非极性介质的冷冻介电谱

基于热平衡态的冷冻介电谱可提供慢极化响应过程的能谱信息，用此方法研究了苯和石 慢极化响应过程，发现在接近各处在的高温极化温度前谱线均发生分裂，研究石蜡的两个冷冻放电过程中束缚电荷引起的活化能与温度的关系，发现温度增加，石蜡的束缚电荷能级势垒降低，极化成份增加，量增大，慢极化电荷对两种冷冻方法表现出没的温度关系。     

电介质的结构级别和性质

用组合系综说明了慢效应中的剩余极化．从时域介电谱的慢分量可计算出驻极体中冷冻极化的理论曲线，其结果和实验一致．慢极化属于非马尔可夫过程，其历史记忆效应使电动力学中除麦克斯韦场方程之外还要补充源方程．证明了线性介电响应中存在复介电常数的充分和必要条件为极化过程是马尔可夫过程．在聚合物的β转变中，二级和三级结构运动的恢复力系数出现抛物线型软化．     

生物溶液在慢速冷冻过程中的极化模型

介电测量的实验表明:由水、氯化钠和低温保护剂组成的细胞低温保存液,经过慢速冷冻之后,在低频下都有很高的介电系数出现。作者们分析了三元溶液在冷冻过程中的物理化学性质,并进一步用低温显微镜对高锰酸钾溶液在低温下的微观结构进行了观察之后,得出了三元溶液在低温下为不均匀体系的结论,并由此引入了新的介质极化模型,从而较圆满地解释了该溶液在慢速冷冻过程中出现高介电系数的机理。     

基于改进广义相对最优极化的极化SAR舰船检测方法

为了提高极化合成孔径雷达(SAR)图像的舰船检测性能,提出了一种基于改进广义相对最优极化模型的极化SAR图像融合方法.改进的模型包含两个因子的乘积.第一个因子是最优极化状态下的雷达接收功率;第二个因子对应最优检测准则下的3个极化参数(极化熵、平面相似性参数、二面角相似性参数)的融合结果.使用该方法融合图像能够使得目标和...     

反式聚乙炔的高激发态极化子

在Su-Schrieffer-Heeger（SSH）模型基础上,计入长程电子关联的影响,研究反式聚乙炔分子链中的高激发态极化子的稳态性质.与一般的低激发态极化子比较,高激发态极化子的晶格畸变更宽更深,能隙中的两个局域几乎重合,除了在1.35 eV附近的peirls吸收峰,高激发态极化子仅有一个约0.65 eV的低能吸收峰,而普通极化子有2个低能吸收峰,一个在0.175 eV附近,一个在0.85 eV附近.这些区别为区分两类极化子提供判据.     

自由空间下多极化MIMO系统信道特性分析

基于HFSS仿真软件,在自由空间下研究并分析了一种六极化MIMO系统.相比于三极化MIMO系统,该系统可以获得更大的信道特征值与信道容量.仿真结果表明在自由空间中,这种六极化MIMO系统可以获得六个非零特征值,而三极化MIMO系统只能获得三个非零特征值.当系统信噪比SNR=20dB,接收距离R＞0.1m时,六极化MIMO系统信道容量达到18.5-24.7bps/Hz,比三个半波电偶极子天线组成的三极化MIMO系统容量大15％左右,比三个环天线组成的三极化MIMO系统容量大32％左右.     

半导体量子点中双激子的双光子共振吸收

从基本的非线性光学三阶极化率出发,分析半导体量子点中双激子的双光子共振吸收三阶极化率,得到2个入射频率光电场和只有1个入射频率光电场的简并情况下双光子共振吸收三阶极化率,讨论了三阶极化率的实部和虚部在双光子共振频率附近的行为,随着共振频率宽度的增大,三阶极化率的实部和虚部很快减小,三阶极化率敏感地依赖于共振频率宽度的大小.     

聚丙烯的准静态热刺激电流与降温极化效应

用阶跃升温热刺激电流（ＴＳＣ）、束缚电荷和剩余电荷等一系列准静态的方法分析了聚丙烯的电荷储存与释放的温度关系，提出了降温极化和循环变温极化的ＴＳＣ方法以研究冷冻过程中极化电荷的变化，三种准静态的ＴＳＣ谱与２℃／ｍｉｎ升温的ＴＳＣ谱相比有－１５℃的温度移动，急速降浊经的电流显示出一个充电峰，其原因是聚合物在低温时保持了高温态的结构，引起了介电常数的突变，导致了聚合物存储较多的束缚电荷，循环变温极化的ＴＳＣ方法证实了在降温极化过程中束缚电荷进入了较的能级，上述循环变温极化的方法有利于制备聚合物驻极体，而急速降温不利于高直流电场或辐射条件下使用的聚合物。     

基态非简并聚合物中极化子对的碰撞

基于紧束缚的Su-Schrieffer-Heeger(SSH)模型,利用非绝热的动力学方法,研究了基态非简并聚合物中负电极化子(电子型极化子)和正电极化子(空穴型极化子)的碰撞过程.研究发现,弱电场下两个极化子碰撞分开再相遇形成极化子激子,中等强度电场下它们碰撞分开后成为两个准粒子,强电场下负电极化子和正电极化子碰撞后直接解离.     

全极化波变极化网络设计

根据任意极化波可由空间两个正交的线极化波合成的理论,提出了一种电控变极化网络设计方案,通过功分器、3 d B电桥和可变移相器的组合形成电控变极化网络,输入的单路信号通过电控变极化网络可以形成任意极化波。仿真计算的结果表明,通过分别控制变极化网络里的两对串联移相器的相位线性变化,可以分别使合成极化波的椭圆倾角和椭圆率角产生线性变化。     

非线性奇异摄动系统的反馈镇定

针对一类关于快系统是线性的、慢系统可部分输入输出线性化的奇异摄动系统,设计了使整个闭环系统渐近稳定的状态反馈控制器.利用奇异摄动中双时间刻度理论将原系统分解为快慢子系统,其中慢系统具有仿射非线性系统的标准形式,并分别建立了慢系统线性部分和零动态部分及边界层系统的Lyapunov函数;最终通过计算复合Lyapunov函数沿原系统轨线的导数,得到了原系统渐近稳定的充分条件,并给出了估计摄动参数ε上界所满足的定量表达式.仿真实例进一步验证了理论方法的有效性.     

Boosting slow oscillations during sleep potentiates memory

There is compelling evidence that sleep contributes to the long-term consolidation of new memories. This function of sleep has been linked to slow (<1 Hz) potential oscillations, which predominantly arise from the prefrontal neocortex and characterize slow wave sleep. However, oscillations in brain potentials are commonly considered to be mere epiphenomena that reflect synchronized activity arising from neuronal networks, which links the membrane and synaptic processes of these neurons in time. Whether brain potentials and their extracellular equivalent have any physiological meaning per se is unclear, but can easily be investigated by inducing the extracellular oscillating potential fields of interest. Here we show that inducing slow oscillation-like potential fields by transcranial application of oscillating potentials (0.75 Hz) during early nocturnal non-rapid-eye-movement sleep, that is, a period of emerging slow wave sleep, enhances the retention of hippocampus-dependent declarative memories in healthy humans. The slowly oscillating potential stimulation induced an immediate increase in slow wave sleep, endogenous cortical slow oscillations and slow spindle activity in the frontal cortex. Brain stimulation with oscillations at 5 Hz--another frequency band that normally predominates during rapid-eye-movement sleep--decreased slow oscillations and left declarative memory unchanged. Our findings indicate that endogenous slow potential oscillations have a causal role in the sleep-associated consolidation of memory, and that this role is enhanced by field effects in cortical extracellular space.     

Slow light in tapered slot photonic crystal waveguide

A slotted single-mode photonic crystal waveguide with a linear tapered slot is presented to realize slow light, whose dispersion curve is shifted by changing the slot width. When the slot width is reduced, the band curve shifts in the tapered structure, and the group velocity of light approach zero at the cut-off frequency. Therefore, different frequency components of the guided light are slowed down even localized along the propagation direction inside a tapered slot photonic crystal waveguide. Furthermore, this structure can confine slow light-wave in a narrow slot waveguide, which may effectively enhance the interaction between slow light and the low-index wave-guiding materials filled in the slot. In addition, this tapered slot structure can be used to compensate group velocity dispersion of slow light by modifying the structure, thus opening the opportunity for ultra-wide bandwidth slow light.     

豚鼠离体小肠电活动与机械收缩

以小肠电活动和环肌张力、纵肌张力为指标，用同步记录的方法研究了豚鼠离体小肠电活动与环肌张力、纵肌张力之间的关系，结果表明：（１）豚鼠离体小肠的电活动包括慢波与峰波；（２）豚鼠离体小肠始终存在着节律性张力活动，其环肌收缩与纵肌收缩的关系表现为拮抗收缩、共同收缩、交互抑制等形式；（３）峰波可增加收缩力，峰波的个数、振幅与小肠张力呈正变关系，尤其与环肌收缩的对应关系更为显著．（４）慢波可触发收缩，尤其是纵肌收缩．在没有峰波仅有慢波时，亦可有收缩活动甚至活跃的收缩活动．     

VO编辑系统制作快慢特技初探

运用平均加帧，平均减帧的思维方式，采用普通ＶＯ编辑系统及一般常用设备，推荐制作快慢特技的两种方法，一种是在ＶＯ系统内部实现快慢特技，另一种是在ＶＨＳ与ＶＯ系统之间的实现快慢特技的制作。     

非线性能量阱系统的强调制响应研究

为了得到谐波激励下本质非线性能量阱系统出现强调制响应的充要条件，开展非 线性能量阱系统的强调制响应研究 . 利用复变量平均法推导主共振下系统的慢变动力流方 程；结合多尺度法实现系统快、慢变流形的分离，得到不同参数下系统的慢不变流形以及全局 分岔特性；通过构建快变流形的一维映射函数，揭示非线性能量阱系统呈现强调制响应状态 的充要条件；搭建非线性能量阱系统的模拟电路，进行强调制响应检测电路试验. 仿真和试验 结果表明，强调制响应是由耦合系统慢变动力流中极限环的鞍结分岔引起的且真实存在，系 统出现稳定的强调制响应必须满足两个条件：一是非线性能量阱系统响应超越慢不变流形上 的极值点，又不吸引至慢不变流形某一分支；二是形成连续跳跃环路而不陷入局部循环时.     

慢滤-消毒对二级出水中污染物去除及影响因素

再生水回用是解决水资源危机的重要途径,但是城市污水厂二级出水中仍含有大量的污染物,对人们的身体健康存在着潜在威胁。为保证再生水回用的安全性,本研究通过探究生物膜慢滤-次氯酸钠消毒组合工艺处理污水厂二级出水的方法研究了该工艺对水中的有机物和条件致病菌的去除效能,并对其影响因素进行分析。结果表明,相同滤速下,生物膜慢滤较慢滤对溶解性有机物的去除效果好,滤速为20 cm/h时对DOC的去除效果最佳;生物膜慢滤对富里酸类有机物、微生物副产物类有机物、腐殖酸类有机物的处理效果均比慢滤好;相同滤速下,生物膜慢滤对浊度的去除效果优于慢滤;在NaClO最佳投加量8.0 mg/L（以有效氯浓度计）的条件下,生物膜慢滤-NaClO消毒组合工艺对军团菌、铜绿假单胞菌均有较好的去除效果,且NaClO对于自由悬浮态条件致病菌的去除效果更优;另外,较低pH值和较高水温更有利于NaClO消毒对水中条件致病菌的去除。可见,生物膜慢滤-次氯酸钠消毒工艺可以有效控制二级出水中的有机物和条件致病菌等污染物,可以一定程度上保证再生水回用的安全性。     

缓倾角断裂隔震效应的定量研究

在对断裂分带研究的基础上 ,尝试对缓倾角断裂 (指倾角小于 45°断层 )建立起等效简化地质模型 ,针对各带的不同衰减机理 ,分别采用不同的力学模型和数值计算方法 ,分析了应力波通过断裂构造的动力响应 ,通过系统的定量研究 ,指出除断层各带自身材料力学性质 (如波阻抗等 )外 ,断层的倾角、各带的厚度、断层泥带的存在及构造透镜体带颗粒大小、拓扑结构是影响应力波传播的重要因素     

Peptidergic transmitters in synaptic boutons of sympathetic ganglia

In sympathetic ganglia of the bullfrog, a slow synaptic potential lasting for minutes--the late slow excitatory postsynaptic potential (e.p.s.p.)--was discovered. This slow response, unlike other previously known synaptic potentials in the autonomic nervous system, is not mediated by acetylcholine or monoamines. Similar non-cholinergic, non-adrenergic slow synaptic potentials have since been found in several other vertebrate autonomic ganglia. We found that the late slow e.p.s.p. is probably mediated by a peptide that is identical to, or closely resembles, mammalian luteinizing hormone releasing hormone (LHRH), because (1) when applied directly to sympathetic neurones, LHRH and its agonists elicit a slow depolarization, associated with similar changes in membrane conductance and excitability as those occurring during the late slow e.p.s.p. Furthermore, both peptide-induced and nerve-evoked responses are blocked by antagonists of LHRH; and (2) radioimmunoassays indicate that a chain of sympathetic ganglia contains 100-800 pg of a LHRH-like peptide. Its distribution among spinal nerves, the great reduction of this substance following denervation, and its release from ganglia following isotonic KCl treatment or nerve stimulation suggest that the LHRH-like material is contained in preganglionic nerve fibres. Here we report that immunohistochemical staining of sympathetic ganglia shows that LHRH-like immunoreactivity is indeed present in synaptic boutons. We also show that the two types of ganglion cells (B cells and C cells) receive strikingly different patterns of peptidergic innervation.     

A lethal mutation in mice eliminates the slow calcium current in skeletal muscle cells

Contraction of a vertebrate skeletal muscle fibre is triggered by electrical depolarization of sarcolemmal infoldings termed transverse-tubules (t-tubules), which in turn causes the release of calcium from an internal store, the sarcoplasmic reticulum (SR). The mechanism that links t-tubular depolarization to SR calcium release remains poorly understood. In principle, this link might be provided by the prominent slow calcium current that has been described in skeletal muscle cells of adult frogs and rats. However, blocking this current does not abolish the depolarization-induced contractile responses of frog muscle, and the function of this slow calcium current is unknown. Here we describe measurements of calcium currents in developing skeletal muscle cells of normal rats and mice, and of mice with muscular dysgenesis, a mutation that causes excitation-contraction (E-C) coupling to fail. We find that a slow calcium current is present in skeletal muscle cells of normal animals but absent from skeletal muscle cells of mutant animals. The effect of the mutation is specific to the slow calcium current of skeletal muscle; a fast calcium current is present in developing skeletal muscle cells of both normal and mutant animals, and slow calcium currents are present in cardiac and sensory neurones of mutant animals. We believe this to be the first report of a mutation affecting calcium currents in a multicellular organism. The effects of the mutation raise important questions about the relationship between the slow calcium current and skeletal muscle E-C coupling.