△-Resonances in Ground State Properties of ^40 20Ca Spherical Cold Finite Nucleus at Equilibrium and under Compression

The ground state properties of the spherical nucleus ^40Ca have been investigated by using constrained spherical Hartree Fock （CSHF） approximation at equilibrium and under high radial compression in a six major shells. The effective baryon-baryon interaction that includes the △（1236） resonance freedom degrees to calculate nuclear properties is used. The nucleon-nucleon （N-N） interaction is based on Reid soft core （RSC） potential. The results of calculations show that much of increase in the nuclear energy generated under compression is used to create the massive △ particles. The number of △ ＇s can be increased to about 2.1% of constituents of nucleus when nuclear density reaches about 1.34 times of normal density. The single particle energy levels are calculated and their behavior under compression is also examined. △ good agreement has been found between current calculations and phenomenological shell model for low lying single-particle spectra. The gap between shells is very clear and L-S coupling become stronger as increasing the static load on the nucleus. The results show a considerable reduction in compressibility when freedom degrees of △＇s are taken into account. It has been found that the total nuclear radial density becomes denser in the interior and less dense in the exterior region of nucleus. The surface of nucleus becomes more and more responsive to compression than outer region.     

From the Thermo Wigner Operator to the Thermo Husimi Operator in Thermo Field Dynamics

Using the thermo entangled state representation and based on the thermo Wigner operator we first introduce the thermo Husimi operator, which turns out to be a projective operator of the thermo squeezed coherent state, therefore the positive definite property of Husimi distribution function can be insured. In addition, we find the use of the thermo Husimi operator in simplifying the form of master equations.     

退激发压缩真空态及其特性

利用退激发压缩真空态归一化函数的产生函数, 获得了归一化的退激发压缩真空态. 借助于此态的归一化常数和中介表象理论, 我们得到了退激发压缩真空态的量子Tomogram函数和一些新的数学公式.     

高分解力CD是如何将20比特以上的数据压缩成16比特的

白1989年索尼公司开始用20比特进行录音以来,相继开发出了几种巧妙地将20比特的数据组合到16比特的CD格式巾去的压缩方法,使CD的音质有所提高,常将这种方式制作的CD称做20比特录音CD。本文将就制作20EL特录音CD的各种比特压缩技术进行介绍。     

手机上能否高清？

iPhone的出现。引领了手机大屏幕时代的风潮。如今,百家齐放,每个品牌的旗舰产品无不在屏幕上做到尽善尽美,让用户达到最佳的视觉感受。 在早期的手机视频播放中,我们需要先压缩视频的格式以及分辨率,然后再拷贝到手机中。繁琐的步骤,往往挫伤了人们用手机看电影的积极性。不过随着硬件设备与软件技术的不断提高,手机对视频的要求越来越高,人们也开始奢求高清电影能够进入手机中。体验手机上的高清世界。     

采用HELICEX~专利技术的18SW1600Nd

18SW1600Nd次低频大功率扬声器采用HELICEX专利冷却技术,额定功率1600W（AES）,功率压缩损失率低。使用过程中,频响准确有力,声压级高且平滑。灵敏度：97dB（2．83V）;最低响应频率：32Hz;控制位移：Xmax±10mm;机械位移：Xpp60mm。所有部件均进行严格选材并通过开发中的严格测试。     

高音、微型及号筒扬声器单元的大信号性能

6．2号筒压缩式驱动器（单元） 这是一个用酚醛树脂含浸的织物为振膜的号筒压缩式单元,音圈直径51nm,卷线高度4．6mm,气隙厚4mm。连接的号筒和相位塞被移走,后腔体积仔细地密封好以避免任何额外的声学共振。     

无线网络中SIP信令组合压缩方案研究

IMS（IP多媒体子系统）采用SIP协议建立和维护多媒体会话,但SIP是基于文本的协议,消息比较大,当应用于带宽小的无线网络时,会增加会话建立的时延。为缩短会话建立时间,有必要对SIP消息进行压缩。针对单一的使用压缩算法在SIP信令压缩性能方面的不足,本文在Deflate压缩算法的基础上,采用不同的压缩策略,对SIP消息实现了压缩。仿真结果表明,静态字典、用户自定义字典和共享压缩的组合方案得到了最好的压缩效果,压缩后的消息平均大小仅为原来消息大小的14％左右。     

一种实时信头压缩上下文转移方法

文章综合F—HMIPv6（次移移动IPv6的快速切换技术）、鲁棒性信头压缩和上下文转移三种机制,提出一种实时上下文转移方和ROHC（鲁棒性信头压缩协议）压缩状态迁移协调策略。在切换的同时将信头压缩上下文转移到新接入路由器中。避免了切换后在新接入路由器上重新运行压缩协议重建上下文的开销。分析表明,该方案能有效解决因切换导致的丢包和时延造成的压缩端与解压端上下文不同步问题。