基于SRM法路基桩板墙支挡效果分析与评价

文章介绍了有限元强度折减法的原理和应用情况,以某铁路工程路基桩板墙工点为研究对象,采用Midas/GTS有限元软件建立2D模型,基于SRM法对路堑边坡进行二维数值模拟分析。通过对比路堑边坡在无桩板墙和有桩板墙支护情况下的安全系数、滑动面情况及整体位移,对路堑边坡桩板墙支挡效果作出分析及评价,为相关铁路路堑边坡支挡结构工程稳定性分析及设计提供参考,具有一定的创新性及工程指导意义。     

试论锚喷技术用于岩质边坡支护中的效果

锚喷技术在岩质边坡支护中发挥着关键性的作用。锚喷技术在岩质边坡支护中主要体现在三方面,分别是锚杆、钢筋网及喷射混凝土,在岩质边坡支护中运用锚喷技术可以提高边坡施工的稳定性,降低岩质的变形机率,因此它在岩质边支护中尤为重要。本文正是针对锚喷技术的概念以及锚喷技术在岩质边坡支护中的效果进行了全面的论述和分析。     

公路建设项目高边坡支护模拟仿真与方案优化

以道路工程为背景,对边坡稳定性进行模拟仿真,并运用离散元法进行数值分析,最后提出边坡支护的两套方案。希望通过文章的分析,为相关从业人员提供借鉴和参考。     

边坡开挖与支护技术在水利水电工程施工中的应用探讨

水利水电工程是我国水利工程中比较重要的构成部分,保证水利水电工程的持续发展,是促进我国社会更加稳定发展的重要因素。边坡开挖技术水利水电工程建立中使用较为广泛的技术,边坡开挖技术可以为水利水电工程提供更加稳定性且安全的支护,对防护边坡岩壁出现塌陷具有很大的帮助,同时也能保证水利水电工程建设质量。文章主要是对边坡开挖和支护技术在水利水电施工中的使用进行分析,提供一些参考对策。     

贵州某高速公路顺层岩质边坡稳定性分析与支护措施探讨

随着西部地区大规模工程建设的开展，在施工过程中不可避免的形成了大量的路堑顺层岩质边坡，文章将从地层岩性、岩体结构、工程环境等方面对贵州某高速公路顺层岩质边坡的稳定性进行分析，并结合工程实际提出支护措施，结论对顺层边坡的开挖防护有一定的参考价值。     

水利水电工程边坡开挖支护施工技术探究

在水利水电工程边坡施工时,由于工程量大,波及范围广,如果支护施工技术不合理,很容易出现滑坡,对于工期和质量产生负面影响。在这种情况下,加强水利水电工程边坡开挖支护施工技术研究显得十分重要。文章阐述了影响水利水电工程边坡开挖支护的因素,分析边坡开挖支护技术的要点,并重点研究水利水电施工边坡开挖支护技术的应用,希望对相关人士有一定的借鉴作用。     

傍山软基高填方路堤边坡稳定性及加固效果分析

以福建省某路基工程傍山软基高填方路堤边坡为例,采用有限元软件GeoStudio,结合极限平衡法和有限元法,对该路堤边坡的稳定性进行动态分析,结果表明:该方法在评价傍山软基高填方路堤边坡稳定性上是有效的,尤其是当安全系数临近1.0时,可以结合有限元模拟的应变变形更准确地判断路堤边坡稳定性,为今后类似路堤边坡工程的稳定性评价提供有益参考.     

沉井技术在水电站埋藏式压力管道工程施工中的应用

四川西里水电站厂房后边坡压力管道为洪积堆积体土质陡坡,该边坡成功地采用沉井支护方式,确保了边坡的稳定和安全,为类似工程施工提供借鉴和成功经验。     

池州市某垃圾焚烧发电厂项目边坡稳定性评价及防治对策

为保障池州市生活垃圾焚烧发电项目的安全,在勘察已发生变形破坏的A-B-D段挖方边坡工程场地的地质环境条件基础上,阐述边坡不稳定因素、边坡破坏模式和边坡滑体形态,分析滑坡形成机理,采用折线法进行土质边坡稳定性计算和评价,并提出具体的防治对策.     

基于FLAC3D高陡边坡下开采挂帮矿的围岩稳定性研究

为了安全的回收大冶铁矿2#挂帮矿,采用FLAC3D有限元法对上向水平分层胶结充填法开采挂帮矿的结构参数和回采工艺工程进行了数值模拟,分析了高陡边坡下挂帮矿开采对围岩稳定性的影响。模拟结果表明:挂帮矿在开采过程中,坡脚始终出现应力集中,最大值为10MPa;随着开采的进行,空场顶板最大位移逐渐向边坡处转移;开采过程中,需要重点监测最大采深上部边坡,必要时候需要支护。生产结果表明:FLAC3D数值结果指导挂帮矿回采工艺设计是合理的。     

易滑地层顺层边坡合理坡形UDEC模拟分析

针对重庆三峡地区易滑地层地质特性,充分收集和分析前人的研究资料及成果,运用通用颗粒离散元程序(UDEC)建立三峡库区顺层三级边坡模型,模拟过程中主要考虑层面倾角、碎落台宽度以及粘聚力等参数对边坡稳定性的影响,分析模拟计算得出的不同参数组合下的安全系数,提出易滑地层三级顺层边坡合理放坡坡形。     

山药饮料的护色和稳定性工艺研究

对山药饮料加工过程中易引起褐变的环节及稳定性进行了研究,比较了不同护色剂的护色效果和不同稳定剂的稳定效果,并确定了最佳护色工艺及稳定剂。结果表明:最佳护色条件为山药在20℃的质量分数0.5%抗坏血酸+0.5%柠檬酸+0.01%氯化钠水溶液中浸泡15 min,可防止其切片后褐变;另外,复配稳定剂(质量分数0.2%CMC+0.15%瓜尔豆胶+0.15%卡拉胶)对山药果肉饮料的稳定效果最为明显,所得山药饮料的浆液组织形态均匀,长时间放置不分层。     

印刷机规矩测试信号分析

为了了解印刷机规矩的动态特性,建立了规矩实验装置。通过对前规、侧规及前规矩板的加速度信号和整机噪声信号分析得知,前规、侧规及规矩板的振动对机器噪声的贡献很小,但会影响到其工作的稳定性和工作寿命。通过对测试信号曲线分析发现,规矩部件对150-300Hz的激励信号的响应比对其他频率信号高3-10倍。     

山杏种皮黑色素理化性质研究

山杏种皮黑色素具有黑色素典型的性质。稳定性研究表明:温度影响该黑色素的氧化还原状态,但对溶液的颜色无显著影响;pH<6时,冷冻使黑色素沉淀;光照使溶液褪色;随pH升高,溶液颜色略有加深;Na_2SO_3、Ca~(2+)、Cu~(2+)和Zn~(2+)有一定的增色护色作用,Al~(3+)、Mg~(2+)、Na~+、氨基酸、糖和淀粉对该黑色素无显著影响;有机酸使溶液略有褪色。本研究尝试以吸光度的对数对波长的回归直线斜率作为衡量黑色素稳定性的指标,该指标能够很好地反映出山杏种皮黑色素结构的改变。     

A Qualitative Approach for the Assessment of the Genetic Stability of the MON 810 Trait in Commercial Seed Maize Varieties

Maize MON 810 is one of the European Union’s (EU) authorized genetically modified organisms (GMO) for placing on the food and feed market. The total number of MON 810 varieties registered in the European Common Catalogue of varieties of agricultural plant species has almost tripled since 2005. One of the requirements described in EU legislation, namely the genetic stability of GM seed varieties, was thus assessed by analyzing the intactness of the entire MON 810 integration and its genotypic stability in commercial varieties available on the market for at least the last 2 years. A combined strategy using qualitative analytical methods made possible to determine the presence/absence of the individual genetic elements and of the whole GM construct. The restriction fragment length polymorphism patterns obtained from amplified whole constructs by long polymerase chain reaction (PCR) were compared side by side. CryIA(b) protein expression levels were determined by enzyme-linked immunosorbent assay. Twenty-four out of the 26 analyzed varieties met the expected stability features. One variety gave negative results in all assays, and one variety contained the necessary genetic elements for expressing CryIA(b) protein although giving negative results for the long PCR product. To our knowledge, this study is the first post-marketing stability analysis performed on GM commercial seed varieties.     

Possible use of texture characteristics of winegrapes as markers for zoning and their relationship with anthocyanin extractability index

Ribeira Sacra Denomination of Origin is a steep slope viticulture area located in Galicia (northwest of Spain), and it is divided into five different subzones. Taking into account that grape composition depends not only on the grape cultivar used but also on the environmental factors and cultural practices, texture analysis has been proposed to assess the grape mechanical properties of those subzones. With the aid of principal component analysis, berry skin break energy measured on bottom side and berry cohesiveness have been suggested as the best mechanical properties for the subzones differentiation. Moreover, significant correlations among mechanical parameters and anthocyanin extractability index were found. A regression hyperplane allowed estimating anthocyanin extractability from berry skin thickness and Young′s modulus measured on the lateral side of grapes. The speed of mechanical analysis facilitates the planning and management of pressing and maceration processes as a consequence of the drastic reduction in sample treatment time.     

脂肪酶固定化新材料

脂肪酶因其在油脂工业中的重要作用而成为酶研究领域的重点。脂肪酶的不稳定性和高昂的价格是限制其广泛应用的主要原因。对脂肪酶进行固定化是增强其稳定性、降低应用成本的关键。改进脂肪酶固定化工艺的一个重要方面就是选择和开发适合相应脂肪酶的固定化材料。从脂肪酶的固定化材料方面,对无机、有机、复合载体等固定化材料进行了综述,特别是对各种新型的固定化材料予以了归纳,对脂肪酶固定化材料的选择有一定的指导意义。     

Effect of 2,2-azobis (2-amidinopropane) dihydrochloride oxidized casein on the microstructure and microrheology properties of emulsions

The impacts of protein oxidation on the droplet size and microrheology properties of casein emulsions with 20% oil content were investigated. The degree of protein oxidation was indicated by carbonyl concentration. The droplets in the emulsions of different-oxidation-degree casein had bimodal distribution, but their size altered due to oxidation. The effects of protein oxidation on the morphology, motion type, viscoelasticity, and stability of droplets were also investigated by microrheology analysis. The droplet motion was blocked by protein oxidation due to mean square displacement slope results. Solid–liquid balance values provided the liquid behavior dominating these emulsions. Oxidation of carbonyl concentration 16.72 raised the primary droplets, increased the elasticity, decreased the viscosity, and promoted the droplet motion rate, resulting in better stability of emulsions. Further oxidation promoted the aggregation of droplets and resulted in poor stability.     

萝卜红色素的酯化修饰及性质研究

萝卜红色素是安全、无毒副作用的天然食用色素,具有抗氧化能力。但是它的稳定性不高,限制了其在食品工业中的广泛应用。通过乙酰水杨酸酯化修饰色素,测定色素的稳定性,并采用ABTS(2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐)法和邻二氮菲法测定色素的抗氧化活性。结果显示,修饰后的萝卜红色素稳定性明显提高,而且仍然保持较高的抗氧化活性。     

Comparison of Correspondence Analysis based on Hellinger and chi-square distances to obtain sensory spaces from check-all-that-apply (CATA) questions

Sample configurations from check-all-that-apply (CATA) questions are obtained using Correspondence Analysis (CA). Classical CA is based on chi-square distance, which has been reported to be strongly affected by infrequently selected terms. The Hellinger distance has been proposed as an alternative distance metric, and the aim of the present work was to compare product spaces from CATA questions obtained using CA based on chi-square and Hellinger distances. Data sets from 71 studies (5121 consumers), differing by product category, number of consumers, number of samples and number of terms included in the CATA question, as well as frequency of infrequently used terms, were analyzed. For each of the studies, frequency tables were input to CA based on chi-square and Hellinger distances. Sample and term configurations in the first two dimensions were compared using the RV coefficient. Furthermore, the stability of sample and term configurations for each type of distance was evaluated by simulating repeated experiments using a bootstraping resampling approach. Sample and term configurations obtained using Hellinger and chi-square distances were similar (average RV coefficients for sample configurations = 0.99; average RV coefficients between term configurations = 0.89). The stability of sample and term configurations were not largely affected by the type of distance used to analyze frequency tables. Results from the present work suggest that CA based on chi-square and Hellinger distances provide similar results. Contributing to guidelines for practitioners, this research therefore supports classical CA analysis as an acceptable approach to the analysis of sensory-specific CATA data.