were substantial compared with other solid tumors. Factors associated with a higher FN management cost may be useful for developing appropriate strategies to reduce the cost of FN for cancer patients

Feedback control architecture and the bacterial chemotaxis network.

PMCID: PMC3088647This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Bacteria move towards favourable and away from toxic environments by changing their swimming pattern. This response is regulated by the chemotaxis signalling pathway, which has an important feature: it uses feedback to 'reset' (adapt) the bacterial sensing ability, which allows the bacteria to sense a range of background environmental changes. The role of this feedback has been studied extensively in the simple chemotaxis pathway of Escherichia coli. However it has been recently found that the majority of bacteria have multiple chemotaxis homologues of the E. coli proteins, resulting in more complex pathways. In this paper we investigate the configuration and role of feedback in Rhodobacter sphaeroides, a bacterium containing multiple homologues of the chemotaxis proteins found in E. coli. Multiple proteins could produce different possible feedback configurations, each having different chemotactic performance qualities and levels of robustness to variations and uncertainties in biological parameters and to intracellular noise. We develop four models corresponding to different feedback configurations. Using a series of carefully designed experiments we discriminate between these models and invalidate three of them. When these models are examined in terms of robustness to noise and parametric uncertainties, we find that the non-invalidated model is superior to the others. Moreover, it has a 'cascade control' feedback architecture which is used extensively in engineering to improve system performance, including robustness. Given that the majority of bacteria are known to have multiple chemotaxis pathways, in this paper we show that some feedback architectures allow them to have better performance than others. In particular, cascade control may be an important feature in achieving robust functionality in more complex signalling pathways and in improving their performance

Method for generating pore networks in porous particles of arbitrary shape, and its application to catalytic hydrogenation of benzene

A method is established to generate pore networks within domains of arbitrary shape, as long as the domain can be mathematically described by a set of inequalities. In this method, a stochastic network algorithm is adopted to construct pore network skeletons, which are then cut into the desired shapes using a new pore network cutting algorithm. The latter can be embedded into other methods to transplant its ‘pore network cutting’ function. Using this method, pore networks with four archetypical two-dimensional shapes (namely, cross-sections of one-holed rings, trilobes, four-holed rings, and wheels) and four three-dimensional shapes (namely, spheres, cylinders, trilobes, and hollow cylinders) are constructed as examples. Then, some of these pore networks are applied to simulate diffusion and reaction in Pd/γ-alumina catalyst particles for hydrogenation of benzene to cyclohexane. It is shown that the randomness of the pore network and the external particle shape significantly affect the performance of catalysts, because of their impact on effective diffusivity and diffusion length, respectively, indicating that this structural information must be accounted for to achieve a model with high accuracy. The versatile method proposed in this article is ideal to study the effect of particle shape and pore network structure on the performance of porous materials for catalysis and other applications

Fine Structure of the Sensilla and Immunolocalisation of Odorant Binding Proteins in the Cerci of the Migratory Locust, Locusta migratoria

Using light and electron microscopy (both scanning and transmission), we observed the presence of sensilla chaetica and hairs on the cerci of the migratory locust, Locusta migratoria L. (Orthoptera: Acrididae). Based on their fine structures, three types of sensilla chaetica were identified: long, medium, and short. Males presented significantly more numbers of medium and short sensilla chaetica than females (p<0.05). The other hairs can also be distinguished as long and short. Sensilla chaetica were mainly located on the distal parts of the cerci, while hairs were mostly found on the proximal parts. Several dendritic branches, enveloped by a dendritic sheath, are present in the lymph cavity of the sensilla chaetica. Long, medium, and short sensilla chaetica contain five, four and three dendrites, respectively. In contrast, no dendritic structure was observed in the cavity of the hairs. By immunocytochemistry experiments only odorant-binding protein 2 from L. migratoria (LmigOBP2) and chemosensory protein class I from the desert locust, Schistocerca gregaria Forsskål (SgreCSPI) strongly stained the outer lymph of sensilla chaetica of the cerci. The other two types of hairs were never labeled. The results indicate that the cerci might be involved in contact chemoreception processes