滚刀式切丝机上排链运动对切丝宽度稳定性的影响

通过对滚刀式切丝机工作原理和上排链运动机理分析,明确了切丝机上排链及上刀门的运动频率影响切丝宽度稳定性的主要原因。为此,提出了上排链运动形式的改进思路:减少切丝机刀门高度的变化频率,改善喂料振槽或垂直送料器的输送效果以降低烟饼厚度的频繁变化,刀门变化时上排链速度随动。但提高切丝宽度稳定性的最佳方法是保证物料输送的均匀性,使物料均匀地进入切丝机,才能从根本上减少刀门变化的频率。     

TOBSPIN切丝机气动反吹式烟叶回收单元的设计

为解决TOBSPIN切丝机烟叶回收单元中存在的物料分离不彻底等问题,采用气动反吹自动循环分离方法,设计了一套气动反吹式烟叶回收单元。该装置主要由折叠空气滤芯、气动三联体、中心轴、反吹管、减速器等部件组成,采用折叠空气滤芯代替原回收单元中的15根滤棒,利用压缩空气推动中心轴及反吹管旋转,对粘附在滤芯上的烟叶进行反吹,实现物料分离。结果表明:改进后有效解决了因滤棒孔堵塞而造成的设备频繁停机等问题,6个月内设备故障停机次数由82次下降为0,排链损坏数量由153件减少为0,烟叶损耗由694.5 kg减少为0,节约生产成本约35.84万元,提高了设备运行效率。     

KTC80型切丝机国产导丝条的改造

KTC80型切丝机导丝条配件国产化后,国产导丝条在生产过程中出现排丝不畅、烟丝粘连等问题,为减少切丝过程中的夹刀现象,通过分析国产和进口导丝条的结构差异,发现抛料槽圆角半径不一致是导致国产导丝条排丝不畅的主要原因.为此,对国产导丝条进行了局部改进,导丝条抛料槽圆角半径由1.75 mm增大到2 mm,导丝条高度由28 m...     

KTC80切丝机驱动系统的改造

KTC80切丝机采用液压驱动,工作压力高,液压油易泄漏污染烟丝,为此对切丝机驱动系统进行了改造.改造后切丝机取消了液压系统及PIV减速器,采用交流异步伺服电机、交流同步伺服电机分别驱动刀辊、排链;采用S7 - 300C PLC对刀辊转速和排链转速实施控制,烟丝宽度通过触摸屏可任意设定;采用气动控制直角曲柄增压机构压实烟草物料.应用结果表明,改造后KTC80切丝机解决了漏油问题,梗丝宽度误差减少了1.41百分点,碎丝率降低了0.03百分点,整丝率提高了0.98百分点.减少了零配件数量,降低了备件费用,操作维修简便,提高了设备的整机技术水平.     

拉带大卷筒自动夹紧装置在YB55透明纸小包机上的应用

YB55透明纸小包机使用拉带小卷筒时,通过人工旋紧螺纹夹紧卷筒,而且更换拉带次数频繁,停机时间长.采用拉带大卷筒自动夹紧装置后,减轻了操作人员的劳动强度,拉带更换周期由原来的4.5 h增加到12 h,停机时间由原来的10 min左右缩短为3 min左右,提高了包装机的有效作业率.     

TOBSPIN切丝机刀盘轴承间隙快速调整装置的设计

为解决TOBSPIN切丝机因刀盘轴承间隙增大而造成刀盘窜动等问题,设计了一种刀盘轴承间隙快速调整装置。在主轴上增加平端调整螺钉和平端紧定螺钉,将主轴轴套内套长度缩短30 mm,通过调节平端调整螺钉可以快速将刀盘轴承间隙由0.35 mm减少到设定值0.05 mm,同时利用SolidWorks simulation软件对主轴进行了受力分析。将HAUNI调整工具与快速调整装置进行对比测试,结果表明:采用快速调整装置后,平均调整时间缩短27.33 h/台,切丝平均合格率提高8.48百分点。该技术可为提高切丝质量的稳定性提供支持。      

热连轧自动辊缝水平调整系统设计及应用

对轧件跑偏的状态进行了分析,得出轧制力差的变化方向和大小可以作为轧件跑偏方向和程度的依据.设计一种自动辊缝水平调整系统,可以实现对轧制跑偏进行有效控制,通过在1 780 mm轧机上试验应用,甩尾率由年均0.8％下降到0.12％左右.带钢楔形平均值由150～200 μm减小到50～100 μm,取得了良好效果.     

SQ35切丝机刀辊进刀压链轮故障分析与改进

SQ35切丝机在生产过程中经常出现刀辊不进刀故障,原因在于压链轮与轴的间隙过大,压链轮中的滑动轴承内圈孔径磨损严重,导致1、2级涡轮蜗杆出现胶合、滚压变形、折断等现象.为此,对SQ35切丝杌的进刀压链轮进行了改进,将滑动轴承改为滚针轴承,采用骨架油封圈结构保证润滑油不受污染,从而降低了摩擦阻力以及链条的张力,提高了轴承的承栽能力,减少了进刀系统故障次数,保证了设备的正常运转以及切丝质量的稳定.实际应用表明,单台切丝机的年换件故障维修次数由改进前的43次减少为12次,由于设备故障造成的不合格烟丝量由2365 kg减少为660 kg.     

TOBSPIN切丝机进刀电机拆卸工具的研制

为解决TOBSPIN切丝机进刀电机拆卸困难等问题,基于Solid Works机械仿真设计软件研制了一种进刀电机拆卸工具。该装置使用了盘式定心拉拔工具组件,主要由定心轴、中心螺杆、法兰、固定丝杆组成。在电机拉拔过程中定心轴起到定心以及支撑电机悬空部分的作用;中心螺杆为M18螺杆,螺纹为梯形螺纹;法兰厚度为20 mm;环形均布的固定丝杆使电机受力更均匀。测试结果表明:采用专用工具拆卸进刀电机的时间比改进前减少34.5 min/台,且避免了对零部件造成损伤,降低了工人劳动强度。该方法可为提高设备维修工作效率提供技术支持。     

平顶链链轮的改进

目前钢制平顶链包装输送线的平顶链轮有两种:第一种为碳钢链轮;第二种为对开式塑料链轮。两者相比,运行时前者为钢与钢接触,相互磨损较快,一旦平顶链轮严重磨损,链板就会产生抖动,如不及时更换,将加剧两者的磨损,同时影响物料的平稳输送一更换链轮时,我们不得不将整根轴从轴承座上取下.由于链板液的浸泡,平顶链轮与轴已锈蚀,拆卸非常困难,有时多排链轮的中间链轮磨损     

一种RNA提取试剂盒--TRIZOL的使用方法初探

以酿酒酵母为原料，利用TRIZOL试剂快速提取法，得到的总RNA不完整，只有5s rRNA一条条带，经过对该试剂盒的改进后提取的总RNA呈现28s rRNA，18s rRNA和5s rRNA三条清晰的条带，很少有降解，其A260／A280值可达1．946，A260／A230值为2．070，具有很高的纯度。     

RC4切丝机切丝宽度误差分析

通过计算和实验发现,RC4切丝机切丝宽度的计算公式中修正系数K取值过大,造成实际切丝宽度偏小,偏离设计值约8%。这是由于RC4切丝机上下排链的进给线速度不一致,造成切丝宽度不均匀。提出了将公式中系数K由0.52改为0.48,将上排链蜗轮蜗杆传动比增大22.1%,改进后保证了烟叶从刀门输出时断面速度一致。     

近红外光谱法快速检测甜菜糖度的模型优化

目的建立起近红外光谱技术关于甜菜糖度的最佳预测模型。方法研究了Savitzky-Golay平滑处理、Savitzky-Golay导数、均值中心化、差分求导、净分析信号、去趋势校正、标准正态变量变换和多元散射校正等8种预处理方法的多方法联用处理进行光谱数据的预处理,结合光谱波段优选,建立甜菜糖度与近红外光谱的预测模型。结果在进行模型的评价时,以误差均方根(SEP)、校正标准误差(SEC)与交叉检验误差(SECV)作为评价指标。结论发现经过光谱波段优选之后,结合Savitzky-Golay平滑、Savitzky-Golay导数、去趋势校正及均值中心化进行光谱数据的预处理得到的模型效果最佳。     

浓香型白酒酒醅中总RNA提取方法评价

为探寻我国特有的复杂微生态环境——浓香型酒醅样品总RNA提取方法,本实验建立了一种改良的十二烷基硫酸钠(sodium dodecyl sulfate,SDS)-苯酚法,并从提取成本及耗时、RNA质量浓度和纯度、电泳结果、反转录效果及高通量测序分析5 个方面,比较其与试剂盒法、Trizol法、十六烷基三甲基溴化铵(hex...     

Assignment of most genes encoding major peroxisomal polypeptides to chromosomal band V of the asporogenic yeast Candida tropicalis

The peroxisomes of the asporogenic yeast Candida tropicalis contain about 20 major polypeptides (PXPs). We have isolated a number of genes encoding them; 11 POX genes encoded independent PXPs and three POY genes were likely to encode three other PXPs. To locate these genes on the chromosomes, chromosomes of C. tropicalis were separated by pulsed-field gel electrophoresis. Eight chromosomal bands were observed over the range of 1.0 Mbp (band 1) to 2.8 Mbp (band VIII); the genome size was estimated to be about 20 Mbp. Southern blot analysis showed that ten genes were on band V, three genes were on band IV, and the other gene was on band VI. Three genes gave hybridization signals of nearly equal intensity on two different chromosomal bands: POX6A and POX8B, on bands V and VII; and POX8A, on bands IV and VI. Ribosomal RNA genes also hybridized to two bands, VI and VII. Most genes assigned to only one band hybridized to two restriction fragments produced by either NotI or SfiI endonuclease. The results suggested that C. tropicalis was diploid and that restriction sites were conserved little between homologues. The three POX genes that were found on two chromosomal bands hybridized to not more than two restriction fragments, implying that the allelic genes were present on different chromosomal bands.     

汾酒大曲酯酶和淀粉酶同工酶的分析

利用同工酶技术进行了清茬、后火和红心3种汾酒大曲酯酶和淀粉酶同工酶的比较研究。大曲电泳参数研究表明:酯酶和淀粉酶同工酶电泳分离胶浓度分别为12%和10%,上样蛋白浓度分别为5.5～11 mg/mL和0.34～0.69 mg/mL,连续抽提10批储存9 d,同工酶电泳图谱一致稳定。3种大曲同工酶酶谱分析表明:每种大曲都含有丰富的酯酶和淀粉酶同工酶酶带。3种大曲酯酶同工酶谱主带的数量和位置基本相同,曲皮、曲心和整曲也基本一致,仅在弱带区有所不同。3种大曲淀粉酶同工酶谱明显不同,后火曲有一条特征主带。曲心明显不同于曲皮和整曲,曲心的淀粉酶同工酶酶谱明显将3种大曲鉴别,其中有一条酶带可作为后火曲的同工酶标记。10批混合生产用曲的同工酶分析,酯酶和淀粉酶同工酶酶谱基本一致,淀粉酶同工酶谱分析混合曲中有后火曲存在。     

Measurement of vertical and horizontal vibrations of a probe for acoustic evaluation of food texture

Two‐dimensional (vertical and horizontal) vibrations of a wedge‐type probe upon food rupture were evaluated separately using two accelerometers placed perpendicular to a guide rod of a swing‐arm device for texture evaluation of the flesh of three varieties of apples and three types of potato chips. Voltage signals from the accelerometers were filtered using a half‐octave band‐pass filter. The energy texture index (ETI), based on kinetic energy of the vertical or horizontal probe vibrations, was calculated over low to high frequency bands (no. 1–21). The spectra for the flesh of the three varieties of apples included two common peaks for vertical ETI at band no. 11 (1,120–1,600 Hz) and 19 (17,920–25,600 Hz) and horizontal ETI at band no. 1 (0–10 Hz) and 15 (4,480–6,400 Hz). The spectra for the three types of potato chips had a common ETI peak at band no. 11 (1,120–1,600 Hz) for horizontal ETI and at no. 15 (4,480–6,400 Hz) for vertical ETI. The three apple varieties gave rise to different intensities of vertical and horizontal ETIs while the two peaks were maintained. The thick potato chip type had higher vertical and horizontal ETIs than the thin and soft varieties in most bands; however, the thin type had the highest vertical ETIs only in lower bands (0–200 Hz). The soft type had the lowest vertical and horizontal ETI. The above results suggest that different food textures can be distinguished by two‐dimensional vibration analyses of probe insertion into a food sample based on frequency bands.     

PCR-DGGE技术对中华开菲尔微生物菌群的分析

为了解中华开菲尔微生物菌群的结构特征,本论文运用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术对开菲尔菌株发酵过程中微生物菌群的结构变化进行了实验分析,结果表明:细菌菌群DGGE图谱上出现有三种不同迁移位置的斑带,而酵母菌群DGGE图谱上只有一条斑带;经过DNA序列的对比分析可知:细菌菌群分别为肠膜明串珠菌(Leuconostoc mesenteroides)、马乳样乳杆菌(Lactobacillus kefiranofaciens)和开菲尔乳杆菌(Lactobacillus kefir),它们的序列同源性都达到100%;酵母菌群为德尔布有孢圆酵母(Torulaspora delbrueckii),其序列同源性为99%。本论文首次报道了德尔布有孢圆酵母在开菲尔菌落中的存在。     

Characterization of protein components of natural and heat-treated milk fat globule membranes

The proteins associated with the milk fat globule membrane (MFGM), isolated from early, mid and late season whole milks, were characterized using one- and two-dimensional SDS-PAGE under reducing and non-reducing conditions. In some experiments, MFGM separated from fresh whole milk was suspended in simulated milk ultrafiltrate (SMUF) and heated at various temperatures and times. SDS-PAGE under reducing conditions followed by staining with Coomassie blue showed the presence of about 37 protein bands, ranging in molecular weight from 15 to 200 kDa. SDS-PAGE under non-reducing conditions showed only about 25 distinct bands and the intensity of xanthine oxidase and butyrophilin bands was much less, while the intensity of PAS 6/7 band was similar compared with the reduced SDS-PAGE. Two-dimensional SDS-PAGE showed that the protein complexes that remained at the top of non-reducing gel were resolved into mostly xanthine oxidase and butyrophilin with a small proportion of PAS 6. These results indicate that xanthine oxidase and butyrophilin may be complexed via intermolecular disulfide bonds in the natural MFGM, although it is not possible to differentiate the individual protein distributions within these aggregates. It was found that the total protein content (mg/g fat) of MFGM and the percentage of xanthine oxidase and butyrophilin in early and late season MFGM were higher than that of mid season MFGM. In heated samples (above 60°C), xanthine oxidase and butyrophilin interacted further to form higher molecular weight protein complexes, while PAS 6/7 was relatively heat stable.