Dynamic analysis on ferromagnetic particles of magnetorheological fluids

Based on the theory of magnetic dipole, this paper analyzes the forces and moments applied on the particles and established the corresponding equations of motion. It compares these forces respectively in order to reduce the computation time in the numerical simulation. It is found that magnetic force, viscous force and repelling force are stronger than other forces, and translation is the main motion. Therefore the governing equation in the numerical simulation can be simplified. The validity of above dynamic analysis is verified by numerical simulation on the microstructure of magnetorheological fluids.     

红掌切花的瓶插保鲜液研究（摘要）（英文）

[目的]研究红掌切花的瓶插保鲜液,为红掌种植及筛选保鲜方法提供参考。[方法]以红掌（Anthurium seherzerianum）中的常用切花品种‘热情’为试验材料,采用3种不同的瓶插液配方,处理①：2%二甲基琥珀酰肼＋1%8-羟基喹啉硫酸盐（HQS） ＋0.1%Ca（NO3）2＋5%蔗糖;处理②：5%蔗糖＋0.1 g/L明矾＋10 mg/L6-BA;处理③：4%蔗糖＋0.08% NaCl＋0.01%过磷酸钙＋0.01%中药杀菌剂（黄连的乙醇提取液） ＋0.1 mmol/LNaOH＋0.1 mmol/L柠檬酸＋10 mg/L6-BA。并与常用红掌保鲜配方（4%蔗糖＋50 mg/LAgNO3＋0.05 g/LNaPO4）进行对比,筛选最佳的红掌瓶插保鲜液。[结果]试验中处理①的配方比较简单,不能很好地杀菌,处理②虽然含有一定的碳源和营养,也有杀菌剂,但组成较简单,仍不能很好地满足红掌切花采后各方面生理的需要,以配方③为最佳的瓶插保鲜液,保鲜期为23 d,比对照延长了13 d,观赏期达31 d,比对照延长了18 d,效果显著;且配方③明显地减少了红掌佛焰苞的水分丧失,有利于维持组织的含水量,降低细胞膜透性,抑制膜脂的过氧化作用,减少丙二醛含量的积累,提高了SOD的活性,提高了细胞保护酶的活性,增加了脯氨酸和可溶性糖的含量,降低了呼吸速率。[结论]4%蔗糖＋0.08% NaCl ＋0.01%过磷酸钙＋0.01%中药杀菌剂（黄连的乙醇提取液） ＋0.1 mmol/L NaOH＋0.1 mmol/L柠檬酸＋10mg/L6-BA配方达到了延长红掌佛焰苞保鲜期的目的。     

Changes in colloid osmotic pressure as a function of anesthesia and surgery in the presence and absence of isotonic fluid administration in dogs

Objective  To determine how a combination of anesthetic drugs; including pre-medication, induction agents and inhalational agents; affect colloid osmotic pressure (COP) in the presence and absence of isotonic fluid administration. Secondarily, to determine if changes in total plasma protein (TPP) correlate with COP in anesthetized patients.
Study Design  Prospective, randomized clinical study.
Animals  Ten female dogs, 4 months to 4 years of age and >8 kg undergoing elective ovariohysterectomy.
Methods  All dogs were anesthetized in a similar fashion. After induction, five dogs received lactated ringer's solution (LRS) at 10 mL kg⁻¹ hour⁻¹ and five dogs received no fluid therapy during anesthesia. Blood samples were collected prior to pre-medication, prior to induction, immediately post-induction/prior to the inhalational agent, 30 minutes post-induction, at the time of recovery and 45 minutes post-discontinuation of inhalant. TPP and COP were measured from each sample.
Results  Administration of fluids resulted in a decrease in COP and TPP over time that did not return to baseline by 45 minutes after recovery. Anesthesia without the administration of fluids also resulted in a significant decrease in COP over time, that was rebounding by recovery (but still significantly less than baseline). TPP had variable correlation with COP at different time points with or without fluid administration.
Conclusions and clinical relevance  Anesthetic drugs alter COP similarly in the presence and absence of isotonic fluids. These changes in COP did not have a simple relationship to TPP and so the latter could not be used to predict COP in this patient population.     

一种新的获取海洋贝类基因组DNA的取样方法（摘要）

[目的]探讨一种新的获取海洋贝类基因组DNA的取样方法,为开展珍稀贝类的分子生物学研究提供参考。[方法]以文蛤、栉江瑶、翡翠贻贝、香港巨牡蛎、毛蚶为供试材料,以闭壳（合）肌全基因组DNA作为参考,采用常规酚-氯仿法抽提贝类贝腔液基因组DNA,使用生物光度计法、琼脂糖凝胶电泳、目的片段扩增测序验证其质量,并建立系统发育树检测其来源的真实可靠性。[结果]采用常规酚/氯仿基因组DNA提取方法获得的贝腔液DNA质量优于闭壳（合）肌DNA,蛋白质、多酚色素污染较少,完全满足目的片段扩增测序;系统发育进化树则证实了贝腔液并非外源污染。[结论]从贝腔液中获取基因组DNA是完全可行的,并可将其用于目的基因片段的扩增。     

不同保鲜剂对哈密瓜采后病原菌抑制性研究

保鲜剂BG1,BG2,Azoxystrobin,Amistar均为瓜类抑菌性保鲜剂,通过这四种不同保鲜剂对哈密瓜采后病原菌抑制效果研究,探索出能控制哈密瓜采后病害的适应性好及效果明显的保鲜剂,以便在哈密瓜生产和经营中推广应用,减少哈密瓜采后运输、贮藏保鲜过程中的损失,提高哈密瓜生产和经营的社会效益及经济效益。经过两年的试验研究结果表明：BG1对青霉属（Penicillium sp.）、交链孢属（Alternaria sp.）、根霉属（Rhizopus sp.）都有较强抑制作用;BG2对交链孢属（Alternaria sp.）抑制作用强;Azoxystrobin对青霉属（Penicillium sp.）抑制作用强;Amistar对根霉属（Rhizopus sp.）抑制作用强。     

油田产出液中产甲烷菌的分离与特性初步研究

采用改良的Hungate厌氧技术以新疆油田区块采出水为接种物,分离出一株产甲烷菌,并评价利用其生理活动及代谢产物来提高原油采收率。该菌经过分离后进行液体纯培养,500ml培养液培养4周后累计产气量达300ml,气相成分经气相色谱检测为甲烷。这在油藏中能够增加地层压力,有利于提高微生物采油效果。     

不同浓度6-BA保鲜剂对切花菊的保鲜效应

研究了6种不同浓度的6-BA保鲜剂对切花菊瓶插期间生理状况及瓶插寿命的影响。结果表明:1 mg/L 6-BA保鲜剂效果最好,花、叶瓶插寿命比对照分别延长3.8和4.4 d;0.5mg/L 6-BA保鲜剂效果较好,花、叶瓶插寿命比对照分别延长3.2和4.0 d。