Cosmology with cluster surveys

Surveys of clusters of galaxies provide us with a powerful probe of the density and nature of the dark energy. The red-shift distribution of detected clusters is highly sensitive to the dark energy equation of state parameterw. Upcoming Sunyaev-Zel’dovich (SZ) surveys would provide us large yields of clusters to very high red-shifts. Self-calibration of cluster scaling relations, possible for such a huge sample, would be able to constrain systematic biases on mass estimators. Combining cluster red-shift abundance with limited mass follow-up and cluster mass power spectrum can then give constraints onw, as well as onσ ₈ and Ω_M to a few per cents.     

Optimization of the Size of Nonsensitiveness Regions

The problem is to determine the optimum size of nonsensitiveness regions for the level of statistical tests. This is closely connected with the problem of the distribution of quadratic forms.     

阴极材料Li1.2Cr0.4Mn0.4O2的制备及其电化学性能

采用溶胶凝胶法制备层状富锂Li1.2Cr0.4Mn0.4O2阴极材料．研究煅烧温度对阴极材料的结构，及电化学性能的影响．利用X-射线衍射(XRD)、扫描电镜(SEM)、X-射线光电子能谱(XPS)等方法对阴极材料的晶体结构、充放电过程中价态的变化、表观形貌、粒径大小等进行分析．结果表明850℃时煅烧后的阴极材料层状结构明显，电化学性能优良．以小放电速度进行恒流(10mA／g)充放电循环，首次放电比容量可以达到280mAh／g，经过40次循环后仍可以达到190mAh／g．研究发现在整个充放电过程中Mn始终保持 4价态，部分Cr作为活性离子价态在 6和 3之间可逆变化．Li1.2Cr0.4Mn0.4O2经过镀银后以大放电速度进行恒流(80mA／g)放电可以达到100mAh／g的比容量．     

Statistical isotropy of the cosmic microwave background

The breakdown of statistical homogeneity and isotropy of cosmic perturbations is a generic feature of ultra-large scale structure of the cosmos, in particular, of non-trivial cosmic topology. The statistical isotropy (SI) of the cosmic microwave background temperature fluctuations (CMB anisotropy) is sensitive to this breakdown on the largest scales comparable to, and even beyond the cosmic horizon. We propose a set of measures,K _l (l = 1, 2,3,...) which for non-zero values indicate and quantify statistical isotropy violations in a CMB map. We numerically compute the predictedK _l spectra for CMB anisotropy in flat torus universe models. Characteristic signatures of different models in theK _l spectrum are noted.     

类氖-锗电子碰撞激发X光激光的增益特性

 电子碰撞激发X光激光的增益特性依赖于电子密度Ne、电子温度Te、增益区宽度D R和介质速度梯度dv/dz等四个表征等离子体内部状态的参数。以类氖-锗离子为例研究了反转和增益特性对Te、Ne的依赖关系，并在典型的增益区宽度（D R=100 μm）和介质速度梯度（dv/dz=1.3×10⁹s^-1）下讨论了共振线俘获对增益特性影响，给出波长为19.6nm, 23.2nm和23.6nm三条激光线的增益目标区域。还讨论了双电子复合过程对离子布居的重要影响。     

An exact estimate of the boundary behavior of functions from hardy-sobolev classes in the critical case

In the critical case αp=n functions from the Hardy-Sobolev spacesH _α ^p (B ⁿ ) have a limit almost everywhere on the boundary along certain regions of exponential contact with the boundary. It is proved in the paper that the maximal operator associated with these regions is bounded as an operator fromH _α ^p (B ⁿ ) toL ^p (ϖB ⁿ ). Translated fromMatematicheskie Zametki, Vol. 62, No. 4, pp. 527–539, October, 1997. Translated by N. K. Kulman     

Confidence intervals and ellipsoids for estimable functions and estimable vectors in models with orthogonal block structure

Sub-models of mixed linear models are considered. The independence of these sub-models leads to sufficient statistics for the parameters relevant for their densities. Using pivot variables, confidence regions are obtained as well hypothesis testing for variance components, estimable functions, and estimable vectors. In addition, to compare the estimators and the models, we present the histograms with the empirical joint densities for positive and negative parts of the estimators. The figures, for the two-dimensional charts, contain the corresponding UMVUE and are all unimodal with the UMVUE near the mode. The nearness of the estimators and the modes validates the presented methodology and allows the safe use of induced densities. A numerical example applied to real data is presented.     

Relative Permeabilities for Strictly Hyperbolic Models of Three-Phase Flow in Porous Media

Traditional mathematical models of multiphase flow in porous media use a straightforward extension of Darcys equation. The key element of these models is the appropriate formulation of the relative permeability functions. It is well known that for one-dimensional flow of three immiscible incompressible fluids, when capillarity is neglected, most relative permeability models used today give rise to regions in the saturation space with elliptic behavior (the so-called elliptic regions). We believe that this behavior is not physical, but rather the result of an incomplete mathematical model. In this paper we identify necessary conditions that must be satisfied by the relative permeability functions, so that the system of equations describing three-phase flow is strictly hyperbolic everywhere in the saturation triangle. These conditions seem to be in good agreement with pore-scale physics and experimental data.     

Diaminodiacid Bridges to Improve Folding and Tune the Bioactivity of Disulfide‐Rich Peptides

Disulfide‐rich peptides containing three or more disulfide bonds are promising therapeutic and diagnostic agents, but their preparation is often limited by the tedious and low‐yielding folding process. We found that a single cystine‐to‐diaminodiacid replacement could significantly increase the folding efficiency of disulfide‐rich peptides and thus improve their production yields. The practicality of this strategy was demonstrated by the synthesis and folding of derivatives of the μ‐conotoxin SIIIA, the preclinical hormone hepcidin, and the trypsin inhibitor EETI‐II. NMR and X‐ray crystallography studies confirmed that these derivatives of disulfide‐rich peptide retained the correct three‐dimensional conformations. Moreover, the cystine‐to‐diaminodiacid replacement enabled structural tuning, thereby leading to an EETI‐II derivative with higher bioactivity than the native peptide.     

Synthesis,Characterization, and Energetic Properties of 6‐Amino‐tetrazolo[1,5‐b]‐1,2,4,5‐tetrazine‐7‐N‐oxide: A Nitrogen‐Rich Material with High Density

The synthesis and energetic properties of a novel N‐oxide high‐nitrogen compound, 6‐amino‐tetrazolo[1,5‐b]‐1,2,4,5‐tetrazine‐7‐N‐oxide, are described. Resulting from the N‐oxide and fused rings system, this molecule exhibits high density, excellent detonation properties, and acceptable impact and friction sensitivities, which suggests potential applications as an energetic material. Compared to known high‐nitrogen compounds, such as 3,6‐diazido‐1,2,4,5‐tetrazine (DiAT), 2,4,6‐tri(azido)‐1,3,5‐triazine (TAT), and 4,4′,6,6′‐tetra(azido)azo‐1,3,5‐triazine (TAAT), a marked performance and stability increase is seen. This supports the superior qualities of this new compound and the advantage of design strategy.