白斑综合症病毒(WSSV)的宿主调查

用地高辛 (DIG)标记的WSSVDNA探针斑点杂交与原位杂交技术 ,在中国对虾、斑节对虾、南美白对虾、刀额新对虾、脊尾白虾、天津厚蟹、日本大眼蟹体内检测到了WSSV ,它们是WSSV的天然宿主 ;在经人工感染的哈氏美人虾、短脊鼓虾、克氏原螯虾、肉球近方蟹、滕壶体内检测到了WSSV ;在球形侧腕水母、病虾池的桡足类等浮游生物、卤虫无节幼体以及人工浸泡感染卤虫成体体内没有检测到WSSV。经原位杂交检测 ,虾类的甲壳下上皮、胃上皮、附肢、造血组织、鳃等组织器官均可被WSSV侵染 ,其中甲壳下上皮和鳃对WSSV敏感 ;蟹类的甲壳下上皮和鳃对WSSV敏感 ;在中国对虾、南美白对虾、脊尾白虾、注射感染的克氏原螯虾的精巢中 ,精荚的结缔组织细胞和血细胞呈阳性 ,在中国对虾、脊尾白虾以及注射感染的短脊鼓虾的卵巢中 ,结缔组织细胞和滤泡细胞被WSSV感染。     

Laser probe Ar/Ar dating: History and development from a technical perspective

The ⁴⁰Ar/³⁹Ar method using a laser probe opened the door to microscale measurements and diffusion profiles frozen in samples. In the first decade since the initial application of a laser for ⁴⁰Ar/³⁹Ar dating in 1973, practical applications have been few. This is due not only to the fact that the laser and vacuum technologies were immature but that mass spectrometry was also in its infancy. In those days, the sensitivity of a mass spectrometer was generally insufficient to measure the small amount of argon degassed from a geological sample by a laser. These problems have subsequently been solved by new technologies. To understand their current status, a brief history of their development is outlined. This outline focuses on the required detection limit in micro scale measurement, practical approaches for accurate measurement are explained through examples in our laboratory specifically relating to the technical aspects of ⁴⁰Ar/³⁹Ar dating.     

国库集中收付与深化地质勘查单位改革若干问题的探讨

从国库集中收付改革的内容、要求,地质勘查单位的现状出发,探讨了国库集中收付改革与深化地质勘查单位改革之间存在的问题,指出国库集中收付制度虽然能够使事业单位的财政收支得到有效监管,但因地质勘查单位具有事业与企业的双重职能,现行的国库集中收付制度不利于地勘单位的深化改革。为有效解决这一矛盾．提出了在国库单一账户体系外,建立地质勘查单位改革性基本账户的建议。     

The timing of ultrahigh-temperature metamorphism in Southern India: U–Th–Pb electron microprobe ages from zircon and monazite in sapphirine-bearing granulites

We report here U–Pb electron microprobe ages from zircon and monazite associated with corundum- and sapphirine-bearing granulite facies rocks of Lachmanapatti, Sengal, Sakkarakkottai and Mettanganam in the Palghat–Cauvery shear zone system and Ganguvarpatti in the northern Madurai Block of southern India. Mineral assemblages and petrologic characteristics of granulite facies assemblages in all these localities indicate extreme crustal metamorphism under ultrahigh-temperature (UHT) conditions. Zircon cores from Lachmanapatti range from 3200 to 2300 Ma with a peak at 2420 Ma, while those from Mettanganam show 2300 Ma peak. Younger zircons with peak ages of 2100 and 830 Ma are displayed by the UHT granulites of Sengal and Ganguvarpatti, although detrital grains with 2000 Ma ages are also present. The Late Archaean-aged cores are mantled by variable rims of Palaeo- to Mesoproterozoic ages in most cases. Zircon cores from Ganguvarpatti range from 2279 to 749 Ma and are interpreted to reflect multiple age sources. The oldest cores are surrounded by Palaeoproterozoic and Mesoproterozoic rims, and finally mantled by Neoproterozoic overgrowths. In contrast, monazites from these localities define peak ages of between 550 and 520 Ma, with an exception of a peak at 590 Ma for the Lachmanapatti rocks. The outermost rims of monazite grains show spot ages in the range of 510–450 Ma.While the zircon populations in these rocks suggest multiple sources of Archaean and Palaeoproterozoic age, the monazite data are interpreted to date the timing of ultrahigh-temperature metamorphism in southern India as latest Neoproterozoic to Cambrian in both the Palghat–Cauvery shear zone system and the northern Madurai Block. The data illustrate the extent of Neoproterozoic/Cambrian metamorphism as India joined the Gondwana amalgam at the dawn of the Cambrian.     

对江西农经网如何更好地提供信息服务的探讨

分析了江西农村经济信息网(www.jxagriec.gov.cn)的现状,指出农经网信息服务正面临着挑战,并在此基础上阐述了农经网信息服务的发展思路。     

Gelifluction within a solifluction lobe in the Kärkevagge valley, Swedish Lapland

Soil displacement, soil temperature, depths of thaw plane and groundwater level were continuously monitored during the period from July 1999 to June 2000 within a solifluction lobe in the Kärkevagge valley, northern Sweden. The strain–probe method was used to measure soil displacement, and we found significant soil displacements in the thawing period 2000. These displacements were the result of gelifluction. The ice content profile showed that gelifluction occurred at the same time as the thaw plane reached the layers with high ice content at shallow soil depths (0–6 and 16–25 cm deep). In contrast, gelifluction did not occur when the thaw plane reached the layers with high ice content at greater depth (46–49 cm deep). These observations indicate that thawing of ice lenses in the near–surface layer triggers gelifluction.     

Detailed geomorphological survey of a small mountain drainage area, Abisko, northern Swedish Lapland

A thorough geomorphological survey of a small (2km²) drainage area has been conducted using digital magnification of aerial photographs in conjunction with field visits. The result presented is a geomorphological map where individual geomorphological features down to metre size can be identified. The study was done in connection with a project focusing on the relationship between geomorphological processes and lacustrine sedimentation. Good knowledge of the geomorphological setting and the related process activity in the catchment is important in studies using lacustrine sediments as environmental archives.
The survey reveals a small–scale geomorphology dominated by a number of different periglacial upfreezing forms together with bedrock–controlled slope processes. Three different geographically separated geomorphological assemblages were recognised with few sediment transportation pathways connecting them. Composition of substrate, soil water content and vegetation cover combined with different slope angles are probably the most important factors controlling the distribution of the geomorphological features.     

探测冰盖和多年冻土层的融冰探头研发

The exploration of ice sheets by melting vertical holes into the ground has some tradition in terrestrial glaciology. Such probes have been used since the 1960's to investigate the vertical structure of the ice in Greenland and Antarctica and in alpine glaciers. In this paper we look into the possibility to develop similar devices for use on extraterrestrial icy bodies, like e.g. the polar areas on Mars or the icy satellites of the outer solar system. We report on some basic experiments performed in the cryo-vacuum laboratory of the Space Research Institute of the Austrian Academy of Sciences, Graz. In these experiments the penetration of a simple melting probe into compact and porous water ice (with a snow-like texture) was monitored, both under vacuum conditions and under air pressure. The observed penetration speeds for a given power supply are compared with a simple mathematical model. We conclude that a miniature melting probe with small overall dimensions and a reasonable power demand could well be part of the payload of a future planetary mission, for example to the poles of Mars. Such missions are currently under discussion in several space agencies. Moreover such probes could also e? ectively be used in terrestrial environments. A possible design is presented at the end of the paper.     

Slow mass movement in the Kangchenjunga area, eastern Nepal Himalaya

Abstract   The rates of the accumulated and continuous displacement of solifluction lobes in the Kangchenjunga area, eastern Nepal Himalaya, were determined using glass fiber tubes and a strain probe. Ground temperature, precipitation and soil moisture were monitored at two sites, whose altitude differed by approximately 100 m, to understand the solifluction process. The average movement rate of the glass fiber tubes on a 31° slope at altitudes of 5412–5414 m a.s.l. was approximately 11 mm/year, being almost threefold greater than that observed on a 22° slope at 5322–5325 ma.s.l. There was no significant difference in the depth of displacement at these sites. The continuous displacement measurement near the ground surface at 5414 m showed permanent downslope movement from early July. Such movement may be attributed to additional moisture supply during the monsoon season. The amplitude of the displacement cycle was highest at the ground surface, and decreased to virtually zero at and below 20 cm in depth. Probable factors leading to the relatively slow rates of downslope displacement at the surface and depth at the studied altitudes are the lack of concurrence of the freeze–thaw cycles and the high moisture condition in the soil, and the low moisture retention capacity of the soil because of steep slopes and superficial desiccation. The rate of displacement may be more pronounced at altitudes above 5600 m because of the freeze–thaw cycles during the summer season.     

Defining the Potential of Nanoscale Re‐Os Isotope Systematics Using Atom Probe Microscopy

Atom probe microscopy (APM) is a relatively new in situ tool for measuring isotope fractions from nanoscale volumes (< 0.01 μm³). We calculate the theoretical detectable difference of an isotope ratio measurement result from APM using counting statistics of a hypothetical data set to be ± 4δ or 0.4% (2s). However, challenges associated with APM measurements (e.g., peak ranging, hydride formation and isobaric interferences), result in larger uncertainties if not properly accounted for. We evaluate these factors for Re‐Os isotope ratio measurements by comparing APM and negative thermal ionisation mass spectrometry (N‐TIMS) measurement results of pure Os, pure Re, and two synthetic Re‐Os‐bearing alloys from Schwander et al. (2015, Meteoritics and Planetary Science, 50, 893) [the original metal alloy (HSE) and alloys produced by heating HSE within silicate liquid (SYN)]. From this, we propose a current best practice for APM Re‐Os isotope ratio measurements. Using this refined approach, mean APM and N‐TIMS ¹⁸⁷Os/¹⁸⁹Os measurement results agree within 0.05% and 2s (pure Os), 0.6–2% and 2s (SYN) and 5–10% (HSE). The good agreement of N‐TIMS and APM ¹⁸⁷Os/¹⁸⁹Os measurements confirms that APM can extract robust isotope ratios. Therefore, this approach permits nanoscale isotope measurements of Os‐bearing alloys using the Re‐Os geochronometer that could not be measured by conventional measurement principles.