Research on the Long-distance Transmission

In view of the imbalanced distribution of power load and resources, including the status of “electric shortage” in some cities in our country, the article discusses the long-distance transmission technology. It mainly analyzed two ways of the long-distance transmission: UHV AC transmission and UHV DC transmission. The fractional frequency transmission technology and half wavelength AC transmission technology of AC transmission are introduced. Some key technologies of long-distance transmission are described. It has a guess for long-distance transmission future direction.

Study on the Technology of Supplying Water Safely by Long-Distance Pipeline

The extensively built long-distance water transmission pipelines have become the main water sources for urban areas. To ensure the reliability and safety of the water supply, from the viewpoint of overall management, it would be necessary to establish a system of information management for the pipeline. The monitoring, calculating and analyzing functions of the system serve to give controlling instructions and safe operating rules to the automatic equipment and technician, making sure the resistance coefficient distribution along the pipeline is reasonable; the hydraulic state transition is smooth when operating conditions change or water supply accidents occur, avoiding the damage of water hammer. This paper covered the composition structures of the information management system of long-distance water transmission pipelines and the functions of the subsystems, and finally elaborated on the approaches and steps of building a mathematics model for the analysis of dynamic hydraulic status.

4.096 Tbit/s multidimensional multiplexing signals transmission over 1000 km few mode fiber

We experimentally transmit eight wavelength-division-multiplexing(WDM)channels,16 quadratic-amplitude-modulation(QAM)signals at 32-GBaud,over 1000 km few mode fiber(FMF).In this experiment,we use WDM,mode division multiplexing,and polarization multiplexing for signal transmission.Through the multiple-input-multiple-output(MIMO)equalization algorithms,we achieve the total line transmission rate of 4.096 Tbit/s.The results prove that the bit error rates(BERs)for the16QAM signals after 1000 km FMF transmission are below the soft-decision forward-error-correction(SD-FEC)threshold of2.4×10^(-2),and the net rate reaches 3.413 Tbit/s.Our proposed system provides a reference for the future development of high-capacity communication.

Seeing at a distance with multicore fibers

Images and videos provide a wealth of information for people in production and life.Although most digital information is transmitted via optical fiber,the image acquisition and transmission processes still rely heavily on electronic circuits.The development of all-optical transmission networks and optical computing frameworks has pointed to the direction for the next generation of data transmission and information processing.Here,we propose a high-speed,low-cost,multiplexed parallel and one-piece all-fiber architecture for image acquisition,encoding,and transmission,called the Multicore Fiber Acquisition and Transmission Image System(MFAT).Based on different spatial and modal channels of the multicore fiber,fiber-coupled self-encoding,and digital aperture decoding technology,scenes can be observed directly from up to 1 km away.The expansion of capacity provides the possibility of parallel coded transmission of multimodal high-quality data.MFAT requires no additional signal transmitting and receiving equipment.The all-fiber processing saves the time traditionally spent on signal conversion and image pre-processing(compression,encoding,and modulation).Additionally,it provides an effective solution for 2D information acquisition and transmission tasks in extreme environments such as high temperatures and electromagnetic interference.

Efficient utilization of wind power： Long-distance transmission or local consumption？

Excess wind power produced in wind-inten- sive areas is normally delivered to remote load centers via long-distance transmission lines. This paper presents a comparison between long-distance transmission, which has gained popularity, and local energy consumption, in which a fraction of the generated wind power can be locally consumed by energy-intensive industries. First, the challenges and solutions to the long-distance transmission and local consumption of wind power are presented. Then, the two approaches to the utilization of wind power are compared in terms of system security, reliability, cost, and capability to utilize wind energy. Finally, the economic feasibility and technical feasibility of the local consumption of wind power are demonstrated by a large and isolated industrial power system, or supermicrogrid, in China. The coal-fired generators together with the shortterm interruptible electrolytic aluminum load in the supermicrogrid are able to compensate for the intermit- tency of wind power. In the long term, the transfer of high- energy-consumption industries to wind-rich areas and their local consumption of the available wind power are beneficial.

RMD根焊技术的应用

介绍了RMD半自动根焊技术所使用设备的工艺原理、新型焊接材料、工艺特点以及RMD根焊技术在X80管线钢焊接中的应用情况。从焊前准备、引弧、收弧、焊枪角度、接头形式、运弧方法、焊接姿势等方面分析了RMD根焊技术应用过程中应注意的事项,同时对根焊过程中产生的缺陷进行了分析,并给出了相应的处理方法。

Importers Drive Leaf-to-Leaf Jasmonic Acid Transmission in Wound-Induced Systemic Immunity

The transmission of mobile wound signals along the phloem pathway is essential to the activation of wound-induced systemic response/resistance,which requires an upsurge of jasmonic acid(JA)in the distal undamaged leaves.Among these mobile signals,the electrical signal mediated by the glutamate-dependent activation of several clade three GLUTAMATE RECEPTOR-LIKE(GLR3)proteins is involved in the stimulation of JA production in distal leaves.However,whether JA acts as a mobile wound signal and,if so,how it is transmitted and interacts with the electrical signal remain unclear.Here,we show that JA was translocated from the local to distal leaves in Arabidopsis,and this process was predominantly regulated by two phloem-expressed and plasma membrane-localized jasmonate transporters,AtJAT3 and AtJAT4.In addition to the cooperation between AtJAT3/4 and GLR3.3 in the regulation of long-distance JA translocation,our findings indicate that importer-mediated cell-cell JA transport is important for driving the loading and translocation of JA in the phloem pathway in a self-propagating manner.

输气管道系统绝缘接头渗漏原因分析及在线堵漏技术探讨

绝缘接头渗漏是输气管道运行中的常见事故,如何在泄漏发生后的最短时间内用尽可能简便的方式进行在线堵漏,是管道抢修面临的重要课题。通过分析绝缘接头的结构形式及受力情况,从产品制造、质量检验、物资采购、施工管理及运行管理等环节查找泄漏原因,并提出杜绝渗漏的对策。输气管道运行和维抢修工作实践证明,顶管法和夹具注剂法两种在线堵漏技术适用性广、消除泄漏快,且不需要停输,可降低抢修作业安全风险,具有良好的环境和经济效益。测试结果表明,两种在线堵漏技术均成熟可靠,填补了国内堵漏技术空白,具有较强的推广价值。

稠油及特稠油长输管道工艺参数分析方法

由于稠油、超稠油长输管道油品的黏温特性,管道的运行压力、温度、管径、集肤效应伴热温度等关键工艺参数的确定成为难题。根据纯油黏温曲线、掺稀油比下的黏度变化曲线及经济指标,综合比选确定低能耗、低投资、高安全性的温度和压力设计参数,从中总结出稠油、特稠油长输管道关键工艺参数分析方法。分析发现,黏温曲线的温度拐点是一个关键的参照点。根据这个方法确定海坨线普通稠油进站最低温度35℃,设计温度80℃,掺稀油比14∶1;特石线超稠油最低进站温度75℃,设计温度110℃,集肤效应伴热温度≥75℃。

Stomatal movement in response to long distance-communicated signals initiated by heat shock in partial roots of Commelina communis L.

The systematic or long-distance signal transmission plays crucial roles inanimal lives. Compared with animals, however, much less is known about the roles of long-distancesignal communication in plant lives. Using the model plant Commelina communisL, we have probed theroot to shoot communication mediated by heat-shock signals. The results showed that a heat shock of5 min at 40°C in partial roots, i.e. half or even 1/4 root system, could lead to a significantdecrease in stomatal conductance. The regulation capability depends on both heat shock temperatureand the amount of root system, i.e. with higher temperature and more roots stressed, the leafconductance would decrease more significantly. Interestingly, the stomatal regulation by heat shocksignal is in a manner of oscillation: when stomata conductance decreased to the lowest level withinabout 30 min, it would increase rapidly and sometimes even exceed the initial level, and afterseveral cycles the stomata conductance would be finallystabilized at a lower level. Feeding xylemsap collected from heat-shocked plants could lead to a decrease in stomata conductance, suggestingthat the heat shock-initiated signal is basically a positive signal. Further studies showed thatheat shock wasnot able to affect ABA content in xylem sap, and also, not able to lead to a decreasein leaf water status, which suggested that the stomatal regulation was neither mediated by ABA norby a hydraulic signal. Heat shock could lead to an increase in xylemsap H_2O_2 content, andmoreover, the removal of H_2O_2 by catalase could partially recover the stomatal inhibition by xylemsap collected from heat-shocked plants, suggesting that H_2O_2 might be able to act as one of theroot signals to control the stomatal movement. Due to the fact that heat-shock and drought areusually two concomitant stresses, the stomatal regulation by heat-shock signal should be ofsignificance for plant response to stresses. The observation for the stomatal regulation in anoscillation manner by presently identified new signals should contribute to further understanding ofthe mystery for the pant systematic signaling in response to stresses.