呼图壁县雀尔沟河洪水成因类型与水文资料“三性”分析

以新疆呼图壁县雀尔沟河流域为研究区域,揭示流域洪水成因、类型,综合历史洪水调查成果对雀尔沟水文资料“三性”进行分析。结果表明:雀尔沟洪水一般发生在春季和夏季,春季洪水以积雪消融水为主,夏季洪水则是暴雨洪水。洪水类型主要为季节积雪融水型洪水、暴雨型洪水和以上两种洪水叠加形成的混合型洪水三类;流域参证站石门站1977-2019年共43年的实测水文资料系列可靠性,一致性和代表性较好,均能满足洪水频率计算对洪水资料的要求。研究结果对流域防洪减灾及洪水预测预报提供参考依据。

昌吉市三工滩前山区洪水特征及水文资料“三性”分析

无水文资料地区洪水对城市防洪尤其重要。本文以新疆昌吉市三工滩前山区为研究区域,针对研究区水文资料缺乏的实际,选取邻近的三屯河流域碾盘庄站和昌吉气象站为参证站,综合参证站长系列水文基础资料,对三工滩前山区洪水成因类型及洪水特征进行分析,并对水文资料的可靠性、一致性及代表性进行论证。结果表明:(1)三工滩前山区洪水主要以暴雨洪水和季节性融雪洪水为主,一般发生在春季和夏季,春季洪水以积雪消融水为主,夏季洪水主要是暴雨洪水。(2)季节性融雪洪水大小与前期积雪面积及储量有密切关系,出现时间早,洪水过程与升温过程关系密切,随气温变化具有明显的日变化过程,洪水涨落变化缓慢持续时间较长;暴雨洪水过程线型多尖瘦,陡涨陡落,突发性强,具有挟沙量大、矿化度高、破坏性大、发生频率较高的特点。(3)参证站水文资料质量可靠,洪水资料系列一致性较好。碾盘庄站41年最大洪峰流量与最大一日降水量系列具有代表性,昌吉气象站最大一日降水量64年系列代表性也较好。研究结论为该流域防洪减灾、洪水预测预报、群众生命财产及基础设施安全保障提供科学依据。

高校图书馆导读的“三性”分析

针对大学生阅读需求和倾向的多元化,分析了高校图书馆导读的必要性,论述了导读需求客观存在的模糊性,在此基础上,提出了搞好高校导读工作具有操作性的对策和措施。

库如克山洪沟洪水特性及水文资料“三性”分析

库如克山洪沟地处天山南部中段,由于库如克山洪沟上无任何水文监测资料,选用距离洪水调查点9km的卡拉苏水文站作为参证站,基于2018年以前的长系列水文资料作为计算依据,对流域洪水特性和水文资料“三性”进行研究。结果可知:库如克山洪沟一般洪水主要为冰雪融水形成的融雪型洪水;而发生的较大的洪水则一般是高温融雪型与暴雨混合型洪水;水文资料的可靠性、代表性和一致性满足规范要求。研究结果以期为库如克山洪沟水利工程开发建设和水资源管理工作提供基础支撑。

托什干河流域径流变化特征及典型测站水文资料“三性”分析

以新疆托什干河流域内的典型测站沙里桂兰克水文站为主要研究对象,基于沙里桂兰克水文站1957-2017年共61年实测径流量资料,通过对该流域径流年内和年际变化特征及水文站长系列水文资料资料的可靠性、一致性和代表性进行分析,结果显示:(1)托什干河径流主要为雨雪混合补给,径流年内分配极不均匀,径流季节分布较为集中,5-8月径流量占全年径流量的77.3%,而1-3月径流量仅占年径流量的2.8%,四季分配不均匀;多年平均年径流量为28.3×10^8m^3,2003年为最丰年,年径流量为41.3×10^8m^3,2014年为最枯年,年径流量为17.0×10^8m^3,与相邻地区河流相比,托什干河的径流年际变化较大。(2)流域沙里桂兰克水文站水文资料无明显错误,成果可靠,径流系列一致性较好,年径流系列具有较好的收敛性,且存在比较完整的年际变化周期过程。研究结果为流域水资源合理开发及防洪安全提供了基础依据。

大型水库年径流系列还原及“三性”分析

文章以大连庄河市朱隈水库为例,对水库年径流系列进行还原,采用差积曲线、累计平均和皮尔逊Ⅲ型曲线适线等方法对该流域水文站径流系列进行“三性”分析。分析结果可为流域内大中型水利工程建设以及水资源管理和开发利用提供技术支持。

新疆大河沿子河流域水文资料“三性”及径流变化特征分析

大河沿子河位于新疆维吾尔自治区西北部,天山以北博尔塔拉蒙古自治州南部,流域设立有三台水文站、大河沿子大桥水文站及沙尔托海水文站三处国家基本水文站,测验项目较齐全,资料可靠,精度较高。本文对流域水文站径流资料的可靠性、一致性和代表性进行分析,并对该流域径流变化特征进行研究。结果显示:流域水文站水文资料无明显错误,成果可靠,径流系列一致性较好,当径流系列达到25 a以上时,模比系数累积平均值已趋近于1,具有一定的代表性。受降水和地形影响,与降水地域分布相一致,河川径流地区差别较大,山地大于平原,南部大于北部;受冰雪融水补给较大影响,径流量年际变幅相对较小,Cv值为0.22,大河沿子流域径流年际变化相对稳定。研究结果为流域水资源合理开发及防洪安全提供了基础依据。

武水流域水文资料“三性”及径流特性趋势分析

武水系长江流域沅江一级支流,流域面积3 691 km^(2)(其中湖南省占3 614 km^(2));流域内设有吉首、凤凰、河溪三个国家基本水文站。文章采用有序聚类法等方法对流域水文站径流资料“三性”进行分析,并利用Kendall趋势检验法、R/S分析法的理论对代表站河溪站年径流量时序变化的趋势特性及丰枯演化规律进行研究。由此得出分析结论,为武水流域的河流治理、水利工程建设、水资源管理和开发利用提供支撑。

福特法则在水文径流序列分析中的探索

将统计学中本福特法则应用于水文径流序列分析,通过淮河干流息县、王家坝、鲁台子和蚌埠站研究表明:水文径流序列首位数字出现的概率值与本福特法则计算值相近,流域上游本福特法则适用性要大于流域下游。研究成果可用于指导水文径流资料分析工作,具有实用价值及参考意义。

Determination of Melamine by Infrared Spectroscopy Based on Nonlinear Modeling

[Objective] The aim was to develop a nonlinear model of quantitative analysis of melamine content by infrared spectroscopy and provide theoretical basis for the nondestructive detection of melamine. [Method] According to dynamics,mathematical modeling and optimization theory,linear and nonlinear models were respectively set up by taking an absorption peak of 1 550 cm-1 as characteristic absorption peak. [Result] The correlation coefficient of nonlinear model was 0.922 7 and the recovery was 96%,which showed that the nonlinear model was more accurate than linearity model with correlation coefficient of 0.904 9 and recovery of 557%. [Conclusion] It is feasible to determine melamine content by using the nonlinear model quantitatively.

The algorithm of 3D multi-scale volumetric curvature and its application

To fully extract and mine the multi-scale features of reservoirs and geologic structures in time/depth and space dimensions, a new 3D multi-scale volumetric curvature （MSVC） methodology is presented in this paper. We also propose a fast algorithm for computing 3D volumetric curvature. In comparison to conventional volumetric curvature attributes, its main improvements and key algorithms introduce multi-frequency components expansion in time-frequency domain and the corresponding multi-scale adaptive differential operator in the wavenumber domain, into the volumetric curvature calculation. This methodology can simultaneously depict seismic multi-scale features in both time and space. Additionally, we use data fusion of volumetric curvatures at various scales to take full advantage of the geologic features and anomalies extracted by curvature measurements at different scales. The 3D MSVC can highlight geologic anomalies and reduce noise at the same time. Thus, it improves the interpretation efficiency of curvature attributes analysis. The 3D MSVC is applied to both land and marine 3D seismic data. The results demonstrate that it can indicate the spatial distribution of reservoirs, detect faults and fracture zones, and identify their multi-scale properties.

Performance analysis in 3G/ad hoc integrated network

An analytical approach to evaluate the performance of the 3G/ad hoc integrated network is presented. A channel model capturing both path loss and shadowing is applied to the analysis so as to characterize power falloff vs. distance. The 3G/ad hoc integrated network scenario model is introduced briefly. Based on this model, several performances of the 3G/ ad hoc integrated network in terms of outage probability, call dropping probability and new call blocking probability are evaluated. The corresponding performance formulae are deduced in accordance with the analytical models. Meanwhile, the formula of the 3G/ad hoc integrated network capacity is deduced on the basis of the formula of the outage probability. It is observed from extensive simulation and numerical analysis that the 3G/ad hoc integrated network remarkably outperforms the 3G network with regards to the network performance. This derived evaluation approach can be applied into planning and optimization of the 3G/ad hoc network.

Three-dimensional stability analysis of anisotropic and non-homogeneous slopes using limit analysis

A method of three-dimensional loaded slope stability for anisotropic and nonhomogeneous slopes was presented based on the upper-bound theorem of the limit analysis approach. The approach can be considered as a modification and extension of the solutions. The influences of friction angle, anisotropy factor, nonhomogeneous factor, slope angle, ratio of width to depth, and load on the slope crest were investigated. The results show that solutions are suitable to deal with the purely cohesive soils and frictional/cohesive soils, isotropic and anisotropic, homogeneous and nonhomogeneous, loaded and unloaded cases.

Three-dimensional nonlinear analysis of creep in concrete filled steel tube columns

This paper proposes a based on 3D-VLE （three-dimensional nonlinear viscoelastic theory） three-parameters viscoelastic model for studying the time-dependent behaviour of concrete filled steel tube （CFT） columns. The method of 3D-VLE was developed to analyze the effects of concrete creep behavior on CFT structures. After the evaluation of the parameters in the proposed creep model, experimental measurements of two prestressed reinforced concrete beams were used to investigate the creep phenomenon of three CFT columns under long-term axial and eccentric load was investigated. The experimentally obtained time-dependent creep behaviour accorded well with the cu~＇es obtained from the proposed method. Many factors （such as ratio of long-term load to strength, slenderness ratio, steel ratio, and eccentricity ratio） were considered to obtain the regularity of influence of concrete creep on CFT structures. The analytical results can be consulted in the engineering practice and design.

Three-dimensional stability of landslides based on local safety factor

Unlike the limit equilibrium method(LEM), with which only the global safety factor of the landslide can be calculated, a local safety factor(LSF) method is proposed to evaluate the stability of different sections of a landslide in this paper. Based on three-dimensional(3D) numerical simulation results, the local safety factor is defined as the ratio of the shear strength of the soil at an element on the slip zone to the shear stress parallel to the sliding direction at that element. The global safety factor of the landslide is defined as the weighted average of all local safety factors based on the area of the slip surface. Some example analyses show that the results computed by the LSF method agree well with those calculated by the General Limit Equilibrium(GLE) method in two-dimensional(2D) models and the distribution of the LSF in the 3D slip zone is consistent with that indicated by the observed deformation pattern of an actual landslide in China.

Strain analysis of buried steel pipelines across strike-slip faults

Existing analytical methods of buried steel pipelines subjected to active strike-slip faults depended on a number of simplifications.To study the failure mechanism more accurately,a refined strain analytical methodology was proposed,taking the nonlinear characteristics of soil-pipeline interaction and pipe steel into account.Based on the elastic-beam and beam-on-elastic-foundation theories,the position of pipe potential destruction and the strain and deformation distributions along the pipeline were derived.Compared with existing analytical methods and three-dimensional nonlinear finite element analysis,the maximum axial total strains of pipe from the analytical methodology presented are in good agreement with the finite element results at small and intermediate fault movements and become gradually more conservative at large fault displacements.The position of pipe potential failure and the deformation distribution along the pipeline are fairly consistent with the finite element results.

Three-dimensional analysis of slopes reinforced with piles

Based on the upper bound of limit analysis, the plane-strain analysis of the slopes reinforced with a row of piles to the 3D case was extended. A 3D rotational failure mechanism was adopted to yield the upper bound of the factor of safety. Parametric studies were carried out to explore the end effects of the slope failures and the effects of the pile location and diameter on the safety of the reinforced slopes. The results demonstrate that the end effects nearly have no effects on the most suitable location of the installed piles but have significant influence on the safety of the slopes. For a slope constrained to a narrow width, the slope becomes more stable owing to the contribution of the end effects. When the slope is reinforced with a row of piles in small space between piles, the effects of group piles are significant for evaluating the safety of slopes. The presented method is more appropriate for assessing the stability of slopes reinforced with piles and can be also utilized in the design of plies stabilizing the unstable slopes.

Failure mechanism and stability analysis of the Zhenggang landslide in Yunnan Province of China using 3D particle flow code simulation

Based on the principle of 3D particle flow code,a numerical landslide run-out model is presented to simulate the failure process of the Zhenggang landslide(in southwestern China) under the effect of water after a rainfall.The relationship between the micro-mechanical parameters and the macro-shear strength of the grain material is determined through numerical calibrations.Then the rainfall effect is considered in numerical simulations and rain-induced sliding processes are performed,which help us to discuss the mechanism of deformation and failure of this landslide together with field observations.It shows the Zhenggang landslide would most likely be activated in Zone I and would gain momentum in Zone II.In order to prevent the potential disaster,a tailing dam is advised to be designed about 175 m downstream from the current landslide boundary of Zone II.Verified by field observations,the presented landslide model can reflect the failure mechanism after rainfall.It can also provide a method to predict the potential disaster and draft disaster prevention measures.

Resistance Analysis of Unsymmetrical Trimaran Model with Outboard Sidehulls Configuration

The application of multi-hull ship or trimaran vessel as a mode of transports in both river and sea environments have grown rapidly in recent years.Trimaran vessels are currently of interest for many new high speed ship projects due to the high levels of hydrodynamic efficiency that can be achieved,compared to the mono-hull and catamaran hull forms.The purpose of this study is to identify the possible effects of using an unsymmetrical trimaran ship model with configuration（S/L） 0.1-0.3 and R/L=0.1-0.2.Unsymmetrical trimaran ship model with main dimensions： L=2000mm,B=200 mm and T=45 mm.Experimental methods（towing tank） were performed in the study using speed variations at Froude number 0.1-0.6.The ship model was pulled by an electric motor whose speed could be varied and adjusted.The ship model resistance was measured precisely by using a load cell transducer.The comparison of ship resistance for each configuration with mono-hull was shown on the graph as a function of the total resistance coefficient and Froude number.The test results found that the effective drag reduction could be achieved up to 17% at Fr=0.35 with configuration S/L=0.1.

Limit analysis of vertical anti-pulling screw pile group under inclined loading on 3D elastic-plastic finite element strength reduction method

Based on the functional theory, catastrophe theory, simultaneity principle and the idea of strength reduction method （SRM）, the bearing capacity functional anti SRM of pile group foundation were established, and the criteria of ultimate load and the concept of safety storage coefficient （Css） were advanced. The inclined ultimate loads by the static loading test, load increment method （LIM） and SRM are compared. Theoretically, the ultimate load of piles does not change with the loading levels when it is calculated by SRM. When the one strength reduction parameter is applied in the calculation boundary, there are calculating errors because the bearing capacity action of soils happened in the finite zone. The inclined 10adings are 108, 132 and 144 kN, and SSC are 1.07, 0.94 and 0.79, respectively, so the calculation values of ultimate loads are about 115.56, 124.08 and 113.76 kN, respectively. The error between calculations and observation values is less than 6%. But .the error between calculations of LIM and observations is 20%. Because of the effect of inclined loading, the push-rotation phenomenon of screw pile group appears. Under this testing, the ultimate bearing capacity of piles is mostly determined by the horizontal ultimate bearing capacity, and the effect of the vertical component of inclined load should also be considered.