影音园地／读者信箱

你们好!我是一名影音爱好者，前不久我在一份电脑刊物上看到一篇文章说电影的清晰度为4000线，对此，我很不理解，因为之前我也在相关资料上了解到电影的清晰度为750线左右，VCD为240线，DVD为540线。DVD作为目前家庭影院的最好讯源何至于跟电影相差这么大，说实在的我有一种失落感。在此，我想请教各位老师，     

野味是怎么炼成的

坚持是一种品德，坚持冒险，坚持挑战，坚持追求。然而变通是一种能力，变冒险为放松，变挑战为习惯，变追求为学习。有些技能需要我们慢慢掌握，例如适应极地之前先走到郊外，例如出发野营之前先享受野餐。五月，爱车，蓝天，草地，氧气，野味，我们一项不落，周密计划，完美演出，这便是DIY生活的最大乐趣所在。     

旋出精彩——夏新移动DVD机PDVD-V10

继今年初的V8风潮，夏新又推出一款力作——PDVD-10，为它在DVD便携机领域添上了新的一笔，为我们带来了新的选择，新的乐趣。     

晶莹剔透：海尔乐趣Q5一体机

作为国内白色家电巨头的海尔，在为这款定位于家庭的一体机进行外观设计时，也为其赋予了浓厚的白色家电味，纯白色的机身显得颇具档次，给人一种非常清爽的感觉。值得一提的是，整个机身除了白色就剩下采用璀璨水晶材质的塑料包边了，这一设计的加入配合采用白色钢琴烤漆的面板，让其整机展现出一股晶莹剔透的质感。并且，其圆润的机身边角线条，也为Q5增加了一丝可爱的味道。     

我的心随鹤飞舞

“君子为鹤，小人为沙。”以鹤言志，以鹤寄情，鹤之翱翔，心之飞舞。对于我来说，摄影已经从一个兴趣变成了一种信念，一份执着。摄影对于我的吸引，建立在它为我带来的认识和思考上。有人是静坐参禅，我对摄影的探索，也不妨以“参”字来形容。摄影对我是一种信念，在”参“这个字里面，包含着几分严肃，也带有锲而不舍的执著，更代表学无止境的追求。     

氮分子激光照射动物试验

为了观察氮激光照射对机体的影响，用它照射了5只家兔。分为三组，一组为对照，另二组为不同剂量，其中一组隔日照射～次，每次10分钟，共三次，另一组每日照射一次，每次20分钟，共7次。照射部位为头顶、心区、肝区。     

法国电信-Orange在四川捐建希望小学

法国电信--Orange集团践行企业的社会责任，在2008年5月地震发生后，积极支持中国青少年基金会发起的“希望工程紧急救灾劝募行动”倡议，并与中国青少年基金会签署一项协议，为四川省地震灾区捐建一所希望小学。中国青少年发展基金会将在一年内选出符合受助条件的学校，法国电信将从其中选定一所小学作为捐建对象。新建的学校为永久性建筑，而不是临时性设施，它将取代中国青基会在震前援建的一所小学。     

从动画取材看创意来源

动画不仅是一种精神文明，也是一种物质文明，并且逐渐发展为一种产业，创造丰厚的经济效益。     

西门子手机电池的修复

故障现象 一部SIEMENS 3518型手机，其所用电池为3．6V／500mAh的镍氢电池。充电器为购机时原配充电器，输出电压为4．5V，输出电流为300mA。由于已使用3年多，电池块待机通话时间很短，充不进也放不出。经过测试，电池的充电电压和电流均正常，充电后的开路电压在3．8V以上，就是通常所说的“一充即饱，     

悦音相伴BOSE助力世锦赛-汇丰冠军赛

2014年11月5日，世锦赛一汇丰冠军赛再次落地上海，作为世界高尔夫锦标赛的最后一站，各位高尔夫顶尖选手已准备完善，为大家奉献一场最精彩的比赛。作为PGATOUR的大中华区官方合作伙伴，全球知名音响品牌Bose再次助阵世锦赛-汇丰冠军赛，为现场嘉宾带来—场高球与极致影音响宴。     

a—SiNx：H薄膜对a—Si：H TFT阈值电压的影响

介绍了测定a－Si：HTFT闽值电压的实验方法。重点研究了改变a－SiNx：H薄膜淀积时反应气体NH3／SiH4流速比以及a－SiNx:H膜厚对a－Si：HTFT阈值电压的影响。对实验结果进行了分析。实验结果表明：a－Si:HTFT的阈值电压随a－SiNx：H的膜厚增加而增大；增大X－SiNx：H薄膜淀积时NH3／SiH4气体流速比，可明显减小a-Si:HTFT的阈值电压。     

A Multirate Switching Network for Broadband Channels

A broadband ISDN switching network model is presented, switching the channel types H2, H3, and H4 envisaged by the CCITT. The synchronous time division multiplex technique is applied. The switching network operates at the basic bit rate of the H2-channel; H3and H4-connections are established via multichannel connections of up to four basic channels. H2-connections which are part of one H3- or H4-connection always have to use common interconnection links. This is a favorable solution to keep digit sequence integrity for multichannel connections, but influences blocking characteristics of the switching network. The implementation of an optimal path selection method plays a fundamental role. In such a multichannel switching network, blocking probabilities for H2-, H3-, and H4-connections must be distinguished. They do not only depend on the total offered load, but also on the proportions of H2-, H3-, and H4-connections (traffic mix). The simulation results presented in this paper prove that multirate switching via multichannel connections is feasible for the broadband channel types H2, H3, and H4, and that the proposed switching network has a sufficiently high traffic capacity whatever the traffic mix may be.     

Photoemission spectroscopy of heterojunctions of amorphoushydrogenated silicon with silicon oxide and nitride

A study of the growth and electronic structure of a-Si:H/a-SiN_x:H and a-Si:H/a-SiO_x:H heterojunctions by photoemission spectroscopy is discussed. The interfaces in a-Si:H/a-SiO_x are atomically abrupt, except for the SiO_x on the Si interface which is graded over ~3 Å due to plasma oxidation. The offset energies between the a-Si:H valence band and those of a-SiN_x:H and a-SiO_x:H are 1.2 and 4.0 eV, respectively. Extra H(~2×10¹⁵) is incorporated in the Si on the SiN_x interface region. The hole wave functions in a-Si:H are localized on a scale of 1-2 interatomic distances     

NIP型非晶硅薄膜太阳能电池的研究

采用射频等离子体增强化学气相沉积(RF-PECVD)技术制备非晶硅(a-Si)NIP太阳能电池,其中电池的窗口层采用P型晶化硅薄膜,电池结构为Al/glass/SnO2/N(a-Si:H)/I(a-Si:H)/P(cryst-Si:H)/ITO/Al.为了使P型晶化硅薄膜能够在a-Si表面成功生长,电池制备过程中采用了H等离子体处理a-Si表面的方法.通过调节电池P层和N层厚度和H等离子体处理a-Si表面的时间,优化了太阳能电池的制备工艺.结果表明,使用H等离子体处理a-Si表面5 min,可以在a-Si表面获得高电导率的P型晶化硅薄膜,并且这种结构可以应用到电池上;当P型晶化硅层沉积时间12.5 min,N层沉积12 min,此种结构电池特性最好,效率达6.40%.通过调整P型晶化硅薄膜的结构特征,将能进一步改善电池的性能.     

飞秒激光场中氯丙烯的光电离/解离机制研究

利用50fs的激光脉冲对氯丙烯在200nm、400nm和800nm下的光电离/解离机理进行了研究. 实验获得了氯丙烯在三种波长下的电离质谱和光强指数,分析了母体和碎片离子强度随波长的变化关系. 在200nm时,C3H5Cl+来源于飞秒脉冲的直接非共振电离,其它碎片离子均来源于母体离子的电离解离过程;在400nm时,部分分子被激发到高里德堡态从而解离产生C3H5,C3H5再次吸收光子电离导致C3H5+的信号增强;在800nm时,部分分子被同时激发到了排斥态nσ*和多个高里德堡态而发生解离.更多通道产生C3H5使得C3H5+产量进一步增加.由于C3H4+来自C3H5Cl+以及C3H5+的电离解离过程,因此,C3H4+产率随波长变化相对较缓.     

Modeling and performance analysis of unlicensed bands MAC strategy in multi-channel LTE-A networks with M2M/H2H coexistence

With the growing use of the machine-to-machine (M2M) communication and the unlicensed band by advanced long term evolution (LTE-A) networks, known as LTE unlicensed (LTE-U), demand for resource access strategy is rapidly increasing and has recently been attracting considerable attention of mobile operators. The requirement set by 3rd generation partnership project in the release 11 about LTE standards will allow LTE-U and other unlicensed band access technology to peacefully coexist and operate in the same unlicensed band. LTE-U supports not only the human-to-human (H2H) communication but also the M2M communication. In this paper, a new MAC protocol for LTE-U that allow friendly co-existence of H2H with M2M communications working in unlicensed bands is presented. The proposed MAC mechanisms is designed to ensure an efficient and fair channel access as well as enabling better H2H/M2M coexistence. The throughput performance of both H2H and M2M systems is evaluated analytically and by simulation. The impact of H2H/M2M transmissions periods and spectrum sensing time on the throughput performance of H2H and M2M systems are also studied.     

Stability of Amorphous-Silicon and Nanocrystalline Silicon Thin-Film Transistors Under DC and AC Stress

Bottom-gated n-channel thin-film transistors (TFTs) were fabricated using hydrogenated amorphous-silicon (a-Si:H)/ nanocrystalline silicon (nc-Si:H) bilayers as channel materials, which are deposited by plasma-enhanced chemical vapor deposition at low temperatures. The stability of these devices is investigated under static and dynamic bias stress conditions. For comparison, the stability of a-Si:H and nc-Si:H single-layer TFTs is investigated under similar bias stress conditions. The overall results demonstrate that the a-Si:H/nc-Si:H bilayer TFTs are superior compared with their counterparts of a-Si:H and nc-Si:H TFTs regarding device performance and stability.     

反应条件对液相沉淀法制备FePO4·2H2O的影响

以FeSO4·7H2O,NH4H2PO4,H2O2和NH3·H2O为原料,通过液相沉淀法制备得到FePO4·2H2O,研究了反应温度、搅拌速度、H2O2加入量和pH值等反应条件对合成FePO4·2H2O的影响.采用TG-DTA,XRD和SEM及ICP等测试方法对FePO4·2H2O的物相、结构及形貌进行表征.结果表明:...     

基于H．263编码标准的H．264实时编码器的优化设计

从实时应用角度出发,参考H.263编码标准,对H.264视频编码器进行精简,并对耗时较大的算法进行改进.仿真结果表明,简化后的H.264编码器编码速度达到20f/s(帧/秒),达到实时编码要求,且编码性能优于H.263编码标准的编码器.     

硅片背面铜污染的清洗

H2SO4/H2O2/H2O、HNO3/HF和HF/H2O2/H2O为半导体芯片生产过程中三种去除硅片背面铜污染的化学清洗液。在单片湿法清洗机上采用这三种化学液对直径300 mm具有类似于实际生产中铜污染的硅片进行了清洗,结果发现H2SO4/H2O2/H2O在清洗过程中不对硅片表面的Si3N4膜产生损伤,但铜污染的去除效率较低;HNO3/HF和HF/H2O2/H2O对Si3N4膜产生微量刻蚀,从而去除扩散至硅片内部铜污染,从而显示出较佳的去除效果。通过比较HF/H2O2/H2O中HF体积分数与Si3N4膜刻蚀深度和清洗后铜原子浓度,HF的体积分数为1.5%时,可以使硅片表面铜原子浓度降至1010cm-2以下,并且Si3N4膜厚的损失小于1 nm。