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日本新一轮电力体制改革启动以后，现货市场的交易量大幅提升，市场结构也逐渐完善，对中国电力现货市场建设有较大的借鉴意义。深入分析日本电力现货市场的结构和运行规律，包括日前市场、日内市场和平衡机制。对改革后市场主体、市场价格、交易量等进行逐年变化趋势分析。总结改革过程中出现的问题和日本的解决方式，最后提出对中国电力市场建设的启示和建议。

在全球气候变暖背景下，以风能为代表的清洁能源生产、传输和调度对气候状况的依赖度越来越高，清洁能源开发利用中的气候服务显得至关重要。为深入了解风能资源开发领域的气候服务技术现状，并探索未来风电开发中的气候科技创新发展趋势，研究综述了全球风能资源长期变化趋势、气候变化对风能资源开发潜力的影响及风能开发与气候环境和谐发展等方面的技术进展，讨论了未来风能资源高效利用所面临的挑战。针对未来风能资源开发利用和安全运营指出：全球和区域气候数值模式为风能资源开发潜力预估提供了必要条件，但需通过多模式集合和“观测约束”等手段来减少预估的不确定性；未来需通过动力降尺度技术及能源服务产品研发等，构建面向风电开发的能源气候预测业务体系，提高风能利用效率；通过实地观测-机理认识-数值模型研发等，建立大规模风电开发的气候环境效应科学评价方法，以期有效支撑环境友好型清洁能源电站的规划设计。

针对现有测量方法存在的问题,基于测量状态与加工状态一致的检测原理,设计了环面蜗杆精度测量原理。通过设置自动标定程序和高精密时栅转台使系统自动建立三维空间的测量坐标系,并利用坐标旋转法测得测头的回转半径。采用随动控制方式来测量环面蜗杆各齿面的点在测量坐标系中的坐标值,从而得到环面蜗杆的精度。系统采用金字塔式的结构使系统更稳定、可靠性强。通过实验,验证了本方案的可行性,测得环面蜗杆螺旋线的误差为±4μm。对系统进行等精度重复性实验,系统的极差为0.9μm,方差分析说明各测量点的误差值无显著差异。

摘要：【目的】比较后腹腔镜肾窦内肾盂切开取石术（RLIP）及经皮肾镜碎石取石术（PCNL）治疗肾盂单发结石的有 效性及安全性。【方法】回顾我院自2012年03月至2016年09月收治的101例肾盂单发结石患者，按治疗方式分为RLIP组 （46例）及PCNL组（55例），并比较两组患者在临床疗效上的差异。【结果】两组患者在年龄、性别、结石患侧及结石大小方面 无统计学差异。RLIP组手术时间虽然长于PCNL组，但结石清除率明显高于PCNL组（P < 0.05）。RLIP组在术后泌尿系感 染并发症方面优于PCNL 组（P < 0.05），但两组在术后出院时间、术后发热（> 38.5℃）、血红蛋白及肾小球滤过率下降值方 面，均无显著性差异。【结论】RLIP相比PCNL具有更好的有效性，且安全性方面也稍优于PCNL，在临床上具有一定的推广 价值。

在新的欧洲钢结构规范EN1993—1—1即将颁布使用之际,本文就规范中压弯杆的计算的新的规定加以说明,解释新规定的来源、背景资料,探讨简化的相关公式。新规定的最主要的发展在于弯扭失稳公式中的相关系数以及稳定系数。本部分工作是基于欧洲钢结构协会（ECCS）第8技术委员会（TC8）的工作成果,新成果更加先进及经济。

甚高速数字用户线（VDSL）是数字用户线（DSL）家族中速率最高的接入方式.新一代VDSL速率最高可到100Mbit/s以上,包括对称传输和非对称传输以及多种不同的传输速率.由于VDSL的传输速率高,其对应的传输距离和其他DSL技术相比较短.调制方式是VDSL中的核心技术,目前有两种并存的方式,离散多音（DMT）与正交/调幅和无载波调幅/调相（QAM/CAP）.文章主要介绍这两种调制方式,并从多个方面对其优、缺点进行比较.

Heat stress has posed a significant threat to the laying hens inside the poultry houses in the Northwest region of China. Significant non-uniformities can be found in the thermal distribution and temperature variations in summer. The ventilation system has been the primary measure to regulate the thermal environment in the poultry houses. Excellent airflow arrangement and ventilation strategies are essential for the ventilation efficiency. Still, the continuous operation of fans can inevitably generate the excessive local cold air, thereby wasting the electrical energy for the high cost of environmental control. Alternatively, intermittent ventilation can serve as an efficient way to improve ventilation effectiveness with energy saving. However, it is notably limited to applying to the summer poultry houses so far. In this study, a novel intermittent ventilation was introduced to alleviate the significant temperature fluctuations and ensure the high stability of the thermal environment in the summer poultry houses. According to the internal air temperature, the fan operations were performed on the conventional tunnel-ventilated poultry houses (control house, CH) and sidewall inlets poultry houses (experimental house, EH). Specifically, the fans were regulated, when the temperature exceeded the upper limit. Once the temperature dropped below the lower limit temperature, the fans were deactivated simultaneously, which was different from the continuous operations of fans throughout the summer. The thermal environment was monitored in the operation periods of intermittent ventilation. The environmental conditions inside the poultry houses were also evaluated. The results revealed that the average internal temperatures of experimental and control poultry houses were 25.3 and 26.5 °C, respectively, under the same external environmental temperatures; While the average relative humidity were 65.8% and 62.7%, respectively. The temperature fluctuations during the EH and CH's intermittent and continuous ventilation were 0.6 and 0.7 °C, 1.2 and 1.0 °C, respectively. The maximal difference of temperature in the horizontal direction of EH and CH were 0.3 and 5.2, 0.8 and 4.7 °C, respectively. Temperature variations were assessed in the four-hour intervals. The EH consistently demonstrated more minor temperature fluctuations than the CH when the fans were operated intermittently. The horizontal temperature difference was less than that in the continuous operation in EH. There was no difference in pressure and air velocity under the intermittent and continuous ventilation in the same number of fans. The pressure difference between the interior and the evaporative cooling pad buffer room increased from 17 to 19 Pa from the fan opposite wall to the fan. Average air velocity at the sidewall inlets and along the aisles in the EH were 3.30 and 0.49 m/s, respectively, which were higher by 1.86 and 0.12 m/s, compared with the CH. Therefore, the intermittent ventilation was suitable for the sidewall inlets, to improve the thermal environment within the poultry house significantly. There was great potential for widespread adoption in the Northwest region of China in the summer. The lifespan of the fan was extended for the maximal economic benefits. The intermittent operation times of fans should be determined according to the local climate, poultry houses’ ventilation requirements and the poultry houses’ size. This finding can provide a foundational reference for designing and adjusting the intermittent ventilation in summer poultry houses in the Northwest region of China. [ABSTRACT FROM AUTHOR]

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Purpose: This article provides a historical overview of the progress made in the moral education curriculum (MEC) reform of China’s elementary and middle schools in the 21st century and discusses its future prospects. Design/Approach/Methods: The main methods used were textual and policy analyses. Findings: While China’s MEC reform is characterized by an openness and modernity achieved through international dialogue, it remains distinctively Chinese. The continued development and improvement of MEC reform can only occur through the careful handling of the various relationships between China and the international community, traditionality and modernity, central and local authorities, as well as theory and practice. Originality/Value: In addition to providing greater insights into and understanding of China’s new MEC reform, this article suggests several ideas for the further development of educational reform.

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The large diameter borehole pressure relief is one of the effective means used to prevent rock burst in coal mines. It is of great significance to study the change of coal body stress during drilling to prevent the rock burst. At present, the relational model between drilling parameters and coal stress is rarely studied, and the precision is limited. Therefore, a new PSO-NGO-SVR coal stress inversion model was proposed based on northern goshawk optimization (NGO) and support vector regression ( SVR). Firstly, the Tent chaotic mapping was introduced into the model during the initialization phase of the NGO population, and the advantages of particle swarm optimization (PSO) were integrated into the northern hawk algorithm, resulting in better performance of the improved northern hawk algorithm. Next, the improved northern eagle algorithm was used to iteratively optimize hyperparameters in support vector regression. Finally, the model was established with the optimal hyperparameters after iteration. The results show that the convergence speed and accuracy of the improved northern eagle algorithm are greatly improved, and the PSO-NGO-SVR coal stress inversion model has relatively high accuracy. [ABSTRACT FROM AUTHOR]

The current farming platform has been widely equipped with unmanned four-wheel independent driving and fourwheel independent steering (4WID-4WIS). However, the control system of path tracking is required for high accuracy and sufficient stability under complex working conditions. There were also complex working conditions under crop ridge cultivation, such as Π type target path, curves, initial pose deviation, various soil moisture, and bumpy ground landscapes. In this study, a control strategy of path tracking was proposed using a nonlinear disturbance observer (NOB). A mathematical insitu steering model was introduced for the relatively low tracking errors in the turn area of the Π type path, compared with the traditional Ackerman steering model. Two steering methods were then used to realize the turn path tracking. Meanwhile, a switch control strategy was designed between yaw angle proportional integral control and pure pursuit control using in-situ steering. Furthermore, the curve and initial pose deviation shared a relatively significant impact on the accuracy of working path tracking. Moreover, the distance traveled by the 4WID-4WIS farming platform was reduced to reach the working path and the maximum lateral deviation. The tracking accuracy of the work paths was improved to design a pure pursuit control using a lookahead distance function, and a fuzzy proportional compensator using the lateral deviation, as well as the curvature of the foresight area in the work path. Besides, the feedforward compensator with NOB was designed to avoid the relatively large yaw speed disturbances from the complex soil moisture, bumpy ground landscapes, kinematic models, and measurement errors. The NOB was also constructed to achieve the precise observation of disturbance for the expected path of farming platforms. The steering compensation angle was then calculated for the feedforward compensator to counteract the disturbance. Finally, the simulation was carried out in the Ubuntu/ROS environment. The NOB strategy of path tracking effectively reduced the distance traveled by farming platforms to reach the working paths, the maximum lateral deviation, and curve tracking errors. The accuracy and stability of path tracking were achieved in the anti-interference performance, where the disturbance momentum was observed accurately. And, the outdoor experiments show that the switch control strategy performed a smaller error of turn tracking on Π type target path, compared with the traditional pure pursuit control. The tracking performance was also effectively improved. The pure pursuit with the look-ahead distance function and fuzzy proportional compensator under different initial pose deviation states reduced the distance traveled by farming platforms to reach the working paths by 32.2%- 43.4%. The maximum lateral deviation, mean absolute errors of the whole line and curved area were reduced by 0-42.4%, 27.7%-49.5%, and 33.7%-39.5%, respectively, indicating the high accuracy of working paths tracking. The NOB-based feedforward compensator was reduced by 6.25% mean absolute error in the steady area under hard slate condition, 33.3% under grassland condition, and 41.7% under farmland condition. This control strategy of path-tracking effectively improved the system's robustness and path-tracking accuracy. The finding can also provide innovative ideas and technical references for the navigation system of unmanned four-wheel drive and four-rotation agricultural machinery in ridge tillage. [ABSTRACT FROM AUTHOR]

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Objectives: To solve the problems of high cost and high complexity of traditional estimation method of the moving vehicles attitude angle, an innovative vehicle heading and pitch estimation model based on optimized time-differenced carrier phase is proposed. Methods: First, we use observation data of one global navigation satellite system receiver and time-differenced carrier phase algorithm with a low-complexity to obtain accurate vehicle displacement vector, further estimate vehicle heading and pitch. In order to improve the estimation efficiency, we optimize the traditional time-differenced carrier phase algorithm. Results: Static and dynamic tests results show that the optimized time-differenced carrier phase is more efficient than the general carrier phase time-difference, and the processing time can be saved by about 40%. The proposed heading and pitch estimation model can provide accurate values of heading and pitch, whose root mean square error is less than 0.2° and maximum error is less than 1.5°.The accuracy of the model will not be affected by the accumulation of errors within one hour. Conclusions: This proposed model uses only one receiver to obtain heading and pitch of moving vehicles, which has the advantages of high accuracy, low cost, low complexity and high efficiency. [ABSTRACT FROM AUTHOR]

To solve the problem of combustion state recognition in solid oxide fuel cell (SOFC) combustor, this paper proposed a combustion state recognition method based on attention mechanism and image feature pyramid. The method adopted the adaptive gamma correction with weighting distribution (AGCWD) to standardize the input images. It combined two single full connections with 1×1 convolution to replace the squeeze and excitation structure, and proposed a hybrid attention structure combined with spatial attention structure to enhance the ability of feature extraction. To provide multi-scale information communication capability, it constructed the multi-scale bidirectional fusion pyramid by means of bidirectional computation and multi-scale fusion. The experimental results show that the proposed method reaches 99.22% accuracy under the premise of 3.98 M parameters and 397 M floating point operations (FLOPs), and effectively identifies the combustion state in SOFC combustor. [ABSTRACT FROM AUTHOR]

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