活塞-缸套周期性瞬态传热仿真

为解决计算柴油机单个零部件传热时边界条件难以确定的问题,用耦合传热的方法,把活塞、缸套传热时的外边界条件变成内边界处理,利用有限元软件进行建模仿真。以X6130型柴油机为例,用有限元分析软件ANSYS建立了活塞-缸套的三维模型,并对其额定工况下一个工作循环内的瞬态传热进行了仿真计算,得到了活塞-缸套上关键点的温度波动曲线。部分计算结果和实验结果对比表明：用耦合方法模拟活塞-缸套之间的传热过程是可行的,且仿真结果与实测数据吻合较好。     

板翅换热器平直翅片的传热与阻力性能试验

对11种不同结构参数的紧凑式板翅换热器平直翅片的传热和流动阻力进行了试验研究,分析比较平直翅片间距、翅片高度、翅片长度对其传热和流动阻力的影响。结果表明,翅片间距对传热和流动阻力影响较小,而翅片长度和高度对其传热和流动阻力有重要影响。同时对11种翅片的220个试验数据点进行了j因子和f因子的试验关联式拟合,拟合关联式的误差范围为±10%。     

Human serum albumin interaction with paraquat studied using spectroscopic methods

The interaction between herbicide paraquat and human serum albumin (HSA) was investigated by fluorescence and UV/Vis absorption spectroscopy. Paraquat can strongly quench the intrinsic fluorescence of HSA by static quenching and nonradiative energy transferring; The hydrophobic and electrostatic interactions play a major role in stabilizing the complex. The binding site number n and apparent binding constant K_A, corresponding thermodynamic parameters ΔG, ΔH, ΔS at different temperatures, were calculated. The distance r between donor (HSA) and acceptor (paraquat) was obtained according to fluorescence resonance energy transfer. The effect of paraquat on the conformation of HSA was analyzed using synchronous fluorescence spectroscopy.     

涉农高校技术转移中心管理模式研究

针对农业技术的特点,农业科技成果转化有其自身的规律和特征,涉农高校技术转移管 理部门要建立推转一体化的管理模式。以安徽农业大学和江南大学的模式,有效的将横向合同 管理,公益推广体系、知识产权建设及平台搭建有机结合起来。     

Natural hybridization between wheat (Triticum aestivum L.) and its wild relatives Aegilops geniculata Roth and Aegilops triuncialis L.

BACKGROUND

Cultivated bread wheat (Triticum aestivum L.) spontaneously hybridizes with wild/weedy related Aegilops populations, but little is known about the actual rates at which this hybridization occurs under field conditions. It is very important to provide reliable empirical data on this phenomenon in order to assess the potential crop–wild introgression, especially in the context of conducting risk assessments for the commercialization of genetically modified (GM) wheat, as gene flow from wheat to Aegilops species could transfer into the wild species genes coding for traits such as resistance to herbicides, insects, diseases or environmental stresses.

RESULTS

The spontaneous hybridization rates between wheat and A. geniculata and A. triuncialis, which are very abundant in the Mediterranean area, have been estimated for the first time in the northern part of the Meseta Central, the great central plateau which includes the largest area of wheat cultivation in Spain. Hybridization rates averaged 0.12% and 0.008% for A. geniculata and A. triuncialis, respectively. Hybrids were found in 26% of A. geniculata and 5% of A. triuncialis populations, at rates that can be ≤3.6% for A. geniculata and 0.24% for A. triuncialis.

CONCLUSION

The detection of Aegilops spp.–wheat hybrids in Aegilops populations indicates that gene flow can occur, although wheat is considered a crop with a low-to-medium risk for transgene escape. These data on field hybridization rates are essential for GM wheat risk assessment purposes. © 2023 Society of Chemical Industry.     

基于深度学习的马铃薯叶片病害检测方法#br# #br#

植物病害对食品安全具有灾难性的影响,它可以直接导致农作物的质量和产量显著下降,因此对植物病害的早期鉴定非常重要。传统的农作物病害诊断需要非常高的专业知识,不仅费时费力,还效率低下。针对这些问题,利用深度学习的方法,以马铃薯叶片为研究样本,基于TensorFlow开发Faster R-CNN网络模型。采用本地增强的方式对带有早疫病、晚疫病和健康的马铃薯叶片进行图像扩充,应用COCO初始权重进行迁移学习,探究了数据类别对模型检测结果的影响。结果表明,随着训练数据类别的增多模型性能会有略微的降低。同时还训练YOLOv3,YOLOv4网络与该模型进行对比,测试结果表明,所提出的Fater R-CNN模型优于其他网络模型。经检测该模型最佳精度达到99.5%,该研究为马铃薯病害检测提供了技术支持。     

外源共生基因对紫云英根瘤菌共生效率的影响

 将豌豆根瘤菌共生质粒pJB5JI、含紫云英根瘤菌共生基因的重组质粒pRaZ15及含苜蓿根瘤菌共生基因的重组质粒pRmSL26导入紫云英根瘤菌野生型菌株7653R，然后对3种转移接合子的共生固氮效率进行了比较全面的测定。结果表明：转移接合子7653R（pJB5JI）的共生固氮能力较出发菌株7653R大幅度提高，而且表现出较高的竞争结瘤能力，转移接合子7653R（pRmSL26）在固氮酶活性、植物干重及结瘤数方面亦显著高于对照菌株7653R；转移接合子7653R（pRaZ15）虽然在固氮酶活性及植物干重方面没有发现显著性差异，但结瘤数显著减少。     

稻田水分监测无线传感器网络优化设计与试验

传感器网络技术为大范围稻田水分信息采集提供了一种新技术手段。利用测量稻田水分含量和水层深度测量的无线传感器WFDMS,探讨了构建稻田水分传感器网络PMSN的关键技术：设计了大面积、大范围应用体系结构模型;提出了一种满足稻田水分采样频率和数据业务需求的低功耗传输控制协议LPTP-PMSN;开发了水分信息监测信息管理系统,实现了完整运行的稻田水分传感器网络整套系统。试验表明,PMSN网络在稻田中的可靠通信距离达60 m,在 3.6 V/2 100 mAh电池供电下,4 h周期采样试验中,在传输协议LPTP-PMSN控制下,传感器、簇首、基站、短信网关、计算机间能够协同工作,整个稻田水分传感器网络可以较可靠运行,节点生命期超过190 d。该研究可为农用信息监控无线传输网络的其他应用提供参考。     

转人MCP和CD59双基因小鼠的制备

采用显微混合注射的方法制备转人MCP(膜辅因子蛋白)和CD59(膜反应性溶解抑制物)双基因小鼠,共注射478枚受精卵,移植于21只受体,其中14只受孕,8只受孕小鼠中途流产,从6只受孕小鼠获得18只仔鼠,经检测,其中9只仔鼠单基因阳性(50％),6只仔鼠双基因阳性(33．3％)。结果表明：通过显微混合注射的方法可以获得转人MCP和CD59双基因小鼠。