球状星团M3 水平支脉动不稳定带红边界附近的小变幅变星(英文)

半个世纪以前，Ｒｏｂｅｒｔｓ 和Ｓａｎｄａｇｅ 在验证Ｓｃｈｗａｒｚｓｃｈｉｌｄ 的理论发现时，在水平支ＲＲＬｙｒａｅ 变星缺口段的红端发现了两颗小变幅的变星。当时定不出类型，标以“？”。以后Ｓａｎｄａｇｅ 在做ＲＲ Ｌｙｒａｅ 变星统计研究时，竟不加解释地当作ＲＲａｂ 型星处理。半个世纪之间，没有人对这颗星的反常加以注意。我们用国内的ＣＣＤ 观测，又发现了一颗类似的小变幅变星，但变幅更小，周期更长。这颗星与以前发现的两颗一起，似乎构成ＲＲ Ｌｙｒａｅ 星的又一个次型。现有的变星脉动理论还不能对之加以解释。我们预计，这将再一次推动脉动理论发展。

不同层序岩相中的不稳定带和岩石的特征变化

盆地形成的原因包括；构造圈深部地带物质的不稳定状态、软流圈厚度的增加和继而地壳厚度的减小。大多数沉积盆地均有一些高能不稳定层，反映了岩石特征的非线性交换。在不同岩石类型的不同深度，密度、孔隙度、水饱和度等的异常均不相同。决定异常存在的主要作用是岩石的构造一组分特征和导热性、导电性。采用与深度和ＰＴ因子一致的温度计算法来建立不同岩石类型和不同地球动力条件和热力条件下岩石特征变化的计算机模型或许是重要的。密度、孔隙度等的非线性变化决定了不同流体循环的环型流动的存在，不稳定层的预测是矿产预测之关键。

走向条带深孔爆破方法开采急倾斜松散不稳定煤层的实践

走向条带深孔毫秒雷管爆破采煤是一种新采煤方法,它解决了传统落后的巷道残柱式采煤法不能开采的急倾斜松散不稳定煤层的采煤问题。此法工序简单,工效、回采率都比残柱式提高、而回采掘进率和坑木消耗大幅度下降,安全情况也良好。

下花园煤矿玉带山不稳定煤层采煤方法改革浅析

对玉带山不稳定煤层老式采煤方法和改革后的采煤方法作了较详细的分析,对其如何适应煤层的不稳定性作了探讨,指出了推行壁式采煤法技术可行、安全可靠、效益显著的前提是先进的支护手段。

不稳固矿带的采矿方法及技术改造

叙述了在丰山铜矿不稳固南缘矿带 ,由使用无底柱分段崩落法过渡到分段碎石胶结充填法的原因、方法和成果。

基于LAMOST巡天证认一颗新脉动白矮星

LAMOST是我国口径最大的光学巡天望远镜,也是迄今为止全球光谱获取率最高的天文望远镜,其海量的巡天光谱库中包含了大量的白矮星.为扩大DA型脉动白矮星样本,以更好地理解这类变星在脉动不稳定带的特性,本文从LAMOST光谱库中选取了6颗脉动白矮星候选体,使用兴隆85cm光学望远镜以及2.16m光学望远镜进行了时序测光观测.发现LAMOST J140918.73+221529.3存在主周期为216.1s的脉动,这是LAMOST巡天数据中一颗新被证认的DA型脉动白矮星.

巧用Windows 7资源监视器删除顽固文件

自从安装了正版的Windows 7系统,因系统不稳定带来的麻烦几乎没有再出现过,用起来也很放心,也许有一部分心理作用吧。不过偶尔出现的小麻烦还是有的。今天我跟大家分享的是Windows 7中的＂资源监视器＂。

地缘政治风险将进一步推涨油价

在剩余开采和炼制能力短缺的情况下,市场很难承受由政治局势不稳定带来的供应风险。投机基金涌入期货市场使得这种供应风险被进一步夸大。

Landform Instability and Land-use Dynamics in Tropical High Mountains, Central Mexico

This investigation is an analysis of the influence of landform instability on the distribution of land-use dynamics in a hydrographical basin, located in the Mexican Volcanic Belt mountain range (central Mexico), currently affected by substantial changes in land use and deforestation. A landform map was produced, in addition to seven attribute maps - altimetry, drainage density, slope, relief energy, potential erosion, geology and tectonics - which were considered as factors for determining landform instability through Multi-criteria Evaluation Analysis. Likewise, the direction and rhythm of land-use dynamics were analyzed in four dates - between 1976 and 2000 - and cross tabulations were made between them, in order to analyze the trends and processes of land-use dynamics. Afterwards, the databases obtained were cross tabulated with the landform variables to derive areas, percentages and correlation indices. In the study area, high-instability landforms are associated with most ancient volcanic and sedimentary landforms, where high altitude, drainage density, slope and potential to develop gravitational and fluvial processes are the major factors favouring a land-use pattern, dominated by the conservation of extensive forest land, abandonment of human land use and regeneration of disturbed areas. In contrast, low-instability landforms correspond to alluvial plains and lava hills covered by pyroclasts, where low potential erosion to develop fluvial processes, added to water and soil availability and accessibility, have favoured a land-use pattern dominated by the expansion of agroforestry plantations and human settlements, showing a marked trend towards either intensification or permanence of the current land use and with little abandonment and regeneration.

Characterization of deformation stability of in-situ TiB2/6351 composites during hot compression based on Murty criterion

In situ TiB2 reinforced 6351 Al alloy composites were subjected to compression testing at strain rates and temperatures ranging from 0.001 to 10 s -1 and from 300 to 550？欲espectively,using Gleeble-1500D system.And the associated microstructural transformations and instability phenomena were studied by observations of the optical and transmission electron microscope.The power dissipation efficiency and instability parameter were calculated following the dynamic material model and plotted with the temperature and logarithm of strain rate to obtain processing maps for strains of 0.2,0.4,and 0.6.The processing maps present the instability zones at higher strain rates.The result shows that with increasing strain,the instability zones enlarge.The microstructural examination shows that the interface separates even the particle cracks or aligns along the shear direction of the adiabatic shear band in the instability zones.Two domains of higher efficiencies correspond to dynamic recovery and dynamic recrystallization during the hot deformation.Using the processing maps,the optimum processing parameters of stain rates and temperatures can be chosen for effective hot deformation of TiB2/6351 composites.

Soil Aggregates, Organic Matter, and Labile C and N Fractions after 37 Years of N, P and K Applications to an Irrigated Subtropical Soil under Maize-Wheat Rotation

Abstract： Physical, chemical and biological soil properties in surface （0-5 cm） and subsurface soil （5-15 cm） were determined in a field experiment conducted with seven treatments consisted of different combinations of fertilizer N （0, 100 and 200 kg N ha^-1）, P （0, 22 and 44 kg P2O5 ha^-1） and K （0, 41 and 82 kg K2O ha^-1） applied both to summer-grown maize （Zea mays L.） and winter-grown wheat （Triticum aestivum L.） crops continuously for 37 years under irrigated subtropical conditions. Application of N, P and K significantly increased water stable aggregates and had profound effects in increasing the mean weight diameter as well as the formation of macro-aggregates, which were highest in both surface （81%） and subsurface （74%） soil layers with application of 100 kg N ＋ 22 kg P2O5 ＋ 41 kg K2O ha^-1 （N100P22K41）. The N100P22K41 treatment also enhanced total organic C （TOC） from 4.4 g kg^-1 in no-NPK control to 4.8 g kg^-1in surface layer and from 3.3 to 4.1 g kg1 in subsurface layer leading to the 20% higher TOC stocks in 0-15 cm soil. The labile C and N fractions such as water soluble C, particulate and light fraction organic matter, potentially mineralizable N and microbial biomass were also highest under the optimized balanced application of N100P22K41. Relatively higher increase in all labile fractions of C and N as proportion of TOC and total N, respectively suggested that these are potential indicators to reflect changes in management practices long before changes in TOC and TN are detectable. These results demonstrated that optimized balanced application of N, P and K is crucial for improving soil health ensuring long-term sustainability of farming systems in semiarid subtropical soils.

Effect of pore pressure on deformation and unstable snap-back for shear band and elastic rock system

Fast Lagrangian analysis of continua(FLAC) was used to study the influence of pore pressure on the mechanical behavior of rock specimen in plane strain direct shear, the distribution of yielded elements, the distribution of displacement and velocity across shear band as well as the snap-back (elastic rebound) instability. The effective stress law was used to represent the weakening of rock containing pore fluid under pressure. Numerical results show that rock specimen becomes soft (lower strength and hardening modulus) as pore pressure increases, leading to higher displacement skip across shear band. Higher pore pressure results in larger area of plastic zone, higher concentration of shear strain, more apparent precursor to snap-back (unstable failure) and slower snap-back. For higher pore pressure, the formation of shear band-elastic body system and the snap-back are earlier; the distance of snap-back decreases; the capacity of snap-back decreases, leading to lower elastic strain energy liberated beyond the instability and lower earthquake or rockburst magnitude. In the process of snap-back, the velocity skip across shear band is lower for rock specimen at higher pore pressure, showing the slower velocity of snap-back.

浦项与NSSC不锈钢继续减产以降低市场供给

因为世界经济不稳定带来的需求疲软，韩国浦项钢铁和日本最大的不锈钢厂新日铁住金不锈钢公司（NSSC）纷纷减产，以降低市场供给。

最脆弱的国家

卡内基国际和平基金会和美国《外交政策》杂志通过使用国家政治、经济和社会因素的12个衡量指标(每个指标10分),对世界上177个国家进行了稳定性分析。衡量指标包括社会指标(人口压力、难民和逃亡人数、种族仇杀、

Prediction of permafrost changes in Northeastern China under a changing climate

Northeastern China has the second largest expanse of permafrost in China,primarily known as Xing'an-Baikal permafrost.Located on the southeastern edges of the Eurasian cryolithozone,the permafrost is thermally unstable and ecologically sensitive to external changes.The combined impacts of climatic,environmental,and anthropogenic changes cause 3-dimensional degradation of the permafrost.To predict these changes on the southern limit and ground temperature of permafrost in Northeastern China,an equivalent latitude model (ELM) for the mean annual ground surface temperature (MAGSTs) was proposed,and further improved to take into account of the influences of vegetation and snow-cover based on observational data and using the SHAW model.Using the finite element method and assuming a climate warming rate of 0.048°C a-1,the ELM was combined with the unsteady-state heat conduction model to simulate permafrost temperatures at present,and to predict those after 50 and 100 a.The results indicate that at present,sporadic permafrost occurs in the zones with MAGSTs of 1.5°C or colder,and there would still be a significant presence of permafrost in the zones with the present MAGSTs of 0.5°C or colder after 50 a,and in those of-0.5°C or colder after 100 a.Furthermore,the total areal extent of permafrost would decrease from 2.57×105 km2 at present to 1.84×105 km2 after 50 a and to 1.29×105 km2 after 100 a,i.e.,a reduction of 28.4% and 49.8% in the permafrost area,respectively.Also the permafrost would degrade more substantially in the east than in the west.Regional warming and thinning of permafrost would also occur.The area of stable permafrost (mean annual ground temperature,or MAGT≤-1.0°C) would decrease from present 1.07×105 to 8.8×104 km2 after 50 a,and further decrease to 5.6×104 km2 after 100 a.As a result,the unstable permafrost and seasonally frozen ground would expand,and the southern limit of permafrost would shift significantly northwards.The changes in the permafrost environment may adversely affect on ecological environments and engineering infrastructures in cold regions.Avoidance of unnecessary anthropogenic changes in permafrost conditions is a practical approach to protect the permafrost environment.

The effects of asymmetric potential vorticity forcing on the instability of South Asia High and Indian summer monsoon onset

Based on the theory of potential vorticity(PV),the unstable development of the South Asia High(SAH)due to diabatic heating and its impacts on the Indian Summer Monsoon(ISM)onset are studied via a case diagnosis of 1998.The Indian Summer Monsoon onset in 1998 is related to the rapidly strengthening and northward moving of a tropical cyclone originally located in the south of Arabian Sea.It is demonstrated that the rapid enhancement of the cyclone is a consequence of a baroclinic development characterized by the phase-lock of high PV systems in the upper and lower troposphere.Both the intensification of the SAH and the development of the zonal asymmetric PV forcing are forced by the rapidly increasing latent heat released from the heavy rainfall in East Asia and South East Asia after the onsets of the Bay of Bengal(BOB)monsoon and the South China Sea(SCS)monsoon.High PV moves southwards along the intensified northerlies on the eastern side of the SAH and travels westwards on its south side,which can reach its northwest.Such a series of high PV eddies are transported to the west of the SAH continuously,which is the main source of PV anomalies in the upper troposphere over the Arabian Sea from late spring to early summer.A cyclonic curvature on the southwest of the SAH associated with increasing divergence,which forms a strong upper tropospheric pumping,is generated by the anomalous positive PV over the Arabian Sea on 355 K.The cyclone in the lower troposphere moves northwards from low latitudes of the Arabian Sea,and the upper-layer high PV extends downwards and southwards.Baroclinic development thus occurs and the tropical low-pressure system develops into an explosive vortex of the ISM,which leads to the onset of the ISM.In addition,evolution of subtropical anticyclone over the Arabian Peninsula is another important factor contributing to the onset of the ISM.Before the onset,the surface sensible heating on the Arabian Peninsula is very strong.Consequently the subtropical anticyclone which dominated the Arabian Sea in spring retreats westwards to the Arabian Peninsula and intensifies rapidly.The zonal asymmetric PV forcing develops gradually with high PV eddies moving southwards along northerlies on the eastern side of the anticyclone,and a high PV trough is formed in the middle troposphere over the Arabian Sea,which is favorable to the explosive barotropic development of the tropical cyclone into the vortex.Results from this study demonstrate that the ISM onset,which is different from the BOB and the SCS monsoon onset,is a special dynamical as well as thermodynamic process occurring under the condition of fully coupling of the upper,middle,and lower tropospheric circulations.