废水生化处理方法进展

介绍了废水生化处理概念、分类,阐述了废水生化处理的重要性,对好氧生物处理和厌氧生物处理进行了比较,介绍了生化法时水质的要求,活性污泥法、生物膜法、厌氧生物处理、好氧厌氧组合工艺发展历程、现状及废水生化处理今后的发展方向.     

Design of a room-temperature phosphorescence-based molecular beacon for highly sensitive detection of nucleic acids in biological fluids

Ultrasensitive fluorescent analysis or monitoring of significant molecules in complex samples is important for many biological studies, clinical diagnosis, and forensic investigations, the major obstacle for which is the background signals from ubiquitous endogenous fluorescent components of the environments. Herein, a room-temperature phosphorescence (RTP)-based molecular beacon (MB), employing a Eu(3+) complex of chlorosulfonylated tetradentate β-diketone (L) and the quencher BHQ-2, was engineered for highly sensitive detection of DNA sequences in biological fluids. Complexation of Eu(3+) with the ligand L formed a strongly luminescent complex EuL(2). But when EuL(2) and BHQ-2 were labeled to two ends of a DNA molecule with hairpin structure, the luminescence of EuL(2) was quenched by BHQ-2 due to the stem-closed conformation of the beacon. Due to very low background luminescence from the probe molecule, >200-fold signal enhancement was achieved when nanomolar target sequence was introduced. This sensitivity is about 20-fold higher than the level achieved with conventional fluorescence-based molecular beacons. Furthermore, because the Eu(3+) complex has a much longer luminescence lifetime (≈0.8 ms) than that of the background (<10 ns), RTP measurements were used to directly detect as low as 500 pM DNA in cell media quantitatively without any sample pretreatment.     

Design of aptamer-based sensing platform using triple-helix molecular switch

For successful assay development of an aptamer-based biosensor, various design principles and strategies, including a highly selective molecular recognition element and a novel signal transduction mechanism, have to be engineered together. Herein, we report a new type of aptamer-based sensing platform which is based on a triple-helix molecular switch (THMS). The THMS consists of a central, target specific aptamer sequence flanked by two arm segments and a dual-labeled oligonucleotide serving as a signal transduction probe (STP). The STP is doubly labeled with pyrene at the 5'- and 3'-end, respectively, and initially designed as a hairpin-shaped structure, thus, bringing the two pyrenes into spacer proximity. Bindings of two arm segments of the aptamer with the loop sequence of STP enforce the STP to form an "open" configuration. Formation of aptamer/target complex releases the STP, leading to new signal readout. To demonstrate the feasibility and universality of our design, three aptamers which bind to human α-thrombin (Tmb), adenosine triphosphate (ATP), and L-argininamide (L-Arm), respectively, were selected as models. The universality of the approach is achieved by virtue of altering the aptamer sequence without change of the triple-helix structure.     

项目业绩系统评价模型及其改良研究

项目系统评价实际上是项目驱动型公司业绩和效率持续提高的重要而必要的手段。通过排除一些评估过程中易于产生歧义的复杂方法和手段,对国际项目管理协会(IPMA)所广泛采用的项目卓越模型(project excellence model,PE模型)进行改良,提出更为合理和透明简约的模型和手段,对项目进行全面而系统的评价,更好地评价项目管理过程、业绩和项目利益相关方的得失。改良后的模型与原模型所提出的评价准则更为一致,更易于进行项目评价的操作与项目驱动型公司的项目知识管理。     

最初形成的喷射沉积Al-Zn-Mg-Cu铝合金的显微组织分析

用喷射成形工艺制备了Al-Zn-Mg-Cu高强铝合金。通过对最初形成的沉积坯的显微组织的观察，分析液滴在飞行和沉积过程中的形核、长大过程，分析均匀化和热挤压后最初形成的沉积材料的显微组织变化。由实验结果，经雾化沉积制备的Al-Zn-Mg-Cu合金。最初沉积坯的沉积态由于经历了两次形核，形成了大小不一的近似等轴晶；均匀化晶粒无明显长大，晶粒进一步球化。同常规的工艺相比，雾化沉积制备的材料可以省略均匀化过程；沉积态组织直接经过热挤压形成均匀致密的组织。     

喷射成形7075+TiC铝合金的半固态组织研究

制备具有不同原位TiC颗粒含量的喷射成形7075铝合金，在610℃和620℃二次加热并保温30min，淬火固定其半固态组织后采用扫描电镜进行观察，利用平均截线法统计其平均晶粒尺寸，分析不同颗粒含量对喷射成形7075铝合金半固态组织的影响规律。结果表明，当原位TiC颗粒含量达到2．91％(体积分数，下同)时已经产生良好的钉扎效果，使得合金基本保持喷射成形组织特征，能够满足后续的半固态成形工艺要求，与7075铝合金相比，抗拉强度提高4．2％，TiC颗粒的含量减少至1．73％和1．15％时，局部区域发生晶粒的异常长大现象，使合金组织的均匀化程度下降。     

Study on the weathering resistance of fly ash-lime compacts

The relationship between the inner quality factors (such as the amount of effective calcium oxide and the pore structure) of steam-cured fly ash-lime compacts (clinker-free) and the environment factors (such as drying shrinkage, freeze-thaw and carbonation, et cetera) have been studied here comprehensively by the simulation weathering examination. Meanwhile, the influences of additives of alkali paste and gypsum on the mechanical properties and pore structure of the compacts have been investigated and discussed, and the effects of interface texture on the mechanical properties have been discussed also. The results suggest that the weathering resistance of the system studied can be improved effectively by means of controlling the fraction of effective calcium oxide (EF_cao) and additives, in turn, to improve the interface interlinking. The optimum fraction of EF_cao is ∼15.3%, alkali paste is about 3.0% and gypsum is 1.7∼2.6% (account by SO₃%) if the as-received low calcium-bearing fly ash with low carbon content (<6.0%) has been selected.     

A theory for wave equation inverse problem: The union method for scattered wave extrapolation and velocity imaging

A new theory for inverse problem of wave equation, that is, the union method for scattered wave extrapolation and velocity imaging, is proposed in this paper. This method is very different from the classical wave extrapolation for migration, because we relate directly the scattered wave extrapolation to velocity inversion. And also this method is different from any linearized inverse method of wave equation, because we needn’t use linearized approximation. Because of this, the method can be applied to strong scattering case effectively (i. e. the value of scattered wave is not small, which can not be neglected). This method, of course, is different from nonlinearized optimum inverse method, because in this paper, the nonlinear inverse problem is turned into two steps inverse problem, i. e. scattered wave extrapolated and velocity imaging, which can be solved easily. Hence, the problem how to get the global optimum solution by using the nonlinearized optimum inverse method doesn’t bother us by using the method in this paper. Project supported by the Natural Science Foundation of Hunan Province Synopsis of the first author Song Shougen, professor, born in May 1960, received Ph D degree in Applied Geophysics, majoring in inverse problem in Mathematical Physics.     

大功率真空断路开关用Cu-Cr触头材料研究现状及发展

总结了CuCr合金触头材料的性能，特点及其在国内外的发展现状，指出混粉烧结法，压力浸渗法的缺点；并总结了现有的改进方法，提出用喷射沉积技术生产CuCr合金触头材料，结果表明，用喷射沉积技术生产的CuCr合金触头材料中Cr颗粒进一步细化，而且均匀分布。     

波场延拓+模糊决策层速度分析

为了获得层状声学介质的层速度参数,文中依据波场延拓理论和模糊决策理论改进了速度分析。首先以傅氏域内的双方根(DSR,即 Double SquareRoot)延拓方程为工具,以一定的试验速度(v_i)和双程旅行时(τ_i)延拓地表的多炮检距波场,获得延拓后的多炮检距波场;然后,根据相干准则计算延拓后波场值沿炮检距方向的相似度,并把它作为对应的速度—时间点(v_i,τ_i)(称之为备择点)处的相似度;改变 v_i,τ_i值,重复上述两个步骤,可获得 v_i-τ_i平面上的相似度,再按相似度准则、趋势贴近准则、距离最小准则将求得的相似度转换为对应备择点的亮度;最后,根据各备择点的亮度便可自动拾取速度和双程旅行时,从而达到从多炮检距波场中自动求取层速度和同时确定最佳层底双程旅行时的目的。对理论模型和实际资料试算的结果表明,用该方法求出的层速度具有精度高、误差不累积的优点,该法还具有适应弱反射和抗干扰的能力。