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1.
T.R.DUDLEY 《青海师专学报》1984,(1)
llex strigillosa T.R.DUDLEY,sp.nov. 〔Section Pseudoaquifolium S.-Y.HU(1950)Series Lougecaudatae S.-Y.HU(1950)〕. DIAGNOSIS: A I.kengii S.-Y.HU(1950)affinis sed ramulis et gemmis terminalis,dense cinerascentibus puberulento-strigillosis,stipulis tenuiter membranaceis minutis0.1mm longis vel minus fugacibus cito caducis,petiolis denso cinerascentibuspuberulento-strigillosis aliquado subglabris laminis versus,laminis foliorum mino-ribus 4—7.5cm longis 1—2cm latis basibus acutis ad attenuatis apicibussensim acuminatis vel caudato-acuminatis acuminibus brevioribus 5—10(—15)mm longis marginibus integris vel subintegris conspicue sinuolatis et apicibus 相似文献
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In this paper, the security technology of ad hoc networks is studied.To improve the previous multi-receiver signcryption schemes, an ID-based multi-message and multi-receiver signcryption scheme for rekeying in ad hoc networks is proposed.In this scheme, a sender can simultaneously signcrypt n messeges for n receivers, and a receiver can unsigncrypt the ciphertext to get his message with his own private key.An analysis of this scheme indicates that it achieves authenticity and confidentiality in the random oracle model while being of lower computation and communication overhead.Finally, for the application of our scheme in ad hoc, a threshold key updating protocol for ad hoc networks is given. 相似文献
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《第二课堂(小学)》2007,(11)
The Coca-Cola Company pays about one billion to invite Su Xing (苏醒), the first champion of "Happy Boys", to act as its ad. spokesman. After the great success with Li Yuchun, champion of "Super Girls", as its ad. spokesman, the Coca-Cola Company realizes that stars from common people can bring great market. As people's attention begins to turn from "Super Girls" to "Happy Boys", the Coca-Cola Company decides to choose Su Xing as its ad. spokesman, in place of Li Yuchun. 相似文献
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细筒苣苔属 Lagarosolen W.T.Wang,gen.nov. (Cyrtandroideae-Didymocarpeae) Affinis Chiritae D.Don a qua corolla elongata,tubo tenuiter cylindrico limbo2.5—3-plo longiore,filamentis rectis,stylo apice 2-lobato,lobis subaequalibusintus stigmatosis differt. Calyx campanulatus,ad basin 5-sectus,segmentis lanccolato-lincaribus.Corollapurpurea,bilabiata,tubo tenuiter cylindrico limbo 2.5—3-Plo longiore utrinquepaulo ampliato,labio postico 2-Jobato,labio antico 3-lobato,lobis angustetriangularibus apice longe attenuatis.Stamina 2 antico-lateralia fertilia,inclusa, 相似文献
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正引子:高中学生在复数学习过程中,经常会遇到这样一个习题:试证(a2+b2)(c2+d2)可表示成x2+y2的形式.事实上,令z1=a+bi,z2=c+di,两数相乘,得(a+bi)(c+di)=(ac-bd)+(ad+bc)i.两边平方可得,|(a+bi)(c+di)|2=|a+bi|2|c+di|2=|(ac-bd)+(ad+bc)i|2,即(a2+b2)(c2+d2)=(ac-bd)2+(ad+bc)2,令x=acbd,y=ad+bc,即得结论. 相似文献
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《作文大王》2006,(5)
nam e杨叶盈sound希望在这烂漫的季节里,我也得到一片粉色的花瓣。ad d.533011广西百色市大华学校初一(1)班............................................................nam e黄婷sound待我们成为知己后,你会发觉你赚了哦!ad d.536000广西北海市第六中学初一(3)班............................................................nam e水梦天蓝sound快拿信来砸偶吧!interests听音乐看小说上网交友ad d.232000安徽省肥东县城关中学初中部葛伦余老师转陈琪............................................................nam e冰清sound武林中… 相似文献
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Ad hoc类别研究：理论与价值 总被引：1，自引：0，他引：1
Ad hoc类别是指根据特定情境的需要,为解决某个具体问题而即时形成的概念类别。当两个概念在特定情境和目标下联系在一起,它们就具有了ad hoc联系。Ad hoc联系和ad hoc类别的形成以心理语境论为基础,蕴涵着丰富的研究价值。我国心理学界对ad hoc联系和ad hoc类别的研究起步较晚,应加强ad hoc类别研究。 相似文献
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大规模ad hoc网络下的高效的主动RSA方案 总被引：1，自引：0，他引：1
A previous proactive RSA scheme for large-scale ad hoc network has been shown to be faulty. In this paper, we present a new proactive RSA scheme for ad hoc networks, which includes four protocols： the initial key distribution protocol, the share refreshing protocol, the share distribution protocol, and the signature generation protocol. This scheme has two advantages： the building blocks are secure, and the system is efficient. 相似文献
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An adaptive load balancing scheme is proposed to balance the load in ad hoc networks. The new scheme can be applied in most on-demand routing protocols resulting in significant performance improvement. The proposed scheme is applied to the ad hoc on-demand distance vector (AODV) routing protocol. Simulation results show that the network load is balanced on the whole, and performance in packet loss rate, routing overhead and average end-to-end delay is also improved. 相似文献
10.
李居强 《语数外学习(高中版)》2007,(7)
<正>对于函数y=(cx+d)/(ax+b)(其中a≠0,c,d不同时为0),当ad=bc时,y=c/a为常函数;当ad≠bc时,函数y=(cx+d)/(ax+b)为分式函数,这个分式函数有着十分简洁而优美的优质.下面笔者尝试着探讨型如y=(cx+d)/(ax+b)(其中a≠0,c,d不同时为0且ad≠bc)的图象和性质的,并透过例题,给出这些性质的一些应用. 相似文献
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李爽 《赤峰学院学报(自然科学版)》2013,(11):10-12
利用水热合成方法,以刚性羧酸配体烟酸或均苯四甲酸为第一配体,以柔性羧酸配体己二酸为第二配体,我们成功设计合成了2个结构新颖的稀土配位聚合物,[Sm(μ3-O)(nic)3(ad)0.5(H2O)](1),[Pr(nic)(ad).2H2O](2)(H4btec=1,2,4,5-均苯四甲酸;Hnic=烟酸;H2ad=己二酸)并通过元素分析、红外光谱、X射线单晶结构分析对标题配合物进行了表征.此外,我们还对标题化合物的热稳定性做了详细的分析. 相似文献
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针对3G/ad hoc融合网络提出了一种性能分析方法.接收功率与路径的衰减关系基于路径的自然损耗与阴影衰落.首先,对3G/ad hoc融合网络的应用场景模型进行了简要的介绍.然后,基于此网络的应用场景,提出了几种性能分析方法来计算融合网络的中断概率、掉话率、新呼叫用户拥塞率等性能指标,随后推导出相应的性能公式并与传统3... 相似文献
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Optimal congestion control algorithm for ad hoc networks： Penalty function-based approach 总被引：2，自引：0，他引：2
XU Wei-qiang WU Tie-jun 《浙江大学学报(A卷英文版)》2006,7(12):2110-2117
INTRODUCTION Congestion control is a critical issue for ensuring the efficient and fair allocation of network resource among communication flows. In wireline networks, TCP has resolved this issue of concern. However, it was reported that TCP performance in a multihop ad hoc environment degrades severely (Xu and Wu, 2006). Thus, some optimization-based congestion control schemes have been proposed to improve TCP performance in ad hoc networks (Chiang, 2005; Chen et al., 2005; Lee et a… 相似文献
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文 [1 ]给出了引理 1 (1 ) ,即命题 1 正实数 a,b,c,d满足 ab c.本文将它改进为 :命题 2 正实数 a,b,c,d满足 ab c.因命题结论与 b,c间的大小无关 ,故由命题 1知命题 2显然成立 .下面举例谈谈命题 2的应用 .例 1 在 Rt△ 相似文献
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设a,b,a>O,。>0,。,‘为整数,a。等。,不妨取那么1.当ad一be=、,分式默可约;2.当ad一bc等O时; ①若a‘一b。{戈(a,e),(a{aj一b el) (a,e)二1,则分式a几+be忍+d可约②若:。‘一。。}·(·,。),分式默不可约. 证:1 _bad一b“二o,则万二d—=六b=ak, 2。d=。k,故分式可约.(i)先设(。,。)=l,则存在不同为零的整数。;,m:,使am:一。二,=z,则a己一bc=士扭(a用:一e切:), }ad一be},=灭云几)一’但a己一be=(ae忍+ad)一(ae升+bc),可令ae几+ad=士扭am:,ae介+be“士仇e切2.由a。等0可知:a刀+b=士。。,,e”+己=士mZ,a兀+be几+dm劝I仇饥2他针‘2 若m等z,即… 相似文献
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丁骏 《初中生世界(初三物理版)》2009,(Z2)
在数学知识中,如果数与数之间满足a/b=c/d,那么ad=bc.如果ad=bc,那么a/bc/d,这是比例的基本性质;如果a/b=c/d,那么(a±b)/b=(c±d)/d,或a/(b±a)=c/(d±c)这就是合分比性质.在物理学中,有许多规律都是描述物理量之间的比例关系,因而上述 相似文献
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陈艺文 《中学数学研究(江西师大)》2008,(2):37-39
定理（a^2＋b^2）（c^2＋d^2）=（ac＋bd）^2成立的充要条件是ad=bc.
略证（a^2＋b^2）（c^2＋d^2）=（ac＋bd）^2互逆反应a^2d^2＋b^2c^2=2abcd互逆反应（ad-bc）^2=0互逆反应ad=bc. 相似文献
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一九八六年全国初中数学联赛的第一、4题是一道填空题:“设a、b、‘、‘都是整数,且m~砂+bt.,,~‘,+矛.则m·,也可以表示成两个整数的平方和,其形式是_。”答案是:(ac一叼),+(ad+bc)’,即:m·n二(ac一bd),+(ad+bc)t。 观察此题的结论可以设想:如果m·n是一个完全平方数,那么〔石万石,a。一bd,ad+加〕将构成一组勾股数.例如a=4,b=2,则m=2.+ 4t=20。c=2,d=1,则,=1.+22=5。由于m,=20 xs== 10.是一个完全平方数,且ac一bd~2 X4一1 XZ一6,ad+bc=1x4+2 xZ,8,则(10,8,6)为一组勾股数.这就是说:由两组已知数(二,a,b)及(二,‘,d)(但二·n应是完全平… 相似文献