The stellar composition of the star formation region CMa R1 – I. Results from new photometric and spectroscopic classifications

A new photometric and spectroscopic survey of the star formation region (SFR) CMa R1 is described. In a sample of 165 stars brighter than 13th mag, 88 stars were found to be probable members of the SFR. They are defined as early-type stars with E ( B − V )0.16 mag, which corresponds to a distance of about 1 kpc. 74 of the probable members are B stars. 19 stars are possibly associated with an IRAS point source. We derive a most probable distance of 1050±150 pc to the association. It appears that about 80 candidate members are pre-main-sequence stars with ages lower than 6 million years, while the main sequence extends over 6.0–7.6 mag, which is consistent with star formation starting about 8 million years ago and continuing until at least half a million years ago. Two bright B stars in the association (GU CMa and FZ CMa) seem to be much older and probably do not originate from the same star formation episode. The star formation efficiency appears to increase roughly monotonically with time up to half a million years ago. From our data, we conclude that only a minor fraction of the stars has been created through the scenario suggested by Herbst & Assousa, in which the members of CMa R1 form by compression of ambient material by a supernova shock wave. An extensive search for candidate members with H α emission did not reveal new Herbig Ae/Be candidates, so that the number of stars in this class seems to be limited to four: Z CMa, LkH α 218, LkH α 220 and possibly HD 53367.     

东亚季风边缘区气候代用指标的分形比较及其意义

利用R/S分析东亚季风边缘区祁连山教德冰心、树木车轮、黄土磁化率、CaCO3含量曲线,得到其分维值分别为1．29、1．30、1．19和1．15,证实近百万年来东亚率风演变的特征是长期持续的,即季风边缘区具有干净化趋势,且旱化趋势的成分更为明显。其中,冰心δ18O比率、年轮指数的分维数与乌鞘岭年平均温度记录的分维值1．25接近,黄土磁化率和CaCO3含量的分维数与年降水量记录的分维值1．19一致。虽然这些气候指标是用不同物理单位测量并在不同时间尺度记录的,但分形分析可对它们进行数学比较,从而揭示出不同信息源所包含的气候意义。     

反复荷载作用下锈蚀钢筋混凝土压弯构件恢复力性能的试验研究

采用外加电流对混凝土压弯构件中的钢筋进行了快速锈蚀试验,通过钢筋锈蚀混土压弯构件在水平反复荷载作用下的试验研究,探讨了钢筋锈蚀程度对混凝土压弯构件的承载力,刚度,延性,耗能能力等的影响,给出了锈蚀构件的滞回曲线和骨架曲线。     

模糊集合理论在化学中的应用Ⅳ——百里酚酞-茜素黄R混合指示剂的研究

本文应用模糊集合理论和计算机研究百里酚酞-茜素黄R混合指示剂的变色现象。发现其变色存在滞后现象。讨论了产生滯后现象的原因。     

Research on heavy metals in Ruditapes philippinarum and soda industry wastes

Heavy metals pollution in Jiaozhou Bay was studied in Ruditapes. philippinarum, a bioindicator of seawater pollution. Heavy metals in soda industry wastes “white mud” were also studied. Comparison of microwave digestion method with general digestion method revealed that microwave digestion is superior to general digestion in precision, recovery, digestion speed and efficiency, etc. Cd concentration in Hongdao R.philippinarum samples exceeded the national standard by 0.046 mg/kg, that of Yinghai sample by 0.02 mg/kg,and that of Hongshiya sample by 0.22 mg/kg. Sample Pb concentration in Hongshiya was found to exceed the national standard by 0.02 mg/kg. However the heavy metals concentration in R. philippinarum near the Qingdao Alkaline Factory was complied with the standard. This was proved by Penaeus chinensis culture experiment.Therefore, the possible contamination source may come from other land areas.     

Distribution of crinoidal remains in the Upper Cretaceous of the U.S.S.R.

A list of all Upper Cretaceous sea-lilies known from the U.S.S.R. is given. Their stratigraphic and geographic distributions are discussed. Three paleogeographic subprovinces, the south-eastern, the northern and the south-western, can be distinguished in the Mediterranean paleobiogeographic province of the U.S.S.R. based on the development and distribution of the Upper Cretaceous crinoids.     

采用耗能减震装置修复震后有损伤钢筋混凝土框架的试验研究

本文通过地震模拟振动台试验研究用耗能减震装置修复后震后有损伤钢筋混凝土框架的效果和可行性，文中制作了两层和三层两座钢筋混凝土剪切型框架，首先进行了地震损伤模拟试验，其次提出了震后有损伤结构的参数识别方法，修复准则和修复用耗能减震装置的设计准则；在此基础上，采用了软钢屈服型耗能器驿两座试验框架在地震损伤后进行修复，并再次对修复后的框架模型进行地震模拟试验，证实了采用这种修复措施可以恢复震后有损伤结构     

南黄海6.4级地震的短临前兆及其震源过程

研究了1996年11月9日南黄海6．4级地震前地震时空分布、应变能释放的异常变化,发现震前地震活动时空分布的异常变化清楚地反映出南黄海6．4级地震的震源过程一“三级跳跃”模式。即早期地震活动增强,形成大的孕震空区;中期在上述背景上地震活动再次向外围扩散并收缩,地震活动逐渐减弱,晚期在孕震空区内形成临震空区和临震小震条带。孕震空区缩小;晚期地震活动出现短期平静（4个月无≥2．0级地震）,显示临震“平静”异常,由R（t）图可以对64级地震的发震时间进行预测。