应对松材线虫传入风险的防控策略

从1982年松材线虫传入我国以来,截至2022年底,在19个省（区、市）的701个县级行政区发现疫情,疫情发生面积151.15万hm2,病死、枯死与濒死松树数量1 040.48万株,造成直接经济损失数千亿元,生态服务价值损失不计其数,松材线虫已成为我国林业头号检疫性有害生物。本文以松材线虫为研究对象,介绍了松材线虫形态特征、生活史、传播途径,概述了虫害发生规律及林木受害症状,并结合本地实际针对松材线虫防控策略,旨在为科学防控提供参考依据。     

木质包装热处理国际标准对松材线虫有效性的试验研究

使用温度为65～85℃、相对湿度50%～90%的热空气,对不同规格和含水率的携带松材线虫(Bursaphelenchus xylophilus)的马尾松(Pinus massoniana)木板进行热处理验证试验,结果显示,当木材中心温度达到56℃并持续30min以上,10cm×10cm×10cm木块、5cm厚度木板以及高含水率10cm厚度木板中线虫死亡几率值达到9的要求,验证了国际植物检疫措施标准第15号所推荐的热处理技术指标对杀灭松材线虫的有效性.试验中也发现10cm厚度含水率低于30%木板的线虫死亡率达不到几率值9的要求,其原因可能是中心温度或持续时间没有达到该标准要求.     

中国松材线虫病的发生现状及治理对策

松材线虫Bursaphelenchus xylophilus (Sterner et Buhrer)Nickle是中国重要的外来入侵种，由它引起的松材线虫病对中国森林构成严重威胁，它对林业将产生重要的影响，包括经济、环境/生态和社会的影响。笔者对中国松材线虫病的发生和发展现状进行了概述，并结合中国在松材线虫病控制方面的实践，提出考虑从五个方面即法律和法规方面，国家体制和机制方面，科学研究与科技支撑方面，技术推广应用方面和科学普及与公众教育方面来考虑中国松材线虫病管理策略问题。     

松材线虫Bx-sHSP16A基因克隆及蛋白质结构研究

分子伴侣小热激蛋白(sHSPs)是线虫度过高温环境的关键因子。为开发直接针对松材线虫的防治技术提供理论依据,对松材线虫小热激蛋白Bx-sHSP16A基因进行了研究。采用SL法进行基因全长克隆,STRING 9.0进行蛋白质互作网络分析,NAMD 2.9进行分子动力学模拟。本研究克隆到松材线虫小热激蛋白基因Bx-sHSP16A。Bx-sHSP16A具α-crystallin保守结构域“F-polar-R-polar-aromatic-x-L-P”序列和“I/L-x-I”序列,初步判断具备分子伴侣功能。Bx-sHSP16A与多个蛋白发生互作,深入研究这些蛋白有助于了解Bx-sHSP16A在应激反应路径中的作用。Bx-sHSP16A二聚体中A亚基的“I/L-x-I”序列可以嵌入B亚基的去水合位点,契合后氢键稳定,说明Bx-sHSP16A可以形成多聚体。在应激反应过程中,去水合位点与多聚体聚合相关,Bx-sHSP16A以多聚体形式发挥分子伴侣功能。     

植物源引诱剂防治松材线虫效果好

<正>由山东省泰山林业科学研究院研发的松材线虫媒介昆虫植物源引诱剂防治松材线虫不仅效果好、成本低,而且环保、易推广。该引诱剂是该院承担完成的"松材线虫媒介昆虫植物源引诱剂及应用技术研究"课题的成果,近日通过了专家鉴定。     

浅析松材线虫的发生及防治

我国的森林资源丰富,尤其是针叶林的发展更为迅速,但森林病虫害的发生会直接影响到树木的正常生长和发育,尤其是松材线虫病害更能给松树带来毁灭性的灾害。从松材线虫病的发病症状入手,对其发病规律及防治措施进行了研究和探讨。     

4项线虫检疫鉴定方法国标6月起实施

<正>国家标准化管理委员会近日发布了以下4项线虫检疫鉴定方法推荐性国家标准,均将自2010年6月1日起开始实施:1.穿刺根腐线虫检疫鉴定方法(标准号:GB/T 24828-2009);2.毛刺线虫属(传毒种类)检疫鉴定方法(标准号:GB/T 24829-2009);     

不同灌水下限再生水灌溉对土壤-小白菜的影响研究

再生水灌溉的安全开展取决于合适的灌溉水质和灌溉制度,为了探明生活污水用于短生育期作物灌溉的可行性并寻求适宜的灌溉制度,以小白菜作为研究对象,采用2种水质（清水、再生水）和4个灌水下限（60%、70%、80%和90%的田间持水率）的两因素盆栽试验,研究了不同灌水下限下再生水灌溉对作物产量和全氮、全磷、重金属（Cu、Cd和Pb）等品质指标以及对土壤盐分、肥力和重金属的影响。结果表明：再生水灌溉对小白菜产量的影响较小,对小白菜吸收氮、磷和重金属的能力影响不显著,而小白菜对不同重金属的吸收能力表现出显著的差异。与清水相比,再生水灌溉条件下土壤有机质、速效氮和速效磷均有增加,且与灌水下限有显著的正相关,同时也会导致土壤盐分的增加、而土壤重金属无明显差异。总而言之,再生水适用于小白菜的灌溉,但不能直接移用清水灌溉的灌溉制度。     

进境木片检疫处理与监管

随着福州新港进境木片数量的逐年增加,其携带的植物疫情也日益严峻.本文简述了福州新港进境木片的概况及检疫监管情况,并针对存在的问题提出了相关建议.     

松材线虫病的危害与防治方法

松材线虫病会造成松树的大范围死亡,对松树健康发展产生严重影响,现阶段已经属于世界范围内的病害。为保证我国林业的健康发展,应加大对松材线虫病防治的研究力度。基于此,对松材线虫病的危害与防治方法进行深入研究,介绍了松材线虫病的症状及危害,并提出几点有效的防治方法,希望对松材线虫病的防治工作提供借鉴。     

The method for removing the spurious modes of eigensystem realization algorithm

Due to the influence of spurious modes on the eigensystem realization algorithm results,singular value decomposition(SVD) and model energy level are introduced to remove the spurious modes of eigensystem realization algorithm,reduce part of the noise modes and improve the accuracy by reducing measurement noise by SVD. The energy matrix of each mode can be calculated by the selection matrices,the eigenvalues and eigenvectors of the state matrix and the input distribution matrix. The largest singular value of the energy matrix obtained by SVD is a measure for the energy contribution of each mode,which is named mode energy level. Spurious modes resulting from noise or model redundancy are indicated according their mode energy level. A numerical example and an experimental example are presented to demonstrate the efficacy of the method.     

胡萝卜叶片线粒体DNA提取方法研究

本实验以胡萝卜叶片为材料,通过高盐差速离心和蔗糖沉淀差速离心两种方法提取线粒体DNA。通过改变分离和沉淀线粒体离心力大小、使用DNaseⅠ处理得到了无核DNA污染的线粒体。用SDS和蛋白酶K 裂解线粒体,经酚/氯仿/异戊醇抽提除去蛋白,并用RNase A 消化从而得到单纯线粒体DNA。本实验还特别设计了叶绿体特异性引物检测线粒体DNA纯度。结果表明：利用优化后的蔗糖沉淀差速离心法提取胡萝卜线粒体DNA,不仅操作简单,而且所得线粒体DNA纯度高、产量高,每克叶片能够得到34.46 μg 线粒体DNA。     

汽车转弯自动照明控制系统数据采集滤波方法

为了减少汽车转弯自动照明控制系统数据滤波处理中的延时,在滑动中值滤波方法基础上,提出了一种带补偿的限幅滑动中值滤波算法,通过补偿的方式跟随信号的变化趋势。该算法通过2个步骤完成滤波,先对数据进行带补偿方式的限幅处理,再进行滑动中值滤波处理。该算法综合了滑动中值滤波法的实时性以及限幅滤波法对偶然性干扰滤除的有效性,实现更准确的滤波。仿真与实测结果表明,与滑动中值滤波方法相比较,改进后的算法滤波能够实时地滤除数据中的干扰,处理时间可减少62%,滤波效果较好,且速度信号的数据滞后时间较短,实时性较高,满足系统设计要求。     

基于模板的生菜参数化几何建模方法

为了对生菜进行快速三维重构,本文将逆向工程的思想引入到生菜几何建模中来,提出了一种基于参数模板的生菜几何建模方法。借助三维扫描设备构造具有多分辨率的生菜器官模板,分析生菜植株形态结构特征,提取特征参数,进而通过形态参数对模板进行控制,并最终组装成为参数化的生菜几何模型。实验结果表明,该方法可以快速、便捷地重构出具有较高真实感的生菜几何模型,对曲面难以构造的植物器官及植株几何建模具有一定的参考意义。     

结缕草种子的休眠机理及其打破休眠的方法

结缕草种子的深休眠特性，是其开发利用的最大障碍。本文通过查阅大量文献，对结缕草种子的休眠机理及打破休眠的方法进行综述，总结了导致结缕草种子休眠的主要原因，并提出了一条综合的解决办法。     

The Gram-Schmidt orthogonal data fitting method for the designing of the gradient magnetic field of the unilateral NMR

By considering the shortcomings of the traditional Halbach magnet structure which is closed and cannot be applied to the open NMR, an open and semi-circle Halbach magnet structure is proposed. Adjusting the semi-major axis of the elliptic curve which the center of magnets are placed on and calculating the flatness of the magnetic field on different heights, a magnet structure with best flatness is achieved by data fitting method. The optimizing result shows that the best magnet structure can generate a magnetic fields which flatly distributes in the horizontal direction of the 50 mm×50 mm area in the YOZ plane. The gradient is distributed in the vertical direction with gradient of 2 mT/mm. Magnetic field is uniformly distributed in the area of 4 mm×4 mm with uniformity of 1.3×10 -3 and magnetic field of 0.073 9 T. An actual magnet model is constructed based on the result of the optimal design; the measurement result is consistent with the design. The advantage of this magnet structure is that the gradient magnetic field is generated by the permanent magnet naturally, and the extra gradient coil isn’t needed, so the designing of the gradient coding system is simplified.     

The compensation method for the random time-delay of the feedbackchannel and the forward channel in the networked control system

An improved predictive control method is presented to compensate the random time delay in the networked control system. The feedback time delay is compensated by predictive controller based on softened increment input strategy. The forward time delay is unknown for controller, so an extra feedback loop is added to compensate the delay by estimating the error between the actual control signal effected on plant and the output of controller in historical moment. For the controlled system with unknown or slowly varying parameters, the networked feedback correction algorithm is discussed based on a modified recursive least-squares identi cation algorithm. The system stability is analyzed and the simulation results show that the time delay in the networked control system can be accurately compensated. The excellent network performance is ensured with this strategy.     

Quantitative assessment method for the quality of anchors

A method is developed to quantitatively assess the quality of anchors. An analytical model is combined with the wavelet analysis and artificial neural network is used to estimate the values of bolt side stiffness coefficients for the anchor system. The samples of bolt’s anchorage system are fed into the artificial neural network for training. It’s a useable intelligent mean to assess the quality of bolt’s anchor system. The dynamic parameters of integrity bolt with different physical and mechanical parameters of surrounding rocks are acquired. A relationship curve between bolt side stiffness and surrounding rock’s modulus of deformation is erected, and its quadratic fitting formula is acquired. The curve and the formula can be used as the assessment standards for the anchor quality. The anchor degree is used to judge the anchor quality. The quantitative assessment method is applied to the engineering field.     

Local adjustment method for field experiments. 1. The method and its examination by computer simulation

Summary The modification of the nearest neighbour method for using various size plots in field trials has been developed and the results of testing its validity by computer simulation are presented. It was found that the Field-S variant of this method using a square pilot area is the best for fields with a low and medium spatial heterogeneity. The Field-L variant using the least quantity of neighbours, offers advantages for fields with a medium and high spatial effect. The optimal values of the controlling coefficients of these variants were computed to allow for the calculation of the environmental indices over a wide interval of spatial heterogeneity with sufficient accuracy. For this reason, this local adjustment method is recommended as an obligatory statistical procedure for a prior data analysis of any field experiments that have fulfilled the necessary requirements. The original Field and CRBSD programs using the local adjustment method developed have been created for IBM-compatible personal computers.     

魔芋无土栽培灌水量与灌水方式的研究

用200、400、600、800、1000ml纯净水定期浇灌无土栽培的种芋大小基本相同的魔芋,结果表明：浇灌600ml纯净水的魔芋长势最强,产量最高。同时对魔芋无土栽培的灌水方式也进行了研究。