Grain growth of continuous casting slab solidification based on cellular automata model

The cellular automaton (CA) method is coupled with finite difference method to establish a stochastic nucleation and growth model. According to the actual production conditions, the solidification structure of continuous casting slab is simulated and the evolution law of the inner structure is reconstructed. It is showed that grain transformation is from equiaxed crystal to columnar crystal and then to equiaxed crystal. Thickness of three crystal layers are different in various production technological systems, thickness of surface equiaxed crystal and inner equiaxed crystal are reduced, and the results of the columnar crystal thickness are contrary, while casting speed and superheat are increasing. The results show well agreement with the stochastic nucleation, preferred growth, competitive growth and random orientation of grain.     

液晶热图诊断乳腺癌指标的研究

经手术切除和病理检查证实有乳腺疾病者２８６例（其中良性病变者１９８例、乳腺癌８８例）的液晶热图△Ｔ和病理Ｐ型检查的结果发现：２８６例的△Ｔ均在２℃以下，其中良性组８１．３％的病例在０．２℃以下，而乳腺癌组仅为４．５％；病理分期热图Ｐ型，７８．４％的病例在４以下。故提出液晶热图诊断乳腺癌的原指标过高，应调整为△Ｔ０．２℃，Ｐ型４以上为宜。     

Effects of liquid crystal/PU composite substrate on osteogenic differentiation of rBMSCs

AIM: To explore the effect of the elastic modulus and sizes of liquid crystal (LC) phases on osteogenic differentiation based on OPC/PU composite substrate by mimicking the microenvironment in rat bone mesenchymal stem cells (rBMSCs). METHODS: A series of composite substrates with different elastic modulus were constructed via modulation of LC content in the composites. The surface phase structure was observed by polarized microscopy, and the mechanical property was measured by a universal material testing machine. Furthermore, the laser confocal microscope was employed to observe the spreading, polarization and the cytoskeleton arrangement of the rBMSCs. The proliferation of rBMSCs was evaluated by CCK-8 assay. The specific mRNA expression of osteogenic differentiation such as collagen Ⅰ, and osteopontin on the composite membranes was detected by real-time PCR. RESULTS: The size and number of LC phase increased and the elastic modulus of the composite substrates decreased with the increase of the LC content. The rBMSCs exhibited better characteristics of initial adhesion, spreading and proliferation on the OPC10-PU and OPC30-PU in the early and medium culturing. The rBMSCs displayed higher expression of collagen Ⅰ and osteopontin on the OPC10-PU in the early and medium osteogenic induction, while the high expression of these osteogenic genes occured on the OPC30-PU and OPC50-PU in later osteogenic induction. The emphasis of genetic expression was switched from collagen Ⅰ in the early and medium osteogenic induction to osteopontin in the later stage. CONCLUSION: When the content of LC remained low in the composite substrates, rBMSCs mainly responded to the mechanical stimuli induced by substrate stiffness and exhibited distinguished cellular behaviors; with the increase in the LC content, rBMSCs had strong interactions with LC by sensing the viscoelasticity of LC, probably resulted from the contribution of both substrate stiffness and the viscoelasticity of LC phase.     

结晶有机肥对土壤水稳性团粒组成及微结构的影响

实验室条件下研究了江西鹰潭红壤、河南焦作褐土、安徽芜湖黄红壤、湖北五峰山地黄棕壤等4种类型土壤在结晶有机肥处理前后它们的水稳性团粒组成及其微结构的变化。结果表明：结晶有机肥处理显著增加土壤0．25～2．0mm粒径水稳性团粒比重；处理后土粒机械强度增大，土粒中微孔增多，淹水后可见大量气泡冒出。扫描电镜下可见处理后土壤微结构得到明显改善。供试4种类型土壤的处理结果一致。     

压电晶体化学传感器研究进展

本文综述了压电晶体化学传感器在气相、液相物质和生物学上的应用，介绍了压电晶体化学传感器的新型装置（如传感器阵列）、新型敏感材料.     

苏云金芽孢杆菌达姆斯塔特亚种新菌株Btd61的鉴定及其晶体蛋白基因型的初步分析

用选择性培养基从舞毒蛾（Ｌｙｍａｎｔｒｉａｄｉｓｐａｒ）死虫体中分离到苏云金芽孢杆菌新菌株Ｂ－６１，经分类鉴定属苏云金芽孢杆菌达姆斯塔特亚种（Ｂａｃｉｌｌｕｓｔｈｕｒｉｎｇｉｅｎｓｉｓｓｕｂｓｐ．ｄａｒｍｓｔａｄｉｅｎｓｉｓ），简称Ｂｔｄ６１．该菌株有８种质粒，４种晶体蛋白，合成二锥体小晶体和不规则大晶体２种伴孢晶体颗粒，对大蜡螟（Ｇａｌｅｒｉａｍｅｌｏｎｅｌａ）和舞毒蛾皆具强毒性．Ｂｔｄ６１携带Ｂ１型的溶原性噬菌体，但又对Ｂ１型的Ｔｂ１０噬菌体有抗性．Ｓｏｕｔｈｅｒｎ杂交实验结果表明Ｂｔｄ６１所含的晶体蛋白基因属ｃｒｙⅠ基因型     

绿茶多酚提高壳聚糖包装膜的抗氧化性能

为了开发新型的抗氧化活性包装材料,该文以壳聚糖/绿茶多酚构成的复合膜为研究对象,比较分析了甘油和聚乙二醇对壳聚糖膜物理、机械、抗氧化和结构特性的影响。结果表明：未加入绿茶多酚前,壳聚糖甘油膜有着较低的水蒸汽透过系数和膨胀程度,其水蒸汽透过系数为8.84×10-11g/(m·s·Pa)。然而,聚乙二醇膜的抗拉强度和穿透力均高于甘油形成的膜。X射线衍射分析（XRD）表明应用质量分数40%的增塑剂导致11.7°和17.9°出现2个结晶峰,分别对应壳聚糖的水合结晶和无水结晶。加入绿茶多酚后,壳聚糖复合膜的抗氧化能力显著提高,1,1-二苯基-2-苦基肼（DPPH）自由基清除能力在5 min内达到83.9%。加入绿茶多酚显著降低了膜溶液的表观黏度,增加了膜的厚度、颜色和阻水性。从2种增塑剂的对比效果看,绿茶多酚对于甘油膜的机械性能影响较大,其断裂伸长率从42.02%急剧下降到9.19%,并且使膜的结晶结构从水合状态转变为非晶状态。但绿茶多酚对聚乙二醇膜的水蒸汽透过系数、膨胀程度和颜色影响较大。壳聚糖复合膜性能的这种差异与增塑剂中所含羟基的数量以及与绿茶多酚的配比有关。研究结果为绿茶多酚复合包装膜在实际中的应用提供了理论依据。     

锦绣杜鹃花柄显微结构的观察

以锦绣杜鹃(Rhododendron pulchrum)花柄为试验材料进行石蜡切片,观察花柄的组织及细胞结构特点.结果表明,锦绣杜鹃花柄的基本结构组成与植物茎的基本结构组成类似,但花柄中皮层及髓部在开花期富含淀粉粒,而子房受精膨大一定时期后淀粉粒完全消失,细胞体积变小,并出现大量含晶细胞,维管束结构随着花部结构的发育而逐渐发育成熟:在开花期维管束中导管结构并不清晰,而子房膨大至一定时期后维管束中导管细胞壁加厚,内含物消失,导管结构清晰.推测开花期淀粉粒的存在是为子房的膨大打下物质基础,而随着子房的膨大维管束逐渐发育成熟,为淀粉粒等养分转移至子房提供了运输空间,但锦绣杜鹃花期短可能与花期维管束发育不成熟有关.     

冠状彩晕的模拟实验分析

不同云层中正六角柱状冰晶对称轴取向不同,面内沿各向分布,使非主截面内光线的最小偏向角不同,验曲线,推证出冠状彩晕的形状．太阳上方冰晶对称轴平行于地面且在平行于地面的层形成了冠状彩晕;用充水三棱镜模拟冰三棱镜做出实     

偃麦草根茎蛋白质修饰冰晶的研究

以哈尔滨地区野生偃麦草(Elytrzgia repens(L.)Desv.)为研究对象,以10℃下生长的植株为对照,比较冷冻处理后,偃麦草根茎可溶性蛋白质种类及修饰单体冰晶形态的差异。结果显示:冷冻处理后缺失两条蛋白质带,分子量分别为33和13 Kda,同时,增加两条新带,分子量分别约为53和35 Kda,而且均有纺锤状或锥状的单体冰晶出现,表明其具有极强抗冻活性。