SOME OSCILLATION THEOREMS OF HIGHER ORDER NON－HOMOGENEOUS LINEAR DIFFERENTIAL EQUATIONS WITH TRANSCENDENTAL MEROMORPIC COEFFICIENTS

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用NJTU模型描述CCITT七号信令系统

本文吸取了UCLA图模型,Unified模型,数值Petri网模型(NPN)的优点,提出一种新的描述通信协议的混合模型(NJTU模型)。 NJTU模型易于描述具有多个并行工作的子系统的通信协议,能充分反映子系统内部的控制转移和各模块间的相互关系。本文第二节给出了NJTU模型的定义,第三节阐明了NJTU模型的特点,并同其它几种模型进行比较,第四节给出了NJTU模型的应用例子。     

Rapid determination of methyl salicylate, a plant-signaling compound, in tomato leaves by direct sample introduction and thermal desorption followed by GC-MS

Many plants infested by herbivores or viruses can rapidly produce and accumulate a plant-signaling compound, methyl salicylate (MeSA), in their leaves to activate disease resistance. In the present work, a simple, rapid, and sensitive method was developed for the determination of MeSA in tomato leaves by direct sample introduction and thermal desorption followed by GC-MS. Results show that the proposed method has a low detection limit (0.08 ng mg(-1)) and good precision (RSD = 8.9%). The present method was applied to the investigation of tomato plant defense response to tobacco mosaic virus (TMV) by rapid analysis of volatile compounds in plant leaves. It was found that tomato plants can produce large amounts of MeSA as a defense response to TMV. This indicates that MeSA may be a plant-signaling compound in tomato plant defense response to TMV.     

Involvement of Jasmonate-signaling pathway in the herbivore-induced rice plant defense

The expression patterns of eight defense- related genes in the herbivore-infested and jasmonate- treated (jasmonic acid, JA and its derivative MeJA) rice leaves were analyzed using RT-PCR. The results showed that Spodoptera litura Fabricius (Lepidoptera: Noctuidae) herbi-vory induced the expression of lipoxygenase (LOX) and al-lene oxide synthase (AOS) genes that are involved in the jasmonate-signaling pathway. Moreover, S. litura damage resulted in the expression of farnesyl pyrophosphate syn-thase (FPS), Bowman-birk proteinase inhibitor (BBPI), phenylalanine ammonia-lyase (PAL) and other rice defense- related genes that were also induced by aqueous JA treat-ment or gaseous MeJA treatment. These indicated that in rice leaves, the JA-related signaling pathway was involved in the S. litura-induced chemical defense. Mechanical damage and brown planthopper (BPH), Nilaparvata lugens (St錶) (Homoptera: Delphacidae) damage induced the expression of LOX gene, but both treatments did not induce the expression of AOS gene. However, BPH damage induced the expression of acidic pathogen-related protein 1 (PR-1a), Chitinase (PR-3), and PAL genes, which is involved in the salicylate- signaling pathway. It was suggested that salicylate-related signaling pathway or other pathways, rather than jas-monate-signaling pathway was involved in the BPH-induced rice plant defense.     

电气化铁道对信号控制系统干扰的分析

电气化铁路的电力牵引适合高速、重载和大密度的要求,符合我国铁路牵引技术政策,是理想的牵引动力.但是对于铁道信号控制系统,电力牵引又是一个极大的干扰源.它在一定程度上影响了信号设备的正常工作.因此信号工作者应搞清:1.电气化铁道究竟会对信号设备产生什么样的干扰,这些干扰强度多大?2.各类信号设备的抗干扰能力如何?3.如何综合分析与治理?本文对上述问题进行了探讨,对作者从事的这方面的科研活动作了介绍.     

浓缩蛋白1号在蛋鸡日粮中完全替代进口鱼粉

浓缩蛋白1号经新乡市预混合饲料厂喂养产蛋鸡541只,133天的试验结果表明,浓缩蛋白1号作为一种新的蛋白质资源完全可以替代产蛋鸡日粮中的进口鱼粉,并且生产性能、经济效益在一定程度上都优于进口鱼粉。     

在现有电话网中发展智能业务的研究

介绍了智能网结构及其通信协议，分析了在现有电话网中可用来迅速开放智能业务的两种智能平台和叠加式智能网的结构及性能，探讨了在省内电话网中建设初级智能网络的方法及策略     

7号公共信道信令系统第二功能级的分析和模拟

本文从系统结构的观点出发,对7号公共信道信令系统第二功能级进行了分析,提出了软件的一些设计方案,并在16位微机上进行了模拟,为测试所验证.同时对影响7号系统工作效率的有关问题作了一些探讨.     

New measurements of the emission spectra of Sm2+ in KMgF3 and NaMgF3 crystals

The fluorescence of divalent samarium in KMgF₃ and NaMgF₃ crystals is investigated. The emission is observed to originate from transitions between the ⁵D_J, and ⁷F_J multiplets of the 4?⁶ configuration. More precisely, the lowest ⁵D_J level, ⁵D₀, appears to be the most efficient emitting level in the temperature range 4–300K. Contrary to what has been reported elsewhere, the Sm²⁺ fluorescence in both crystals does not exhibit any broad band emission even at room temperature. The great number of lines in the ⁵D₀→⁷F_J patterns gives evidence of the multiple-center origin of the fluorescence.