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181.
浙江地处中国东南沿海大陆边缘火山岩成矿带,已发现众多金(银)矿床(点),它们在空间上往往不是孤立地出现,而是在数十至数百平方公里内围绕岩浆热中心相对集中,并与有色金属在矿田范围内伴生。研究证明,金(银)及有色金属矿床是同一火山—侵入旋回过程中形成的有成因联系的矿床。笔者将这种在同一火山—侵入旋回间,围绕同一个岩浆热中心,在不同深度和水平距离内形成的一系列具有成因联系的金(银)和有色金属矿床的总和称为火山岩金矿成矿系统。本文在此概念基础上,详细论述了浙江中生代陆线火山岩金矿成矿系统的类型。时空结构和物质来源。 相似文献
182.
The Seasonal Variabilities in the Concentration of Atmospheric Aerosols over Qingdao, China 总被引:2,自引:0,他引:2
SHENG Lifang FU Ying QIU Mingyan GAO Huiwang 《中国海洋大学学报(英文版)》2005,4(4):383-390
Mass concentrations of Total Suspended Particles (TSP) and size-segregated particles were obtained from July 2001 to June 2002 in Qingdao to characterize the seasonal variations of atmospheric aerosols and to show the impact of dust events on the air quality in Qingdao. Data on size-segregated aerosols show that 73.74% of the TSP mass concentration is contributed by particles with diameters less than 11 μm. Particles with diameters less than 1.1μm have a higher concentration during the winter. In spring, larger particles tend to have higher mass concentrations. Bimodal particle size distributions have been observed, with maxima around 4.7-7 μand 0.43-0.65 μm in the winter season, and 7-11 μm and 0.65-1.1 μm in the autumn season. Measurements made during the dust events in March 2002 show high concentrations of particles in the size range 2.1-7μm. 相似文献
183.
184.
A number of high resolution and high signal-to-noise ratio spectra of mildly metal-poor stars were obtained with the coudé echelle spectrograph attached to the 2.16m telescope at Xinglong Observation Base of Beijing Astronomical Observatory. The spectra of seven mildly metal-poor stars were processed with the MIDAS software package, and the equivalent widths of their spectral lines were measured. The measured equivalent widths together with an error analysis are presented. 相似文献
185.
G. Pignata F. Patat S. Benetti S. Blinnikov W. Hillebrandt R. Kotak B. Leibundgut P. A. Mazzali P. Meikle Y. Qiu P. Ruiz-Lapuente S. J. Smartt E. Sorokina M. Stritzinger M. Stehle M. Turatto T. Marsh F. Martin-Luis N. McBride J. Mendez L. Morales-Rueda D. Narbutis R. Street 《Monthly notices of the Royal Astronomical Society》2004,355(1):178-190
186.
“Elementary bursts” refer to fine time structures on scales of tens of milli-second to a few seconds in flare radiations.
In this paper, we investigate temporal and spatial properties of elementary bursts by exploiting high-cadence Hα (100 ms)
and hard X-ray (125 – 500 ms) observations of an impulsive flare on March 16, 2000. We find that the time scale of 2 – 3 s
is likely an upper limit of the elementary bursts in this event, at which hard X-ray emissions observed by different instruments
correlate, low energy (≤30 keV) hard X-rays and Hα flux correlate, and Hα emissions at conjugate flare kernels correlate.
From our methods, and also largely limited by instrument resolutions, there is a weak indication of existence of sub-second
structures. With the high-resolution Hα data, we also attempt to explore the spatial structure of “elementary bursts” by determining
the average spatial displacement of Hα peak emission between successive “elementary bursts” defined from hard X-ray light
curves. We find that, at the time scale of 3 s, the smallest spatial scale, as limited by the imaging resolution, is about
0.4″. We discuss these results with respect to mechanisms of fragmented magnetic energy release. 相似文献
187.
Acute toxicities of potassium permanganate, formalin, and Lugol’s iodine solution to a commonly occurred marine ciliate Pleuronema coronatum (Ciliophora, Scuticociliatida) were measured. Linear regression analysis of the results highlighted the close relationships
between doses of the medicines and mortalities of the organisms, thus providing a capability to predict toxicity effects from
the dose. Toxic effects of the medicines on the ciliates were described in the present paper, and the median lethal concentrations
(LC50 values) were given. Results of measurements indicated that 2 h-LC50 and 12 h-LC50 values of formalin on P. coronatum were 59.00×10−6 and 43.57×10−6, while those of Lugol’s solutions were 90.13 and 67.84×10−6 respectively. The tolerance of P. coronatum to formalin is apparently lower than that to Lugol’s iodine solution and potassium permanganate is a suitable medicine to
kill ciliates in short time. 相似文献
188.
A linear regression analysis of 28 selected tide-gauge stations of the Zhujiang Estuary shows that there has been a tendency of local sea level rise at a rate of 2.028 mm per year. The origin of the variation is significantly attributed to the local tectonic movement of discrepant fault-block. Based on this, four types of relative local sea level changes are classified. According to calculation, half of the fertile land, or 800 km2 of the delta plain will have been submerged by sea water by about 2040. This will yield a significant influence on the economic construction and human activities. 相似文献
189.
In our paper we supposed that the Paleozoic ages of the Bixiling eclogitic garnets by 40Ar/39Ar crushing in vacuo were related to the UHP metamorphism. Zhao and Gao [Zhao Z.-F. and Gao T.-S. (2007) Comment on “Paleozoic ages and excess 40Ar in garnets from the Bixiling eclogite in Dabieshan, China:Newinsights from 40Ar/39Ar dating by stepwise crushing” by Qiu and Wijbrans (2006). Geochim. Cosmochim. Acta71(24), 6046-6050] dispute our conclusions and re-interpret them as “the age of garnet growth by low-T/HP blueschist/eclogite-facies metamorphism of the UHP eclogite precursor during arc-continent collision in the early Paleozoic” without presenting any new petrological evidence. Based on our present understanding of 40Ar/39Ar crushing technique and petrological observations, we do not agree with their re-interpretation and still prefer our original interpretation. 相似文献
190.
Hu Sheng Qiu Haijun Wang Ninglian Wang Xingang Ma Shuyue Yang Dongdong Wei Na Liu Zijing Shen Yongdong Cao Mingming Song Zhaopeng 《Landslides》2022,19(6):1265-1295
Landslides - According to local villagers, the main Beiguo landslide on the Heyang Loess Tableland in China occurred several decades ago (the specific time is unknown). After the initial occurrence... 相似文献