碳纳米管在高压下的电学性质与状态方程

 在金刚石压砧装置上，采用电阻测量方法研究了多层碳纳米管在室温下、23 GPa内的电阻与压力的关系。实验结果表明，在1.5～4.6 GPa内，电阻急剧减小，而在5.7 GPa左右，电阻出现一个极大值。这些变化与碳纳米管的结构、形状和层间距离的变化有关。同时，还在活塞-圆筒式p-V关系测量装置上首次研究了多层碳纳米管在室温下、4.5 GPa内的p-V关系，给出了它在第一次和第七次压缩时的状态方程。     

规模生猪养殖液态生物质资源循环开发仿真分析

对银河杜仲基于沼气工程的液态生物质资源的循环开发进行仿真分析。根据历史数据和公司五年、十年发展规划,使用基于反馈调控参数的入树逐步建模法,构建7棵入树仿真模型;通过仿真定量揭示公司规划实施过程中将产生大量废弃物类生物质,沼气工程对废弃物开发产生的沼液和沼气中含大量的生物质能;为此,基于仿真结果及系统反馈结构,提出促进消除环境与猪肉产品双污染,实现绿色安全猪肉生产和改善环境双重目标的三条管理对策,并进行初步实施。     

p73变异体研究现状及其在肿瘤放疗中的应用前景

p73基因是p53抑癌基因家族的新成员。 p73有两组蛋白异构体: TAp73和DNp73。 TAp73具有诱导细胞周期停滞和细胞凋亡的能力, 而DNp73却有与之相反的能力, 具有肿瘤促进作用。 对p73基因两面性的特点及研究进展作一综述。 最后结合重离子治疗肿瘤, 探讨了p73联合重离子治疗的新思路。 p73 was the first identified homologue of the tumor suppressor gene, p53. p73 has two groups of protein isoforms: TAp73 and DNp73. TAp73 can induce cell cycle arrest, resulting in the ability of apoptosis, however DNp73 has antagonistic property of a tumor promoting effect. In this paper, the dual roles of p73 gene and its research progress was reviewed. Finally, combined with heavy ion treatment of tumor, we explored some new ideas of p73 heavy ion joint therapy.     

Resonance Light Scattering Method for Determination of Amikacin with Potassium Ferrioxalate as a Probe

In a weak acid medium, potassium ferrioxalate(PF) can react with some aminoglycoside(AGs) antibiotics, such as amikacin(AMK), kanamycin(KANA), tobramycin(TOB) and gentamicin(GEN), to form ion-association complexes. It results in the enhancement of resonance light scattering(RLS) in different degrees. The maximum scattering peaks are all located at 345 nm. Among them, the relative scattering intensity(?IRLS) of AMK system is much higher than that of KANA, TOB or GEN. Therefore the method is more propitious to the determination of trace amounts of AMK. The optimum reaction conditions, influencing factors, and the relationship between scattering intensity and concentration of antibiotics were investigated by means of the proposed method. The enhancement of RLS signals is directly proportional to the concentration of antibiotics in a certain range of concentration. A new resonance light scattering method for the determination of AMK and other aminoglycoside antibiotics with [Fe(C2O4)3]3– as a probe is thus established based on it. The method exhibits high sensitivity and good selectivity. The detection limit(3σ) for AMK is 1.8 ng/mL. The method can be applied to the determination of AMK in clinical serum samples. The reaction mechanism and the reasons for RLS enhancement are discussed in this paper.     

NaYF4∶Er3＋, Yb3＋纳米晶的液相合成

采用丙三醇液相结晶法制备了NaYF4∶Er3＋, Yb3＋上转换纳米晶, 合成步骤被简化. 常温下, 用980 nm的红外激光激发可以观察到很强的绿光、红光发射, 用荧光光谱仪记录了该上转换光谱. X射线粉末衍射(XRD)结果表明, 该方法制备NaYF4∶Er3＋, Yb3＋纳米晶属于立方混合六方晶系. 研究了纳米晶的上转换发光机理, 根据晶体场理论对Er3＋的两个上转换能级进行了Stark分裂计算, 对两个能级之间的谱线进行了归属, 进一步证实了980 nm光子激发Er3＋离子的上转换机理, 一个是连续吸收两个980 nm光子的过程(激发态吸收), 另一个是吸收980 nm光子后, 电子转移到亚稳态能级, 然后再吸收980 nm光子过程(能量转移上转换).     

Improvements of preconditioned AOR iterative method for L-matrices

In this paper, we improve the preconditioned AOR method of linear systems considered by Evans et al. [The AOR iterative method for new preconditioned linear systems, Comput. Appl. Math. 132 (2001) 461–466]. In Evans’ paper, the coefficient matrix of linear system have to be an L  -matrix with _ai,i+1ai+1,i>0$a_{i,i+1}{a}_{i+1,i}>0$, i=1,…,n-1$i=1,\dots ,n-1$ and 0<_a1nan1<1$0<a_{1n}{a}_{n1}<1$. When _ai,i+1ai+1,i=0$a_{i,i+1}{a}_{i+1,i}=0$ for some i∈N={1,…,n-1}$i\in N=\{1,\dots ,n-1\}$, the preconditioned method is invalid. In order to solve the above problem, a new preconditioner is presented. Meanwhile, some recent results are improved.     

蛋白质对测定血清中抗精神病类药物的影响及消除

以人血清白蛋白(HSA)为模型,研究了蛋白质对测定血清样品中抗精神病类药物(APDs：安定、盐酸氯丙嗪及奋乃静)的影响。以分子荧光光谱法详细研究了抗精神病类药物与HSA的相互作用,以瑞利散射光谱研究了不同浓度乙醇对蛋白质变性的影响。研究表明：药物与HSA存在牢固结合作用,体积分数为80%的乙醇水溶液为萃取液提取血清样品中的APDs时,可以使血清中蛋白质缓慢变性,充分释放与其结合的药物。乙醇水溶液萃取液中加入K₂HPO₄无机盐后可形成双水相体系,APDs可进入双水相上相实现药物的均相高效萃取,上相经过滤后可直接进行高效液相色谱(HPLC)检测。该方法用于人血清中三种抗精神病类药物的检测,检出限为18.8～38.4 ng·mL-1,回收率为94.2%～98.7%。方法步骤简单,绿色环保,准确。     

集簇性DNA损伤在辐射研究中的进展

高LET重离子引起的集簇性DNA损伤会造成细胞突变、 癌变和凋亡。 促进肿瘤细胞凋亡一直是治愈肿瘤的出发点, 所以集簇性DNA损伤已经成为放射生物学领域研究的热点问题。 由于其提取和检测方法多样, 但并没有一个详细和完整的方案对集簇性DNA损伤进行透彻分析。 综述了集簇性DNA损伤的特点和详细讨论了集簇性DNA损伤最新研究进展, 简介了集簇性DNA损伤的研究方法, 以期为集簇性DNA损伤在放疗中的研究提供一些参考。 Clustered DNA damage which caused by high LET heavy ion radiation can lead to mutation, tumorigenesis and apoptosis. Promoting apoptosis of cancer cells is always the basis of cancer treatment. Clustered DNA damage has been the hot topic in radiobiology. The detect method is diversity, but there is not a detail and complete protocol to analyze clustered DNA damage. In order to provide reference for clustered DNA damage in the radiotherapy study, the clustered DNA damage characteristics, the latest progresses on clustered DNA damage and the detecting methods are reviewed and discussed in deteil in this paper.     

金融资产多分辨风险识别及投资组合策略

为有效地揭示金融市场微观结构、反映和分散金融风险,基于最大重复离散小波变换对高频数据进行了多分辨分析,利用小波方差和小波协方差给出多分辨Beta系数的计算方法,讨论了高频金融资产不同时间尺度下的风险组成。针对收益与风险的多分辨特征,提出多分辨投资组合策略,改进了Markowitz的静态投资组合方法。实证研究表明,同一金融资产在不同时间尺度下的收益与风险存在多分辨特征;CAPM的表现也具有多分辨特征;而多分辨的投资组合策略则将不同时间尺度下的投资风险降到了最低。