利用FOCMEC方法计算震源机制解的影响因素分析——以九江—瑞昌Ms5.7地震为例

应用Snoke最新发展的利用P波、SV波和SH波的初动和振幅比联合计算震源机制解的方法(FOCMEC),以2005年11月26日九江—瑞昌MS5.7地震为例,分析速度结构模型、震源定位误差、初动与振幅比资料和台站分布等对计算震源机制解的影响.结果表明,FOCMEC方法应采用研究区内的精细速度结构模型,各层速度误差在5％...     

Effect of foundation flexibility on ductility reduction factors for R/C stack-like structures

The most important parameter used to determine force reduction factors in force-based design procedures adopted in the current seismic codes is the structural ductility. For a structure supported on a flexible foundation, the ductility factor could be affected by foundation compliances. The ductility factors given in the current codes are mostly assigned ignoring the effect of SSI and therefore the objective of this research is to assess the signifi cance of SSI phenomenon on ductility factors of stack-like structures. The deformed confi guration of stack-like structures is idealized as an assemblage of beam elements considering nonlinear moment-curvature relations, while a linear sway-rocking model was implemented to model the supporting soil. Using a set of artifi cial records, repeated linear and nonlinear analyses were performed by gradually increasing the intensity of acceleration to a level where the fi rst yielding of steel in linear and nonlinear analyses is observed and a level corresponding to the stack collapse in the nonlinear analysis. The difference between inelastic and elastic resistance in terms of displacement ductility factors has been quantifi ed. The results indicate that foundation flexibility can decrease the ductility of the system and neglecting this phenomenon may lead to erroneous conclusions in the prediction of the seismic performance of flexibly-supported R/C stack-like structures.     

A Comparative Study of Ozonation,Homogeneous Catalytic Ozonation,and Photocatalytic Ozonation for C.I. Reactive Red 194 Azo Dye Degradation

In this study, the decolorization, dearomatization, and mineralization efficiencies of different advanced oxidation processes (AOPs; namely O₃, O₃/Fe(II), O₃/Fe(II)/UVA, and O₃/TiO₂/UVA) were investigated for the azo dye C.I. Reactive Red 194 (RR194). The effects of pH (3–11), amount of TiO₂ (0.05–1 g/L), and concentration of Fe(II) (0.1–1.6 mM) were investigated for the applied methods. The decolorization and mineralization efficiencies of the photocatalytic ozonation system (O₃/TiO₂/UVA) were increased by decreasing the pH of the dye solution in contrast to the ozonation system (O₃). Decolorization of RR194 was increased in the photocatalytic ozonation system with an increasing amount of catalyst however, a decreasing was occurred for the homogeneous catalytic system (O₃/Fe(II)) when increasing the concentration of catalyst. The decolorization efficiency of the homogeneous catalytic system (O₃/Fe(II)) was enhanced when combined with UVA light. In our study, the most efficient method for dearomatization and mineralization was the O₃/TiO₂/UVA among the applied AOPs.     

Sorption of ortho‐Phenylphenol to Soils

Conflicting sorption coefficients for ortho‐phenylphenol (OPP) have been reported in the literatures, which resulted in the conflicting assessments on OPP mobility in soil. To ascertain the sorption coefficient of OPP, batch experiments were performed based on OECD guideline 106, using three types of soils. Headspace solid‐phase microextraction (HS‐SPME) and GC‐MS were applied to the determination of OPP concentration in the liquid phase. The sorption isotherms obtained for all three soils under equilibrium conditions were described well, assuming linear sorption. The organic carbon normalized distribution coefficients (K_oc) ranged from 894 to 1703 L kg^?1, which suggested that OPP is moderately mobile in soil. The results also showed that the K_oc value of OPP can be predicted precisely from K_ow, whereas it was underestimated by one order of magnitude when water solubility is used.     

New Larvicidal Acetogenin from the Red Alga Laurencia papillosa

A new C₁₅ acetogenin, cyclic enyne (12E)‐cis‐maneonene‐E ( 1 ) and (12Z)‐trans‐maneonene‐B ( 2 ), together with different secondary metabolites including sesquiterpenoid 2,10‐dibromo‐3‐chloro‐α‐chamigrene ( 3 ) and fatty acid aldehydes ( 4–8 ) were isolated from the petroleum ether extract of a red alga, identified as Laurencia papillosa, collected from the Saudi Red Sea coast. The L. papillosa crude extract and its active ingredient acetogenin ( 1 ) have been evaluated for the ability to control two main economically important pests, the confused flour beetle larvae Tribolium confusum and Culex pipiens mosquito larvae. Compound 1 showed high potential as a natural insecticide against these two pests. In the case of T. confusum larvae, the LD₅₀ values were 0.21 and 0.16% after 6 and 12 days of treatment with crude extract and acetogenin, respectively. On the other hand, the resulting LC₅₀ values of mosquito larvae bioassay were 30.7, 36.9, and 41.8 ppm after 24 h treatment against 2nd, 3rd, and 4th larval instars, respectively. Also, an increase of the insecticidal effects against mosquito larvae was recorded after extending treatment time to 48 h.     

川东地区石炭系碳酸盐岩碳、氧、锶同位素特征及其成因分析

利用微量元素和碳、氧同位素特征对样品有效性作出了检验.在证明样品未受明显蚀变的前提下对川东地区石炭系碳酸盐岩碳、氧、锶同位素进行了分析.在层序地层格架中对比不同体系域、不同岩性的碳、氧同位素特征,87Sr/86Sr比值特征,Z值与古温度特征,分析了碳酸盐岩的成岩环境.低位体系域以膏盐湖及萨巴哈环境为主,炎热干旱,陆源淡...     

浅析GPS在龙岩市高等级控制网建设中的应用

通过龙岩市框架网和C级GPS控制网的建立,探讨在山地、丘陵和高差相对较大地区,解决区域似大地水准面精化,以及分析了龙岩市现代测绘基准体系的精度情况.     

Platinum‐Group Element Results for Two Cobalt‐Rich Seamount Crust Ultra‐Fine Reference Materials: MCPt‐1and MCPt‐2

Two Co‐rich seamount crust reference materials, MCPt‐1 and MCPt‐2, were prepared using ultra‐fine particle size milling technique and characterised for the platinum‐group elements (PGEs). The raw material for these two reference materials was collected separately from the Magellan seamounts of the western Pacific Ocean and the seamounts of the central Pacific Ocean by Russian and Chinese scientists. First, they were ground by ball mill to a ?200 mesh powder, then further processed by ultra‐fine jet mill and well‐mixed. The particle size distributions of the samples were tested by a laser particle analyser; the average particle size was 1.8 and 1.5 μm (equal to about 2000 mesh) respectively. The homogeneity of six major and minor elements in these two materials was tested at the milligram level of sampling mass by high‐precision wavelength dispersive X‐ray fluorescence (XRF) spectrometry and at the microgram level of sampling mass by electron probe microanalyser. The homogeneity of more than forty trace elements, including Pt, was tested at the microgram level of sampling mass by LA‐ICP‐MS. Except for Rh, all PGEs were determined by isotope dilution‐ICP‐MS. Platinum in MCPt‐1 and MCPt‐2 was characterised as certified values, whereas the other five PGEs in MCPt‐1 and MCPt‐2 were reported as reference values. In addition, the information values of sixty‐two major, minor and trace elements were obtained by XRF, ICP‐AES and ICP‐MS. The minimum sampling mass for the determination of PGEs was 1 g, while the minimum sampling mass for the determination of the other elements was 2–5 mg.     

An Isotope Dilution ICP‐MS Method for the Determination of Mg/Ca and Sr/Ca Ratios in Calcium Carbonate

Mg/Ca and Sr/Ca ratios in calcium carbonate are important components of many palaeoclimate studies. We present an isotope dilution method relying on a single mixed spike containing ²⁵Mg, ⁴³Ca and ⁸⁷Sr. Dozens of samples per day, as small as 10 μg of carbonate, could be dissolved, spiked and run in an ICP‐MS with a precision of 0.8% (2 RSD). Two instruments types, a sector field and a quadrupole ICP‐MS, were compared. The best long term precision found was 0.4% (2 RSD), although this increased by up to a factor of two when samples of very different Mg or Sr content were run together in the same sequence. Long term averages for the two instruments concurred. No matrix effects were detected for a range of Ca concentrations between 0.2 and 2 mmol l^‐1. Accuracy, tested by measuring synthetic standard solutions, was 0.8% with some systematic trends. We demonstrate the strength of this isotope dilution method for (a) obtaining accurate results for sample sets that present a broad Mg and Sr range and (b) testing solid carbonates as candidate reference materials for interlaboratory consistency. Mg/Ca and Sr/Ca results for reference materials were in good agreement with values from the literature.     

Multi‐Element Determination of Trace Elements in Natural Water Reference Materials by ICP‐SFMS after Tm Addition and Iron Co‐precipitation

We report on an improved method for determining trace element abundances in seawater and other natural waters. The analytical procedure involves co‐precipitation on iron hydroxides after addition of a Tm spike, and measurement by inductively coupled plasma‐sector field mass spectrometry (ICP‐SFMS). The validity of the method was assessed through a series of co‐precipitation experiments, using ultra‐diluted solutions of a certified rock reference material (BIR‐1). Results obtained for four natural water reference materials (NASS‐5, CASS‐4, SLEW‐3, SLRS‐4) are in agreement with published working values for rare earth elements, yttrium, vanadium and, when available, for hafnium, zirconium, thorium and scandium. A set of proposed values with uncertainties typically better than 8% RSD is proposed for Hf, Zr and Th.