相接双星能量转移过程研究

从流体力学方程出发,分析和讨论了相接双星公共包层内湍流和环流对能量转移的作用,并给出了能量转移的表达式。计算结果表明:处于相接阶段的双星系统,公共包层底部环流速度较大,可达～9×103cm/s,而湍流的速度在外部较大,可达～2.4×105cm/s。环流与湍流均是小质量相接双星能量转移两个不可或缺的重要因素。在t=1.454 8×109a,环流携带能量为ΔLcirc=0.14 L⊙,t=1.454 8×109a湍流携带能量为ΔLturb=0.72 L⊙。     

振动磨筒体内部的能量传递规律

在对大量摄像实验反复观测和研究后发现:磨筒内的磨介存在抛射、整体回转和本身自转3种运动状态;磨介与筒壁的抛离与接触是沿着振动方向发生的,此过程是周期性的,其周期与振动周期相同. 在此基础上,建立了粉磨介质冲量传递模型,探讨了振动磨筒体内部的冲量传递、能量传输和能量耗散的分布规律,揭示了振动磨的粉碎机理. 以此为理论依据,提出了减小磨筒内的惰性区、提高粉磨效率的途径.     

振动磨简体内部的能量传递规律

在对大量摄像实验反复观测和研究后发现:磨筒内的磨介存在抛射、整体回转和本身自转3种运动状态;磨介与筒壁的抛离与接触是沿着振动方向发生的,此过程是周期性的,其周期与振动周期相同．在此基础上,建立了粉磨介质冲量传递模型,探讨了振动磨简体内部的冲量传递、能量传输和能量耗散的分布规律,揭示了振动磨的粉碎机理．以此为理论依据,提出了减小磨筒内的惰性区、提高粉磨效率的途径．     

混合染料分子系统内能量转移

研究阴、阳离子型染料分子荧光素钠（ＦＳ）、诺单明（Ｒｈ６Ｇ）的吸收光谱及荧光光谱．发现这两种混合染料之间存在能量转移效应,能量转移属激基复合物内部的交换能量转移．     

Energy transfer mechanism of PBS-thylakoid complexes

Conclusion In this work, we studied the energy transfer mechanism among PBS and two reaction centers (PS I and PS II) in PBS-thylakoid complexes by using steady-state spectra (77 K) and spectral deconvolution techniques. The experimental results indicated that the PBS-thylakoid complexes could perform the function of light state transition just like intact algae cell, and confirmed that PBSs were directly connected with PS I and PS II reaction centers separately. The energy transfer pathways from PBSs to two reaction centers are PBS-PS I and PBS-PS II.     

基团转移聚合法合成山梨酸酯类聚合物的研究

设计及合成不同官能团的山梨酸酯类单体,以有机催化剂膦腈碱(1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)phosphoranylidenamino]-2Λ~5,4Λ~5-catenadi(phosphazene),t-Bu-P4)为催化剂(1-methoxy-1-trimethylsilyloxy-2-methyl-propene)MTS为引发剂,采用基团转移聚合法(Group Transfer Polymerization,GTP)精确合成分子量可控的聚山梨酸酯。通过核磁氢谱、凝胶渗透色谱表征聚合物的结构及分子量,分散性指数(PDI)在1.16～1.25之间,分子量与理论分子量相吻合;利用差示扫描热量法(DSC)测试聚合物的玻璃化转变温度(-27.38℃～33.94℃),并讨论官能团对玻璃化转变温度的影响及规律。     

RAFT聚合制备星型聚合物

通过先臂法合成PBA/HDDA型星型聚合物。首先,以丙烯酸丁酯(BA)为单体,巯基乙醇苄基三硫碳酸酯(BSSE)为链,转移剂合成线形大分子链转移剂PBA。然后以双官能团的偶联剂1,6-己二醇二丙烯酸酯(HDDA)为交联剂,合成星型聚合物。交联剂HDDA与PBA的摩尔比影响星型聚合物的转化率。用GPC测定PBA和星型聚合物的分子量和分子量分布,结果表明,HDDA与PBA的摩尔比越高,星型聚合物的合成转化率越高;但星型聚合物的分子量不会有太大变化。当HDDA与PBA的比例超过一定值时,会产生凝胶。星型聚合物的分子量分布很窄(PDI<1.1)。     

原子转移自由基聚合法合成端氨基聚合物

以溴异丁酸对硝基苄酯为引发剂、溴化亚铜(CuB r)/2,2′-联吡啶为催化体系进行了甲基丙烯酸甲酯的原子转移自由基聚合;以对硝基溴化苄为引发剂、溴化亚铜(CuB r)/2,2′-联吡啶为催化体系进行了苯乙烯的原子转移自由基聚合;将得到的端硝基聚合物进一步还原,制得端氨基聚合物。结果表明,上述两个聚合过程均为活性自由基聚合过程,得到窄分子量分布的聚合物;1H-NMR分析表明,得到的端氨基聚合物链的α端都有1个氨基,ω端都有1个溴原子,还原过程没有破坏原有的聚合物链结构。     

大间隙磁力传动系统能量传递效率

为了解大间隙、高转速条件下磁力传动系统的能量传递规律,研究行波磁场驱动的大间隙磁力驱动技术;通过微型轴流式血泵外磁场驱动,对大间隙磁力驱动系统各部分能量耗散进行研究,建立系统能量传递效率的数学模型.通过轴流式血泵泵水实验,得到血泵在耦合距离20 mm和30 mm时的最大能量传递效率,即磁力传动系统的最佳工作点,并通过与理论解析值相比较,得到大间隙磁力驱动系统的能量传递效率的变化趋势,确定磁力驱动系统能量传递效率的主要影响因素,为提高磁力驱动系统的能量传递效率提供了途径和依据.     

Gene transfer to plants by diverse species of bacteria

Agrobacterium is widely considered to be the only bacterial genus capable of transferring genes to plants. When suitably modified, Agrobacterium has become the most effective vector for gene transfer in plant biotechnology. However, the complexity of the patent landscape has created both real and perceived obstacles to the effective use of this technology for agricultural improvements by many public and private organizations worldwide. Here we show that several species of bacteria outside the Agrobacterium genus can be modified to mediate gene transfer to a number of diverse plants. These plant-associated symbiotic bacteria were made competent for gene transfer by acquisition of both a disarmed Ti plasmid and a suitable binary vector. This alternative to Agrobacterium-mediated technology for crop improvement, in addition to affording a versatile 'open source' platform for plant biotechnology, may lead to new uses of natural bacteria-plant interactions to achieve plant transformation.     

Chemically tailorable colloidal particles from infinite coordination polymers

Micrometre- and nanometre-sized particles play important roles in many applications, including catalysis, optics, biosensing and data storage. Organic particles are usually prepared through polymerization of suitable monomers or precipitation methods. In the case of inorganic materials, particle fabrication tends to involve the reduction of a metal salt, or the controlled mixing of salt solutions supplying a metal cation and an elemental anion (for example, S2-, Se2-, O2-), respectively; in some instances, these methods even afford direct control over the shape of the particles produced. Another class of materials are metal-organic coordination polymers, which are based on metal ions coordinated by polydentate organic ligands and explored for potential use in catalysis, gas storage, nonlinear optics and molecular recognition and separations. In a subset of these materials, the use of organometallic complexes as ligands (so-called metalloligands) provides an additional level of tailorability, but these materials have so far not yet been fashioned into nano- or microparticles. Here we show that simple addition of an initiation solvent to a precursor solution of metal ions and metalloligands results in the spontaneous and fully reversible formation of a new class of metal-metalloligand particles. We observe initial formation of particles with diameters of a few hundred nanometres, which then coalesce and anneal into uniform and smooth microparticles. The ease with which these particles can be fabricated, and the ability to tailor their chemical and physical properties through the choice of metal and organic ligand used, should facilitate investigations of their scope for practical applications.     

流动注射-化学发光法测定湖水中的 As（Ⅲ）

基于As（ III）在碱性介质中对Luminol -KMnO4体系化学发光抑制作用，建立一种测定湖水中As （ III）的新方法。工作中，对泵速、光电倍增管高压、Luminol和KMnO4的浓度等实验参数进行了优化。结果表明，在优化条件下，1×10-4～1．2×10-2 mg/L的As（III）对Luminol-KMnO4发光的减弱有良好的线性关系（R2＝0．9970），检出限为8．2×10-5mg/L，相对标准偏差（RSD）（n＝11，c ＝5×10-3mg/L）为0．5％.该方法具有简便、快速、准确、重现性好等特点，可用于湖水中As（III）的测定，结果令人满意。     

低碳视角下我国能源发展战略研究

能源低碳化是我国能源战略定位的根本,也是我国顺利实现低碳经济的重要保证。通过分析低碳能源内涵,阐述我国发展低碳能源面临的机遇、挑战和现实路径,以期对我国经济的转型发展有一定参考意义。     

Helical self-assembled polymers from cooperative stacking of hydrogen-bonded pairs

The double helix of DNA epitomizes this molecule's ability to self-assemble in aqueous solutions into a complex chiral structure using hydrogen bonding and hydrophobic interactions. Non-covalently interacting molecules in organic solvents are used to design systems that similarly form controlled architectures. Peripheral chiral centres in assemblies and chiral side chains attached to a polymer backbone, have been shown to induce chirality at the supramolecular level, and highly ordered structures stable in water are also known. However, it remains difficult to rationally exploit non-covalent interactions for the formation of chiral assemblies that are stable in water, where solvent molecules can compete effectively for hydrogen bonds. Here we describe a general strategy for the design of functionalized monomer units and their association in either water or alkanes into non-covalently linked polymeric structures with controlled helicity and chain length. The monomers consist of bifunctionalized ureidotriazine units connected by a spacer and carrying solubilizing chains at the periphery. This design allows for dimerization through self-complementary quadruple hydrogen bonding between the units and solvophobically induced stacking of the dimers into columnar polymeric architectures, whose structure and helicity can be adjusted by tuning the nature of the solubilizing side chains.     

广东省6种蝙蝠寄生2种斜睾科吸虫的记述

2008～2010年对广东省3个产地的3科4属6种129只蝙蝠的与化道寄生虫进行调查,发现斜睾科Plagiorchiidae斜睾属Plagiorchis吸虫2种：坞蝠钭睾吸虫Plagiorhis tespertilionis（Muller,1780）Braun,1900和朝鲜钭睾吸虫P．koreanus Ogata,1...     

EDTA萃取法分离自然水体中生物膜胞外聚合物

用EDTA水溶液作为萃取剂，对自然水体中培养的生物膜胞外聚合物进行了萃取和分离．通过对糖类、蛋白质、DNA含量的测定，选择了最佳萃取分离条件．结果表明该方法萃取效率高、操作简便、重现性好．