钎焊金刚石工具磨粒有序排布研究现状

文章综合国内外钎焊金刚石工具的研究成果,对比几种典型金刚石工具容屑空间和磨粒有序排布对工具性能的影响,总结了国内外金属结合剂金刚石工具磨粒有序排布的研究成果,介绍了当前金刚石磨粒有序排布常用的几种方法,原理及其优缺点。     

1979-2007年中国造纸术发明者争议的回顾

造纸术是由东汉宦官蔡伦还是西汉工匠发明,是一个有争论的学术问题.1949-1979年两种观点争鸣是正常的学术现象.但自1979年轻工部造纸局行政干预以来,有关中国造纸术发明者的争议已经脱离正常讨论轨道.政府机构利用职权和行政资源推行官方观点,将蔡伦造纸说奉为“历史定论”,以“爱国与维护国家尊严”为名,树立学术禁区,打压不同意见,对出土西汉纸作歪曲事实的反检验和反断代,以政令方式对纸史争议作“最后裁决”.潘吉星作为参与这项纸史争议的见证人,揭示了这场争议中的某些真相.     

简论“赋得”诗体并赏析张九龄《赋得自君之出矣》

“赋得”诗体是一种古老的诗歌创作形式。以“自君之出矣”为题材的五言诗小品，历来被诗人用来借题发挥，抒发各种个人情感。其q-以张九龄的《赋得自君之出矣》为这一类体裁的杰作。     

Landfill leachate treatment by MBR： Performance and molecular weight distribution of organic contaminant

A membrane bioreactor (MBR) with an air-lift bioreactor and gravity flow is applied to treating landfill leachate. More than 99% of BOD5 (biochemical oxygen demand for five days) removal effi-ciency is achieved with less than 35 mg/L of BOD_5 in the effluent at less than 1.71 kg BOD5/m~3·d of BOD_5 loading rate. When DO (dissolved oxygen) is maintained at the range of 2.3―2.8 mg/L and the loading rate of NH_4~ -N (ammonium nitrogen) is kept at 0.16― 0.24 kg NH_4~ -N/m~3·d, the NH_4~ -N in the effluent is less than 15 mg/L. However, compared with high removal rates of BOD_5 and NH_4~ -N, the removal effi-ciency of soluble chemical oxygen demand (SCOD) varies between 70% and 96%. The investigation of molecular weight (MW) distribution has been carried out by the gel permeation chromatography (GPC) so as to understand the fate of organic matters in the MBR treating of landfill leachate. Results indicate that organic matters of the landfill leachate are composed of a high MW fraction (MW of the peak, MWp = 11480―13182 Da) and a low MW fraction (MWp = 158―275 Da). The high MW fraction is not biode-gradable, but can be decreased with microfiltration membrane. The most of the low MW fraction is bio-degradable, but the residue of the low MW fraction is able to permeate through the membrane, thus re-sulting in high SCOD in the effluent of the MBR.     

控制馏出液体积 降低对原样品的检出限

文章探讨对氰浓度低于1/2最低检出限的样品，通过控制接收馏出液体体积来降低对原始样品的检出限。     

STUDY ON AN SIS EPIDEMIC MODEL WITH TIME VARIANT DELAY

In this paper, we study an SIS epidemic model with a time variant delay. By means of Liapunov functional, some sufficient conditions of global stability to endemic equilibrium and disease free equilibrium have been obtained. The influence of time delay on the stability of equilibria is displayed.     

碘的测量方法

本主要从药品的来源，实验反应设备、条件、灵敏度，实验结果的偏差及回收率等方面比较了多种测量碘的方法，从中选出了最佳测量碘的方法。     

发酵料袋栽鸡腿菇新技术

一、栽培时间与菌种选择 菇农可依自己的实际情况于秋、冬、春三季投料生产．由于鸡腿菇具有不覆土不出菇的特点，因此可在农闲时大规模制菌袋，然后依市场需求提前20～30天覆土出菇。菌种应选择菇体肥大，个体适中，鳞片少，抗病高产的品种；另外，鲜销宜用单生品种，盐渍加工时宜用丛生品种。     

在氨三乙酸中阳极溶出伏安法测定微量镓

本文研究了镓在氨三乙酸中的阳极溶出峰及其测定条件。在0.15mol/L氨三乙酸和0.8mol/L氯化铵(pH=5.7)混液中,富集电位-1.5伏,富集10分钟,镓的检出极限为1.77×10(-7)mol/L,在此条件下,测出纯铝样中镓的含量约为0.009％。     

慢性兔出血症的研究

对北京和河北等地的一些獭兔养殖场发生的以瘫痪为主要症状的慢性型兔出血症进行了研究。结果表明 ,自然感染病例和人工感染病例的临床症状、病理学变化和血清学特性相似 ,通过分析这些獭兔养殖场慢性型兔出血症发生的原因 ,提出了诊断和防治措施