钢管对接环焊缝超声波检测对比试块改进的设想

讨论了石油、电力、机械等行业钢管对接环焊缝超声波检测对比试块数量太多给超声波检测带来的问题,针对这一问题设计了通用螺线型对比试块,即将大量常用规格的对比试块整合成少数几块螺线型试块,该试块具有连续的曲率,完全能在其适用范围内很好地与各种管径的管件相对应,成功地解决了对比试块数量多、单块适用范围小、携带不便等问题。     

动态力学及介电法研究蓖麻油丙烯酸酯共聚网络悬挂链的弛豫运动

用动态力学（内耗）和介电方法研究了由蓖麻油（ｃａｓｔｏｒｏｉｌ）、甲苯二异氰酸酯（ＴＤＩ）、丙烯酸羟乙酯（ＨＥＭＡ）组成的网络（Ａｉ）和由正己醇取代Ａ网络中部分ＨＥＭＡ组成的网络Ｂｉ（ｉ＝０，１，２，３）两种网络的内耗及介电损耗，内耗峰强度随悬挂链数目增加而升高，证实了网络破坏后形成的悬挂链的运动对内耗及介电损耗峰高有明显的贡献。     

聚酯－聚醚嵌段共聚物的合成及抗静电性能研究

研究和分析了ＰＥＧ分子量、加料次序、反应时间和温度、物料比例、分散剂和固相缩聚等因素对ＰＥＴ－ＰＥＧ嵌段共聚物分子量和耐水性的影响。合成的嵌段共聚酯醚与ＰＥＴ共混纺丝可以显著改善ＰＥＴ纤维的抗静电性能。     

MCS接枝共聚物的结构和形态

将甲基丙烯酸甲酯（ＭＭＡ）、苯乙烯（Ｓ）在氯化聚乙烯（ＣＰＥ）存在下进行悬浮接枝共聚，获得ＭＣＳ树脂。本文着重考察了ＭＣＳ树脂的化学结构及胶粒形态。结果表明，确实发生了接枝共聚。ＣＰＥ用量、ＲＳＨ含量、引发剂浓度、反应温度、溶胀时间及聚合转化率对ＭＣＳ树脂的接枝率、接枝效率均有影响。ＭＣＳ树脂是接枝共聚物、ＭＭＡ／Ｓ共聚物与ＭＭＡ均聚物的混合物，橡胶相ＣＰＥ在ＭＣＳ树脂中的分散情况为“海岛结构”，     

PC／ABS合金的研制及其在汽车上的应用

对ＰＣ／ＡＢＳ合金开发和研制及其在汽车上的应用作了评述。介绍了上海杰事公司在该领域的进展。     

聚乙烯接枝改性及其与铝的粘结性

聚乙烯在过氧化二异丙苯存在下分别与丙烯酸，顺丁烯酸酐，顺丁烯二酸，顺丁烯二酸钠，丙烯酸羧丙酯，甲基丙烯酸环丙酯等单体熔融挤出，产物的红外光谱表明聚乙烯不同程度地接了各种极性基团。     

CS3000顺控表的组态和应用

介绍CS3000系统顺控表的结构、参数定义和功能块组态,以聚丙烯加氢控制为例,描述顺控表的组态方法、顺控动作和操作步骤等。     

An oblivious fragile watermarking scheme for images utilizing edge transitions in BTC bitmaps

As one of the famous block-based image coding schemes,block truncation coding(BTC) has been also applied in digital watermarking.Previous BTC-based watermarking or hiding schemes usually embed secret data by modifying the BTC encoding stage or BTC-compressed data,obtaining the watermarked image with poorer quality than the BTC-compressed version.This paper presents a new oblivious image watermarking scheme by exploiting BTC bitmaps.Unlike the traditional schemes,our approach does not really perform the BTC compression on images during the embedding process but utilizes the parity of the number of horizontal edge transitions in each BTC bitmap to guide the watermark embedding and extraction processes.The embedding process starts by partitioning the original cover image into non-overlapping 4×4 blocks and performing BTC on each block to obtain its BTC bitmap.One watermark bit is embedded in each block by modifying at most three pixel values in the block to make sure that the parity of the number of horizontal edge transitions in the bitmap of the modified block is equal to the embedded watermark bit.In the extraction stage,the suspicious image is first partitioned into non-overlapping 4×4 blocks and BTC is performed on each block to obtain its bitmap.Then,by checking the parity of the number of horizontal edge transitions in the bitmap,we can extract one watermark bit in each block.Experimental results demonstrate that the proposed watermarking scheme is fragile to various image processing operations while keeping the transparency very well.     

护坡工程空心螺母块立浇及安装施工技术研究与应用

空心螺母块因其外形简单,近年来在河湖生态护坡工程中被广泛应用。但护坡工程使用的空心螺母块数量较多,传统的平浇法预制,所需预制场地大且平整度要求高,螺母块运输安装费时费力、外观质量难以保证。文章针对护坡工程空心螺母块浇筑和安装的特点研究出一种操作简便、切实可行的连续立浇预制安装的施工方法,经过工程实际应用,有效保证了预制块的浇筑质量,提高了预制块的运输铺设效率,节约了预制场地的兴建面积。     

Speech Enhancement via Residual Dense Generative Adversarial Network

Generative adversarial networks (GANs) are paid more attention to dealing with the end-to-end speech enhancement in recent years. Various GAN-based enhancement methods are presented to improve the quality of reconstructed speech. However, the performance of these GAN-based methods is worse than those of masking-based methods. To tackle this problem, we propose speech enhancement method with a residual dense generative adversarial network (RDGAN) contributing to map the log-power spectrum (LPS) of degraded speech to the clean one. In detail, a residual dense block (RDB) architecture is designed to better estimate the LPS of clean speech, which can extract rich local features of LPS through densely connected convolution layers. Meanwhile, sequential RDB connections are incorporated on various scales of LPS. It significantly increases the feature learning flexibility and robustness in the time-frequency domain. Simulations show that the proposed method achieves attractive speech enhancement performance in various acoustic environments. Specifically, in the untrained acoustic test with limited priors, e.g., unmatched signal-to-noise ratio (SNR) and unmatched noise category, RDGAN can still outperform the existing GAN-based methods and masking-based method in the measures of PESQ and other evaluation indexes. It indicates that our method is more generalized in untrained conditions.