基于CFF码和I码的抗合谋数字指纹编码

随着抗合谋参数值增大,CFF码的编码效率呈下降趋势。为解决该难题,提出一种新的抗合谋数字指纹编码方案,并设计相应的编码生成算法和检测算法。生成算法以小参数构建的CFF码为内码、I码为外码生成级联编码,编码效率等同于嵌入CFF码的编码效率,降低了编码难度。检测算法在确定编码所在的CFF子块位置后,对指纹特征码字位置进行跟踪从而发现叛逆者。在基于非对称数字指纹的音频盗版追踪系统上进行测试,结果表明,该方案保持了CFF码抗多种类型合谋攻击的特性,叛逆者追踪成功率超过80%,且未发生误判现象,能为依法制裁叛逆者提供法律证据。     

超声波对Al-20Si合金中初晶Si的影响

采用高能超声波对Al-20Si合金熔体进行处理,研究超声波以不同的导入方式对过共晶Al-Si合金中初晶Si的细化效果的影响。试验表明,在Al-20Si合金凝固过程中进行超声波处理,可以促进形核,破碎组织中粗大块片状初晶Si,减小晶粒尺寸,提高圆整度,并使其分布均匀。由于超声波的衰减效应,采用不同方式导入超声波进行处理时,对合金凝固组织的作用效果有较大区别。采用超声波导入杆在距熔体中心1/2半径处做环绕运动导入超声波,能够对初晶Si产生较好的细化效果,所获得的凝固组织细化区域更大,初晶Si分布更加均匀。     

采用随机探测的改进FSOA

针对FSOA中渔夫搜索效率低且易陷入局部极值等不足,提出了一种采用随机探测的改进FSOA算法。该算法采用随机选点与旋转定点相结合的选择探测点方法,并对渔夫的收缩搜索操作做了一定的限制,以进一步提高渔夫的搜索效率。从数值实验仿真结果上看,该改进方法是有效的和可行的。     

An oxides-hydrothermal approach from bulky V2O5 powder to V3O7·H2O nanoribbons or V3O7 nanoflowers in various ethanol/water mixed solvent

V₃O₇·H₂O nanoribbons and V₃O₇ nanoflowers are firstly obtained via facile oxides-hydrothermal (O-HT) route. V₂O₅ bulk-phase powder is directly used as precursor. The 1:1 ethanol/water and absolute ethanol are made as solvent for obtaining nanomaterials of vanadium oxides with different morphologies and structures. Characterizations of the samples are carried out using XRD, TG, FTIR, Raman-Spectra, SEM, TEM, HRTEM, SAED, and UV-vis. The large-scale fine ribbon-like V₃O₇·H₂O nanobelts with thickness ca. 20 nm and length ca. 20-40 μm are obtained in 1:1 (v/v) ethanol/water mixed solvent. The V₃O₇ nanoflowers are constructed by numerous whisker-like nanocrystal or petal-like are obtained in absolute ethanol solvent with the thickness about 20 nm and the size ca. 2-3 μm. The formation mechanism of the sample is discussed.     

无溶剂法合成环氧蓖麻油的工艺研究

以可再生的蓖麻油为主要原料,H3P04作为催化剂,30% H2O2作为氧源,在无溶剂条件下合成环氧蓖麻油.通过正交实验的方法对蓖麻油环氧化反应进行了研究和探讨,得出最佳反应条件为:n(H202):n(蓖麻油双键)=1.4:1,n(甲酸):n(蓖麻油双键)=0.5:1,催化剂H3POa质量分数为蓖麻油的0.3%,反应时间...     

Effects of alkaline treatment on the structure of phosphorylated wheat starch and its digestibility

Phosphorylated wheat starch (PWS) was prepared with sodium trimetaphosphate and sodium tripolyphosphate (99/1, w/w), and the modified starch gave 88.8% total dietary fibre by the Prosky method and 68.7% resistant starch (RS) by the Englyst method. The stability of the phosphate esters in aqueous sodium hydroxide was investigated and related to total dietary fibre and RS contents. The phosphorylated starch was slurried (40%, w/w) at 40 °C for 4 h at pH 9.0, 10.0, 11.0, and 12.0. The phosphorus content of the PWS decreased from 0.37% to 0.29% after treatment at pH 12.0, whereas only a slight decrease in phosphorus content occurred after treatments at pH 9.0–11.0. Despite the 22% decrease in total phosphorus content, total dietary fibre content and RS content of the alkali-treated PWS changed only slightly. ³¹P nuclear magnetic resonance spectroscopy showed that after the alkali treatment at pH 12.0, cyclic monostarch monophosphate and monostarch diphosphate were not detectable and that the level of total monostarch monophosphate decreased from 0.077% to 0.067%. Conversely, distarch monophosphate increased from 0.17% to 0.20%, of ≈18%. The increase in distarch monophosphate (cross-linking) content after alkali treatment at pH 12.0 probably explained the retention of total dietary fibre and RS contents in the alkali-treated PWS.     

胍与磷氧化合物从碱性氰化液中萃取金的研究

研究了胍与磷氧化合物从碱性氰化液中萃取金的性能，考察了胍、磷酸三丁酯（TBP）和三丁基氧化膦（TBPO）的浓度对金萃取性能的影响。结果表明：Au（Ⅰ）的萃取率均随着胍，TBP，TBPO浓度的增大而增大。由胍与磷氧化合物组成的萃取体系对Au（CN）2^-的萃取速度比较快，当[Au（CN）2^-]：100mg·L^-1，胍浓度为0．1mol·L^-1，TBP在有机相中的体积比为30％及相比为1时，萃取2min已基本上达到平衡。水相中金的浓度越高，金的萃取率越低。水相的pH值从10增至13时，金的萃取率逐渐升高。研究了含有Au（CN）2^-，Ag（CN）2^-，Zn（CN）4^2-及Cu（CN）3^3-混合液中对金的萃取选择性，实验表明在pH值为10时金的选择性能最高。实验用亚硫酸钠溶液和硫氰化钾溶液来反萃金，结果表明：硫氰化钾溶液能有效反萃金，且硫氰化钾的浓度为12g·L^-1时，金的反萃率为87．9％。     

Agglomeration detection based on attractor comparison in horizontal stirred bed reactors by acoustic emission sensors

In industrial propylene polymerization technology of Innovene and Chisso, agglomeration of polymer particles in horizontal stirred bed reactors (HSBR) has significant negative impacts on the reactor efficiency. If the hydrodynamic change could be detected early enough, then large chunks may not be formed nor cause an unscheduled shutdown of the plant. A novel non‐invasive acoustic emission (AE) technique combined with an attractor comparison method is presented. It is based on the comparison of the time series of AE signals acquired from a normal state with the time series measured during operation of the bed. The nature of the method is to determine whether or not two time series are generated by the same mechanism. A statistical characteristic S is used to test the null hypothesis that the two multidimensional probability distributions are identical. Experiments were carried out at room temperature in a 475 mm i.d. laboratory HSBR. The results demonstrated that the method is sensitive to small changes in the particle size distribution. It is, therefore, indicated that the proposed method not only can offer “early and accurate warning,” but also has the potential to locate the agglomeration in HSBR with multiple AE sensors. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

安全事故通报引发的思考

2004 年5 月12 日,河南省安阳信益电子玻璃有限公司信益二期玻壳项目 10 号屏炉烟囱工地,施工人员在拆除井架时,由于违章拆除井架缆风绳,导致井架倾覆,造成施工人员 21人死亡、10 人受伤,直接经济损失268.3万元。国务院领导对此高度重视并做出批示。建设部办公厅于同年 11 月19日发布了建办质(2004)100 号《关于对河南省安阳市信益二期工程“5·12”特大施工伤亡事故的通报》(以下简称“通报”),并附有《河南省对安阳市信益二期工程“5·12”特大施工伤亡事故处理的情况》。通报公布了建设部对施工单位给予降低资质等级处罚;同时对该项目的…     

再生铜熔炼过程节能与提质关键技术研究

通过对再生铜熔炼系统进行热工测试及其设备运行状况的分析,发现再生铜直接熔炼制造光亮铜杆的生产过程中存在燃气品质低、燃烧器结构不合理、金属回收率低、产品杂质含量偏高的问题。为解决这些问题,开发出一种净化与水封一体化的重力水除尘器以提高燃气品质;采用螺旋式高速配风燃烧器提高燃料燃烧效率及反射炉内温度分布均匀度;在反射炉熔炼过程中采用低温扒渣技术解决铁类杂质污染液态铜的问题;采用氧化还原期温度调控技术,以提高铜回收率及产品品质、缩短熔炼周期。通过以上多项技术措施的应用,降低了再生铜熔炼过程的能耗及铜损耗,提高了光亮铜杆产品的质量,使产品的伸长率及扭转等性能优于行业标准,同时降低了废气对环境的污染。