Spanish Melon Landraces: Revealing Useful Diversity by Genomic,Morphological, and Metabolomic Analysis

Spain is a secondary centre of the diversification of the melon (Cucumis melo L.), with high diversity represented in highly appreciated landraces belonging to the Flexuosus and Ibericus groups. A collection of 47 accessions of Flexuosus, Chate, Piel de Sapo, Tendral, Amarillo, Blanco, and Rochet was analysed using a genotyping-by-sequencing (GBS) approach. A total of 66,971 quality SNPs were identified. Genetic analysis differentiated Ibericus accessions and exotic materials (Ameri, Momordica, Kachri, and Agrestis), while Flexuous accessions shared ancestry between them. Within the Ibericus group, no clear genomic distinction could be identified for the different landraces evaluated, with accessions of different landraces showing high genetic similarity. The morphological characterization confirmed that the external colour and fruit shape had been used as recognition patterns for Spanish melon landraces, but variability within a landrace exists. Differences were found in the sugars and acid and volatile profiles of the materials. Flexuosus and Chate melons at the immature commercial stage accumulated malic acid and low levels of hexoses, while Ibericus melons accumulated high contents of sucrose and citric acid. Specific trends could be identified in the Ibericus landraces. Tendral accumulated low levels of sugars and citric acid and high of malic acid, maintaining higher firmness, Rochet reached higher levels of sugars, and Amarillo tended to lower malic acid contents. Interestingly, high variability was found within landraces for the acidic profile, offering possibilities to alter taste tinges. The main volatile organic compounds (VOCs) in Flexuosus and Chate were aldehydes and alcohols, with clear differences between both groups. In the Ibericus landraces, general trends for VOC accumulation could be identified, but, again, a high level of variation exists. This situation highlights the necessity to develop depuration programs to promote on-farm in situ conservation and, at the same time, offers opportunities to establish new breeding program targets and to take advantage of these sources of variation.     

一种基于全变分技术和Lp伪范数的椒盐噪声去除方法

针对传统各向同性全变分（Isotropy total variation,ITV）去噪算法容易导致图像边缘模糊、不易保持图像细节信息等问题,提出一种基于L _p 伪范数和各向同性全变分的图像去噪方法。该方法将L _p 伪范数代替ITV模型中的L ₁范数,利用交替方向乘子算法（Alternating direction method of multipliers, ADMM）将能量泛函拆解成若干个子问题,并将差分算子视为卷积算子;然后引入卷积定理和快速傅里叶变换(Fast Fourier transform, FFT)提高算法运算效率;最后通过Matlab进行仿真实验,运用图像质量的客观和主观评价方法进行评价分析。结果表明,本文方法能够较好地保留图像的边缘特性,有效提升去噪效果。     

LDC1000电感数字传感器的转速测量设计

不同于传统检测转速的方法,本测量方法在金属齿轮转速的检测方法中提出了新的设计思路,以LDC1000电感数字传感器为核心,以低功耗、低成本的MSP430F149为主控芯片,加上自制电感线圈来完成转速测量.射频收发芯片nRF24L01作为转速信息数据传输装置,发展前景良好.本文分析了转速测量的理论依据,给出电路原理图及其程序流程,实现对金属齿轮的转速测量、数据的传输共享.     

一种低功耗的振弦式传感器测频系统设计

为实现无市电情况下振弦式传感器对被测对象的长期实时监测,介绍了一种基于STM32L152微处理器的高精度、低功耗振弦式传感器测频系统。系统硬件包含传感器激振、信号调理、数据存储以及电源管理等模块。软件上利用Rife与Quinn算法,降低传感器激振电压、缩短激振时间,极大地减少了测频系统的功耗。实验结果表明：系统的平均工作电流为23.2 mA,休眠电流为15μA,频率测量相对误差小于0.025%,满足工程上振弦式传感器对测频精度和功耗的要求。     

基于ATmega128的步进电机细分驱动技术

本文根据合成电流矢量恒幅均匀旋转法,利用AVR高档8位单片机ATmega128的16位PWM模块产生双PWM信号,结合双全桥功率驱动芯片L298N来实现二相混合式步进电机的细分驱动,给出了细分驱动的硬件设计原理图以及相应的软件控制流程图。实验结果表明:该细分驱动器具有控制精度高、低频运行平滑度稳定、并且根据具体应用场合要求有细分数可调等特点。     

Integrated Analysis of Microarray,Small RNA,and Degradome Datasets Uncovers the Role of MicroRNAs in Temperature-Sensitive Genic Male Sterility in Wheat

Temperature-sensitive genic male sterile (TGMS) line Beijing Sterility 366 (BS366) has been utilized in hybrid breeding for a long time, but the molecular mechanism underlying male sterility remains unclear. Expression arrays, small RNA, and degradome sequencing were used in this study to explore the potential role of miRNA in the cold-induced male sterility of BS366. Microspore observation showed defective cell plates in dyads and tetrads and shrunken microspores at the vacuolated stage. Differential regulation of Golgi vesicle transport, phragmoplast formation, sporopollenin biosynthesis, pollen exine formation, and lipid metabolism were observed between cold and control conditions. Pollen development was significantly represented in the 352 antagonistic miRNA-target pairs in the integrated analysis of miRNA and mRNA profiles. The specific cleavage of ARF17 and TIR1 by miR160 and miR393 were found in the cold-treated BS366 degradome, respectively. Thus, the cold-mediated miRNAs impaired cell plate formation through repression of Golgi vesicle transport and phragmoplast formation. The repressed expression of ARF17 and TIR1 impaired pollen exine formation. The results of this study will contribute to our understanding of the roles of miRNAs in male sterility in wheat.     

基于窄带物联网的水务管网参数监测系统设计

近几年随着城市供水管道的日益复杂化,城市供水系统的监测变得难以管理.为了更好地监测城市供水系统的运行状态,借助窄带物联网(Narrow Band Internet of Things,NB-IoT)的低功耗优势,设计了一个基于NB-IoT的水务管网参数监测系统.该系统以低功耗STM32L4芯片为控制核心,实现了供水管网...     

扫描速度对激光选区熔化成形304L不锈钢板材高温持久性能的影响

目的 以激光选区熔化（SLM）成形304L不锈钢为对象,研究激光扫描速度对其组织及性能的影响,为优化304L不锈钢成形参数提供试验依据。方法 采用单因素试验研究了扫描速度对304L不锈钢微观组织、孔隙率、相对致密度、硬度、持久寿命等性能的影响,得到了304L不锈钢SLM成形相对最佳工艺参数。结果 当激光功率为300 W、扫描间距为0.1 mm、层厚为0.03 mm时,SLM成形304L不锈钢的最优扫描速度为1 000 mm/s,在此参数下试样持久时间为62.5 h,相对密度为99.5%,室温洛氏硬度为91.3HRB,700℃下维氏硬度为126.2HV。结论 在最优成形条件下,显微胞状结构组织均匀致密且气孔较少,熔池边界细小晶粒取向基本随机,熔池内偏大的柱状晶取向沿着<001>方向有一定的择优性,具有弱织构特征;相主要由奥氏体组成,持久断口呈灰黑色,无明显的颈缩现象,断口呈现锯齿状起伏滑移,并伴有明显的撕裂特征,断口为韧性撕裂断口。     

HA177-2A海水淡化蒸发塔结垢堵塞及清洗

某石化公司海水淡化装置的核心设备海水蒸发器,由于堵塞严重影响了装置的正常运行,分析了结垢的组成后提出了具体解决措施,在确保不损害设备的情况下进行了化学清洗.清洗效果理想,没有发生铝黄铜选择性腐蚀及点蚀,除垢率达到98%以上,达到了预期的目的.