Boron cosmochemistry. Part I: Boron in meteorites

Abstract Thirty-six fragments of meteorite falls, never touched by water or other possible sources of B contamination, were analyzed for B by prompt gamma-ray neutron activation analysis at McMaster University and at the U.S. National Institute of Standards and Technology. Boron concentrations are close to the sensitivity limit in both laboratories. Results between the two laboratories agree well but with slight systematic differences attributable to blank and background correction factors. The mean B concentrations in different meteorites are similar, from 0.5 to 1.1 ppm. The ranges in different CC, OC and ACH classes overlap, mostly from 0.4 to 1.4 ppm, which is similar to previous measurements on falls. The H, L and LL meteorites overlap in B content with Antarctic chondrites. The solar system abundance, taken as the mean B content of the matrix in all CC, was calculated from seven samples and is 0.69 ± 0.09 ppm. When normalized, this abundance is 16.9 ± 2.2 (atoms/10⁶Si). Normalized B and S concentrations show a linear relationship in the CC; the average OC lies on the same line, but individual OCs are dispersed.     

塔里木盆地库车河及柯坪地质

库车河剖面是塔里木盆地中─新生界典型地质剖面，三叠系─第三系出露齐全，显示清楚，参观者可看到湿润气候环境下形成的三叠系─侏罗系陆相合煤─生油碎屑岩建造，有独具特征的煤层自燃形成的烧变岩，有30余米厚的油页岩；柯坪剖面是塔里木古生代克拉通边缘场陷盆地的典型代表，出露了完整的震旦系─二叠系海相沉积层序，深海─浅海─潮坪等沉积特征明显，沉积构造，古生物门类繁多，可见到代表半深海环境的寒武系底部的磷矿层、寒武系─奥陶系灰岩中的晶洞油苗、志留系中的沥青砂岩。     

The fragment of Paleo-Tethys ophiolite from central Qiangtang, Tibet:Geochemical evidence of meta-basites in Guoganjianian

N-MORB-type metabasites are discovered in the Guoganjianian area, central Qiangtang, Tibet, which are mainly metagabbro with cumulate structure and metabasalt. The rocks are distributed nearly from west to east unconformably underlying the Wanghuling Group of upper Triassic. On the basis of geo- chemical analysis, we find that the content of SiO2 is 43.03%―53.42%, and TiO2 1%―2.67%, Al2O3 16.75%―21.52%, CaO 7.03%―11.13%, K2O 0.05%―0.38%; the REE pattern is slight depletion or flat, and the trace spider diagram is like that of N-MORB, so we consider that the metabasite was formed under the setting of mid-ocean ridge or adult back-arc basin, and it is the fragment of Paleo-Tethys ophiolite.     

远震前的地电场潮汐波异常

分析了5次远强震前河北省昌黎台、兴济台记录到的电场异常,发现该异常主要集中在震前2个月左右的时段内, 具有很好的短临预报意义. 震前电场呈现不同的异常特征,但与固体地球潮汐波变化关系密切,如半日、半月等潮汐波周期信号增强,引起电场变化幅度增大;或本该正常记录到的潮汐变化幅度突然减小或消失;以及高频信号增多并伴有跃变现象. 分析异常产生机理认为,强震前的这种异常现象是震源区临震孕育过程中岩石弱化产生的电场异常,经自由空间或地壳传播到达地电台站后,与台站记录的电场潮汐波相叠加产生潮汐波增强或减弱现象. 高频异常可能与台站下方岩石孔隙度、渗透率等介质性质的改变有关,反映了强震的远场动态效应.      

对虾饵料水中稳定性测定方法的研究

对虾饵料水中稳定性,是衡量对虾饵料质量的一个非常重要的指标。本文通过对对虾饵料在海水中损失机理的探讨,提出了一个测定对虾饵料水中稳定性的新方法,并对方法中可能的影响因素进行了研究。经实际应用,本方法6次测定精密度（RSD）为1．24％。     

Comparison of the <Emphasis Type="Italic">in vitro</Emphasis> and <Emphasis Type="Italic">in vivo</Emphasis> toxic effects of three sizes of zinc oxide (ZnO) particles using flounder gill (FG) cells and zebrafish embryos

Nano-sized zinc oxide (nZnO) particles are one kind of the most commonly used metal oxide nanoparticles (NPs). This study compared the cytotoxic and embryotoxic effects of three increasing sized ZnO particles (? 30 nm, 80-150 nm and 2 μm) in the flounder gill (FG) cells and zebrafish embryos, and analyzed the contribution of size, agglomeration and released Zn²⁺ to the toxic effects. All the tested ZnO particles were found to be highly toxic to both FG cells and zebrafish embryos. They induced growth inhibition, LDH release, morphological changes and apoptosis in FG cells in a concentration-, size- and time-dependent manner. Moreover, the release of LDH from the exposed FG cells into the medium occurred before the observable morphological changes happened. The ultrasonication treatment and addition of serum favored the dispersion of ZnO particles and alleviated the agglomeration, thus significantly increased the corresponding cytotoxicity. The released Zn²⁺ ions from ZnO particles into the extracellular medium only partially contributed to the cytotoxicity. All the three sizes of ZnO particles tested induced developmental malformations, decrease of hatching rates and lethality in zebrafish embryos, but size- and concentration- dependent toxic effects were not so obvious as in FG cells possibly due to the easy aggregation of ZnO particles in freshwater. In conclusion, both FG cells and zebrafish embryos are sensitive bioassay systems for safety assessment of ZnO particles and the environmental release of ZnO particles should be closely monitored as far as the safety of aquatic organisms is concerned.     

Photoelectric photometry of eclipsing binary V375 cassiopeiae

Some 604 photoelectric BV observations of the eclipsing binary V375 Cas were obtained at Beijing Observatory from August to November 1982. Photometric solution was carried out using the Wilson-Devinney program for the BV light curves. The system is found to be a semidetached binary in which the less massive component fills its Roche lobe and the more massive component nearly does so. It is very similar to RZ Dra. This very interesting system is important for the understanding of the evolution of close binaries.     

Variation of pH in atmospheric precipitation in cities of Jilin province

Acidrainhasbeenaglobalenvironmentalprob-lem.SouthChinaandthesouthwestpartarethetwomainacidrainareasinChinawiththerangeof'pHvariationfrom4.5to4.O,andseientificstudiesonacidrainfocusontheseareas(WANGetal.,l997).Inre-centyears,however,inthenorthpartofChinaacidrainoccurred'notunusuallyandevenmoreseriouslysuchasincitiesofTumenandHunchuninJilinProvince.Itisessentialtodelveintothetemporalandspatialvariationsofatmosphericprecipitationacidityandthevariationscausesintheseareastoprovidesci-entificba…     

食双星船底ST(ST Car)和印第安RY(RY Ind)的光变曲线Roche模型分析

本文采用Wilson-Devinney的Roche模型,对两颗短周期食双星ST Car和RY Ind的光变曲线,进行了再分析。结果表明ST Car的测光质比q=0.60,RY Ind的q=0.50,两颗均属分离的不接双星,但它们的小质量次子星几乎充满Roche临界面。两星的测光特性说明,它们可能是Algol演化阶段后的双星。     

Changes in Extreme Maximum Temperature Events and Population Exposure in China under Global Warming Scenarios of 1.5 and 2.0°C: Analysis Using the Regional Climate Model COSMO-CLM

We used daily maximum temperature data (1986–2100) from the COSMO-CLM (COnsortium for Small-scale MOdeling in CLimate Mode) regional climate model and the population statistics for China in 2010 to determine the frequency, intensity, coverage, and population exposure of extreme maximum temperature events (EMTEs) with the intensity–area–duration method. Between 1986 and 2005 (reference period), the frequency, intensity, and coverage of EMTEs are 1330–1680 times yr^–1, 31.4–33.3°C, and 1.76–3.88 million km², respectively. The center of the most severe EMTEs is located in central China and 179.5–392.8 million people are exposed to EMTEs annually. Relative to 1986–2005, the frequency, intensity, and coverage of EMTEs increase by 1.13–6.84, 0.32–1.50, and 15.98%–30.68%, respectively, under 1.5°C warming; under 2.0°C warming, the increases are 1.73–12.48, 0.64–2.76, and 31.96%–50.00%, respectively. It is possible that both the intensity and coverage of future EMTEs could exceed the most severe EMTEs currently observed. Two new centers of EMTEs are projected to develop under 1.5°C warming, one in North China and the other in Southwest China. Under 2.0°C warming, a fourth EMTE center is projected to develop in Northwest China. Under 1.5 and 2.0°C warming, population exposure is projected to increase by 23.2%–39.2% and 26.6%–48%, respectively. From a regional perspective, population exposure is expected to increase most rapidly in Southwest China. A greater proportion of the population in North, Northeast, and Northwest China will be exposed to EMTEs under 2.0°C warming. The results show that a warming world will lead to increases in the intensity, frequency, and coverage of EMTEs. Warming of 2.0°C will lead to both more severe EMTEs and the exposure of more people to EMTEs. Given the probability of the increased occurrence of more severe EMTEs than in the past, it is vitally important to China that the global temperature increase is limited within 1.5°C.