绿鳍马面鲀烂嘴症致病菌的分离鉴定及药敏试验

为确定绿鳍马面鲀烂嘴症的致病菌及筛选敏感药物,通过平皿划线法将患病组织内的细菌进行分离纯化,得到1株优势菌,命名为QZG3。该菌株在硫代硫酸盐柠檬酸盐胆盐蔗糖琼脂(TCBS)弧菌选择性培养基上为绿色、圆形、黏稠状菌落,经革兰氏染色判断为革兰氏阴性菌；对该菌株的16S rRNA基因进行测序、鉴定,并经系统进化树分析,发现该菌株与阿尔法克弧菌(Vibrio alfacsensis)聚为1支,因此判断该菌株为阿尔法克弧菌。人工回感试验表明,该菌株为绿鳍马面鲀烂嘴症的致病菌；药敏试验结果显示,该菌株仅对氟苯尼考、恩诺沙星两种抗生素高度敏感,对土霉素、青霉素、头孢氨苄、庆大霉素、卡那霉素、四环素以及红霉素均表现出耐药性。因此建议养殖生产上选用氟苯尼考和恩诺沙星进行药物防治。     

小麦温光敏雄性不育系BNS育性恢复性测定及杂种优势

以小麦温光敏雄性不育系BNS为母本，480个常规品种（系）为父本配制组合，研究BNS育性的恢复性。结果表明，BNS不育系具有可恢复性，但恢复源很窄。在480个组合中筛选出自交结实率达50%以上的组合22个，对这22个组合杂种F₁自交结实率和7个农艺性状的杂种优势进行分析，发现22个杂种F₁组合恢复幅度为53.47%~93.81%（国际法）、42.42%~76.43%（国内法），其中3个组合的育性得到较好恢复，分别是BNS/西农9062、BNS/N9209选、BNS/K460，其自交结实率（国际法）分别为93.81%、91.67%和91.38%，说明这3个材料携带有BNS的育性恢复基因。22个组合杂种F₁普遍存在一定的杂种优势，7个农艺性状大都表现出正向优势，组合BNS/西农9062、BNS/N9209选和BNS/K460杂种F₁，除千粒质量正向优势不明显外，其余性状都表现出一定的正向优势，这3个组合杂种优势表现强，具有应用于生产的潜力。     

旱稻干旱敏感突变体的筛选与鉴定

本研究将常规旱稻品种旱稻616(HD616)经60Coγ射线200 Gy辐射诱变处理,从其变异后代获得对干旱十分敏感的突变体M616。采用田间不同程度干旱胁迫试验和根系培养试验,考察了二者的与抗旱相关的地上地下部形态、水分生理指标和产量性状。结果表明,干旱胁迫下,粒小、根细、细根多、单株产量低是M616区别于亲本HD616的基本特征,而叶片损伤度、主茎基粗、叶宽、根长、根粗、根干重是M616地上地下部对干旱反映最敏感性状。相对于亲本HD616,突变体M616根系性状发生了一系列有害变异,表现为根明显变短、变细、细根增多,因而对干旱胁迫表现十分敏感,使地上部植株明显变矮,茎秆变细弱,叶片变细窄,保水性差,因严重失水而枯萎,生物量减低,结实率下降,最终导致谷物产量严重降低,这也表明根系的生长状况与地上部的生长发育密切相关,并最终影响生物产量和谷物重量。该材料的获得为栽培稻抗旱性及其分子机理研究提供了稻种资源抗旱鉴定敏感指示品种。     

考虑温度系数的盘式制动器热力耦合分析

以合作企业提供的某款盘式制动器为研究对象,将制动盘材料的温度系数考虑在内,并加入了连续制动工况,在有限元分析软件ABAQUS中进行热力耦合分析,得到制动盘的温度场及应力场结果。在合作企业的LINK3900制动惯量试验台上进行试验,对比结果后验证了该应用的准确性。     

某加热炉炉管的数值计算与寿命预测

以某加氢加热炉对流室炉管为研究对象,使用ANSYS Workbench软件的热流固耦合分析功能对管内渣油工质的流场、炉管的温度场以及应力场进行分析,观察流体的出口温度是否达到设计要求,找出炉管最大应力位置,之后将模拟应力结果与理论计算应力值进行比较。最后,根据拉森-米勒蠕变寿命评价方程对该加热炉管的寿命进行预测。结果表明,炉管弯头在渣油冲刷和高温蠕变的作用下应力值最大,最容易导致管子失效。渣油出口温度符合设计要求,炉管在考虑蠕变的作用下可以服役5.0×10⁶ h。     

Greening urban road verges highlights diverse views of multiple stakeholders on ecosystem service provision,challenges and preferred form

Globally, there is growing recognition of the potential of road verges to contribute to urban greening and ecosystem service provision, beyond their original functions of utility provision and public access. Numerous, diverse stakeholders are involved in their management, yet their shared and diverging perspectives on verge greening are poorly understood. This research examined the perspectives on road verge greening by 30 respondents from eight stakeholder groups from the Perth Metropolitan Area, Australia. Stakeholders spanned local and state governments, developers, peak bodies, utility providers, environmental consultants, verge treatment providers and urban greening advocates. Semi-directed interviews and Likert scales were used to assess respondents' perspectives and perceived importance of urban verge functions and ecosystem services, risks and challenges associated with verge greening, and preferred verge vegetation composition. The most important ecosystem services for all stakeholders were temperature regulation (through the provision of street trees), those associated with water management and aesthetically interesting streetscapes. Perceived challenges included limited knowledge for the management of native species verges and streetscapes, organisational costs for verge managers and utility providers, and the need to engage with multiple local government authorities with widely varying management and financial valuation of verge vegetation. Stakeholders’ preferred verge reflected diverse uses, local characteristics, and was climate and water resilient (particularly ‘waterwise’). A majority of stakeholder groups felt greater attention to the ‘understorey’ of the ‘urban forest’ was warranted. An emerging perspective across four stakeholder groups identified the potential for verges to grow a local ‘sense of place’, through plantings emphasising local native species and highlighting local Whadjuk Noongar seasons. These findings support policies and programmes associated with urban greening, and assist in navigating the contestation often associated with new or transformative uses of land at the public-private interface.     

光敏感核不育水稻农垦58S雄性不育性的遗传学研究

以套袋自交结实率为主要指标,观察分析了农垦58S与不同生态型的9个粳稻品种杂交的F_1,F_2,BCF_1代的抽穗期与育性。结果表明,农垦58S光敏雄性不育性由2对隐性主基因控制:这2对基因在不同类型的梗稻品种中其互作方式表现差异,即在早、中稻品种中表现积加作用,在晚稻品种中为独立分高,在农垦58品种本身的背景中表现隐性上位作用,这种相互作用方式差异与分离世代植株的出穗期限有一定关系;农垦58S光敏不育性在不同的遗传背景中都能表达,但受到光、温2组微效基因修饰。“重复基因位点平行突变假说”,可以较完满地解释农垦58S的遗传机制。本文还就光敏感雄性不育系的遗传分类和选育温光弱感型光敏雄性不育两用系进行了讨论。