用三维荧光光谱-平行因子分析法研究长江口南部有色溶解有机物荧光的季节变化

The southern Changjiang River Estuary has attracted considerable attention from marine scientists because it is a highly biologically active area and is biogeochemically significant.Moreover,land-ocean interactions strongly impact the estuary,and harmful algal blooms(HABs) frequently occur in the area.In October 2010 and May 2011,water samples of chromophoric dissolved organic matter(CDOM) were collected from the southern Changjiang River Estuary.Parallel factor analysis(PARAFAC) was used to assess the samples' CDOM composition using excitation-emission matrix(EEM) spectroscopy.Four components were identified:three were humic-like(C1,C2 and C3) and one was protein-like(C4).Analysis based on spatial and seasonal distributions,as well as relationships with salinity,Chl a and apparent oxygen utilization(AOU),revealed that terrestrial inputs had the most significant effect on the three humic-like Components C1,C2 and C3 in autumn.In spring,microbial processes and phytoplankton blooms were also important factors that impacted the three components.The protein-like Component C4 had autochthonous and allochthonous origins and likely represented a biologically labile component.CDOM in the southern Changjiang River Estuary was mostly affected by terrestrial inputs.Microbial processes and phytoplankton blooms were also important sources of CDOM,especially in spring.The fluorescence intensities of the four components were significantly higher in spring than in autumn.On average,C1,C2,C3,C4 and the total fluorescence intensity(TFI) in the surface,middle and bottom layers increased by123%–242%,105%–195%,167%–665%,483%–567% and 184%–245% in spring than in autumn,respectively.This finding corresponded with a Chl a concentration that was 16–20 times higher in spring than in autumn and an AOU that was two to four times lower in spring than in autumn.The humification index(HIX) was lower in spring that in autumn,and the fluorescence index(FI) was higher in spring than in autumn.This result indicated that the CDOM was labile and the biological activity was intense in spring.     

孕镶金刚石复合材料用纳米级胎体粉末的脉冲电流烧结试验

为降低孕镶金刚石复合材料的烧结温度,采用脉冲电流烧结法,对纳米Cu粉末、纳米WC-12％Co粉末及常规的63^#配方胎体进行了烧结实验。结果表明,纳米Cu粉在700℃可实现致密化,纳米WC-12％Co粉末、63^#配方胎体可分别在1100℃、850℃实现致密化,均大大低于常规烧结方法的烧结温度,还起到保护金刚石、降低能耗、增加石墨模具寿命的作用。     

多层建筑抗震分析用的两个计算机程序

提供两个高效而实用的FORTRAN程序（例行子程序形式）,用于对称三对角矩阵的两个计算问题（其一是线性代数方程组的求解,其二是广义特征值问题的计算）。在工程应用中,它们可用于多层建筑的振动特性分析、反应谱法地震变形计算、Pushover静力推覆分析和时程法地震反应分析等问题中。     

Characterization of serpentinization in olivine-orthopyroxene-H2O system revealed by thermogravimetric and multivariate statistical analyses

Thermogravimetric (TG) analyses were used to characterize the products and quantify the extent of serpentinization as a stepwise weight loss during heating (TG loss) or its derivative (DTG). Multivariate analyses are powerful tools for extracting information from complicated spectrum data; however, no studies have applied them to characterize serpentinites. In this study, hydrothermal experiments of olivine-H₂O, olivine–orthopyroxene-H₂O and orthopyroxene-H₂O were conducted at 250–400°C and under vapor-saturated pressure. The product minerals observed were serpentine+brucite+magnetite in the olivine-H₂O experiments and serpentine±talc in the orthoyroxene-H₂O and olivine-orthopyroxene-H₂O experiments. These results are consistent with those of previous studies; however, the positions and width of DTG peaks for individual minerals were varied depending on the experimental conditions. To extract systematics from the TG spectra, non-negative matrix factorization (NMF), an unsupervised machine learning technique, was applied to the DTG spectra of the experimental products. NMF revealed that the DTG profiles were explained by a linear combination of six basis spectra, which corresponded to the characteristic products, including three types of serpentine minerals (low-, medium-, and high-T), two types of brucite (low-and high-T), two type of talc (talc+serpentine mixture, well-crystallized talc) with different crystallinity, and noise during the TG measurement. Systematic changes in the factor loading revealed that, in the olivine-H₂O systems, the products changed from medium-T serpentine+low-T brucite to high-T serpentine+high-T brucite as serpentinization progressed. In the olivine-orthopyroxene system, low-T serpentine or poorly crystallized talc+serpentine mixture was initially formed, followed by the formation of well-crystallized talc, resulting in dehydration. Applying NMF to DTG showed the mineralogical differences between olivine and orthopyroxene systems and increases of the crystallinity during the progress of serpentinization, suggesting its potential for characterizing various serpentinites within oceanic lithospheres that suffer from several stages of alteration and weathering at different temperatures.     

测量平差电算程序中矩阵求逆实现与优化

随着计算机件技术与数学科学的不断发展,虽然测量平差技术已经取得了很大的进步,但在技术实现方面还存在不少问题。目前,市场上推出的测量平差软件或平差大全,大都是在PC-1500机上用QBASIC语言进行平差处理,在使用时常会遇到无法满足现实测绘工作的要求,而且很难对其源程序进行改进。现充分利用矩阵行列式初等变换性质以及C语言中指针动态性优于函数递归调用的特性来实现并优化了测量平差电算程序中的关键技术——矩阵求逆。     

稀疏约束下的MVC-NMF算法研究

最小体积约束的非负矩阵分解算法(MVC-NMF)不需要假定纯像元的存在,并且在自动提取端元的同时,能够获取每种端元所对应的丰度图,然而该方法并没有考虑丰度矩阵的稀疏特性。提出了将稀疏约束引入MVC-NMF算法中,提高了算法的精度。实验结果表明:该方法在相同迭代次数条件下比MVC-NMF算法解混的精度更高。     

小波包变换空间滤波法分离信号研究

利用小波包分析在时域和频域同时具有良好的局部化特性,对信号进行小波包变换后,用谱矩阵法计算质点的空间运动特性,构造相应的滤波函数,对分解后的信号进行滤波,将滤波结果用逆小波包变换进行重构,实现了滤除干扰、保留有用信号的目的,取得了非常满意的效果。      

关于矩阵秩显示双边正交分解RRURVD的应用

矩阵分解是矩阵计算的重要工具。针对整体最小二乘、子集选择、子空间计算等实际问题,通过比较应用ＲＲＵＲＶＤ和ＳＶＤ两种分解方法得到的结果,说明ＲＲＵＲＶＤ是ＳＶＤ的良好替代方法。     

Direct Trace Element Determination in Oil and Gas Produced Waters with Inductively Coupled Plasma‐Optical Emission Spectrometry: Advantages of High‐Salinity Tolerance

Waters co‐produced during petroleum extraction are the largest waste streams from oil and gas development. Reuse or disposal of these waters is difficult due to their high salinities and the sheer volumes generated. Produced waters (PWs) may also contain valuable mineral commodities. While an understanding of produced water trace element composition is required for evaluating the associated resource and waste potential of these materials, measuring trace elements in brines is challenging due to the dilution requirements of typical methods. Alternatively, inductively coupled plasma‐optical emission spectrometry (ICP‐OES) has shown promise as being capable of direct measurements of trace elements within PWs with minimal dilution. Here, we evaluate direct ICP‐OES trace element quantification in PWs for seventeen trace elements (As, Al, Ba, Be, Cd, Cr, Co, Cu, Hg, Mo, Ni, Pb, Rb, Sb, U, V and Zn) within fifteen PWs from five U.S. continuous reservoirs. The total analytical uncertainties associated with the trace element levels determined using ICP‐OES were estimated to be better than ± 30% (2s) except for Rb, which could not be determined due to ionisation interferences. The ICP‐OES results are compared with trace element levels determined using inductively coupled plasma‐mass spectrometry from the same samples. Our results demonstrate the potential for direct analysis of high‐salinity waters using ICP‐OES with minimal dilution and provide trace element concentrations in waters from several important U.S. petroleum‐generating reservoirs where available data are sparse.     

机载POS的航空影像自动校正的方法与实现

针对每次航空摄影有大批量的影像需要进行几何校正处理,分析了正射纠正算法的全过程,提出利用索引矩阵来进行图像整体运算,利用航空相机的内方位元素和POS系统所提供的外方位元素,用IDL编程开发了航空影像的全自动批处理正射校正的软件,并对其处理结果与ERDAS9.1的LPS所做出来的正射影像图进行比较。