超声波辅助酶解法提取食用猪油工艺优化及胆固醇脱除

为开发猪油的提取新工艺,以猪脂肪组织为原料,采用超声波辅助中性蛋白酶酶解法提取食用猪油。在单因素试验的基础上,以猪油的提取率为考察指标,采用正交试验方法研究蛋白酶添加量、酶解时间、超声波功率和超声时间对猪油提取率的影响,并通过吸附条件的优化,研究β-环糊精、羧甲基纤维素及马铃薯变性淀粉3 种吸附剂对猪油胆固醇的脱除效果。结果表明：各因素对猪油提取率的影响从大到小依次为蛋白酶添加量＞酶解时间＞超声波功率＞超声时间;超声波辅助酶解提取食用猪油的最优工艺为蛋白酶添加量550 U/g、酶解时间80 min、超声波功率720 W、超声时间120 s,在此条件下,猪油的提取率为（95.14±1.65）%;3 种吸附剂对猪油胆固醇均具有明显的吸附效果,脱除能力依次为β-环糊精＞羧甲基纤维素＞马铃薯变性淀粉。     

Optimizing bioconversion of ferulic acid to vanillin by <Emphasis Type="Italic">Bacillus subtilis</Emphasis> in the stirred packed reactor using Box-Behnken design and desirability function

A stirring bioreactor packed with a carbon fiber textiles (FT) biofilm formed by Bacillus subtilis was used to produce vanillin from ferulic acid. Biofilm formation was characterized by scanning electron microscopy. The interactive effects of three variables on vanillin molar yield (M) and conversion efficiency of ferulic acid (E) were evaluated by response surface methodology (RSM) with a Box-Behnken design (BBD). The optimal conversion conditions with a maximum overall desirability D of 0.983 were obtained by a desirability function. Considering the actual operation, the confirmation tests were performed using the slightly modified optimal conditions (initial ferulic acid concentration 1.55 g/L, temperature 35°C, stirring speed 220 rpm). The results showed that M and E were 57.42 and 93.53%, respectively. This was only 1.03% and 1.87%, respectively, different from the predicted values, confirming the validity of the predicted models. These revealed that the stirred packed reactor could be successfully used in vanillin bioconversion from ferulic acid.     

Adaptive residual-based distributed compressed sensing for soft video multicasting over wireless networks

Recently, multicasting of video signals has become a useful technology in wireless networks, in which the main challenge is to scalably serve multiple receivers that have different channel characteristics. In this paper, we propose an adaptive residual-based distributed compressed-sensing scheme for soft video multicast (ARDCS-cast). At the encoder, we first adaptively determine if a block in a non-reference frame should be measured directly or predictively during compressed-sensing. The resulting adaptive measurements from non-reference frames are then packeted together with the measurements of the reference frames. We further derive the optimal power allocation scheme for the measurements from each frame within each packet. The packets are then transmitted over the wireless channel. At the decoder, the receivers with different channel characteristics obtain different numbers of packets and reconstruct videos with different quality. Experimental results show that the proposed ARDCS-cast is more effective than the state-of-the-art SoftCast-2D, SoftCast-3D and DCS-cast schemes in both unicast and multicast scenarios.     

改进的DetNet大规模MIMO检测器

对DetNet结构进行改进以提升大规模MIMO（Multiple-Input Multiple-Output）信号检测性能。首先,去除输入端的冗余向量简化网络中每个检测单元的结构;其次,为了进一步提升网络性能,借鉴随机森林在每个决策树的输入端引入随机性的思想,通过复制网络将原网络中的检测单元扩充为两个,构造成孪生网络的结构,并在其输入端设置不同的初值向量。仿真结果表明,结构优化后的网络比原DetNet具有一定的性能提升。     

宽带大规模MIMO-OFDM系统自适应稀疏信道估计方案

大规模MIMO-OFDM系统下行链路利用压缩感知算法获得信道状态信息需要已知信号的稀疏度作为先验条件,然而实际环境中,无线信道的稀疏度是未知的。利用大规模MIMO信道的空时共同稀疏性的特点与不同SNR下设置不同停止迭代阈值的思想改进压缩感知重构算法,目的在于使所提算法不仅提升估计性能,还可以准确获得信道的动态稀疏度。通过实验可知,相比传统的CoSaMP算法和S-CoSaMP算法,SSA-CoSaMP算法在同等信噪比下具有更良好的信道估计性能,并且可以自适应地获取稀疏度。更适合实际工程中应用。     

应用多重PCR快速鉴定自然发酵肉制品中6 种葡萄球菌

肉葡萄球菌（Staphylococcus carnosus）、木糖葡萄球菌（S. xylosus）、腐生葡萄球菌（S. saprophyticus）、表皮葡萄球菌（S. epidermidis）、马胃葡萄球菌（S. equorum）和松鼠葡萄球菌（S. sciuri）是发酵肉制品中常见的葡萄球菌,为准确、快速地检测和鉴定这些菌种,建立6?种葡萄球菌的多重聚合酶链式反应（polymerase chain reaction,PCR）方法并进行验证。以上述菌种的gap、rpoB、SodA和SNc为靶基因,设计和筛选菌种特异性引物6?对,优化PCR体系,建立6?种葡萄球菌的多重PCR鉴定方法。实验结果显示多重PCR的基因组DNA检测灵敏度可达到4?pg,活菌检测灵敏度可达到2×102?CFU;采用建立的多重PCR方法对传统肉制品中分离的8?株葡萄球菌进行鉴定,结果与16S rDNA序列分析、生理生化鉴定结果一致。建立的多重PCR方法具有较高的种间特异性,可快速、准确地用于发酵肉制品中肉葡萄球菌、木糖葡萄球菌、表皮葡萄球菌、马胃葡萄球菌、松鼠葡萄球菌和腐生葡萄球菌的检测和鉴定,具有较好的应用前景。     

低聚半乳糖分离纯化研究进展

低聚半乳糖（GOS）是一种功能性低聚糖,因其具有独特的理化性质及生理功能,被广泛地应用于食品、医药等领域,市场前景十分广阔。该文综述了低聚半乳糖的性质及制备方法,对其分离纯化方法进行重点介绍,最后对高纯度的GOS的制备进行了展望。     

基于GIS的长白山地区山体滑坡易发程度分析

将地理信息系统（GIS）和遥感技术（Rs）相结合,利用地质图、土壤图、土地利用图、坡度图、坡向图对长白山地区进行了山体滑坡易发程度分析．首先基于遥感技术对长白山地区的卫星图像进行了分类,并绘制了土地利用图,然后用长白山地区的数字高程模型分别获取了坡度和坡向信息;其次利用AHP技术计算了5种山体滑坡影响因子的重要度,结果显示坡度重要度最高,坡向重要度最低;最后根据山体滑坡影响因子的重要度,使用GIS的栅格数据叠置功能绘制了山体滑坡易发区划图,图中显示最危险区域（危险度≥O．9）主要分布在集安市、临江市和和龙市周围的山区地带中靠近中朝边界的地区．     

季铵盐类表面活性剂的生物降解性与其结构的关系

引　言季铵盐是一类阳离子表面活性剂 ,2 0世纪以来已越来越多地应用于工业和日用品中 .随着表面活性剂工业的发展 ,该系列化合物不断开发出新用途 ,在许多行业和领域发挥了重要作用 ,例如在轻工、纺织助剂、石油化学品、卫生用品添加剂等领域用作抗静电剂、柔软剂、腐蚀抑制剂     

HTA隐性酸完井液体系的室内研究

针对因钻井液完井液与水泥浆滤液不配伍而产生沉淀,对储层造成损害的问题,研究出本身对储层无损害、且能消除沉淀的ＨＴＡ隐性酸完井液体系。室内和现场试验表明,该完井液能消除钻井液与水泥浆作用后所产生的无机垢和有机垢,提高岩心渗透率,对钢材的腐蚀影响满足水质腐蚀要求,值得推广应用。