胃肠道褪黑素的合成及其对消化道微生物群体影响的研究进展

胃肠道褪黑素主要是由肠嗜铬细胞分泌,具有一定昼夜节律性。褪黑素通过调控细胞因子或NF-κB等调控肠道微生物及其代谢,进而影响动物肠道微生物群体结构以及某些细菌的昼夜节律。本文主要对近几年胃肠道褪黑素的合成分泌及其生理功能、肠道微生物节律性以及褪黑素对肠道微生物的调控作用等研究进行综述,以期为胃肠道褪黑素与菌群之间调控关系的研究提供一定参考。     

不同氨基酸对泰万菌素发酵影响的研究

通过单因素试验考察了泰万菌素发酵培养基中不同氨基酸种类对其发酵过程的影响,并利用正交试验对发酵培养基中3种主要氨基酸的用量配比进行了优化,结果表明发酵培养基加入0.2%亮氨酸、0.1%色氨酸、0.1%甘氨酸对泰万菌素发酵转化率影响显著,发酵摇瓶效价从14000μ/mL提高到18000μ/mL,效价提高了28.5%,完成了对泰万菌素提高发酵转化率和发酵单位的目的,并为大规模商业化生产泰万菌素奠定了良好的基础。     

去花对菊芋数量学性状的影响

以白皮菊芋为试材,通过对现蕾期菊芋去除1/4花、1/3花、1/2花、全部去除和不去花等5个处理,测定叶片、小花、分枝和块茎数量等相关指标,探讨了去花对菊芋数量学性状的影响规律,为提高菊芋块茎生物产量提供理论依据。结果表明:去花1/3、1/2和全株去花提高了单株菊芋块茎数量,降低单株块茎质量,1/4去花对菊芋单株块茎数量和单个块茎质量影响不显著;去花处理降低了二级分枝和一级分枝的数量;去花处理增加了单株叶片的数量和单片叶片的质量;随着去花数量的增加,单株小花数量呈现"降-升-降"的变化规律,单个小花质量呈现"降-升"的变化趋势。     

广东省稻菜轮作区中牛筋草对十种除草剂的抗性水平及靶基因序列分析

为明确广东省稻菜轮作区中牛筋草对10种常用除草剂的抗性水平及抗性分子机制,采用整株生物测定法测定广东省稻菜轮作区内8个牛筋草种群P1～P8对草甘膦、草铵膦和乙酰辅酶A羧化酶(acetyl-CoA carboxylase,ACCase)抑制剂类等10种除草剂的抗性水平,并进一步分析P1和P8种群相关靶标酶基因5-烯醇丙酮酰莽草酸-3-磷酸合酶(5-enolpyruvyl-shikimate-3-phosphate synthase,EPSPS)、谷氨酰胺合成酶(glutamine synthetase,GS)和ACCase的部分功能区序列特征。结果显示,牛筋草P1～P8种群对草甘膦抗性指数为敏感种群的5.9倍～17.7倍,其中P8种群对草甘膦的抗性水平最高;8个种群对草铵膦也产生了不同程度的抗性,抗性指数为敏感种群的2.3倍～14.2倍,其中P1种群抗性最高。牛筋草P1和P8种群均对ACCase抑制剂类除草剂精喹禾灵、氰氟草酯和噁唑酰草胺产生了交互抗性;P1种群ACCase基因在第2 041位氨基酸处发生突变,该突变在牛筋草种群中首次发现;而P8种群ACCase基因则在第2 027位氨基...     

Research on the Realization of Remote Controlling for Multi-output Power Supply of Communication Equipment Based on Ethernet

According to the requirements of communication power supply, such as high reliability, wide application and high availability, the authors raise a new remote control design for a multi-output power supply for communication equipment based on TCPIP protocol and embedded technology. Then the hardware design is given for the system is discussed based on Ethernet professional chip PRTL8019AS and related circuits. The firmware software design for the salve-computer based TCPIP technology, and the soft design of communieation and control for the master-computer are proposed based on Winsoek and MFC technology in detail A test machine is built to do the testing, the test results prove that the test machine works stably and well, satisfies the design rules and also provides a feasible method for the remote supervise in communication power supplier whose requirement includes remote supervise, no-people on duty and so on.     

One-cycle Technique Based Adjustable Ac Source

By using one-cycle control theory, a novel voltage source inverter is proposed. The conventional one-cycle control technique needs that the integrator is reset instantaneously. But it is very difficult to realize with hardware due to the finite time constant of the reset circuitry. Therefore, based on the one-cycle technique, the paper gives a new control scheme to resolve the problem with dual switched integrator, and the performance of the integrators is close to ideal. The paper also uses the dc offset to implement the voltage measurement. Furthermore, the amplitude and frequency of the output voltage are effectively adjustable. The one-cycle control technique not only provides fast dynamic response, but also can admirably suppress the perturbation yielded by dc source and abate the undesired harmonic contents. Simulation studies were performed to prove the proposed scheme. The results show that the one-cycle control based voltage source inverter makes good use of dc source that is 92.8% and THD is only O. 255 9%.     

A New Method for Parameterized Design of Metallic Doors and Windows

According to the graphics characteristics of metallic doors & windows design and based on the research of graphics dimension restriction problems. This paper provides a new method for parameterized design of metallic doors & windows in virtue of expression solution. In this method, the restrictions of graphic elements have been changed into the parameter expressions of sizes and positions of graphic elements. Through the calculation of such expressions, the parameter driven method has been reached. Thus the parameterization of graphics can be easier and quicker than before. It can be used to setup the open parameterized graphics libraries.     

Brightness and Its Application

This paper provides a conception of brightness and puts stress upon application of brightness to science of illuminating engineering and actual illuminating engineering.