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Control cooling is essential method for microstructure and mechanical properties control in hot rolling strip making. It is vital to realize high precises temperature distribution prediction and control in cooling process to ensure the industrial production. In this paper, a traditional mechanism model based on finite-difference method and combining with online cycle velocity calculation strategy was introduced as one of estimating temperature distribution baseline method. However, considering calculation time, variable-velocity rolling makes it difficult to rapidly realize temperature and water distribution modifying of each segment in cooling zone. Herein, a temperature distribution prediction method based on recurrent neural network was proposed, instead of only final cooling temperature prediction. And temperature distribution prediction performance of model with different recurrent cell and time steps were evaluated. The results indicated that the proposed model could realize temperature distribution prediction and the model based on bi-LSTM and 48 timesteps has the highest determination coefficient value of 0.976 and lowest root mean square error of 8.03 and mean absolute error of 5.7. Furthermore, compared with baseline model, the proposed model retained lower computational cost, making it applicable in industrial application by providing real-time temperature distribution prediction.

LEAF is a heavy ion experimental facility with low energy, high intensity and high charge state. It belongs to the strong current linear accelerator, and its maximum beam power can reach 10 kW. High-power beams can pose a great risk of damaging field devices in continuous beam mode due to high-power beam bombardment. In order to ensure the safe operation of field devices and key equipment, an interlocking control system for LEAF is designed by using the control board of FPGA and PLC controller. The FPGA-based interlock system mainly implements the real-time monitoring of the arc fault signals from the RFQ cavity, a few fast fault signals from LLRF system and beam diagnostic system. When a valid fault signal is detected, the system will send its protection instruction to the chopper power supply to cut off the beam rapidly. The PLC-based interlock system mainly handles the fault state detection and safety operation of field devices with a slower protective action, and the action time is in a millisecond range. The protective action time of the FPGA interlock system has been achieved within 10 µs. This system adopts two sets of control and protection logic, which are implemented in the control board of FPGA and the PLC controller. It can ensure the safety of the core devices through the double-redundant beam-cutting actions if the key equipment fails or the beam parameters are abnormal. The complete system has a simple structure. The redundant technique is used in the design of the control protection logic and data transmission path. This provides a reliable safety measure for beam commissioning and physical experiment of the LEAF facility.

The characteristics of tropical cyclone (TC) extreme rainfall events over Hainan Island from 1969 to 2014 are analyzed from the viewpoint of the TC maximum daily rainfall (TMDR) using daily station precipitation data from the Meteorological Information Center of the China Meteorological Administration, TC best-track data from the Shanghai Typhoon Institute, and NCEP/NCAR reanalysis data. The frequencies of the TMDR reaching 50, 100 and 250 mm show a decreasing trend [−0.7 (10 yr)−1], a weak decreasing trend [−0.2 (10 yr)−1] and a weak increasing trend [0.1 (10 yr)−1], respectively. For seasonal variations, the TMDR of all intensity grades mainly occurs from July to October, with the frequencies of TMDR - 50 mm and - 100 mm peaking in September and the frequency of TMDR - 250 mm [TC extreme rainstorm (TCER) events] peaking in August and September. The western region (Changjiang) of the Island is always the rainfall center, independent of the intensity or frequencies of different intensity grades. The causes of TCERs are also explored and the results show that topography plays a key role in the characteristics of the rainfall events. TCERs are easily induced on the windward slopes of Wuzhi Mountain, with the coordination of TC tracks and TC wind structure. A slower speed of movement, a stronger TC intensity and a farther westward track are all conducive to extreme rainfall events. A weaker northwestern Pacific subtropical high is likely to make the 500-hPa steering flow weaker and results in slower TC movement, whereas a stronger South China Sea summer monsoon can carry a higher moisture flux. These two environmental factors are both favorable for TCERs.

LEAF is a complicated and integrated facility, which includes several different subsystems. In order to realize the remote control of field equipment and meet the requirements of the beam commissioning, a LEAF control system has been designed. The developed control system includes the following sub-systems: timing systems, data archiving systems, personnel safety systems, and machine protection systems. The control system for LEAF is developed using the EPICS software toolset and the distributed control architecture. This is designed in a three-layer structure. At the equipment layer, the control of the low-level equipment is mainly done by various industrial controllers, including programmable logic controllers, controllers for serial devices, and motion controllers based on EtherCAT fieldbus. At the middle layer, the Ethernet switches are used to implement a Gigabit local area network. At the operation layer, high-level application software has been developed for the beam commissioning and the operation of the accelerator. The designed system can realize remote monitoring and control of field devices, provide synchronous timing and machine protection for key equipment, and automatically archive historical data for on-site running equipment. The complete system has a clear structure and stable operation and has been successfully applied to beam commissioning and operation of the LEAF facility.

The composite-drought index (CI), improved weighted average of precipitation index (IWAP), and the objective identification technique for regional extreme events (OITREE) were employed to detect China's regional meteorological drought events (CRMDEs) during 1961–2010. Compared with existing references, CI and IWAP both showed strong ability in identifying CRMDEs. Generally, the results of CI and IWAP were consistent, especially for extreme and severe CRMDEs. During 1961–2010, although the frequencies of extreme and severe CRMDEs based on CI and IWAP both showed weak decreasing trends, the two mean-integrated indices both showed increasing but not significant trends. However, the results of IWAP were more reasonable than CI’s in two aspects. Firstly, the monthly frequency of extreme and severe CRMDEs based on IWAP showed a clear seasonal variation, which coincided with the seasonal variation of the East Asian monsoon over central–eastern China, whereas the frequency based on CI presented a much weaker seasonal variation. Secondly, the two sets of results were sometimes inconsistent with respect to the start and end times of a CRMDE, and CRMDEs based on CI generally showed two unreasonable phenomena: (1) under non-drought conditions, a severe drought stage could suddenly occur in a large area; and (2) during the following period, drought could alleviate gradually in cases of non-precipitation. Comparative analysis suggested that the IWAP drought index possesses obvious advantages in detecting and monitoring regional drought events.

The control system for ion source is based on distributed architecture. The hardware structure, working principle, interlock design and graphics interface design are introduced and stated in this paper. To improve the accuracy and usability of the electron cyclotron resonance ion source with advanced design for HIMM. The data acquisition system is based on PLC and FPGA integrated circuit. Interlock protection is designed for vacuum system, power supplies system and cooling water system. The control system is tested with C5+ ion beam, where fast reaction time and high-precision data processing during beam tuning have verified the stability and maintainability of the control system. The latest results and the reliable long-term operation of the accelerator demonstrate that the performance has been continually improved with the development of the optimized control system.

HIRFL is a heavy ion accelerator built by the Institute of Modern Physics, Chinese Academy of Sciences, which constitutes a total length of over 900 m by the SFC, SSC, CSRm, CSRe and so on. It bears a lot of research task of the country, so to ensure its safe operation is very important. Cool-water system is a key part in HIRFL, and the parameters of the cool-water system need to be monitored before an accident occurs. This article describes three aspects of the system, from the water leakage detection, pressure monitoring, to the water-level monitoring. A complete monitor system was designed and constructed, including the hardware structure; the data transfer mode, as well as specific control program. C++, FLASH and SCADA are used in the monitoring system. Fault alarm was performed timely and accurately by the monitoring system, and many accidents were avoided. Water system monitoring is an important part of the accelerator control system. It will also play a major role in the construction of large-scale scientific device named HIAF in the further.

In this paper, we detail the architecture, design, and testing of an accurate and usable electronic cooler control system for the cooling storage main ring at the Heavy Ion Research Facility, Lanzhou, China (HIRFL-CSRm), and present the results of its use. A control system must manage devices with a high degree of accuracy to satisfy various physical requirements, and to ensure the accuracy of the data acquisition and control characteristics. The software for the system, based on the C++, was developed following the model-view-controller architecture pattern. On the hardware side, an I-7017R module was adopted for analog-to-digital conversion and an I-7065D module for electronic delay. The communication protocol was analyzed, discussed, and implemented. The control system was then tested with the $$^{12}$$ C $$^{3+}$$ carbon beam at HIRFL-CSRm. The fast reaction time and high-precision data processing exhibited during beam tuning verified the stability and maintainability of the proposed control system.

Nature Communications 8: Article number: 15653 (2017); Published: 15 June 2017; Updated: 30 August 2017 Supplementary Fig. 4 of this Article contains errors. Supplementary Fig. 4c shows the T2-weighted phantom images in reverse order, and Supplementary Fig. 4d is a duplicate of Fig. 3d. The corrected version of Supplementary Fig.

An objective identification technique for regional extreme events (OITREE) and the daily compositedrought index (CI) at 101 stations in Southwest China (including Sichuan, Yunnan, Guizhou, and Chongqing) are used to detect regional meteorological drought events between 1960 and 2010. Values of the parameters of the OITREE method are determined. A total of 87 drought events are identified, including 9 extreme events. The 2009–2010 drought is the most serious in Southwest China during the past 50 years. The regional meteorological drought events during 1960–2010 generally last for 10–80 days, with the longest being 231 days. Droughts are more common from November to next April, and less common in the remaining months. Droughts occur more often and with greater intensity in Yunnan and southern Sichuan than in other parts of Southwest China. Strong (extreme and severe) regional meteorological drought events can be divided into five types. The southern type has occurred most frequently, and Yunnan is the area most frequently stricken by extreme and severe drought events. The regional meteorological drought events in Southwest China have increased in both frequency and intensity over the study period, and the main reason appears to be a significant decrease in precipitation over this region, but a simultaneous increase in temperature also contributes.