高档金刚石工具的研究开发及应用

随着我国石材加工业的高速发展,必须发展高档金刚石工具。高档金刚石砂轮和涂附磨具在玻璃、陶瓷、木材加工和汽车制造业的需求量日益增大,而在半导体单晶硅、多晶硅以及其他晶体的加工中,对其性能要求越来越高,市场的潜力巨大。文章简介石材加工用高档激光焊接圆锯片和薄壁钻头以及金刚石串珠绳锯的研制,特别介绍金刚石涂附磨具的研制和应用。此外在电子信息和光电子产业的晶体加工中,高档金刚石工具占据重要的地位,以往未受业界重视,制造难度较大,文章亦提出了见解。     

激光加工技术在珠宝首饰业中的应用

激光加工技术在珠宝首饰业中的应用越来越广泛.介绍了该技术的基本特点以及其在珠宝首饰业中的典型应用现状.这些技术涉及激光焊接、激光快速原型技术、激光打标、激光雕刻和激光切磨钻石等领域.激光焊接比传统的焊接技术具有显著的优点;快速原型技术的引入大大缩短了从首饰图样到制出原版的时间;激光打标和激光雕刻的使用丰富了首饰表面处理的手段,可进一步满足首饰个性化需求;激光切磨钻石原石可达到最小的损耗.激光加工技术在珠宝首饰业中发挥着越来越重要的作用.     

Application of femtosecond laser ablation for detaching grown protein crystals from glass capillary tube

We developed a novel technique for detaching protein crystals from glass capillary tube using the counter diffusion crystallization technique by femtosecond laser irradiation. X-ray diffraction analysis demonstrated that femtosecond laser irradiation has little effect on crystallinity. This technique will contribute to progress in structural genomics as a powerful tool.     

激光技术在纺织行业中的应用

比照激光技术在机械加工行业的应用与发展,概述了激光加工技术在纺织行业中的应用情况。对其应用领域和技术类别进行了归纳,并介绍了各类技术的开发应用现状。这些技术涉及激光裁剪、激光雕刻、激光切割、激光缝纫、激光变形、激光改性、激光固色、激光漂白、激光防伪等。研究认为,激光技术在纺织行业的应用具有潜在发展前景,在国际市场上具有不可忽视的竞争力,我国纺织行业应积极关注该技术在国内外的发展动向。     

Short communication: Multi-component interactions causing solidification during industrial-scale manufacture of pre-crystallized acid whey powders

Acid whey (AW) is the liquid co-product arising from acid-induced precipitation of casein from skim milk. Further processing of AW is often challenging due to its high mineral content, which can promote aggregation of whey proteins, which contributes to high viscosity of the liquid concentrate during subsequent lactose crystallization and drying steps. This study focuses on mineral precipitation, protein aggregation, and lactose crystallization in liquid AW concentrates (～55% total solids), and on the microstructure of the final powders from 2 independent industrial-scale trials. These AW concentrates were observed to solidify either during processing or during storage (24 h) of pre-crystallized concentrate. The more rapid solidification in the former was associated with a greater extent of lactose crystallization and a higher ash-to-protein ratio in that concentrate. Confocal laser scanning microscopy analysis indicated the presence of a loose network of protein aggregates (≤10 µm) and lactose crystals (100–300 µm) distributed throughout the solidified AW concentrate. Mineral-based precipitate was also evident, using scanning electron microscopy, at the surface of AW powder particles, indicating the formation of insoluble calcium phosphate during processing. These results provide new information on the composition- and process-dependent physicochemical changes that are useful in designing and optimizing processes for AW.     

激光电雕机多工艺技术的实现

激光电子雕刻技术是现代高精度凹印制版常用的先进技术。在针对激光电子雕刻的特殊处理方式中，传统的激光电雕处理软件存在着图像存储量大、图像处理速度缓慢以及图形和文字边缘精度较低等缺陷，难以达到最完善的效果。通过对图文信息的工艺ID、边处理模式、边加网参数、填充处理模式以及填充加网参数等前期图文标定和之后的图文专门处理，可以很好地解决该过程所遇到的特殊多工艺要求，并实现极高精度的图文表现。     

X-ray computerized microtomography and confocal Raman microscopy as complementary techniques to conventional imaging tools for the microstructural characterization of Cheddar cheese

This study explored the use of X-ray computerized microtomography (micro-CT) and confocal Raman microscopy to provide complementary information to well-established techniques, such as confocal laser scanning microscopy (CLSM), for the microstructural characterization of cheese. To evaluate the potential of these techniques, 5 commercial Cheddar cheese samples, 3 with different ripening times and 2 with different fat contents, were analyzed. Confocal laser scanning microscopy was particularly useful to describe differences in fat and protein distribution, especially between the 2 samples with different fat contents. The quantitative data obtained through image analysis correlated well with the nutritional information provided in the product labels. Conversely, micro-CT was more advantageous for studying the size and spatial distribution of microcrystals present within the cheese matrix. Two types of microcrystals were identified that differed in size, shape, and X-ray attenuation. The smallest, with a diameter of approximately 10 to 20 μm, were more abundant in the samples and presented a more uniform roundish shape and higher X-ray attenuation. Larger and more heterogeneous crystals with diameters reaching 50 μm were also observed in scarcer numbers and showed lower X-ray attenuation. Confocal Raman microscopy was useful not only for identifying the distribution of all these components but also allowed comparing the presence of micronutrients such as carotenoids in the cheeses and provided compositional information on the crystals detected. Small and large crystals were identified as calcium phosphate and calcium lactate, respectively. Overall, using micro-CT, confocal Raman microscopy, and CLSM in combination generated novel and complementary information for the microstructural and nutritional characterization of Cheddar cheese. These techniques can be used to provide valuable knowledge when studying the effect of milk composition, processing, and maturation on the cheese quality attributes.     

菜籽蛋白超滤液反冲对超滤膜污染的控制研究

超滤是制备植物油料蛋白的先进工艺技术，但膜的污染问题严重影响超滤技术的推广应用。本文在研究了菜籽蛋白水溶液在中空纤维超滤装置中的超滤行为之后，研究了膜面透过液反冲对膜污染的控制作用。实验结果表明：菜籽蛋白水溶液的超滤浓缩速率随时间延长而下降；对工作中的超滤膜进行定期间歇反冲（反冲时间20s、反冲频率为1次／15min、反冲压差为0．2MPa），是控制膜污染程度的有效措施，这样可以使超滤膜的透水速率恢复90％以上。     

PROCESSING WHEY-TYPE BY-PRODUCT LIQUIDS FROM COTTONSEED PROTEIN ISOLATION WITH ULTRAFILTRATION AND REVERSE OSMOSIS MEMBRANES

Cottonseed wheys resulting from protein isolation from cottonseed flour were processed by semi-permeable ultrafiltration (UF) and reverse osmosis (RO) membranes. The UF membrane fractionated the soluble whey constituents by retaining protein and passing through salts, carbohydrates and other non-protein components along with most of the water. The UF membrane effluent was then processed through an RO membrane to recover a secondary product containing the whey materials not retained in the protein product from the UF membrane. The feasibility of recycling effluent from the RO membrane for reuse in subsequent protein extractions was demonstrated. Thus, the threat of water pollution from effluent disposal could be eliminated completely and process water requirements drastically reduced. Spray-dried UF protein concentrates were tested for utilization in protein fortification of breads and noncarbonated beverages and as whipping products. They exhibited commercial potential for use in these food applications. The economics of processing the whey-type liquids by the membrane process under investigation were analyzed. Membrane processing of wheys by each of two alternative whey processing systems proved to be economically attractive.     

现代激光技术在食品和农产品加工中的应用

本文综述了激光技术在食品和农产品加工中的应用。分别介绍了激光在酿造食品中的应用;激光用于酵母菌诱变;激光用于食品加工和农产品加工的检测和监控;激光切削技术用于食品和农产品加工;激光技术在食品包装中的应用。     

激光共聚焦扫描显微镜技术在不同食品体系中的应用研究

激光共聚焦显微镜(confocal laser scanning microscope,CLSM)是现代食品科学研究中最通用的荧光显微成像工具之一,该技术以其优越的光学切片和3维(3D)重建功能,可快速获得较厚食品样本的清晰的光学切片,还可以在虚拟空间中任意角度观测食品内部微观结构。本文介绍了激光共聚焦显微镜的基本原理和功能,综述了该技术在食品原料和成分、乳状液体系、脂质、凝胶、食品加工过程中微观结构变化等研究中的应用进展,并简要分析了激光共聚焦显微成像技术在实际使用中的局限性和发展趋势,以期对我国相关研究人员的研究工作提供参考。     

共焦激光扫描显微镜及其在造纸科学中的应用

共焦激光扫描显微镜（CLSM）是一种综合了光学，电子，机械和计算机及数字图像处理等高新技术的具有高的横向和纵向分辨率的新型表面检测设备，它具有独特的光学切片功能，可以在自然环境下对样品表面进行无损探测，本文介绍了共焦激光扫描显微镜的组成和工作原理，并讨论了其在研究纤维超微结构，纤维形态学，纸张结构和性能等造纸科学研究中的应用。     

菜籽蛋白水溶液的超滤行为及在线控制膜污染的研究

研究了菜籽蛋白水溶液在中空纤维超滤膜膜管中的超滤行为，探讨了菜籽蛋白对超滤膜的污染机理，设计安装了反冲装置，摸索出了可在线控制膜污染的最佳反冲工艺参数。实验结果表明：菜籽蛋白水溶液的超滤浓缩速率随时间延长而下降，当超滤时间接近15min时，膜面上会形成凝胶层“二次膜”；对工作中的超滤膜每隔15min就用0．2MPa的压差反冲20s，可使透水速率恢复94％以上。     

Effect of reverse osmosis and ultra-high-pressure homogenization on the composition and microstructure of sweet buttermilk

Buttermilk (BM), the by-product of butter making, is similar to skim milk (SM) composition. However, it is currently undervalued in dairy processing because it is responsible for texture defects (e.g., crumbliness, decreased firmness) in cheese and yogurt. One possible way of improving the incorporation of BM into dairy products is by the use of technological pretreatments such as membrane filtration and homogenization. The study aimed at characterizing the effect of preconcentration by reverse osmosis (RO) and single-pass ultra-high-pressure homogenization (UHPH) on the composition and microstructure of sweet BM to modify its techno-functional properties (e.g., protein gel formation, syneresis, firmness). The BM and RO BM were treated at 0, 15, 150, and 300 MPa. Pressure-treated and control BM and RO BM were ultracentrifuged to fractionate them into the following 3 fractions: a supernatant soluble fraction (top layer), a colloidal fraction consisting of a cloudy layer (middle layer), and a high-density pellet (bottom layer). Compositional changes in the soluble fraction [lipid, phospholipid (PL), protein, and salt], as well as its protein profile by PAGE analysis, were determined. Modifications in particle size distribution upon UHPH were monitored by laser diffraction in the presence and absence of sodium citrate to dissociate the casein (CN) micelles. Microstructural changes in pressure-treated and non-pressure-treated BM and RO BM particles were monitored by confocal laser scanning microscopy. Particle size analysis showed that UHPH treatment significantly decreased the size of the milk fat globule membrane fragments in BM and RO BM. Also, pressure treatment at 300 MPa led to a significant increase in the recovery of total lipids, CN, calcium, and phosphate in the BM soluble fraction (top layer) following ultracentrifugation. However, PL were primarily concentrated in the pellet cloud (middle layer), located above the pellet in BM concentrated by RO. In contrast, PL were evenly distributed between soluble and colloidal phases of BM. This study provides insight into the modifications of sweet BM constituents induced by RO and UHPH from a compositional and structural perspective.     

基于有限元的热裂法切割液晶玻璃的仿真分析

介绍了激光热裂法,即利用移动热源控制裂纹切割玻璃.运用有限元软件Ansys的参数化设计语言建立二维模型,对激光扫描玻璃模型进行仿真.通过该仿真研究了切割过程中裂纹尖端附近的应力和裂纹尖端的应力强度因子,讨论了激光功率和激光扫描速度两关键加工参数对切割的影响,并给出了裂纹可连续扩展的加工参数范围.仿真结果表明,以裂纹尖端...     

基于三维投影矩阵的生产流水线对接系统平台构建

针对工作台扭摆会导致机械加工对接产生误差,提出基于三维投影矩阵构建生产流水线对接系统平台,以降低对接误差。三维运动平台采用脉冲信号控制的步进电机进行驱动,达到机床限位控制;通过控制激光器开关和控制激光器的输出功率实现系统的激光控制;通过多普勒频差测量位移技术,采用交流前置放大器替换常规直流放大器等,获取精准实时测量数据;根据三维立体视觉校对原理提取对接区域图像特征点,依据特征点校验机械加工平台三维对接图像时,采用Powell方法求解三维阶段投影矩阵对接目标函数最小值,实现机械加工的高精准度对接。结果表明:机械加工对接的最大相对误差为1.50%,精准度高,进行机械加工耗时18～23min,花费时间较短。     

单增李斯特氏菌MALDI-TOF-MS鉴定与分型研究

为建立单增李斯特氏菌的基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)快速鉴定与分型方法,实验收集37株单增李斯特氏菌分离株,应用MALDI-TOF-MS采集图谱,获取独特的蛋白质指纹图谱,汇总成标准图谱,建立单增李斯特氏菌鉴定数据库。采用单增李斯特氏菌标准菌株进行验证,表明鉴定结果的可信度很高。在数据库信息的基础上,对37株单增李斯特氏菌分离株进行聚类分型。分型结果表明,在蛋白质水平上,MALDI-TOF-MS可把37株单增李斯特氏菌分成9个型别。     

Possibilities for application of laser ablation in food technologies

This work considers the possibility for using laser ablation in food technologies. It was found for the fruits and vegetables under study that laser ablation provided an efficient peeling of the materials while preserving the organoleptic properties, such as freshness, naturalness, and texture.After a laser treatment of citrus fruit (oranges and lemons), the fruits were peeled and pectin was extracted from the peels via a classical type of extraction in HCl water solution. The pectins obtained were assayed for yield, degree of esterification, polyuronic content, molecular weight, gel strength and other physico-chemical properties. For all samples it was found that laser pretreatment of the materials led to an increase in pectin yield, gel strength and purity, at an insignificant reduction of molecular weight and degree of esterification.Laser ablation of fruits and vegetables was used as an alternative to traditional methods for producing edible films. The cell particles, removed by means of laser ablation and containing plant waxes, cellulose fibers and pectic substances, were applied aseptically onto a hard surface and the obtained edible films showed a lasting antimicrobial effect.As a result of the treatment of fruits and vegetables with CO₂ laser, a number of aroma substances were released and they could be captured and used.

Industrial relevance

The work described in this research is relevant to the laser ablation of peeled fruit and vegetables used in food technologies. Laser treatment for peeling fruit and vegetables can be used not only by food processing enterprises, by catering companies and by fast food establishments as a preliminary treatment of fruit and vegetables, but also by pectin producers. There is also a prospect for the application of laser ablation in extracting aroma substances from various materials, as well as in obtaining edible films.     

矢车菊素-3-O-葡萄糖苷进入巨噬细胞的荧光检测

利用荧光技术探索矢车菊素-3-O-葡萄糖苷（cyanidin 3-O-glucoside,C3G）在体外培养的巨噬细胞中的分布。首先采用荧光分光光度法扫描C3G的特异激发波长和发射波长,再利用激光共聚焦技术探讨C3G进入小鼠和人巨噬细胞的过程以及C3G在细胞中的定位,并分析C3G孵育时间对细胞内荧光强度变化的影响。结果表明：在488 nm和520 nm的激发波长下,C3G孵育15 min的细胞质内开始呈现绿色和红色荧光,并且随着孵育时间的变化,细胞内荧光强度逐渐增强,其中孵育60 min可观察到荧光布满细胞核,其荧光强度是孵育前的6.45 倍。研究表明采用特异波长的激光共聚焦断层扫描技术可示踪到花色苷在干预细胞内的分布,结果显示花色苷C3G可快速穿过巨噬细胞的细胞膜和核膜,直达细胞核。