某工程吹填泥沙堆积数值模拟及施工方法优化

在实际近岸吹填工程中,由于无法形成有效的围堰保护导致吹填沙流失、水质污染等严重后果,进而影响施工项目的整体建设,故利用Mike21FM和Mike21ST模型对非洲某吹填工程进行数值模拟,得到该吹填工程附近海域的水面线、流速、泥沙淤积等流场数据,并基于模拟结果对施工方法进行改进。结果表明,施工期间,排沙管口附近水面高程会产生波动且管口两侧流速较大,致使排沙方向偏移,影响最终吹填效果;优化后的施工方法可有效完成吹填任务。     

面向维修的备件共享服务及配置优化

备件的共享服务及配置优化水平对装备维护水平起着关键作用.针对现有备件管理在服务能力和配置优化方面存在的不足,提出基于维修BOM的备件共享服务方法,在备件库存确定的情况下,实现了备件利用率和精准服务能力的提升;提出基于备件BOM的串联系统备件配置优化方法,实现以系统备件满足率和保障任务时长为约束、以备件配置成本最小为目标...     

某铁矿尾砂充填材料的力学性能试验研究

结合某铁矿实际情况,为满足某铁矿地下开采扩建工程充填采矿的需要,开展矿山生产现状与充填物料调研与分析、充填材料基础物理化学性质研究、充填材料配比试验研究、充填料浆流变特性试验研究、新型胶凝材料的探索试验等一系列测试与试验分析研究工作,为充填系统设计提供依据。根据测试结果和分析结论,针对某铁矿充填料浆输送能力100～120m3/h,充填倍线约为5的情况下,推荐输送浓度66%～68%,推荐输送管径100～110mm。     

Comparative analysis of two different types of fills used in wet cooling tower for higher‐scale water with conventional film type fill

In the present study, an induced draft wet cooling tower has been experimentally investigated using film, glass, and ball fills. Film fills are used only in industry where scaling is less or low‐scale process water is used because of clogging of fills. Whereas, glass fills and ball fills are used for higher‐scale water. The main objective of this study is to investigate the performance and compare the result of film fills with glass fills and ball fills and also predict the loss as compared to film fills when glass and ball fills were used for high‐scaling water under such environmental conditions and different ratio of water to air flow and water inlet temperatures. Various performance parameters are analyzed for each of the fills and it was found that tower characteristics of film fills are 18.56% and 15.59% more than that of glass and ball fills, respectively, at water inlet temperature of 43°C and water‐to‐air flow ratio of 0.62. Moreover, exergy destruction was also calculated for each of the fills and it was observed that film fills destruct less exergy as compared with glass and ball fills.     

Equation to predict feed intake response by lactating cows to factors related to the filling effect of rations

Our objective was to predict the dry matter intake (DMI) response during ration formulation to factors related to the filling effect of rations and their interaction with milk yield (MY) by lactating cows past peak lactation. A data set was developed consisting of 134 treatment means from 34 experiments reported in 32 peer-reviewed articles published from 1990 through 2015. The data set included data for cows ranging from 60 to 309 d postpartum with mean DMI ranging from 17.6 to 30.6 kg/d and MY ranging from 20.3 to 51.1 kg/d. Ration composition among treatments ranged from 12.7 to 21.8% of dry matter (DM) for crude protein, 11.5 to 31.0% of DM for acid detergent fiber (ADF), 25.5 to 48.2% of DM for neutral detergent fiber (NDF), 9.9 to 39.3% of DM for forage NDF (FNDF), and 0.45 to 0.84 for the ratio of ADF% to NDF% (ADF/NDF). Laboratory measures of digestibility of NDF (in vitro or in situ, FNDFD) for the sole or major forage ranged from 24.1 to 72.7%. The model included the random effect of study to account for various experiment-specific effects including different methods of measurement of NDF and FNDFD among studies. The full model also included linear and quadratic effects of crude protein, ADF, NDF, FNDF, ADF/NDF, and FNDFD, as well as their linear and quadratic interactions, and mean MY for each study and its interaction with ration factors. The proposed prediction equation is DMI (kg/d) = 12.0 ? 0.107 × FNDF + 8.17 × ADF/NDF + 0.0253 × FNDFD – 0.328 × (ADF/NDF – 0.602) × (FNDFD ? 48.3) + 0.225 × MY + 0.00390 × (FNDFD ? 48.3) × (MY – 33.1) with mean bias = 0.00 kg/d, root mean square error = 1.55 kg/d, and concordance correlation coefficient = 0.827. Dry matter intake was positively related to MY and ADF/NDF and negatively related to FNDF, and FNDFD was positively related to DMI for cows with high MY but negatively related to MY for cows with low MY. In addition, DMI was positively related to FNDFD for low ADF/NDF but negatively related to FNDFD for high ADF/NDF. The ADF/NDF was included to represent differences in forage fragility between grasses and legumes. The proposed model was compared with the equation recommended by the National Research Council (2001) that was developed using only animal factors by fitting each equation to a subset of the data set that included the required inputs for both. The National Research Council (2001) equation without diet factors had a higher root mean square error and over-predicted DMI at high DMI and under-predicted DMI at low DMI. Our proposed equation should be useful to predict DMI response to factors related to the filling effects of rations during ration formulation.     

堆石料的剪切强度与应力-应变特性

通过对堆石料的大型三轴剪切试验结果进行分析,揭示了堆石料的强度及应力–应变的变化规律,堆石料的强度包络线呈非线性,应力–应变曲线多呈现软化型或弱硬化型。并对邓肯模型的修正及其模型参数试验值的变化规律进行了讨论。     

砂–聚苯乙烯颗粒轻质填料工程特性试验研究

砂–聚苯乙烯颗粒轻质填料是由工程标准砂和超轻质聚苯乙烯颗粒按一定质量配比均匀混合而成的土工合成材料,研究其变形和剪切强度特性是掌握其工程力学特性的重要内容,也是解决实际工程中变形和稳定的重要依据。根据单向压缩试验和三轴固结排水压缩试验研究了此种轻质填料的压缩变形特性、剪切变形特性及剪切强度特性。在单向压缩试验的基础上,分析了轻质材料的压缩变形规律和机制,提出了适合该材料的广义孔隙比概念,并得出一般压缩曲线方程,该方程能考虑孔隙比随荷载和配比的变化。在三轴压缩试验的基础上,观察了轻质填料在三维应力状态下的偏应力–轴向应变–体变的剪切变形规律及K f线的变化规律,并分析了配比和应力状态对三轴剪切变形及剪切强度特性的影响,同时得出了K f线形态变化的分界点。     

考虑性能优化的冗余金属填充算法

冗余金属填充改善了化学机械抛光对于金属和介质表面平坦化的均匀性,却大大地影响了互连线性能．提出一种性能优化的冗余金属填充算法,可减少对关键线网的时延影响．该算法利用扫描线算法找到填充区域,根据线网关键度将填充区域分类,按照优先级对填充数量进行分配,对每个填充区域采用解析式沙漏模型进行冗余金属插入．实验结果表明,该算法在减少冗余金属填充对关键线网的时延影响方面比传统的填充算法平均减少15％．     

超深层致密砂岩储层构造裂缝分布特征及其成因——以塔里木盆地库车前陆冲断带克深气田为例

综合采用岩心、薄片及成像测井等资料,对塔里木盆地克深气田巴什基奇克组超深层致密砂岩储层构造裂缝的基本特征与形成序列进行了分析,在此基础上讨论了裂缝产状、力学性质、密度、开度、充填性和充填物的差异性分布及其成因,最后探讨了不同气藏应采取的储层改造措施和有利勘探目标。结果表明:克深气田主要发育3期构造裂缝,各个气藏之间构造裂缝具有明显差异性,主要受构造变形时间和成岩孔隙水介质环境控制。北部克深5和克深6气藏为早期缓慢挤压变形,主要形成与背斜长轴近似平行的直立或高角度张性裂缝;中部克深2气藏变形时间稍晚,近NS走向剪切裂缝和近EW走向张性裂缝共存,并且前者略占优势;南部克深8和克深9气藏变形时间最晚,主要形成近NS走向的直立剪切裂缝。自北向南,主差应力与岩石抗压强度的比值先增大后减小,裂缝密度随之先增大后减小,同时裂缝优势走向与现今水平最大主应力之间由大角度相交逐渐变为近似平行,并且裂缝形成时间越来越晚,充填率逐渐降低,因此裂缝有效开度逐渐增大。巴什基奇克组沉积期的水体总体呈咸化状态,北部克深5、克深6和克深2区块为淡水-半咸水介质成岩环境,裂缝充填物主要为方解石,储层改造措施应以酸化为主;...     

土石坝健康诊断重要性确定的模糊一致矩阵法

文章提出适用于土石坝健康诊断的多诊断项目重要性确定方法.重点探讨基于总体模糊一致矩阵的诊断重要性确定方法,给出模糊一致矩阵法的具体计算步骤,并结合计算实例予以验证.