Sub-arcsec 10 μm imaging of β pictoris and other star disk candidates

We have used the ESO 10 m camera, TIMMI, to image with a very high angular resolution (PFoV: 0.3; FWHM:0.9) several main-sequence star disk candidates. Information on the -Pictoris dust disk has been obtained in a region largely inaccessible to previous observations: 0–80 AU, with a resolution of about 5 AU after deconvolution. Another promising target for 10 m imaging, 51 Ophiuchi, appears point-like.based on data collected at the European Southern Observatory (ESO), La Silla, Chile     

Channel overflows of the Pōhue Bay flow,Mauna Loa,Hawai'i: examples of the contrast between surface and interior lava

A number of overflows from a large lava channel and tube system on the southwest rift zone of Mauna Loa were studied. Initial overflows were very low viscosity gas-rich phoehoe evidenced by flow-unit aspect ratios and vesicle sizes and contents. Calculated volumetric flow-rates in the channel range between 80 and 890 m³/s, and those of the overflows between 35 and 110 m³/s. After traveling tens to hundreds of meters the tops of these sheet-like overflows were disrupted into a surface composed of clinker and phoehoe fragments. After these 'a' overflows came to rest, lava from the interiors was able to break out on to the surface as phoehoe. The surface structure of a lava flow records the interaction between the differential shear rate (usually correlated with the volumetric flow-rate) and viscosity-induced resistance to flow. However, the interior of a flow, being better insulated, may react differently or record a later set of emplacement conditions. Clefts of toothpaste lava occurring within fields of clinker on proximal-type 'a' flows also record different shear rates during different times of flow emplacement. The interplay between viscosity and shear rate determines the final morphological lava type, and although no specific portion of lava ever makes a transition from 'a' back to phoehoe, parts of a flow can appear to do so.     

依靠科技进步加快经济发展

河南省煤田地质局经济的持续快速发展,得益于不断推进科技进步。表现为着力巩固发展地勘优势,使核心技术得到不断升级和创新,形成强势竞争力。科技进步的核心问题是人。尊重人才的关键是改革用人机制,用事业留人,用待遇留人,用感情留人。     

壳聚糖酶基因在解脂耶氏酵母中的表达及重组酶性质研究

为构建高效表达壳聚糖酶工程菌株,以Microbacteriumsp.基因组为模板扩增壳聚糖酶基因,目的基因与表达载体pINA1317连接构建重组质粒,重组质粒NotⅠ酶切线性化后转化解脂耶氏酵母Y.liPolytica Po1h。所得结果为PCR扩增得到约1000bp的特异性片段,序列分析表明含有壳聚糖酶全长基因,开放阅读框801bp,编码266个氨基酸残基。转化子酶活力为10.4U/mL,是原菌株酶活力的3.15倍。重组蛋白经DEAE-Sepharose FF分离纯化,达到电泳纯,SDS-PAGE显示单一条带,分子量约41kDa。重组酶反应最适温度为45℃,最适pH为5.6,Km和Vmax分别是0.926mg/mL和6.15U/mL。质谱分析酶解产物主要为三糖和五糖。实现了壳聚糖酶在解脂耶氏酵母中的分泌表达,为壳聚糖酶的工业化生产奠定了理论基础。     

小区域地震预测的新方法

本文应用动态系统时间连续模型建立的新方法（ＤＭ（ｎ，ｈ）模型），通过对唐山老震区ＭＬ＞４．７级地震的建模，讨论ＤＭ（ｎ，ｈ）模型对唐山老震区晚期强余震预测的可行性。并比较了ＤＭ（ｎ，ｈ）模型与ＧＭ（ｎ，ｈ）模型，发现ＤＭ（ｎ，ｈ）模型优于ＧＭ（ｎ，ｈ）模型，同时，给出了唐山老震区晚期强余震的预报结果。     

When are relative variograms useful in geostatistics?

The relative variogram has been employed as a tool for correcting a simple kind of nonstationarity, namely that in which local variance is proportional to local mean squared. In the past, this has been linked in a vague way to the lognormal distribution, although if {Z_t; t D}is strongly stationary and normal over a domain D,then clearly {exp (Z_t); t D}will stillbe stationary, but lognormal. The appropriate link is made in this article through a universal transformation principle. More general situations are considered, leading to the use of a scaled variogram.     

Gas and Particulate Products Distribution from the Photooxidation of α-Humulene in the Presence of NOx, Natural Atmospheric Air and Sunlight

The photooxidation of -humulene in the presence of NO_x, natural sunlight, and rural background air was investigated using a combination of gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC). Identification and quantification of gas and particulate reaction products were reported over the course of the reaction. The daytime photooxidation was carried out in a large outdoor smog chamber (190 m³). A wide range of ring retaining and ring opening products in the gas and particle phase are reported. On average, measured gas and particle phase products accounted for 44% of the reacted -humulene carbon. Measurements show that a number of reaction products with low vapor pressures (e.g. 3-seco--humulone aldehyde, 7-seco--humulone aldehyde, -humulal aldehyde, -humulene 3-oxide or -humulene 7-oxide, -humulaic/alic acid isomers, and 3-seco--14-hydroxyhumulone aldehyde) were found in the early stage of the reaction and may play an important role in the early formation of secondary organic aerosol. A detailed mechanism is proposed to account for most products observed in this investigation.     

Scale invariant theory for Bianchi Type VIII and IX space-times with perfect fluid

In this paper we have taken an attempt to study the feasibility of scale invariant theory (Wesson, 1981a,b) in Bianchi type VIII and IX space-times with a time dependent gauge function (Dirac Gauge i.e. βα )and a matter field in the form of a perfect fluid. It is found that Bianchi type VIII (δ=1) space-time is feasible in this theory whereas Bianchi type IX (δ=-1) space-time is not feasible. In this feasible case a radiating model is constructed and its physical behaviour is discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Giant Vibrations in Dip

This work reports the discovery of solar-type oscillations in thegiant star Hydrae.     

Accelerator mass spectrometry radiocarbon dating of 1994 Lake Winnipeg cores

Conventional radiocarbon dating of Lake Winnipeg core samples has produced erroneously old ages due to the incorporation of pre-Quaternary carbon derived from carbonaceous rocks, soils and sediments in the watershed, as well as a hard-water effect resulting from leaching of calcareous rocks and soils. To circumvent these problems and develop a reliable chronology for the Lake Winnipeg core series, a total of 64 samples from the Lake Winnipeg core series were processed to isolate well preserved macrofossils suitable for Accelerator Mass Spectrometry (AMS) radiocarbon dating. Here we report six radiocarbon ages derived from plant macrofossils and ostracodes, and reconstruct aspects of the depositional environment of each sample based on the associated macrofossil assemblage.