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袁苏春 《数理化学习(初中版)》2012,(5):16-17,46
引例:苏科版教材八(上)第38页灵活运用第9题:如图1,点A、B在直线l的同侧,点B′是点B关于l的对称点,AB′交l于点P.(1)AB′与PA+PB相等吗?为什么?(2)在l上再取一点Q,并连接AQ和QB,那么QA+QB与PA+PB哪一个大?为什么?解:(1)AB′=PA+PB.因为点B′是点B关于l的对称点,所以PB′=PB.所以AB′=PA+PB′=PA+PB. 相似文献
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Pek Leng NG ;Nor Fadilah RAJAB ;Sue Mian THEN ;Yasmin Anum MOHD YUSOF ;Wan Zurinah WAN NGAH ;Kar Yong PIN ;Mee Lee LOOI 《Journal of Zhejiang University. Science. B》2014,15(8):692-700
研究目的：探讨萎叶（PB）提取物对5-氟尿嘧啶（5-FU）抑制结肠癌细胞HT29和HCT116生长的影响。研究方法：HT29和HCT116细胞分别给予PB、5-FU以及两种药物联合治疗24小时,应用等效线图法分析PB和5-FU的药效学相互作用,AnnexinV／PI染色法检测HT29和HCT116细胞的凋丁L=情况,高效液相色谱法排除PB和5-FU间任何可能的相互化学作用。重要结论：联合PB,低剂量5-FU可以在短时间内起到细胞毒作用,而单独应用PB或5-FU治疗较联合治疗可以诱导更多细胞发生凋亡。进一步采用等效线图法分析显示PB和5-Fu的联合作用在抑制结肠癌细胞HT29和HCT116的生长中分别体现出协同和拮抗作用。因此可以认为在HT29细胞中,PB使得较低剂量5-FU发挥最大抑制结肠癌细胞生长效果,然而在HCT116细胞中,PB没有显著降低5-FU的药物浓度,说明PB和5-FU的相互作用不仅仅体现在诱导细胞凋亡方面。 相似文献
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Pek Leng NG Nor Fadilah RAJAB Sue Mian THEN Yasmin Anum MOHD YUSOF Wan Zurinah WAN NGAH Kar Yong PIN Mee Lee LOOI 《Journal of Zhejiang University. Science. B》2014,(8)
研究目的:探讨蒌叶(PB)提取物对5-氟尿嘧啶(5-FU)抑制结肠癌细胞HT29和HCT116生长的影响。研究方法:HT29和HCT116细胞分别给予PB、5-FU以及两种药物联合治疗24小时,应用等效线图法分析PB和5-FU的药效学相互作用,Annexin V/PI染色法检测HT29和HCT116细胞的凋亡情况,高效液相色谱法排除PB和5-FU间任何可能的相互化学作用。重要结论:联合PB,低剂量5-FU可以在短时间内起到细胞毒作用,而单独应用PB或5-FU治疗较联合治疗可以诱导更多细胞发生凋亡。进一步采用等效线图法分析显示PB和5-FU的联合作用在抑制结肠癌细胞HT29和HCT116的生长中分别体现出协同和拮抗作用。因此可以认为在HT29细胞中,PB使得较低剂量5-FU发挥最大抑制结肠癌细胞生长效果,然而在HCT116细胞中,PB没有显著降低5-FU的药物浓度,说明PB和5-FU的相互作用不仅仅体现在诱导细胞凋亡方面。 相似文献
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PowerBuilder(以下简称PB)是Sybase公司推出的开发基于数据库应用的快速开发平台．PB以其使用简单、开发开速、数据库支持能力较强，而得到广大程序员的青睐．然而，在用户交互、界面处理方面PB显得功能不足.本文结合实例，从PB弹出菜单这一个方面介绍了如何使用API增强PB处理能力的一种方法． 相似文献
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例1 如图,若PA=PB,∠APB=2∠ACB,AC与PB交于点D,且PB=4,PD=3,则AD·DC等于（ ） 相似文献
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方荟玲 《沈阳教育学院学报》2002,4(4):107-109
PB作为开发语言，对数据库的处理有着强大的功能，但PB的多媒体特性却存在着很大的不足，本文着重介绍利用PB开发动画功能的方法。 相似文献
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本文研究了槟榔(Piperbetle,PB)水提取物对癌细胞转移能力的调节作用及其对微管蛋白结构和网络的影响。采用亚毒剂量对PB和5-氟尿嘧啶(5-FU)处理的癌细胞进行抗迁移研究,观察细胞迁移20小时。在所有处理组中,100μg/m L PB处理的癌细胞均显示出最大的抗迁移作用(P=0.016)。总体上,PB对癌细胞的抗迁移作用高于5-FU。通过细胞形态观察发现,PB处理的细胞表现出与标准微管抑制剂(紫杉醇)相似的细胞特征,并在PB和紫杉醇处理的癌细胞中发现M期细胞群。通过对微管结构和网络进一步研究,我们发现PB和紫杉醇处理的癌细胞表现出长期破坏的纺锤体。因此,我们认为PB具有对癌细胞的抗迁移作用,并可能改变蛋白结构和网络。 相似文献
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本研究从新采集的鲜牛奶、蔬菜及青草中分离筛选到数株乳酸菌.通过凝乳实验、生理生化实验、耐性实验确定两株为胞外多糖产量较高的乳链球菌PB1和PB6,其中PB1菌株初步鉴定为乳脂链球菌. 相似文献
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题目:一个圆台的上、下底面半径分别为 R、r,母线长为 l.求过下底面圆周上一点绕侧面一周的最短距离.图2是圆台 O_1O 的轴截面 ABCD 和圆台侧面展开图.由 r/R=(PB)/(PA)得 r/R=(PB)/(PB l),∴PB= 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
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Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
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Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献