麦饭石促进异养反硝化去除水中硝酸盐的研究

微生物异养反硝化技术是市政污水处理中广泛应用的技术,但在实际应用中,微生物活性易受冲击负荷、重金属胁迫等环境条件影响,使出水效果不稳定。麦饭石作为一种天然硅酸盐矿物,能有效提高微生物活性及对环境胁迫的抗性,可以将其应用于微生物污染治理领域。通过批实验研究麦饭石的剂量、处理方式对异养反硝化的促进作用并探究麦饭石作用于微生物的机理。结果表明,麦饭石的投加剂量和处理方式均显著影响了微生物对硝酸盐的去除效果。硝酸盐去除率与麦饭石投加量呈正相关,麦饭石投加量为350 g/L时硝酸盐去除率可达96%,未添加麦饭石的空白组硝酸盐去除率仅为25%;处理方式会影响麦饭石对反硝化过程的强化作用,研磨后过200目筛的麦饭石在投加量<150 g/L时具有优势,投加量继续增大后,未经处理的麦饭石表现出更强的反硝化促进作用。进一步采用未经处理的麦饭石、研磨后过200目筛麦饭石及球磨麦饭石浸出液进行反硝化的促进实验及微生物毒性实验探究麦饭石作用于微生物的机理。实验结果表明,麦饭石浸出液能够提高微生物的活性及对环境胁迫的抗性,影响麦饭石生物促进作用的主要因素为其溶出微量元素的成分及浓度。本研究为天然矿物麦饭石应用于微生物污染治理提供理论依据和实际应用价值。     

基于流速衰减特征的泥石流冲出距离预测方法

泥石流冲出距离的确定是泥石流灾害评价及防治中的关键环节。基于泥石流在堆积区流速的变化特征,提出了泥石流流速"衰减系数"的概念。通过对泥石流流速衰减系数的定义和计算公式的推导,提出了一种基于泥石流流速衰减系数来确定泥石流冲出距离的新方法,并以四川省泸定县干沟泥石流为实例进行计算和验证。研究结果表明:当干沟泥石流在堆积区的流速大于初始(沟口)流速的15%时,流速的衰减程度极为显著;而当堆积区流速小于初始速度的15%时,流速的衰减极为缓慢。研究结果对泥石流灾害的危险性评价及防灾减灾具有一定的理论和实践意义。     

白山地区难选金矿石新方法选金试验研究

研究分析对比了不同类型选金矿石的特点，采用复合处理剂湿法预处理－提金新方法使吉林白山地区微细浸染型难选金矿石选金回收率由27％－57％提高到92％以上。     

铀水冶尾矿库地下水流特征与模拟分析：以某矿为例

铀水冶尾矿库中地下水流动特征控制了核素向周围环境扩散与迁移。本文以某矿山谷型尾矿库为例,运用二维有限元模拟了库内地下水分布及流动,结合水文地质条件进行了分析与讨论。     

CLIMATE CHANGE DUE TO GREENHOUSE EFFECTS IN CHINA AS SIMULATED BY A REGIONAL CLIMATE MODEL-PART I:EVALUATION OF THE MODEL SIMULATIONS*

Impacts of greenhouse effects(2×CO₂) on climate change over China as simulated by a regional climate model have been investigated.The model was based on RegCM2 and is nested in one-way mode within a global coupled atmosphere-ocean model(CSIRO R₂₁L₉ AOGCM).Two multi-year simulations,the control run with normal CO₂ concentration and the sensitivity run with doubled CO₂ concentration are conducted. As Part I of the publications,results of control run of the CSIRO,i.e.its simulation of present climate in China,are analyzed briefly.It shows that the model can basically reproduce the surface air temperature and precipitation pattern over China.Therefore,its outputs can be used to drive the regional model. Analysis of control run of RegCM shows that with a high resolution,the model improves the simulations of surface air temperature and precipitation in China as compared to the CSIRO model, especially for the precipitation.The spatial correlation coefficient between simulated and observed annual temperature increased from 0.83 in the CSIRO to 0.92 in the RegCM and for annual precipitation from 0.48 in the CSIRO to 0.65 in the RegCM.A similar improvement in the RegCM compared to the CSIRO was found in all simulated months.The main improvement for surface temperature is that RegCM can simulate the fine scale structure of temperature caused by topography.RegCM greatly improved the spatial distribution of precipitation by eliminating the virtual precipitation center in central China,which was simulated by many other GCMs.The precipitation simulated by RegCM in North and Northwest China is smaller than that by CSIRO, which makes it closer to the observation.     

潜孔锤反循环钻进技术在复杂地层中的试验研究

贯通式潜孔锤反循环连续取芯(样)钻进技术在钻进复杂地层时有独特效果,依托中国地调局项目,通过野外生产试验,加深了贯通式潜孔锤反循环机理的理论研究,对贯通式潜孔锤及其配套钻具的结构进行了合理的优化,大大提高了其对复杂地层的适应能力,完善了操作技术和工艺方法,使潜孔锤反循环钻进技术达到了可以广泛推广应用的水平.     

Incorporating spatially heterogeneous infiltration capacity into hydrologic models with applications for simulating post‐wildfire debris flow initiation

Soils in post‐wildfire environments are often characterized by a low infiltration capacity with a high degree of spatial heterogeneity relative to unburned areas. Debris flows are frequently initiated by run‐off in recently burned steeplands, making it critical to develop and test methods for incorporating spatial variability in infiltration capacity into hydrologic models. We use Monte Carlo simulations of run‐off generation over a soil with a spatially heterogenous saturated hydraulic conductivity (K_s) to derive an expression for an aerially averaged saturated hydraulic conductivity ( ) that depends on the rainfall rate, the statistical properties of K_s, and the spatial correlation length scale associated with K_s. The proposed method for determining is tested by simulating run‐off on synthetic topography over a wide range of spatial scales. Results provide a simplified expression for an effective saturated hydraulic conductivity that can be used to relate a distribution of small‐scale K_s measurements to infiltration and run‐off generation over larger spatial scales. Finally, we use a hydrologic model based on to simulate run‐off and debris flow initiation at a recently burned catchment in the Santa Ana Mountains, CA, USA, and compare results to those obtained using an infiltration model based on the Soil Conservation Service Curve Number.     

南钢无锡金鑫轧钢厂设备基座搬迁精密工程测量方法

本文主要介绍了针对无锡轧钢厂设备基座的精密工程测量,并结合测量中的实际情况,重点提出如何避免和降低误差对大型机械设备测量的影响.     

不锈钢薄钣轧机滚筒轴线检测

论述用基准尺和全站仪进行轧机滚筒轴线检测和计算的高精度工业测量方法.介绍轴线平行线和垂直线的精密测设、按滚筒圆周点测定滚筒轴线的平差计算和精度评定,以及采用本方法的要点.     

An analysis of the error space of a high-resolution implementation of the GHER hydrodynamic model in the Mediterranean Sea

An ensemble of 250 model setups covering the Mediterranean Sea is built by perturbing various parameters: the bathymetry, the initial conditions, atmospheric forcing fields (air temperature, cloud coverage, wind), and internal model parameters (diffusion coefficients). The ensemble is then forwarded in time using the GHER hydrodynamic model, allowing to obtain information about the expected error associated with the forecast in a natural way. The evolution of this error is analyzed. In particular, we examine the time evolution and stationarity of its spatial average, and the spatial distribution of the error at different instants, by means of its first to fourth order moments, and of empirical orthogonal functions. We verify whether the a posteriori error distribution is Gaussian using the Anderson-Darling test. From these results, we are able to assess what parameters and forcing fields are most critical for the forecast. Qualitative conclusions are obtained throughout the text, in accordance with our expectations. Moreover, quantitative estimations of the expected error are also given.