Results 111 to 120 of about 4,430 (197)
提耍通过病理形态学诊断与化学分析的原子吸收法相结合测定10 例结肠癌、3 例胃癌及 癌旁正常组织中元素M n 、 C r 、 dC 、 P b 的含量, 以探讨肿瘤组织中这些重金属含量与无癌组织的差 异. 结果表明, 10 例结肠癌组织中的4 种重金属元素含量均比正常组织高, 经统计学处理, 两者有 非常显著性差异( P < 0 . 0 1 ) ; 而3例胃癌组织中这4 种重金属元素的含量虽有差异, 但无显著性意义 (尸> 0 .
doaj
为初步了解林蛙油重金属的污染现状,采集东北林蛙、黑龙江林蛙和中国林蛙的林蛙油,以湿法消化法消化,利用荧光比色法测定锡含量、原子吸收法分别检测镉、铬、铜和铅的含量,并采用单因子污染指数及每周可耐受摄入量分别评价5种重金属在3种林蛙油中的污染程度并对其食用安全进行评价。结果表明,该批次样品中东北林蛙蛙油重金属含量分别为锡10~20、镉50~90、铬670~720、铜100~250和铅60~90 μg/kg; 黑龙江林蛙蛙油重金属含量分别为锡12~22、镉80~110、铬700~820、铜150 ...
王静涵 肖向红 柴龙会 王伯驹 徐美瑶 曲俐俐
doaj
Big Ding 鼎 and China Power: Divine Authority and Legitimacy [PDF]
Paleographic, art historical, metallurgical, and archaeological data are used to identify the monumental bronze tetrapod ding vessel as a preeminent symbol of state authority and divine power during the Shang era of ca. 1640–1046 b.c.e .
Childs-Johnson, Elizabeth
core
Research for Automatic Gain Control System of Infrared Remote Receiver [PDF]
红外遥控接收头是红外遥控技术的核心器件,起到接收红外遥控信号,并进行光电转换,滤波和解调的作用。对噪声干扰的抑制能力,和对不同类红外遥控协议的兼容能力是红外遥控接收头最主要的性能,而二者在一定程度上是对立的,因此研制出具有优秀噪声抑制能力和较好红外遥控协议兼容能力的红外遥控接收头是行业内共同的课题。 本文首先简单介绍了红外遥控接收头的结构和工作原理,分析其主要的抗干扰机制,突出自动增益控制电路的核心作用。然后通过对常见光干扰源的测试分析,将各类干扰噪声和遥控编码就数据间隔等四项基本参数进行汇总对比 ...
段果
core
Lembrar é fácil, difícil é esquecer
This article discusses Palestinian memories and exiles due to migration. Six Brazilian-Palestinian women exercise their right to narrate their experiences and record their individual memories. Connected by the Nakba, these memories are also collective.
Ashjan Sadique Adi +2 more
openaire +1 more source
使用猎枪射击动物,不需要像军用枪那样进行瞄准,因为猎枪射击的不是单个弹丸,而是许多霰弹(铅砂、铅丸)。霰弹脱离枪口以后,均各自单独向前运动,数量很多的霰弹一同运动时,便形成了霰弹束。霰弹束距离枪口10—20米时呈穗状,前端宽些 ...
林里
doaj
[Effect of nanohydroxyapatite on surface mineralization in acid-etched dentinal tubules and adsorption of lead ions]. [PDF]
Yang J +5 more
europepmc +1 more source
Microstructures and Performances of Novel Three-dimensional Porous Titanium Anodes [PDF]
钛阳极在湿法冶金、阴极保护、电解铜箔、铝电极箔和电化学合成丁二酸等领域具有广泛的应用。钛阳极一般要由钛基体和活性涂层两部分组成,目前,析氧用钛阳极的涂层材料是以贵金属铱的氧化物为主要成分,这种涂层材料具有低的析氧电位和长的使用寿命。但是,铱的价格昂贵,用量大,造成电极成本过高,因此,有必要研究和开发非贵金属涂层,以逐步取代贵金属涂层。此外,钛基体只起到传导电流和稳定尺寸的作用,并没有发挥出钛阳极的整体功效,如何设计出更好的基体材料,把涂层的性能完全发挥出来,也是目前急需解决的问题 ...
范亚卓
core
Este texto, publicado na revista Critical Inquiry, em 2000, aborda as relações entre o Minimalismo e a arte contemporânea. O autor propõe a análise daquilo que entende como uma retórica da Arte Minimalista, vinculada a uma ideologia da pureza do espaço e da forma e a uma noção de transcendência que encontram seus antecedentes, em parte, no Puritanismo.
openaire +4 more sources

