有机-无机压电材料TMCM-MnCl3的研究

有机-无机压电材料是一种分子铁电体，具有柔性、结构灵活、易成膜、全液相合成及环保节能等优点，可满足新一代薄膜器件及可穿戴设备的需求。该文以三甲基卤代甲基铵(TMXM, X=F, Cl, Br)为有机部分，MnCl₂为无机部分，通过溶液蒸发法制备了具有钙钛矿分子结构的有机-无机压电材料三甲基氯三氯化锰(TMCM-MnCl₃)，并对其分子结构组成、压电、热学、声学及铁电性进行表征。结果表明，TMCM-MnCl₃的压电常数为106 pC/N，居里温度为130 ℃，声阻抗值约为16.5 MRayl，低于压电陶瓷PZT-4(大于33 MRayl)，具有广阔的应用前景。     

基于小波神经网络的信号识别

信号的分选和识别技术在当今信号处理的系统中占有相当重要的地位.小波分析和神经网络是近年来兴起的一种分析信号方法.文中对二者的结合问题进行了研究.小波空间可以作为信号分类的特征空间,进而可以通过神经网络对信号进行特征识别.小波神经网络是基于小波分析而构造的神经网络模型.在信号调制类型识别中,利用小波伸缩平移把信号分解到不同频道上进行特征提取;把提取的特征信息输入神经网络进行分类.仿真结果表明,利用此方法可以较好的对信号进行分选和识别.     

CuMgAl类水滑石的制备和表征

用盐-碱制备法合成了CuMgAl三元类水滑石化合物。探讨了原料配比、合成方式、水热处理温度和时间对合成过程的影响,筛选出合成HTLcs的适宜条件,并对HTLcs结构的热稳定性进行初步研究。结果表明,制备HTLcs主要取决于pH值,同时由于Cu2+的姜-太勒效应,合成结构单一的CuMgAl类水滑石要求原料配比中n(Cu)∶n(Mg)不得超过1.0,CuMgAl-HTLcs热稳定性较差,300℃焙烧2h结构破坏,600℃开始烧结,在300~500℃之间,随焙烧温度提高所得复合氧化物比表面积增大,最高可达200 m2/g。     

Cloning, tissue expression, and chromosomal localization of the mouse IRS-3 gene

Insulin receptor substrate (IRS) proteins are key regulators of basic functions such as cellular growth and metabolism. They provide an interface between multiple receptors and a complex network of intracellular signaling molecules. Two members of this family (IRS-1 and IRS-2) have been identified previously. In this investigation, we analyzed a mouse expressed sequence tag clone that proved to be a new member of the IRS family. Sequence analysis of this clone and comparison with the sequences deposited in GenBank demonstrates this protein may be the murine homolog of rat IRS-3, recently purified and cloned from rat adipocytes. Accordingly, we have named our protein mouse IRS-3. The expressed sequence tag clone contains the complete coding sequence of 1485 bp, encoding a protein of 495 amino acids. Sequence alignment with the other members of the IRS family shows that this protein contains pleckstrin homology and phosphotyrosine-binding domains that are highly conserved. In addition, there is conservation of many tyrosine phosphorylation motifs responsible for interactions with downstream signaling molecules containing SH2 domains. The murine IRS-3 messenger RNA (2.4 kilobases in length) is expressed in many tissues, with highest levels in liver and lung. Mouse IRS-3 is highly expressed in the first part of the embryonic life, when IRS-1 messenger RNA is barely detectable. Unlike the genes encoding IRS-1 and IRS-2, the IRS-3 gene contains an intron (344 bp in length) in the region between the pleckstrin homology and the phosphotyrosine-binding domains. Fluorescent in situ hybridization localized the mouse IRS-3 gene on the telomeric region of chromosome 5G2. Cloning of the murine IRS-3 gene will make it possible to apply genetic approaches to elucidate the physiological role of this new member of the IRS family of proteins.     

双乙醛草酰二肼直接快速光度法测定食品中痕量铜

研究了双乙醛草酸二肼与铜的显色反应，建立了分光光度法直接测定铜的新方法。试验结果表明，在pH8．0－10．0范围内，Cu2 与双乙醛草酸二肼形成稳定的紫红色配合物。该配合物在540nm处有一最大吸收峰，其表明摩尔吸光系数为2．4×104，铜量在0－12mg／50ml范围内符合比尔定律。共存离子干扰，误差仅 2.00％。用于食品中痕量钢测定．结果准确、可靠。     

一种考虑不同期合闸的行波合闸保护新方法

当线路末端故障时，行波在线路末端的反射情况比较复杂，反向电流行波的极性有可能与正向电流行波的极性相反，而此时测距结果又与线路无故障时相同。因此，会造成行波测距式与行波极性比较式合闸保护的不正确动作。根据行波的折、反射理论，分析出当线路无故障时正向电流行波仅在线路末端发生反射，且电流行波的反射系数为-1，而当线路存在故障时，正向电流行波将在故障点发生反射，无论故障是否在线路末端，电流行波的反射系数都不会是-1。根据这一特征，提出了一种新的行波合闸保护方法。从原理上保证了在各种情况下保护都可以正确动作，大量的电磁暂态仿真结果也证明了这一点。     

重庆双龙湖富营养化限制性因素确定试验研究

双龙湖是浅水型城市湖泊,一度为重富营养化湖泊。综合治理后水体仍处于中-富营养化。探求富营养化限制性因素对于防治双龙湖富营养化、维护双龙湖水质至关重要。本文通过双龙湖藻类增长潜力试验研究,确定双龙湖富营养化限制性因素是磷,这对于采取适宜管理措施修复水体、保持水质具有重要意义,为湖泊治理、水环境保持提供科学依据。     

C51嵌套汇编子程序在阻抗测试仪研制中的应用

C51嵌套汇编子程序，充分发挥了两种语言自的优势，介绍了C51调用汇编子程序的接品规则，并通过阻抗测试仪程序开发的例子予以详细说明。     

Amifostine (WR-2721) shortens the engraftment period of 4-hydroperoxycyclophosphamide-purged bone marrow in breast cancer patients receiving high-dose chemotherapy with autologous bone marrow support

4-Hydroperoxycyclophosphamide (4-HC), a commonly used marrow-purging agent, is active against many tumors, but is also toxic to normal marrow progenitors. Amifostine (WR-2721) is a sulfhydryl compound with chemoprotectant activity. Preclinical studies using suspensions of bone marrow and breast cancer cells demonstrated that ex vivo treatment with amifostine followed by 4-HC resulted in protection of marrow progenitors, with no compromise in the antitumor effect of 4-HC. This fact stimulated the development of a clinical trial. Bone marrow was harvested from 15 poor-prognosis breast cancer patients and randomly assigned to ex vivo treatment with amifostine followed by 4-HC (amifostine + 4-HC), or treatment with 4-HC alone. High-dose chemotherapy was then administered followed by infusion of the purged autologous bone marrow support (ABMS). Leukocyte engraftment, defined as a white blood cell count > or = 1 x 10(9)/L, was achieved in an average of 26 days for patients whose marrow was purged with amifostine + 4-HC versus 36 days for patients whose marrow was purged with 4-HC alone (P = .032). The average number of platelet transfusions (12 v 29; P = .017) and days of antibiotic therapy (28 v 40; P = .012) were significantly less for patients whose marrow was exposed to amifostine + 4-HC, compared with 4-HC alone. Unpurged backup marrow fractions were infused into three patients whose marrow was purged with 4-HC alone, because of inadequate marrow recovery. None of the patients who received amifostine + 4-HC-purged marrow required a backup marrow fraction. Complete remissions were achieved in 83% of patients with measurable disease, with no difference between the two cohorts. Forty-three percent of patients remained alive and progression-free at a mean of 13 months posttransplant. There was no significant difference in the rate or pattern of relapse for patients whose marrow was purged with amifostine + 4-HC compared with those whose marrow was purged with 4-HC alone. Ex vivo treatment of marrow with amifostine significantly shortens the time to marrow recovery, thereby reducing the risk of myelosuppressive complications in breast cancer patients receiving high-dose chemotherapy and 4-HC-purged ABMS. Since supportive care requirements are also significantly decreased, amifostine may reduce the cost of such therapy.