CSAMT方法对虎跳峡龙蟠右岸变形体的反应特征

为了查明虎跳峡龙蟠右岸斜坡变形体的形态和结构,从而对其稳定性进行综合评价,利用地球物理手段做了CSAMT方法的勘察工作。结合地质信息得到了关于斜坡变形体的分布范围、规模及内部不均匀性的结果。认为该结果对认识变形体的特性提供了物性依据,为进一步综合评价其稳定性及可能引起的地质灾害提供了地球物理证据。     

PtFe掺杂石墨烯抗CO中毒性能的理论研究

基于密度泛函理论第一性原理研究了以单空位缺陷(SV)石墨烯为载体的Pt,Fe及PtFe二元金属催化剂的抗CO中毒能力.结果表明,对于单金属原子Pt和Fe,Fe更易吸附在SV石墨烯上;而对于PtFe二元金属催化剂,SV石墨烯对其固定能力明显好于Pt-SV,即Pt催化剂中掺杂Fe大大增加了SV石墨烯对金属催化剂的稳定性.Pt,Fe及PtFe二元金属催化剂抗CO中毒能力的研究结果表明,PtFe-6结构的抗CO中毒能力明显强于Pt-SV,接近于Fe-SV的抗CO中毒能力,在所有二元金属催化剂中PtFe-6的稳定性最好,明显优于Pt在SV石墨烯上的稳定性.通过在Pt中加入非贵金属Fe既可提高DMFC中阳极Pt催化剂的抗CO中毒能力,又可提高其催化活性.     

A facile synthesis and fungicidal activities of novel fluorine-containing pyrido[4,3-d]pyrimidin-4(3H)-ones

Sixteen novel 2-substituted-5,8,9-trimethyl-3-(4-fluoro-substituted)phenyl-thieno[3′,2′-5,6] pyrido[4,3-d]pyrimidin-4(3H)-ones 5a-5p were designed and have been successfully synthesized via tandem aza-Wittig and annulation reactions of the corresponding iminophosphorances 1, para-fluoro phenyl isocyanate, and substituted phenols or amines in 73-90% isolated yields. Their structures were clearly verified by IR, ¹H NMR, EI-MS spectroscopy and elemental analysis, and in the case of compound 5a, analyzed by single-crystal X-ray diffraction further. The results of preliminary bioassay indicated that some compounds possess inhibition activities against Rhizoctonia solani and Botrytis cinereapers at a dosage of 50 mg/L.     

Bactericidal mechanism of Ag/Al2O3 against Escherichia coli

The bactericidal process of Ag/Al2O3 to Escherichia coli has been investigated to clarify the bactericidal mechanism. In SEM images, the configuration of E. coli cells contacting with the catalyst surface was quite different from that contacting with AgNO3 solution, which indicated that the Ag+ eluted from the catalyst did not play an important role in the bactericidal process. The bactericidal experiments strongly confirmed the contribution of multiform reactive oxygen species (ROS) (super oxide dismutase (SOD) and catalase as the scavengers for O2*- and H2O2, respectively) to bactericidal effect on the catalyst surface. Furthermore, the surface modification of Ag/Al2O3 by ultraviolet and formaldehyde influenced the bactericidal effect obviously, which not only confirmed the bactericidal mechanism of catalytic oxidation but also provided evidence for the synergistic effect between Ag and Al2O3 on the catalyst surface.     

光照法研究超氧化物歧化酶及其模型化合物与超氧离子的反应动力学

用改进的光照法研究了超氧化物歧化酶及其模型化合物μ-桥基·二(2,6-二乙酰基吡啶)缩二丙二胺合铜(Ⅱ)(桥基为SCN^-,N₃^-,I^-,Br^-,Cl^-,OH^-)与超氧离子的反应动力学,测定了反应速率常数k_Q,结果表明,超氧化物歧化酶的k_Q与脉冲辐解法及黄嘌呤氧化酶法的结果一致。6种配合物中,Cu₂L(SCN)(ClO₄)₃的k_Q最大,Cu₂L(N₃)(ClO₄)₃的最小,并讨论了真k_Q不同的原因。     

A Study on Coordination Compounds of Diacetylpyridine bis (semi-carbazone) with Some Transition, Metal Ions by Spectrophotometry

We synthesized 2,6-diacetylpyridine bis(semicarbazone)(DAPSC) and studied its coordination reaction with Cu, Co, Ni and Zn, in ethanol and in DMF spectrophotometrically. We realized that the ligand DAPSC in ethanol and in DMF does not dissociate and exists in ketonic form by conductometry and IK. The composition and stability constants of coordination compounds were calculated by graphic method and by self-written program. The results obtained by the two methods are in agreement with each other. The results showed that complexes of ML type were formed in ethanol and those of M3L2 tyPe in DMF. The sequence of lgβ is as follows: Co > Cu >Ni >Zn.     

Intersystem Crossing in Naphthalenediimide–Oxoverdazyl Dyads: Synthesis and Study of the Photophysical Properties

Oxoverdazyl (Vz) radical units were covalently linked to the naphthalenediimide (NDI) chromophore to study the effect of the radical on the photophysical properties, especially the radical enhanced intersystem crossing (REISC), which is a promising approach to develop heavy-atom-free triplet photosensitizers. Rigid phenyl or ethynylphenyl linkers between the two moieties were used, thus REISC and formation of doublet (D₁, total spin quantum number S=1/2) and quartet states (Q₁, S=3/2) are anticipated. The photophysical properties of the dyads were studied with steady-state and femtosecond/nanosecond transient absorption (TA) spectroscopies and DFT computations. Femtosecond transient absorption spectra show a fast electron transfer (<150 fs), and ISC (ca. 1.4–1.85 ps) is induced by charge recombination (CR, in toluene). Nanosecond transient absorption spectra demonstrated a biexponential decay of the triplet state of the NDI moiety. The fast component (lifetime: 50 ns; population ratio: 80 %) is assigned to the D₁→D₀ decay, and the slow decay component (2.0 μs; 20 %) to the Q₁→D₀ ISC. DFT computations indicated ferromagnetic interactions between the radical and chromophore (J=0.07–0.13 eV). Reversible formation of the radical anion of the NDI moiety by photoreduction of the radical-NDI dyads in the presence of sacrificial electron donor triethanolamine (TEOA) is achieved. This work is useful for design of new triplet photosensitizers based on the REISC effect.     

Bladder cancer hunting: A microfluidic paper-based analytical device

Bladder cancer is the fourth most common cancer in men, and it is becoming a prevalent malignancy. Most of the regular clinical examinations are prompt evaluations with cystoscopy, renal function testing, which require high-precision instrument, well-trained operators, and high cost. In this study, a microfluidic paper-based analytical device (μPAD) was fabricated to detect nuclear matrix protein 22 (NMP22) and bladder cancer antigen (BTA) from the urine samples. Urine samples were collected from 11 bladder cancer patients and 10 well-beings as experiment and control groups, respectively, to verify the working efficiency of μPAD. A remarkable checkout efficiency of up to 90.91% was found from the results. Meanwhile, this method is feasible for home-based self-detection from urine samples within 10 min for the total process, which provides a new way for quick, economical, and convenient tumor diagnosis, prognosis evaluation, and drug response.     

Epilepsy as a dynamical disorder orchestrated by epileptogenic zone: a review

Nonlinear Dynamics - Epilepsy is a group of chronic neurological disorders characterized with recurrent and hypersynchronous discharge. In the epileptic brain, epileptogenic zone (EZ) with abnormal...     

Stimulus-induced transition of clustering firings in neuronal networks with information transmission delay

We propose a conceptually novel method of reconstructing the topology of dynamical networks. By examining the correlation between the variable of one node and the derivative of another node’s variable, we derive a simple matrix equation yielding the network adjacency matrix. Our assumptions are the possession of time series describing the network dynamics, and the precise knowledge of the internal interaction functions. Our method involves a tunable parameter, allowing for the reconstruction precision to be optimized within the constraints of given dynamical data. The method is illustrated on a simple example, and the dependence of the reconstruction precision on the dynamical properties of time series is discussed. Our theory is in principle applicable to any weighted or directed network whose interaction functions are known.