介孔分子硅剂改善茶浓缩膜结构特性应用研究

为有效提高功能性茶浓缩反渗透膜的回收效率和抗污性能,探究了3种介孔分子硅材料(MCM-41、SBA-15和MCFs)对浓缩膜面聚酰胺层聚合形成过程的结构影响。结果表明,添加质量分数0.02%经磺化预处理的MCM-41于间苯二胺水相可接枝酰氯基团,形成的聚酰胺结构层峰谷粗糙跨度仅为220 nm且交联紧致,膜抗拉伸强度增加37.8%;SBA-15和MCFs相膜面峰谷跨度达500~780 nm,横向褶皱和团聚,结构存在孔道塌陷;改性膜在3 h内对茶多酚、茶多糖、茶蛋白即可达到最大浓缩度,减少50%浓缩时间;MCM-41和SBA-15膜长时间运行的浓缩降率仅为2.8%~6.1%,48 h下降率比显示改性膜达标使用时长增加112.5%~137.5%,亲水性和抗污堵能力均大幅提升,可有效满足功能化茶浓缩精度。     

影响煤层气开发效果的地质因素再认识

地质特征认识对煤层气开发效果起着重要作用。在资源特征相差不大的情况下,发现煤层气相邻井的产量差异仍较大。排除工程因素后,通过选取8类地质参数,细致比对了保德区块低产井与邻井的参数特征,筛查出其关键因素为煤层微幅构造与顶板封盖条件,其中以微幅构造为主。据此,重新认识并划分出区块新的次生褶皱背斜单元、向斜单元和斜坡单元,获得了不同次生褶皱构造单元的开发特征。结果表明,高、低产井分布与次生褶皱背斜、向斜相关性高达92%。其中:高产井主要分布在次生褶皱背斜变化较缓、呈隆起状的“平台”,且煤层顶板以泥岩、碳质泥岩为主,封盖性较好;低产井主要分布在次生褶皱向斜,同一井台各井开发效果差异表现为从向斜条带轴部—向斜条带内—向斜条带外的煤层气井平均单井产量不断增加,到向斜轴部的距离大于向斜曲率半径73.5%的范围为主力产气区,小于向斜曲率半径40.0%范围为产水主力区。这对煤层气新井部署、生产管理、开发调整等,具有一定的指导意义。     

铝碳质长水口用低铝抗氧化涂层的研制

为抑制铝碳质长水口使用过程中石墨的氧化，其表面会涂覆含 20%~30%Al₂O₃的抗氧化涂层，但切割丝钢等特种钢冶炼过程必须严格控制钢液中夹杂的 Al₂O₃的含量，因此需要制备低氧化铝含量的抗氧化涂层。本文通过调节涂料组成、加水量和水玻璃加入量制备了低铝抗氧化涂层，并利用扫描电镜分析了抗氧化实验后试样断口的显微结构。结果表明：以粘土粉、钾长石粉和硅砂为主要原料，添加 10%硼砂的涂料可在 800 ℃形成良好的釉层，此时涂料中 A12O3的含量可降至 12%，得到了低铝涂料；当加入占涂料质量 80%的水和 40%的水玻璃时，涂层具有最佳的涂覆性能和抗氧化性能，涂层和长水口基体结合致密，保护了长水口中的石墨不被氧化。     

Image and Feature Space Based Domain Adaptation for Vehicle Detection

The application of deep learning in the field of object detection has experienced much progress. However, due to the domain shift problem, applying an off-the-shelf detector to another domain leads to a significant performance drop. A large number of ground truth labels are required when using another domain to train models, demanding a large amount of human and financial resources. In order to avoid excessive resource requirements and performance drop caused by domain shift, this paper proposes a new domain adaptive approach to cross-domain vehicle detection. Our approach improves the cross-domain vehicle detection model from image space and feature space. We employ objectives of the generative adversarial network and cycle consistency loss for image style transfer in image space. For feature space, we align feature distributions between the source domain and the target domain to improve the detection accuracy. Experiments are carried out using the method with two different datasets, proving that this technique effectively improves the accuracy of vehicle detection in the target domain.     

A Novel Beam Search to Improve Neural Machine Translation for English-Chinese

Neural Machine Translation (NMT) is an end-to-end learning approach for automated translation, overcoming the weaknesses of conventional phrase-based translation systems. Although NMT based systems have gained their popularity in commercial translation applications, there is still plenty of room for improvement. Being the most popular search algorithm in NMT, beam search is vital to the translation result. However, traditional beam search can produce duplicate or missing translation due to its target sequence selection strategy. Aiming to alleviate this problem, this paper proposed neural machine translation improvements based on a novel beam search evaluation function. And we use reinforcement learning to train a translation evaluation system to select better candidate words for generating translations. In the experiments, we conducted extensive experiments to evaluate our methods. CASIA corpus and the 1,000,000 pairs of bilingual corpora of NiuTrans are used in our experiments. The experiment results prove that the proposed methods can effectively improve the English to Chinese translation quality.     

基于3D打印技术复制砂浆节理的剪切试验及峰值抗剪强度模型

为进一步研究节理三维形貌特征与节理峰值抗剪强度的关系,首先采用巴西劈裂试验获取了自然劈裂岩石表面,通过三维扫描技术获取了节理面形态的高精度点云,通过逆向建模得到了自然岩石表面的立体模型,结合3D打印技术制作出了与自然岩石表面一致的PLA模具,以3D打印获得的底模通过水泥砂浆浇筑了含有自然结构面形貌的相似节理面试样。PLA模具与复制材料差异较大,复制材料在凝结过程中不易与PLA模具黏结,进而使脱模过程较为方便,不会破坏节理面。同时PLA模具可重复进行相似材料复制工作,具有可重复使用的优点。然后进行了具有5组形貌面的20个水泥砂浆节理面在4种不同法向荷载情况下的结构面剪切试验,得到了结构面剪切位移-荷载曲线。研究了结构面峰值抗剪强度、峰值位移、剪切刚度影响因素。节理经过剪切后形貌面出现不同程度的磨损,其磨损范围与等效高差分布范围基本一致,并且在等效高差为剪断破坏模式且成片的区域磨损较为严重。在新粗糙度指标基础上提出了新的峰值抗剪强度模型,经试验对比显示出新模型的有效性。在新模型基础上提出了一个简化模型。对比发现新模型简化后其计算精度较新模型有所降低但由于所需参数减小计算较为方便,新模型简化结果精度虽然有所下降但是还是比Barton公式精度高。     

乌拉根锌矿排土场稳定性分析

排土场的稳定性研究是露天矿山安全性管理的重点，也是矿山可持续发展的关键。以乌拉根锌矿排土场为例，在岩土工程勘察的基础上，利用Geo slope软件，运用极限平衡法和有限元法对排土场边坡危险剖面在正常工况下及降雨入渗工况下的稳定性进行数值模拟。计算结果表明，正常工况下，边坡处于基本稳定状态；降雨入渗后，边坡安全系数降低3.9%，处于欠稳定状态，应加强排土场降雨预报和监测管理。