磷酸三丁酯三苯基膦醋酸纤维富集-等离子体发射光谱法测定地质样品中的痕量金银

地质样品经王水分解后,在一定浓度的王水和盐酸介质中,以磷酸三丁酯三苯基膦醋酸纤维富集金银,用20g/L硫脲溶液解脱,采用等离子体发射光谱法测定,金、银的回收率为98%~101%,方法检出限金为0.001μg/g,银为0.001μg/g。     

MIBK负载泡塑吸附-中子活化法在金标样定值中的应用

试样经焙烧、王水分解后,在8％的王水介质中,MIBK负载泡塑吸附[AuCl_4]~-。灰化吸附泡塑或硫脲溶液解脱,用中子活化法测定Au。取10g样品,可测定0.000x～xxμg/g的Au。用于金标样的定值,具有良好的精密度和准确度。     

影响金分析精密度的几个因素

用王水溶样，泡塑吸附，硫脲溶液解脱，原子吸收光谱法测定Au含量时，除了介质和仪器条件外，所用的泡塑、硫脲及样品测定时的温度对精密度影响均很大。应采用经过10g／L NaOH预处理0．5h的泡塑，使其内存全部变为有效吸附面积。选择好的硫脲，样品解脱后放置30min，在待测溶液温度达到室温时进行测定。对标样GAu—17和GAu—18平行测定6次，相对标准偏差小于7％。     

Z-2000偏振塞曼石墨炉原子吸收分光光度计测定地球化学样品中痕量金

用φ=50%的王水分解样品,聚氨酯泡沫塑料吸附富集金,10g/L硫脲为解脱剂,偏振塞曼石墨炉原子吸收分光光度计测定痕量金。对干燥、灰化、原子化、净化温度和时间,以及载气流量和灯电流强度进行了讨论;对影响金吸附效果的泡塑载体和王水浓度等因素进行了研究。通过实验得到了Z-2000偏振塞曼原子吸收分光光度计最佳石墨炉分析测试条件。方法检出限为0.3ng/g,回收率为95.0%~101.0%,精密度(RSD,n=12)低于8.0%,经国家一级标准物质(GBW07243~GBW07245)分析验证,结果与标准值相符。     

石墨炉原子吸收法测定化探样品中的痕量金

试样经灼烧、王水(1 1)分解后,置于10%±的王水介质中经泡塑富集,高温灰化,小体积王水浸取后,以N i作为A u的稳定改进剂,用石墨炉原子吸收法测定A u。本方法检出限为0.18ng/mL,相对标准偏差为3.98%~6.12%。适用于地质、化探样品中痕量金的测定。     

流动注射-火焰原子吸收光谱法测定地质样品中的常量金

样品经室温烧至650℃高温后灼烧保持1.5 h,用浓王水溶解。用泡塑分两次吸附富集样品中的常量金,将富集同一样品中金的两块泡塑置于盛有10 mL 10 g/L硫脲溶液的玻璃试管中,沸水浴保持20 min,使金释放出来,所得溶液应用原子吸收分光光度计采用流动注射测定。对仪器的测定条件进行了优化比较。方法检出限(3σ)为0.022μg/g,精密度(RSD,n=11)小于8.0%,测定范围为0.05～60μg/g。经国家金矿石分析标准物质验证,其测定值与标准值基本一致。     

阴离子树脂—活性炭吸附石墨炉测定铂钯

将样品用王水分解定容静置后,采用阴离子树脂—活性炭混合吸附体系进行静态吸附,将吸附体高温灰化后再以王水分解定容,用石墨炉原子吸收光谱仪测定溶液中的铂、钯.该方法检出限为铂0.084ng/g,钯0.025 ng/g,回收率铂为95％～ 103％,钯为95％～ 98％.     

地电化学（泡塑）样品中金与锑的预处理

通过模拟实验获得附载金、锑的泡塑样品，并对其进行了硫脲解脱法、灰化法、硝酸加氧化剂消解法的比较实验，确定采用硫脲解脱法是地电化学(泡塑)样品金、锑的最佳解脱方法，通过正交实验及其结果分析确定了最佳实验条件。利用硫脲解脱一原子吸收光谱法对某隐伏金锑矿床82件地电化学(泡塑)样品进行了测试，分析结果显示出有明显的金、锑异常，指示了重要的勘探靶区。     

巯基棉富集-分光光度法测定铂

样品溶解后,加入还原剂氯化亚锡及助吸附剂水合肼,用巯基棉吸附微量铂。吸附物灰化后,灰分用王水溶解,溶液用双十二烷基二硫代乙酰胺(DDO)分光光度法测定铂。方法检出限为0.2μg/g(10.0g样品),铂量在0~20μg/g线性关系较好。方法经国家一级标准物质验证,铂的测定结果与标准值相符,12次测定的相对标准偏差(RSD)小于10%。     

二苯硫脲泡塑富集-原子吸收光谱法连续测定化探样品中金和银

传统的发射光谱、化学光谱、泡塑富集分离-原子吸收光谱法测定化探样品中的金和银,分析结果不稳定,效率低。本研究提出用50%的王水分解化探样品,负载二苯硫脲泡塑吸附金银,石墨炉和火焰原子吸收光谱法对金和银进行联合测定。在二苯硫脲浓度、吸附酸度、吸附温度、振荡时间等优化的实验条件下,金和银的回收率分别达到97.9%和98.8%,检出限为0.25 ng/g和0.038μg/g,准确度(RE,n=9)为2.0%～14.0%和7.7%～13.3%,精密度(RSD,n=9)为3.1%～12.4%和5.1%～13.2%。经国家标准物质分析验证,测定值与标准值基本相符。该方法实现了在同一份溶液中同时测定金和银,与现行的石墨炉原子吸收光谱测定金、发射光谱测定银的方法相比,称样量达到10 g,样品的代表性显著增加,提高了准确度和精密度,简化了金银分析的程序,化学试剂用量少,分析成本低。     

明沟排水与竖井排灌

本文在分析干旱细土平原区水文地质条件的基础上 ,论述了盐渍化地区在不同排水条件下水中盐份的运移和积聚的过程 ,比较了明沟排水和竖井排灌的优劣 ,从而提出竖井排灌是改良土壤盐渍化 ,防止土壤返盐的有效措施     

改革创新谋机遇,引导示范促发展

2000年以来,我厅在建设部的关心和指导下,认真落实全国建设技术创新大会精神,紧紧围绕科学技术与经济建设相结合这个核心,以涉及建设事业全局的重大课题研究为龙头,着力实施“科教兴业”战略,加大科技项目管理力度,狠抓“四新”成果的推广应用,经过全省建设科技人员的共同努力,较好地完成了各项工作任务,推动了全省建设事业的健康、快速发展,为全省城市化和城市现代化建设做出了贡献。 宏观战略研究取得丰硕成果。两年来,我厅集聚全厅、相关部门和社会     

Smoothing and interpolation by kriging and with splines

Let scalar measurements at distinct points x₁, , x_n be y₁, , y_n.We may look for a smooth function f(x)that goes through or near the points (x_i, y_i).Kriging assumes f(x)is a random function with known (possibly estimable) covariance function (in the simplest case). Splines assume a definition of the smoothness of a nonrandom function f(x).An elementary explanation is given of the fact that spline approximations are special cases of the solution of a kriging problem.     

Annual stream flow simulation by ARMA processes and prediction by Kalman filter

Algeria is a semi-arid country where water resources are not sufficient to cope with the important socio-economic development demands. Any sustainable development strategy is basically dependent on a rigorous management of water resources potential, which presents a true challenge to be tackled for such countries. Classic mathematical models based on time invariability and ignorance of the stochastic and non-linear nature of hydrological variables are not sufficient for simulation and prediction studies. The present study subscribes to the stochastic hydrological processes modeling and prediction in case of time-varying linear systems through adaptive Kalman filter (KF) methodology. It focuses upon stream flows as a water resources component, which is directly related to the socio-economic development meanwhile it opts for Kalman filter as principal tool of work. The main objective is the application of (KF) technique to model and predict annual streamflow volumes in Northern Algeria and the obtained results are satisfactory.     

Isopropylxanthate ions uptake by modified natural zeolite and removal by dissolved air flotation

This work describes a laboratory study concerning the adsorption of isopropylxanthate ions onto modified zeolites particles. The separation of the loaded carrier and their removal, from aqueous solutions, was conducted by flocculation followed by dissolved air flotation, DAF. The zeolite employed was a natural sample (approximately 48% clinoptilolite and 30% mordenite) which was previously treated with sodium ions (activation) and modified with copper ions (Cu–Z) before the xanthate ions uptake. Adsorption capacities (q_m) for Cu–Z were 0.34 meq g^− 1 for the powdered form, and 1.12 meq g^− 1 for the floc form. The adsorption capacity for the floc form appears to involve an enhanced electrostatic adsorption due to the positive sites on the floc surface. In all cases, the isopropylxanthate concentration in the treated water was found to be negligible (< 0.04 mg L^{− 1}). The flotation technique showed to be a fast process, requires a low recycle ratio (20%) in air saturated water, and the treated water ended up with a very low residual turbidity (6.8 NTU). It is believed that this adsorption–flotation technique, here named adsorptive particulate flotation, using activated and modified natural zeolite has a high potential as an alternative for pollutants removal (copper and isopropylxanthate ions) from waste mining effluents.     

Adsorption of aluminium by a latosol as affected by phosphate and glutamic acid

The effect of phosphate and glutamic acid on adsorption of aluminium onto a latosol was investigated as a function of pH and ligand concentrations through batch equilibrium experiments. The results showed that adsorption of aluminium by the soil was enhanced after addition of phosphate at low pH, and this promotive effect was gradually eliminated with the increase in pH. The positive effect of phosphate on aluminium adsorption onto latosol was attributed to phosphate-induced surface negative charge and formation of ternary surface complexes involving aluminium and phosphate. While using silica as adsorbent, the inactive surfaces for phosphate, promotion of adsorption of aluminium by phosphate was also found. Then it was proposed that additional aluminium might bind to the phosphate adsorbed onto the silica in the form of surface complexes silica–aluminium–phosphate again, and the mechanism might operate in the soil systems as well. Glutamic acid exhibited no influence on the adsorption of aluminium by the soil at low pH. After increasing the pH, adsorption of aluminium was inhibited especially with the highest addition of glutamic acid, probably owing to weak affinity of complexes between glutamic acid and aluminium to the soil.     

The orthoenstatite to clinoenstatite transformation by shearing and reversion by annealing: Mechanism and potential applications

Clinoenstatite (CE) was produced by deforming single-crystal specimens of ortho-enstatite (OE) in several different sorta of experiments. Examination with light and trans-mission electron microscopes shows that the transformation is coherent and involves a macroscopic shear on (100) [001] through an angle of 12.8±1.3 °, in good agreement with the theoretically expected value of 13.3 °, and that the transformation is accomplished by glide on (100) of partial dislocations with b= 0.83[001]. Structural analysis provides further insight into the transformation mechanism. Reversion occurs in specimens annealed under a variety of conditions, and thin lamellae of CE in unconstrained, low-strain specimens recover their original shape during transformation back to OE. Our experiments and thermodynamic estimates both suggest that the equilibrium transition temperature is raised roughly 300 ° C per kilobar of shear stress on (100) [001]. This provides the basis of a method by which it may be possible to determine the magnitude as well as the orientation of the principal stresses that produce CE in nature during deformation of enstatite-bearing rocks.     

锚杆桩加固基础与掏土纠偏施工的实践

介绍了利用锚杆静压桩加固基础与沉井掏土纠偏方法纠治某厂房的施工过程，先用锚杆静压桩加固厂房基础，然后再用沉井掏土法纠治厂房，使偏斜率由３２‰纠到了３‰的安全界限。     

Photoluminescence and cathodoluminescence by cosmic dust

The photoluminescence and possible cathodoluminescence of cosmic dust is considered. It is shown that the dust of planetary nebulae can luminesce under the action of fluxes of charged particles. The results of a comparative analysis of unidentified emission features in the optical spectrum of the nebula NGC 7027 and the luminescence emission of a number of minerals is presented. It is shown that the dust in this nebula includes diamond grains.     

Investigation of slope instability induced by seepage and erosion by a particle method

A novel particle based Bluff Morphology Model (BMM) developed by the authors is extended in this paper to investigate the effect of two dimensional seepage on the stability and collapse of soil slopes and levees. To incorporate the seepage in the model, Darcy’s law is applied to the interactions among neighbouring soil particles and ghost particles are introduced along the enclosed soil boundary so that no fluid crosses the boundary. The contribution of partially saturated soils and matric suction, as well as the change in hydraulic conductivity due to seepage, are predicted well by the present model. The predicted time evolution of slope stability and seepage induced collapse are in reasonable agreement with the experimental results for homogeneous non-cohesive sand and multiple layered cohesive soils. Rapid drawdown over a sand soil is also investigated, and the location and time of the levee collapse occurrence are well captured. A toe erosion model is incorporated in the BMM model, and the location and quantity of erosion from lateral seepage flow is well predicted. The interplay of erosion, seepage and slope instability is examined.