氨活塞式双级制冷压缩机轴功率和单位轴功率制冷量的计算

根据生产厂家[2]提供的产品样本和A．C．Cleland[3]提出的制冷剂热力学参数快速求值的方法，采用计算机绘制活塞式双级制冷压缩机在实际工况下的轴功率和单位轴功率制冷量变化曲线，计算和拟合出双级制冷压缩机轴功率数学模型，为实现制冷系统节能提供理论依据。     

K系数—双波长标准加入法测定镀镍溶液中的钴含量

提出了一种Ｋ系数－双波长标准加入法，应用于镀镍溶液中钴的测定。通过加入掩蔽剂氨三乙酸（ＮＴＡ），使得Ｎｉ（Ⅱ）与５－Ｂｒ－ＰＡＤＡＰ形成的配合物的吸光度显著降低，而相对应的Ｃｏ（Ⅱ）配合物的吸光度基本不变，提高了在大量Ｎｉ（Ⅱ）存在下测定Ｃｏ（Ⅱ）的准确度。     

一类渐近平直的五维Kaluza-Klein时空解及引力源的探讨

对于一般的谐和函数给出了度规函数Γ、引力势和标量势的明晰的形式.通过分析它们的渐近行为得到了与谐和函数相关的额外的引力质量和标量荷贡献.     

1坚韧图最长圈的新的充分条件

设G是 p阶l坚韧图。本文证明:如果对任意d(u,v)=2的u,v∈V(G),有max{d(u),d(v)}≥b,则除图Y_1,Y_2,Y_3外,G包含一个长至少为min{p,2b+2}的圈,且是最好可能的。     

Examination of the chemical composition of propolis I. Isolation and identification of the 3,4-dihydroxycinnamic acid (caffeic acid) from propolis

Zusammenfassung Erstmalige Isolierung von Kaffeesäure aus Propolis mittels Papierchromatographie und UV-Spektroskopie. Identifizierung als 3,4-Dihydroxyzimtsäure.     

中国柳珊瑚化学成分的研究(Ⅵ) Junceella squamata中一个新的多乙酰氧基含氯二萜Junceellin B

从鳞丁心柳珊瑚Janceella squamata中分离出一个新的具有Briarein A骨架的含氯二萜,命名为Junceellin B.它带有四个乙酰氧基,两个双键,一个三元环氧基和一个羟基.分子式C_(28)H_(35)O_(12)Cl,熔点228—230°,比旋光度[α]_D~(25)-13.48°.通过IR,~1HNMR,~(13)CNMR和M_s推导出结构.     

Corticosterone secretion after neurogenic stress in intact and hypophysectomized rats

Summary The time course of blood and adrenal corticosterone elevation after immobilization stress has been studied in intact and hypophysectomized male rats. The results suggest that the adrenal gland is able to respond to neurogenic stress, increasing the synthesis and release of corticosterone, in the absence of ACTH.     

STRONG LAWS OF LIFETIME FOR A CONSECUTIVE K-OUT-OF-N: F SYSTEM

ＳＴＲＯＮＧＬＡＷＳＯＦＬＩＦＥＴＩＭＥＦＯＲＡＣＯＮＳＥＣＵＴＩＶＥＫ－ＯＵＴ－ＯＦ－Ｎ：ＦＳＹＳＴＥＭ￥ＱＩＹｏｎｇｃｈｅｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＰｒｏｂａｂｉｌｉｔｙａｎｄＳｔａｔｉｓｔｉｃｓ，ＰｅｋｉｎｇＵｎｉｖｅｒｓｉｔｇ，Ｂｅｉｊｉ...     

A PROBLEM WORTHY OF NOTICE IN THE USE OF PCD DRESSER

It is proved that PCD dresser is an economic and effective substitute for single grain mined diamond one as dressing corundum wheels. In this paper, the effect ofcollans on the wear resistance of PCD dresser is tested. Tests show that as dressing corundum wheels, the wear resistance of PCD dresser is the best without collant, or dry dressing.