风速对声点阵立靶系统建模及算法的影响研究

室外靶场中点阵声学立靶应用时风对报靶精度有较大影响。使用几何方法推导了激波到达时间、矢量风速、弹丸速度和入射角、着靶位置之间的模型方程,然后将激波到达时间显式表述。该显式表达式可简化非线性最小二乘法求解并加速了收敛性,可同时求得弹丸着靶位置以及速度、入射角,可适用于不同的传感器阵列样式。通过仿真给出了风速对报靶精度影响的误差图。     

大型空间环境模拟设备试验数据管理研究

针对国内外空间环境模拟设备试验系统数据管理模式,从试验数据采集、试验数据处理、试验数据存储归档以及试验数据移交利用这四个方面进行对比分析,提出国内空间环境模拟设备试验系统在增强试验数据处理能力、建立卫星故障模式分析和危险分析系统(FMECA)以及局部试验数据应用模式向远程同步试验数据应用模式发展的建议。     

Geometric phase,entanglement, and quantum Fisher information near the saturation point

Considering a collection of two-level atoms in the presence of a saturating monochromatic, steady-state field, we investigate the geometric phase (GP) of an arbitrary medium’s atom. We find that it is possible to detect the saturation of the atomic response by the GP computation. This is an interesting result, because we can predict the collective behaviour of the atomic system—i.e., the saturation of the optical response of the medium- by investigating the GP of a single medium’s atom, described as a qubit. Moreover, we find that the plot of the atomic GP in terms of the detuning Δ$\Delta$ is very similar to the absorption spectrum of the medium. In addition, it is shown that when the intensity of the driving laser field tends to saturation intensity, the qubit approaches maximum correlation with its environment described by the driving field and other qubits in the atomic system. Furthermore, we find that the behaviour of the entanglement is very analogous to that of the GP and the absorption coefficient. Besides, we adopt the atom to estimate the decoherence parameter by using the quantum Fisher information (QFI), an important measure of the information content of quantum states. Interestingly, we find that when the atomic system approaches its saturation point, the QFI decays with increasing the laser intensity, and therefore the parameter estimation becomes more inaccurate.     

Analysis of geometric scaling of miniature,multi-electrode assisted corona discharges for ionic wind generation

The assisted corona discharge is a unique discharge configuration that utilizes multiple collecting electrodes to minimize the voltage required to initiate a corona discharge and to generate an ionic wind. In this work, the geometric parameters that govern the formation of the assisted corona discharge and subsequent ionic wind are evaluated. Flow velocity measurements suggest that the geometry of the electrode spacings is optimized for ionic wind generation when the current flowing to the collector electrode is maximized, and that as the electrode gap is decreased to microscale dimensions, ionic wind production is inhibited.     

An empirical model for ionic wind generation by a needle-to-cylinder dc corona discharge

We present the results of an experimental study on ionic wind generation by a needle-to-cylinder dc corona discharge. A strong electrical field in the air generates air flow driven by the motion of ionized gas molecules along electric field lines. We measured the ionic wind velocity and discharge current with respect to various electrode geometries, distances between electrodes, and applied voltages. Our measurements suggest an empirical model for the ionic wind velocity as a function of the geometric factors of the collector electrode and the applied electric potential, which is useful for designing ionic wind cooling systems for small electronics.     

Pharmaceuticals and their metabolites in the marine environment: Sources,analytical methods and occurrence

The occurrence of pharmaceuticals in the environmental waters is a global concern. There is little research conducted on the monitoring of pharmaceuticals in the marine environment. In this article, the occurrence of pharmaceuticals and their metabolites in the coastal waters as well as associated risks related to their uptake by marine organisms are critically reviewed. The literature showed antibiotics as the most plentiful pharmaceuticals in the marine environment. Other therapeutic classes of pharmaceuticals appeared prominently in the marine environment are non-steroidal anti-inflammatory drugs and β-blockers, while gemfibrozil and carbamazepine were singled-out as the most studied lipid regulator and antiepileptic, respectively. Some pharmaceuticals have been found present in the marine organisms that are regarded as important food sources for humans. We reviewed the negative effects associated with the presence of pharmaceuticals in the marine environment. This article is concluded by deliberating on the possible future studies in this research niche area.     

Luminescent silver nanoclusters for efficient detection of adenosine triphosphate in a wide range of pH values

In this work, polymethacrylic acid (PMAA)-templated silver nanoclusters (Ag NCs) were developed as the fluorescent probe for the efficient and sensitive detection of adenosine triphosphate (ATP) in a wide range of pH values. The fluorescence intensity of the Ag NCs could keep stable with pH values ranging from 2.5 to 9.3. The detection of ATP was based on the quenching of the fluorescent Ag NCs in the presence of ATP. The fluorescence quenching of the Ag NCs with increasing ATP concentration was studied at pH 2.5, 4.5, 7.0 and 8.5 which involved a wide pH environment in body fluids. The limit of detection (LOD) for ATP was as low as 0.1 mmol/L in an acidic environment with pH of 2.5 and all the linear correlation coefficients were satisfactory under wide-span pH values from 2.5 to 8.5. In addition, the sensitive determination of ATP was also achieved by adding copper ions (Cu²⁺). The high selectivity and rapid detection process proved that the fluorescent probe had great potential to detect ATP in biological samples under different pH conditions.     

一种带吡啶悬臂大环异双核Zn（Ⅱ）-Ni（Ⅱ）配合物的合成、晶体结构及其DNA结合/切割性质

合成了一种带吡啶悬臂的不对称大环异双核金属Zn（Ⅱ）-Ni（Ⅱ）配合物[ZnNi （L）]（ClO₄）₂·H₂O （H₂L=3,3''-（（ethane-1,2-diylbis （（pyridin-2-ylmethyl） azanediyl）） bis （methyl ene）） bis （2-hydroxy-5-methylbenzaldehyde））,通过红外光谱、电喷雾质谱、单晶X射线衍射对其结构进行了表征。结果表明Zn（Ⅱ）和Ni（Ⅱ）的配位环境分别为扭曲的三角锥和正四面体。利用紫外光谱、粘度实验和循环伏安法对该配合物与DNA的相互作用模式进行了研究,结果表明配合物与小牛胸腺DNA （CT-DNA）的结合方式为插入模式,其相应的结合常数K_b=1.05×10⁵ L·mol^-1。另外,该配合物对pBR322 DNA有一定的切割作用。     

The effect of the wind velocity on the uptake rates of various diffusive samplers

This paper examines the results of experiments carried out in an exposure chamber to determine the wind effects on the performance of various diffusive sampler types commonly used for measuring gaseous pollutants in air. The resistance to wind of six diffusive samplers, two Palmes tubes, a badge with diffusion membrane, the EMD sampler and two radial diffusive samplers for different pollutants was compared in a range of velocities from 0 to 300?cm?s^?1. For all diffusive samplers tested, an increase in uptake rate was observed with increased air velocity usually following a logarithmic function. The consequences are an underestimation in the concentration measured by the diffusive samplers for low wind velocities below 30?cm?s^?1 and conversely an overestimation from 60?cm?s^?1. The magnitude of wind effects depends on diffusive sampler type and exceeds an uptake rate variation of ±20% for the axial diffusion tubes and the EMD sampler. With regard to the characteristics of each diffusive sampler, the dependence of uptake rate on wind velocity was analysed and discussed. The radial diffusive samplers for benzene and particularly the ones having a large and thick porous membrane appear to be the most effective design to minimise the influence of air velocity on passive sampling.     

Application of NMR spectroscopy for analysis of the composition of pine needle essential oil

We have used ¹H and ¹³C NMR spectroscopy to analyze the chemical composition of essential oils of pine needles grown in different regions of the Republic of Belarus. We consider the change in the composition of the oils depending on the area where the pines were grown. We suggest using pine essential oil as a biological indicator of environmental conditions. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 246–249, March–April, 2006.