Utilisation of free and protein-bound methionine sulphoxide by the chicken

The biological availability of free and protein-bound methionine sulphoxide (MSO) was examined in nine growth experiments with chickens. The source of protein-bound MSO was fish meals oxidised with hydrogen peroxide. Bound MSO in oxidised fish meals was equally well utilised by the chicken as was bound methionine in unoxidised fish meals when the meals were the sole protein sources in the diet. When used as supplements to a low-methionine diet, oxidised fish meals were slightly less well utilised than L -methionine and unoxidised meals at the highest supplementation levels. At a low level there was no difference. Free L -MSO was less well utilised than free L -methionine when added to a soya bean meal diet and when used in purified diets. In the latter cystine was found to improve the utilisation of MSO. High levels of MSO were found in muscle extracts of chickens even when no MSO was present in their diet.     

超临界二氧化碳富集提纯鱼油中EPA和DHA的研究进展（Ⅱ）鱼油的预处理和实验装置

综述了近年来人们用超临界二氧化碳（ＳＣ－ＣＯ_２）从鱼油中富集提纯ＥＰＡ（廿碳五烯酸）和ＤＨＡ（廿二碳六烯酸）的各类实验装置。讨论了鱼油的预处理方法、萃取操作条件对ＳＣ－ＣＯ_２提纯ＥＰＡ和ＤＨＡ的纯度和收率的影响。介绍了一个工业化双塔连续逆流萃取模拟流程。对我国鱼油资源的利用进行了分析。     

原煤识别模式在煤炭产量计量系统中的应用

为了准确计算煤矿的产量,需要把煤矸石的量减掉,针对这个问题,研究了基于图像识别的煤矸石识别技术,从煤矸石与煤炭的样本数据中分离数据,最终完成煤矸石的识别系统。采用自适应增强算法（ AdaBoost 算法）对实现目标的检测达到了很好的效果,虽然原煤图像存在着多样性,受到遮挡、光照、视角等的影响,通过Ada-Boost算法对原煤数据库和非原煤数据库训练逐步提升原煤分类器性能,能成功实现原煤识别检测。论文中识别系统充分利用图像识别技术和人工智能思想,将机器学习引入煤矸石模型的建模环节,成功实现煤炭和煤矸石的区分。     

Data Randomization Scheme for Endurance Enhancement and Interference Mitigation of Multilevel Flash Memory Devices

In this letter, we propose a data randomization scheme for endurance and interference mitigation of deeply‐scaled multilevel flash memory. We address the relationships between data patterns and the raw bit error rate. An on‐chip pseudorandom generator composed of an address‐based seed location decoder is developed and evaluated with respect to uniformity. Experiments performed with 2x‐nm and 4x‐nm NAND flash memory devices illustrate the effectiveness of our scheme. The results show that the error rate is reduced up to 86% compared to that of a conventional cycling scheme. Accordingly, the endurance phenomenon can be mitigated through analysis of interference that causes tech shrinkage.     

基于人工鱼群的中继卫星多用户检测方法

随着航天技术的发展,未来的中继卫星系统需要为多个用户航天器提供码分多址通信服务。因此需要采用多用户检测技术来抑制多个用户航天器信号之间的多址干扰。文中将人工鱼群优化算法引入到中继卫星系统多用户检测中,通过模拟人工鱼群觅食过程中的觅食行为、聚集行为以及尾随行为,利用人工鱼群的迭代优化,实现多址干扰的最小化。为加快人工鱼群算法的收敛速度,文中将解相关多用户检测的结果作为人工鱼群算法的迭代初值。结果表明,基于人工鱼群算法的多用户检测方法误码率在信噪比为10 dB时可以达到10 ^-6数量级,在误码率、远近效应以及用户容量等方面的性能优于传统的多用户检测方法。     

Use of β-hydroxyacyl-CoA-dehydrogenase (HADH) activity to differentiate frozen from unfrozen fish and shellfish

 Further work on an enzymic method to differentiate frozen from unfrozen fish and shellfish is reported. The method is based on the release of the β-hydroxyacyl-CoA-dehydrogenase (HADH) from mitochondria during freezing. Enzymic activity was evaluated in fresh and frozen thawed samples from sole (Solea solea), sea bream (Pagellus centrodontus), hake (Merluccius merluccius), gilt headed bream (Sparus aurata), sea bass (Dicentrarchus labrax), salmon (Salmo salar), prawn (Penaeus japonicus) and Norwegian lobster (Nephrops norvegicus). Changes in the HADH activity of fresh and frozen thawed samples were compared after freezing at –196  °C for 15 min. Two values were obtained: U (by dividing: HADH activity of samples frozen at –196  °C, then thawed/HADH activity of unfrozen samples) and F (by dividing: HADH activity of samples frozen at –18  °C, thawed, then frozen at –196  °C /HADH activity of samples frozen at –18  °C, then thawed). Statistical analysis showed significant differences (P≤0.05) between both quotients for gilt headed bream, salmon, sea bream, sole and prawn, and an arbitrary limit was set at 2 to differentiate frozen thawed from unfrozen samples. The application of this limit made it possible to discriminate the unfrozen from the frozen thawed state of around 90% of the total samples analysed. Best results were obtained for prawn (100% of samples differentiated). In the present paper, a laboratory routine is proposed based on the comparison of the HADH activity of a sample analysed straight away and that of a sample frozen at –196  °C and then thawed. The reported method is simple and fast. The entire laboratory procedure can be performed in 45 min. Received: 20 July 1998 / Revised version: 2 November 1998     

用于果汁和蔬菜汁生产的分离机和卧螺（续）

表１２　用于红醋栗汁和接骨木汁生产的卧螺的生产能力卧螺型号ＣＡ５０５生产能力ｍ３／ｈ干固形物％凝固物含量％红醋栗汁８～１４４３～４９０－１～０－２接骨木汁７－５～１２－０４４～４５０－３～２－０　　图１２说明了草莓汁的加工工艺。新鲜的或解冻的水果经压碎、加热和酶处理（在所需的停留时间后）,然后被送入卧螺分离成汁液和果渣。原料产品→清洗／解冻→粉碎→变速Ｍｏｈｎｏ泵→管式热交换器（３８℃）→卧螺→进一步加工成所需的产品图１２　草莓汁加工工艺表１３列出了用于草莓汁和树莓汁生产的ＣＡ４５８型和ＣＡ５０…     

罗非鱼油的制取工艺及其氧化防止方法

以罗非鱼的鱼内脏为研究对象 ,采用钾盐蒸煮法从罗非鱼内脏中提取鱼油的工艺条件和纯化不饱和脂肪酸 (PUFA)的方法 ,对精制鱼油的氧化性及人工合成抗氧化剂 (TBHQ)、VE、茶多酚 3种抗氧化剂对鱼油的抗氧化性能进行了研究 .通过正交试验及对比试验 ,结果表明 ,从罗非鱼内脏中制取鱼油的最佳工艺条件 :水解温度 70～ 80℃ ,水解时间 4 0min ,KNO3用量 6 g/dL ,盐析时间 10min ;采用低温 钾盐乙醇法纯化鱼油PUFA的效果比尿素包埋法好 ;TBHQ、VE、茶多酚 3种抗氧化剂对鱼油抗氧化作用以茶多酚效果最好     

长江葛洲坝下游鱼类资源量的关键水文指标识别

采用遗传规划法和相关系数法识别影响鱼类资源量的关键水文指标,结果显示坝下经济鱼类天然捕捞产量与年最大流量、高流量脉冲历时、10月和12月的月均流量正相关;四大家鱼鱼苗丰度与涨水率、7日最大流量、5月和6月的月均流量正相关;中华鲟繁殖群体数量与基流指数和涨水率呈正相关,与年最小流量、日均流量逆转次数负相关。这些水文指标分别反映了流量的量值、变化率和历时等特征对鱼类的影响。建立了关键水文指标与鱼类资源量之间的非线性函数关系式,通过对比计算值与实测值发现遗传规划法的拟合效果明显优于相关系数法,表明遗传规划法更适用于识别影响鱼类资源量的关键水文指标。     

为我国造纸工业现代化开拓前进：———建议制定我国造纸工业发展纲要

根据美国制定造纸工业２０２０年议程的经验,探讨了从原料方针、产品结构、环保、节能降耗等诸方面入手,实现我国造纸工业现代化的途径。建议结合我国实际情况制定中国造纸工业的发展纲要,并在纳要基础上制定具体的分步实施方案。