等离子电场辅助冷冻羊肉过程中冰晶变化及热力学分析

为探究等离子电场辅助冻结对羊肉品质及冻结过程的影响，选用羊背最长肌作为试验材料，研究辅助不同场强(1，3 kV/m和5 kV/m)的等离子电场对羊肉冻结速度的影响，以及对冻结过程中肉中冰晶分布及冰晶粒径和圆度的影响，并用热力学理论进行分析。结果表明:在-20 ℃和-35 ℃时，辅助5 kV/m等离子电场环境下的肉样通过最大冰晶生成带的时间最短，分别为70 min与40 min，与对照组相比均有差异显著(P<0.05)。组织切片显示-35 ℃辅助5 kV/m等离子电场冻结时形成的冰晶面积和粒径最小，-20 ℃辅助5 kV/m等离子电场冻结的冰晶圆度最高，平均值为0.88。以上指标与对照组相比均有显著差异(P<0.05)。运用波尔兹曼公式分析体系的熵，结果显示:在-20 ℃和-35 ℃时，辅助5 kV/m等离子电场冻结的肉样的熵最小，与对照组相比有显著性差异(P<0.05)，表明辅助5 kV/m等离子电场可以显著提高体系冷冻肉水分玻璃化程度，可使结晶过程更加可控，电场辅助冷冻所需的能量更低，提高过冷度，加快肉样的冻结速率，且场强越大作用越显著。综合试验结果以及实际生产中节约能源，认为-20 ℃辅助5 kV/m电压冷冻可以作为一种新型冷冻方式应用于生产。     

Magnetic alignment of cellulose nanowhiskers in an all-cellulose composite

Unidirectional reinforced nanocomposite paper was fabricated from cellulose nanowhiskers and wood pulp under an externally applied magnetic field. A 1.2 Tesla magnetic field was applied in order to align the nanowhiskers in the pulp as it was being formed into a sheet of paper. The magnetic alignment was driven by the characteristic negative diamagnetic anisotropy of the cellulose nanowhiskers. ESEM micrographs demonstrated unidirectional alignment of the nanowhiskers in the all-cellulose composite paper. Comparing with control paper sheets made from wood pulp only, the storage modulus in the all-cellulose nanocomposites increased dramatically. The storage modulus along the direction perpendicular to the magnetic field was much stronger than that parallel to the magnetic field. This new nanocomposite, which contains preferentially oriented microstructures and has improved mechanical properties, demonstrates the possibility of expanding the functionality of paper products and constitutes a promising alternative to hydrocarbon based materials and fibers.     

Artificial immune system based approach for solving resource constraint project scheduling problem

In this paper, resource-constrained project scheduling problem (RCPSP) is discussed with an objective of minimizing the makespan of a project. Due to its universality, it has a variety of applications as in manufacturing, production planning, project management and elsewhere. It is a well known computationally complex problem, thus warrants the application of heuristics techniques or AI based optimization tools to achieve optimal or near optimal solution in real time. In this research, the artificial immune system (AIS) approach is proposed to solve the aforementioned problem. It exploits the beauty of learning and memory acquisition to ensure the convergence with faster rate. During extensive computational experiment, it is found that the performance of the AIS algorithm on a well known data set of resource-constrained project scheduling problem is superior as compared to GA, fuzzy-GA, LFT, GRU, SIO, MINSLK, RSM, RAN, and MJP based approaches.     

Application of DNA-Alkylating Pyrrole-Imidazole Polyamides for Cancer Treatment

Pyrrole-imidazole (PI) polyamides, which target specific DNA sequences, have been studied as a class of DNA minor-groove-binding molecules. To investigate the potential of compounds for cancer treatment, PI polyamides were conjugated with DNA-alkylating agents, such as seco-CBI and chlorambucil. DNA-alkylating PI polyamides have attracted attention because of their sequence-specific alkylating activities, which contribute to reducing the severe side effects of current DNA-damaging drugs. Many of these types of conjugates have been developed as new candidates for anticancer drugs. Herein, we review recent progress into research on DNA-alkylating PI polyamides and their sequence-specific action on targets associated with cancer development.     

生物基炭质催化剂催化大豆皂脚酸化油制备生物柴油

选择大豆皂脚作为原料制备酸化油,并选用废弃的落叶松木屑,直接磺化制备生物基炭质催化剂,催化皂脚酸化油制备生物柴油.考察了生物基炭质催化剂催化皂脚酸化油生产生物柴油的工艺,得出最佳反应条件为:催化剂用量为皂脚酸化油的5.0%,反应温度70℃,甲醇与皂脚酸化油摩尔比7.5:1,醌化反应5 h,生物柴油酯化率为97.22%.与相同磺酸根基团当量的H2SO4相比,生物基炭质催化剂催化酯化反应能力更佳.     

辣白菜中乳酸菌的分离鉴定

从沈阳市7 个区25 份朝鲜族家庭制作的传统发酵辣白菜中分离出81 株乳酸菌疑似菌株,初步鉴定34 株为杆菌,47 株为球菌。进一步采用16S rDNA序列分析对81 株菌进行分子鉴定,通过序列分析进行属种鉴定。结果表明：81 株菌均为乳酸菌,分别来自2 个属6 个种,45 株为屎肠球菌,25 株为植物乳杆菌,4 株为干酪乳杆菌,3 株为戊糖乳杆菌,2 株为短乳杆菌,2 株为坚强肠球菌。研究结果为我国东北辣白菜中乳酸菌作进一步研究奠定了基础。     

低聚木糖对AA肉仔鸡生产性能和屠宰性能的影响

研究添加不同水平低聚木糖对AA肉仔鸡生产性能和屠宰性能的影响.结果表明,添加不同水平低聚木糖的试验组与对照组相比,21～42日龄平均体增重分别提高19.63%(P＜0.01)、24.34%(P＜0.01)、34.42%(P＜0.01);平均日采食量分别提高9.8%(P＜0.01)、12.7%(P＜0.01)、16.05%(P＜0.01);料重比分别降低8.9%(P＜0.05)、11.1%(P＜0.01),13.6%(P＜0.01);屠宰率、全净膛率、半净膛率差异均不显著,腹脂率分别降低27.19%(P＜0.05)、22.37%(P＞0.05)、24.54%(P＜0.05).添加水平为0.006%组效果最佳.     

牛初乳和牛常乳乳清N-糖蛋白质的差异分析

为阐明牛乳蛋白质N-糖基化,采用糖蛋白质组学技术,在牛初乳和牛常乳乳清中共鉴定到154 个N-糖蛋白和246 个糖基化位点,其中,牛初乳鉴定到117 个N-糖蛋白和183 个糖基化位点;牛常乳鉴定到109 个N-糖蛋白和145 个糖基化位点。初乳中丛生蛋白（P17697）糖基化位点N-283表达量最高,常乳中α-乳白蛋白糖基化位点N-93表达量最高。考虑定量差异及有无差异,在牛初乳和牛常乳乳清中共鉴定到129 个糖蛋白的190 个差异表达糖基化位点。基因本体论功能注释表明,差异表达糖蛋白参与的生物学过程是生物调节、刺激性反应、多细胞生物过程、定位、免疫系统过程等;主要分布为细胞外区域和细胞器;主要的分子功能是结合作用、催化活性和分子功能调节。差异表达糖蛋白参与的代谢通路主要是补体与凝血级联、金黄色葡萄球菌感染和溶酶体等。此外,通过蛋白互作分析,找到一些具有高连接度的重要糖蛋白。本研究丰富了牛乳N-糖蛋白质组成及其糖基化位点信息,阐明了牛乳乳清N-糖基化的功能,为评价和改善牛乳品质、研发婴幼儿配方乳中糖蛋白质的改良及功能食品的生产提供了理论依据。     

ω-Computations on Turing machines

The paper develops the theory of Turing machines as recognizers of infinite (ω-type) input tapes. Various models of ω-type Turing acceptors are considered, varying mainly in their mechanism for recognizing ω-tapes. A comparative study of the models is made. It is shown that regardless of the ω-recognition model considered, non-deterministic ω-Turing acceptors are strictly more powerful than their deterministic counterparts. Canonical forms are obtained for each of the ω-Turing acceptor models. The corresponding families of ω-sets are studied; normal forms and algebraic characterizations are derived for each family.     

Upconversion Luminescent Properties of YVO4:Yb3+, Er3+ Nano-Powder by Sol-Gel Method

YVO4:Yb3 , Er3 nano-sized upconversion luminescent powder was prepared by sol-gel method in the presence of citric acid. It was characterized by XRD, TEM and emission spectrum. The results show that the grain size of YVO4:Yb3 , Er3 is under 100 nm, and its grain size and upconversion luminescent intensity all increase with roasting temperature raises. Under 980 nm laser diode(LD) excitation, two strong green emissions that centered around 523 and 551 nm were observed with naked eyes at room temperature, corresponding to the 2H11/2→4I15/2 and 4S3/2→4I15/2 transitions of Er3 , respectively. According to the dependence of green upconversion emission intensity on excitation power, it can be concluded that these two kinds of green emissions all belong to two-photon process.