运用Simulink实现抑制载波双边带调制的载波提取

分析了在接收端对抑制载波双边带调制信号的载波提取的重要性和可行性,运用matlab中的仿真工具箱simulink实现了载波提取的具体过程。其中包括:平方变换法提取载波和插入导频法提取载波,并举例验证其可行性。最后比较了两个方法的适用范围。结论表明:实验仿真和理论推导的结果基本一致,并可推广到单边带和残留边带调制信号的载波提取中。     

微波加热中试装置的研制及再生载金炭的试验

介绍了自行研制的微波加热中试装置 ,进行了微波加热再生载金炭的试验。试验结果表明 ,当微波功率为 1 8k W、加热时间为 3 0 min时可将预处理后的废活性炭再生 ,按 GB/ T1 2 496.8-1 999分析活性炭的碘吸附值 ,达到 1 1 0 0以上 ,得到了高质量的活性炭。     

Pilot‐Based Coding Scheme for Parametric Stereo in Enhanced aacPlus

We propose a pilot‐based coding (PBC) scheme for lossless bit rate reduction of parametric stereo (PS) in enhanced aacPlus. It uses PBC in addition to the existing frequency and time differential coding to encode and decode PS parameter indexes. We also design optimal Huffman codebooks (HCBs) for PBC in the proposed scheme. Experiments show that the proposed scheme is superior to the original coding scheme, where both the new coding structure and the optimal HCBs contribute to the bit rate reduction.     

Horn meal hydrolysate–chromium complex as a high exhaust chrome tanning agent––pilot scale studies

Acid hydrolysis of horn meal (obtained from raw horns of slaughtered cattle and buffaloes) yields a mixture of water soluble and low molecular weight peptides with average particle size of 3,838 nm (3.84 μm) and mean intensity of 5,243.7 nm (5.24 μm) and mean volume of 6,228.1 nm (6.23 μm). These peptides on reaction with Cr(III) yield a product that exhibits high exhaustion of chromium bath (above 92%) during tanning of hides and skins. To consolidate the results, the process was up-scaled in Central Leather Research Institute (CLRI) pilot plant for commercial trials. This material is applied directly to the pickled pelts at 8% w/w level and then the pelt is converted to wet blues and crust leathers. Control leathers were also processed concurrently using standard chrome tanning salts (8% w/w). Leathers showed the desired level of softness, fullness, shrinkage temperature and physical properties, and are comparable with control ones. Our results have indicated the use of Cr(III)–keratin complex could considerably reduce pollution load of Cr salts in leather processing.     

云南保山矽卡岩型铜铅锌共生矿选矿中间试验

在选矿中间试验条件下,对云南保山地区矽卡岩型铜铅锌共生矿进行了浮选试验研究,取得了较好的选矿指标。中间试验选矿指标为:铜精矿铜品位18.57%,回收率78.04%;铅精矿铅品位67.37%,铅回收率58.26%;锌品位49.11%,锌回收率88.57%。为开发该矿提供了选矿技术依据。     

Dimensional analysis for assessing the performance of electrostatic precipitators

Electrostatic precipitators (ESP) are widely used in industry today and much research has been carried out during the last decades. Dimensional analysis (DA) allows to reduce the number of parameters necessary for defining the ESP performance and provides a reliable scaling-up of the desired operating conditions from the pilot-scale to full-scale plant (based on the invariance of the pi-space). Likewise, DA gives a consistent extrapolation within the range covered by dimensionless number and a greater flexibility in choice of parameters. DA together with similarity analysis is presented in this work in order to obtain a functional dependence between a target number and a set of few dimensionless numbers. The target selected has been the penetration, i.e., the ratio of particle dust concentration at the outlet of the ESP (C_o) and that at the inlet of the ESP (C_i). The results can be valuable to assess the data from ESP of different operating characteristics, under geometric, electrical, fluid dynamics and electro-hydrodynamics similarity. Thus, as a consequence of these analyses, several quite reduced models have been formulated theoretically and later tested and validated with experimental data obtained in a pilot ESP in order to show an application of the study. Four models have been fitted by linear regression, resulting unsatisfactory. However, two additional models fitted by non-linear regression predict values of particle removal efficiency that agrees well with the experimental data. Thus, this paper is focused towards dimensional analysis in ESP model building, showing both the reduction in effort and more effective modeling that can result.     

Entwurf und Konstruktion der Egg‐Graben Brücke

Aufgrund der hohen Erhaltungskosten von Brücken gibt es mittlerweile unterschiedliche Ansätze, um die Dauerhaftigkeit zu erhöhen. Vorgespannte Brücken ohne Betonstahl stellen hierfür einen neuen Ansatz dar. Zur Erforschung des Tragverhaltens solcher Strukturen wurde ein Forschungsprojekt gestartet und Großversuche durchgeführt. Die Landesbaudirektion Salzburg war von dieser innovativen Idee überzeugt und hat deshalb die Technologie beim Bau der Egg‐Graben Brücke ausgeschrieben. Die Egg‐Graben Brücke ist eine im Grundriss gekrümmte Bogenbrücke mit einer Länge von 50 m. Nach einer Bauzeit von 18 Monaten erfolgte im November 2009 die Freigabe für den Verkehr. Der vorliegende Aufsatz beschreibt die Technologie, den Entwurf sowie die beim Bau der Brücke gesammelte Erfahrung. Design and Construction of the Egg‐Graben Bridge Due to the high maintenance costs of bridges, there are now various approaches to enhance the durability. Post tensioned bridges without steel reinforcement represent one of these approaches. To investigate the structural behaviour of such constructions, a research project was started and large‐scale tests were carried out. The government of the province of Salzburg could be convinced of this innovative technology and tendered out the method for the construction of the Egg‐Graben Bridge. For the arch bridge, which is curved in plan, the superstructure is prestressed without using further steel reinforcement. After a construction period of 18 months the bridge was opened to traffic in November 2009. The paper describes the technology, the design and the experience gained from the construction of the bridge.     

Fermentation and elutriation of primary sludge: effect of SRT on process performance

A primary sludge fermentation-elutriation pilot plant was operated using in-line and side-stream schemes. The influence of solids retention time, recirculation sludge flow-rate and solids concentration on the fermentation-elutriation process performance has been assessed in this paper. The use of high elutriation flows (12% of influent flow) improved the volatile fatty acids (VFA) concentration in the effluent stream. Suspended solids removal efficiency decreased in the primary settler when the solids retention time (SRT) was increased from 4 to 8 days. Disintegration step during hydrolysis process was pointed out as the main reason for that decrease. Maximum VFA productions were achieved at SRT between 6 and 8 days at the highest elutriation flow tested for both configurations. Propionic, butyric and valeric volatile fatty acids percentage increased when total solids sludge concentrations above 23,000mgl(-1) were used. Hydrogen accumulation, causing acetogenic bacteria inhibition, was indicated as the reason for C(3)-C(5) fatty acids accumulation.     

啤酒酿造酵母原生质体融合株GR5的中试

报道了啤酒酵母原生质体融合株GR5的中试结果。融合株GR5的凝絮性较强 (本斯值为 2 .7) ,以12°Bx麦芽汁为培养基 ,用 5 0 0L发酵罐在 12℃下发酵 ,发酵至第 8d菌株GR5的发酵度为 6 9.2 % ,发酵液中的双乙酰含量为 0 .0 4 98mg/L、乙醛含量为 6 .34mg/L ,总高级醇含量为 74 .4mg/L ,该菌株生产的啤酒 ,口感柔和、协调 ,略带酯香味。融合株GR5的遗传性稳定 ,是一株具有工业应用前景的啤酒酿造酵母菌株