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In our study on the synthesis of glucosaminides we have employed 2,4-dinitropheuyl group (DNP) to protect the amino group of glucosamine, and foundthat DNP substitution brings forth an anomalous change in the optical rotation. By following Kent's procedure we obtained from 2-amino-2-deoxy-D-glucose hydrochloride (Ⅰ) N-DNP-2-amino-2-deoxy-D-glucose (Ⅱ). Its meltingpoint, 194°(200--202°, Kofler block), agrees with that reported by Meyer et al.(196±2°) and Morgan et al. (202-4°), but differs from that given by... In our study on the synthesis of glucosaminides we have employed 2,4-dinitropheuyl group (DNP) to protect the amino group of glucosamine, and foundthat DNP substitution brings forth an anomalous change in the optical rotation. By following Kent's procedure we obtained from 2-amino-2-deoxy-D-glucose hydrochloride (Ⅰ) N-DNP-2-amino-2-deoxy-D-glucose (Ⅱ). Its meltingpoint, 194°(200--202°, Kofler block), agrees with that reported by Meyer et al.(196±2°) and Morgan et al. (202-4°), but differs from that given by Kent(167-9°). The specific rotation values reported by all workers being practicallythe same([α]_D~(23)+50°; [α]_(5463)~(23)+68.7° in 80% ethanol). Acetylation of (Ⅱ) withacetic anhydride and pyridine gave a tetra-acetyl derivative (Ⅲ). Its meltingpoint (214-5°) and [α]_D~(20)(+12°, CHCl_3) also differed from those given by Kent(159-60°; [α]_D~(19)+73°, CHCl_3). (Ⅲ) was nearly quantitatively converted into1-bromo-3, 4, 6-tri-O-acetyl-N-DNP-2-amino-2-deoxy-α-D-glucose (Ⅴ) in usualway. Compound (Ⅴ) is identical with Stacey's bromo-compound (m. p. 162-4°[α]_D~(19)+46.0°, CHCl_3), obtained from another tetraacetyl-N-DNP-derivative (Ⅳ).Since (Ⅳ) was derived from the known 1, 3, 4, 6-tetra-O-acetyl-2-amino-2-deoxy-β-D-glucose (Ⅵ), and (Ⅲ) has also been prepared by us from 1, 3, 4, 6-tetra-O-acetyl-2-amino-2-deoxy-α-D-glucose hydrobromide (Ⅶ) of well establishedα-configuration, these two DNP-compounds (Ⅲ and Ⅳ) should form a pairof α- and β-anomers. Merely on the basis of Hudson's isorotation rule, it shouldbe predicted that (Ⅳ) wore tho α- and (Ⅲ) the β-anomer, which are contradictoryto their configurations as expected from the starting materials used. In order toconfirm the configuration of the C_(1)-atom of the compounds in question, otherpairs of DNP-derivatives of glncosamine, such as (Ⅷ) and (Ⅸ), (Ⅹ) and (Ⅺ),together with (Ⅻ) and (ⅩⅢ) were prepared according to the methods sketchedin Fig. 1. Melting points and specific rotations of these products are presentedin Tablo Ⅰ. Since (Ⅸ) and (Ⅺ) possess higher values of [α]_D than the correspondinganomers (Ⅷ and Ⅹ), (Ⅸ) and (Ⅺ) would be assigned as α-glucosaminides and(Ⅷ) mid (Ⅹ) as the β-anomers, if Hudson's isorotation rule were also applicableto N-DNP-glucosamine derivatives as usual. However, after removal of DNP-groupwith barium hydroxide, (Ⅺ) yielded the known methyl-β-D-glucosaminide (ⅩⅢ)and (Ⅹ), the corresponding α-D-glucosaminide (Ⅻ) (Ⅻ). The configurationsof (Ⅹ) and (Ⅺ) have been further confirmed by direct syntheses of these anomersfrom tho known methyl N-acetyl-α-and β-D-glucosamindes (ⅩⅠⅤ and ⅩⅤ). Con-sequently, (Ⅷ) and (Ⅹ) must be α-type, and (Ⅸ) and (Ⅺ) β-type. The N- DNP-substitution causes an anomalous change in the rotatory power, so that thesubstituted β-glucosaminides are considerably more dextro-rotatory than the cor-responding α-anomers. From Table Ⅰ, it is clear that the differences between the molecular rotations[M]_D of the anomeric pairs (Ⅲ) and (Ⅳ), (Ⅷ) and (Ⅸ) its well as (Ⅹ) and(Ⅺ), (i. e. 2A values) are all negative in sign, while the 2A values for anomericD-glucosamines, D-glucosamine hydrochlorides, pentaacetyl-D-glucosamines andmethyl-D-glucosaminides hydrochlorides are all positive. The 2B values of N-DNP-substituted products have the same sign and nearly the same magnitudeas those of the ordinary anomeric glucosamine derivatives. Thus DNP groupat C_(2)NH_2 has greater influence on the [M]_D of C_(1)-atom than on that of theremaining part of the molecule. This vicinaI effect of DNP-substitution on [M]_Dof the C_(1)-atom may be (i) due to change in polarity , (ii) due to increasein the number of conjugated double bonds (or shift in the absorption bands ofthe substituent, or (iii) due to steric interaction between vicinal substituensof the molecule. 在2-氨基-2-脱羟-D-葡萄糖的氮原子上引入2,4-二硝苯基后,其旋光性有显著的变化。自2-氨基-2-脱羟-D-葡萄糖(Ⅰ),我们获得一新的四乙酰-N-二硝苯基衍生物(Ⅲ), 该物经证明系属于吡喃糖α-型,但其旋光率比其β-端基差向异构体(Ⅳ)更向左旋,而与一般糖类α-与β-异构体之间的旋光率的关系不符。我们再观察N-二硝苯-2-胺基-2-脱羟-D-葡萄糖甲甙及其乙酰衍生物的α-与β-异构体的旋光率,也有相同的反常现象。 Hundson同旋律不完全适用于以上的N-二硝苯-D-胺基葡萄糖及其衍生物的原因可能由于C_(2)原子上N-二硝苯基对邻位C_(1)旋光性的影响所致。 In this paper is presented a simplified two-variable approximate theory, based on the C. Libovc and S. B. Batdorf's theory[6] for elastic orthotropic plates with transverse shear deformations. Assuming that there exists a potential function (x, y) for the traps-verse shear angles rx and ry (see eq. (2.9)), the total potential energy If (eq. (2.8)) can be expressed in terms of two independent unknown functions, the plate deflection w(x, y) and the potential (x, y). By the use of the principle of minimum potential... In this paper is presented a simplified two-variable approximate theory, based on the C. Libovc and S. B. Batdorf's theory[6] for elastic orthotropic plates with transverse shear deformations. Assuming that there exists a potential function (x, y) for the traps-verse shear angles rx and ry (see eq. (2.9)), the total potential energy If (eq. (2.8)) can be expressed in terms of two independent unknown functions, the plate deflection w(x, y) and the potential (x, y). By the use of the principle of minimum potential energy the Eulcr dcffercntial equations (1.11) for w and and the boundary conditions (1.12)-(1.15) are obtained in Appendix I. The comparision between the results for critical compressive load for a particular case of square simply-supported plate based on the present theory and Robinson's results[8] based on [6] shows that the discrepancy is small, if the anisotropy is not too significant (Table I). It is shown in Appendix H. that for polygonal simply-supported isotropic plates for both the bending and the stability problems the present theory always gives the same results as the theory in [6]. Two kinds of free edges arc distinguished: "entirely free edges" with the boundary conditions as (3.14) and the "stiffened free edges" with the boundary conditions as (3.17). Analysis of examples for orthotropic plates with free edges shows that, in general, cannot be interpreted as the shear deflection. 本文根据C.Libove与S.B.Batdorf关于考虑剪切变形的正交各向异性弹性平板理论建立了一种简化的二变量近似理論。假设横向剪切角r_x与r_y具有势函数φ(见式(2.9),总位能Π(式(2.8))可以通过两个独立函数即板的挠度w(x,y)与势函数φ(x,y)表出。在附录1中利用最小位能原理推出了w与φ的Euler微分方程(1.11)与边界条件(1.12)-(1.15)。計算了四边簡支的方板的一个特例的临界受压載荷,计算結果与Robinson根据文献[6]所作的結果的比較,表明其间的差异很小,如果各向异性的程度不过于显著的話。在附录Ⅱ中证明了,对于直线多边形各向同性簡支板来讲,无論是弯曲或稳定問題,本文結果恆与根据文献[6]的理諭得到的結果一致。区別了两种不同的自由边:“完全自由边”,其边界条件的形式如式(3.14);“加强自由边”,其边界条件形式如式(3.17)。对具有自由边的正交异性板的分析表明,一般說来,φ不能解释为剪切挠度。 Summary This paper discusses the circuit synthesis and development technique of a transistor pulse synchronized frequency division system.It consists of many ele- mentary pulse networks such as:Transistor forming and shaping circuit,trrnsistor blocking oscillator,multivibrator,time delay circuit and “and” gate,etc.The master signal of this system is supplied from a 100—KC/S crystal controlled oscillator.With the use of many stages of both-side synchronized frequency di- viders,the system simultaneously delivers... Summary This paper discusses the circuit synthesis and development technique of a transistor pulse synchronized frequency division system.It consists of many ele- mentary pulse networks such as:Transistor forming and shaping circuit,trrnsistor blocking oscillator,multivibrator,time delay circuit and “and” gate,etc.The master signal of this system is supplied from a 100—KC/S crystal controlled oscillator.With the use of many stages of both-side synchronized frequency di- viders,the system simultaneously delivers stable sharp pulses of 100—KC/S, 10—KC/S,1—KC/S and 100—C/S repetition frequency.The duration of each pulse of the lowest repetition frequency is about 0.4μs,and shorter for the high repetition frequencies.The amplitudes of the pulaes of the different repetition frequencies are more than 3 volts.The resulting phase shift and drift instability of the cascade synchronized frequency dividers are eliminated by pulse selection method in this system,Hence the output pulses are accurately positioned in time relative to each other.Test results coincide fairly well with theoretical analysis. 在精密的时间测量系统中,为了获得严格的定时同步脉冲,必须消除多级分频器所产生的误差,因而需用比较复杂的分频系统。本文专门讨论了利用脉冲选择的晶体管化同步分频系统的线路综合原理和研制技术问题,对组成系统的各种单元脉冲电路,如晶体管窄脉冲形成器,晶体管间歇振荡器,晶体管多谐振荡器,晶体管延迟电路以及晶体管门电路等均作了较深入的分析,并给出相应的实验结果。系统的主振信号是由一100千赫晶体稳频的振荡器产生,通过多级脉冲选择的双侧同步分频电路,可以同时获得稳定的100千赫,10千赫,1千赫及100赫等重复频率同步窄脉冲,同步脉冲的宽度为0.4微秒,幅度大于3伏。实验结果与理论分析基本上是一致的。
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