Functional magnetic resonance imaging of tonic pain and vasopressor effects in rats

In functional magnetic resonance imaging (fMRI) studies, an elevation in blood pressure (BP) in individuals with a poor autoregulatory response may increase cerebral blood flow, potentially enhancing the blood oxygenation level dependent response. To investigate the role of BP changes, the cerebral activation to either tonic pain or the infusion of the vasopressor norepinephrine was correlated with the accompanying BP changes in alpha-chloralose anesthetized rats. Immediately after formalin (2%) injection into the forepaw, fMRI detected an activation that was correlated with the BP increase and additional activations that were independent of blood pressure changes 5–40 minutes later. The activation detected with the administration of the vasopressor norepinephrine, which does not cross the blood-brain barrier was correlated to both the amount and rate of increase in BP. The response ranged from being sparse, localized within cortex or widespread during modest, moderate or severe elevations in BP, respectively. The cerebral circulatory effects of hypertension should be considered as contributing to changes in cerebral blood oxygenation in fMRI studies involving increases in BP.     

大气中固体燃烧等离子体与微波相互作用的实验研究

 设计制造了含特定组分的化学药剂，利用热力学方法对其在大气中燃烧所产生的等离子体的电子密度进行了理论计算，对该等离子体对2~15 GHz波段微波的透射衰减和反射进行了测试。测试结果表明，该等离子体对该波段微波具有宽波段强吸收和弱反射性能，波段内的平均吸收大于25 dB，反射信号几乎淹没在背景噪声中。并从理论上分析了带电子与中性粒子的造成这一现象的主要原因是碰撞吸收。     

二次喉道扩压器对COIL的影响实验

 氧碘化学激光器分别采用二次喉道扩压器和8°扩压器时，对在不同阀门开度下的气流方向的壁面静压曲线和背压曲线，光轴壁面静压曲线，出口总压与上游压比值曲线，输出功率曲线进行了测量。对两种扩压器的数据进行了对比，结果表明：与8°扩压器相比，二次喉道扩压器能够有效隔离扩压器下游气流对光腔的干扰，显著减小捩区长度，并将转捩区控制在扩压器内。在激光器背压升高时，二次喉道扩压器的稳定性更强。     

Menisci in a Diamond-Shaped Capillary

This paper presents a closed form analytical solution to the augmented Young-Laplace equation for the meniscus profile in a capillary formed between four equal-sized tangent cylinders centered on the vertices of a square. The solution is valid for a large class of disjoining pressure isotherms and contact angles.     

Noise in porous silicon structures in air and in conditions of gas adsorption

Low-frequency noise, in the range 1–500 Hz, is measured at room temperature in samples of Au/PS/SCS/Al structure with a layer of porous silicon. Numerical values of the Hooge parameter α_H are estimated and the dependence of α_H on the composition of the gaseous environment, where the sample is placed, is determined. Possible reasons of observed high values of α_H for the samples in air and of the increase in α_H in conditions of gas adsorption are discussed. Introducing of carbon oxide in air changes the shape of spectrum.     

Structural properties of silver iodide and copper iodide

The structural changes within the Silver iodide (AgI) and Copper iodide (CuI) induced by pressure have been investigated using an effective interaction potential. CuI and AgI in their parent zinc blende (ZnS) to rock salt (NaCl) through an intermediate structure have been reported. The calculated values for the phase transition pressures and associate volume collapses are generally in good agreement with measured data.      

Liquid–Vapor Phase Transitions for Systems with Finite-Range Interactions

We consider particles in ^d , d2, interacting via attractive pair and repulsive four-body potentials of the Kac type. Perturbing about mean-field theory, valid when the interaction range becomes infinite, we prove rigorously the existence of a liquid–gas phase transition when the interaction range is finite but long compared to the interparticle spacing for a range of temperature.     

Effects of Buffer Gas N2 on Miniature Optically Pumped NH3 Submillimeter Wave Cavity Laser Emission at 67.2 μm

The effect of buffer gas N₂ on miniature optically pumped NH₃ submillimeter wave (SMMW) cavity laser emission at 67.2m was studied theoretically and experimentally. It has been found that: 1. N₂ had a positive effect on laser output of 67.2m, 2. sharp absorption in laser spectrum under certain gases mixture pressure corresponded to the threshold of 'bottleneck effect.     

也谈理想气体定义——兼对“理想气体的定义”一文质疑

主张为物质的理想模型下定义时要注意实验基础,在不同的数学阶段使用不同的理想气体定义,文中分析了从玻意耳－马略特定律导出焦耳定律某些方法的缺陷,指出了合理的证明方法。