风铃变奏曲——风铃草的故事

风铃是古老的宗教建筑如佛殿、宝塔等檐下悬挂的铃,由铜、银、金等金属铸制;在风中,铃身摇动,发出清朗的悦音。近代,剔透的玻璃风铃又应运而生,只不过外形由铃形变成条状,由多根细柱状的彩色玻璃组成,悬挂在门窗旁或廊檐下,微风过处发出美妙的声音。风铃,宛如有形的音符给我们留下了太多轻松愉悦的记忆。殊不知,大自然在植物界也为人类创造出众多形如风铃般的花卉,其中在形神方面最贴切的还是桔梗科风铃草属(Campanula)     

以水稻为主的种植系统对土壤有机质状况的影响

A long-term simulation experiment was carried out to study the effect of rice-based cropping system, green manure and ground-water level on soil organic matter. Soil organic matter content increased when upland soil was puddled and cropped under submerged conditions. Among all treatments, soil organic matter contents in the treatments of rice-rice-flooded fallow in winter (WF) were the highest, those in the treatments of rice-rice-astragalus (WG) came the second, and those in the treatments of rice-rice-rape (WR) were the lowest. At the same rate of green manure application, the degrees of organo-mineral complexing in soils of treatments WG and WR were higher than those of treatment WF. After 9-year rice cultivation, the state of combination of humus in heavy fraction varied with treatments. The relative content of loosely bonded humus decreased in the order of WR > WG > WF, and it correlated significantly with Se availability.     

金属预处理对镉急性毒性的缓解作用

镉与其它金属的联合毒性作用十分复杂，与金属种类、县及它们之间的比例相关。本文简要综述了金属预处理对镉急性毒性的缓解作用及其可能机理。     

某硫矿重金属分级及土柱淋溶

Fractions of various heavy metals in a sulfidic minespoil were investigated.Column leachine experiment was also conducted to simulate “acid mine drainage“(AMD) from the minespoil.The results show that leaching of heavy metals from the minespoil was extremely significant during the initial water flushing.The amounts of heavy metals leached out dramatically reduced after leaching twice.It is worthwhile to note that in this study,Zn,Mn,Fe,As and Ni in the first leachate exceeded the total amount of each corresponding water-extractable(1:5,soil:water)metal contained in the minespoil sample.This appears to suggest that 1:5 water extraction did not allow accurate estimation of water-leachable concentrations of the above heavy metals.This work has implications for the management of sulfidic minespolis.Acid drainage of great environmental concerns is likely to occur only during heavy rainfall events after substantial soluble and readily exchangeable acid and metals are accumulated in the minespoils.The slow-reacting fractions other than water-soulble and readily exchangeable fractions may pose little environmental hazards.This is particularly true for Pb,As and Ni.     

论立式金属罐参照高度变化的随机性

当前，对动作中立式储罐的参照高度认为是固定值的看法，是不切剑实际的。在立式罐结构分析中，认为参照高度实际产生随机变化有其必须性，并通过国内外立式罐参照高度的实测数据和资料予以证实。确认立式罐参照高度在立式罐容量标定和计量过程中实际存在着０变化的随机性，而且会对立式罐容量的标定和计量的准确度产生明显的影响，在大多数情况下已超过允许误差范围。     

固液反应球磨制备Al-Cu-Co三元金属间化合物

利用固液反应球磨技术制备了Al-Cu-Co三元合金．分别采用Co球球磨Al-33．2％Cu(此文中的百分比为质量分数)，Al-54％Cu(A12Cu)和Al-70％Cu(A1QJ)二元合金熔体，在923K和973K球磨Al-33．2％Cu熔体12h后生成Al65Co15Cu20粉末；在923K和1023K球磨24h后生成Al69Co25Cu6粉末，在893K和993K分别球磨Al-54％Cu(A12Cu)合金熔体12h和24h后均生成Al65Co15Cu2n粉末；在1123K球磨Al-70％Cu合金熔体24h后生成Al65Co15Cu20粉末．采用Al-Cu-Co固液反应球磨得到的金属间化合物粉末为纳米粒子．同时，对Al-Cu-Co三元合金相形成的规律进行了研究，对固液反应球磨机理进行了探讨．在固液反应球磨过程中，三元合金产物的元素摩尔比接近于二元母合金中的元素摩尔比；三元合金产物成分中固相第三组元的成分含量与二元母合金熔体成分有很大关系；提高反应球磨温度、延长球磨时间有利于三元合金产物的形成；延长球磨时间，形成的三元合金产物中磨球的成分增加；反应球磨温度超出二元母合金熔点越高，球磨反应越容易进行．     

羟基喜树碱(HCPT)对乳腺癌细胞中TIMP-3表达及细胞侵袭能力的影响

目的:探索羟基喜树碱对乳腺癌细胞MCF-7细胞信号转导相关基因金属蛋白酶组织抑制剂-3(TIMP-3)表达的影响,寻找羟基喜树碱(HCPT)在乳腺癌治疗中的潜在新靶点.方法:分别采用Q-PCR,Western-blot和免疫细胞化学等方法验证不同剂量组HCPT诱导MCF-7细胞的TIMP-3表达特征.结果:不同质量浓度的HCPT均可在mRNA水平和蛋白水平诱导MCF-7细胞的TIMP-3表达上调,且具有统计学意义,与前期的基因芯片研究结果相符合;实验同时观察了HCPT对细胞侵袭迁移能力的影响,结果亦显示HCPT可在TIMP-3表达上调的同时抑制细胞侵袭迁移能力.结论:HCPT可诱导乳腺癌细胞的TIMP-3上调表达,抑制细胞侵袭能力.     

固液反应球磨制备Al-Cu-Ni三元金属间化合物粉末

利用固液反应球磨技术制备了Al-Cu-Ni三元合金粉末.采用Ni球球磨wAl-33.2%wCu,wAl-54%wCu(Al2Cu)和wAl-70%wCu(AlCu)二元合金熔体,在893 K分别球磨wAl-33.2%wCu熔体12 h和24 h后均生成了Al7Cu4Ni粉末;在893 K球磨wAl-54%wCu12h后生成Al7Cu4Ni粉末,在993 K和1 123 K球磨wAl-54%wCu(Al2Cu)24 h后均生成Al0.28Cu0.69Ni0-粉末;在1 123 K球磨wAl-70%wCu(Al2Cu)24 h后生成Al0.28Cu0.69Ni0-粉末.同时,对Al-Cu-Ni三元合金相形成规律进行了研究,对固液反应球磨机理进行了探讨.     

酶抑制率法检测农药残留技术

酶抑制率法属高科技生物技术,利用一些农药对酶的抑制作用进行农药分析,其检测对象为有机磷及氨基甲酸酯类农药,此法简单、快速、灵敏,应用范围广,可鉴别"有毒物质",且不需贵重仪器.     

肠镜摘除回肠金属异物2例

肠内异物多是患者有意或无意吞食的 ,由于异物形状特殊或肠道部位狭窄 ,致异物难以自行排出或嵌顿于某个肠段。如不及时取出异物 ,易造成肠壁黏膜糜烂、出血 ,进而溃疡甚至肠穿孔[1 ] 。笔者遇大肠内金属异物 2例 ,现报道如下。1　临床资料病例 1 :男 ,4 1岁 ,因大便次数增多伴黏液就诊。常规肠道清洁准备后 ,用日本Olmypus公司生产的 2 4 0Ⅰ型电子肠镜行常规检查。循肠腔进镜至回肠末段约 2 0cm处 ,发现一长约 2cm的银色金属线。该金属线弯曲、柔软 ,疑为家用洗锅钢丝刷脱落物 ,经钳出后证实。 3个月后该患者复查肠镜 ,回肠末段黏膜正常…