手动仿形雕刻机的设计

木雕制品是对木质材料的艺术处理。这种处理主要通过减除材料将形体挖掘显现出来。随着经济水平的提高,木雕制品制造已成为木工产品加工的重要组成部分。本文介绍一种新型仿形雕刻机的结构和工作原理,该装备动作单元具有空间5自由度,具有对复杂形面复制加工的能力,利用该装备可以实现对木雕制品的仿形加工。     

中耕苗间除草单体机构的研究与设计

中耕苗间除草单体机构是保证除草效果和控制伤苗率的关键工作部件。根据现在中耕苗间除草单体机构在实际作业中普遍存在的问题,研究设计了仿形功能好、除草效果佳、伤苗率低的中耕苗间除草单体机构。该单体机构结构简单,操作调整     

小黑杨APETALA1基因的克隆与花芽发育中的表达模式

APETALA1(AP1)基因既是花分生组织特征基因又是花器官形成发育基因,在花发育过程中起着关键作用。根据Genbank已知的AP1同源基因序列设计合成一对简并引物,以小黑杨(Popu-lus simonii×P.nigra)cDNA为模板,采用PCR方法分离克隆得到一个AP1同源基因全长,推测是小黑杨AP1基因,命名为XxAP1(GenBank accessionNo.XM₀02316040.1)。XxAP1编码249个氨基酸,开放阅读框长度747bp,蛋白质分子量28.67kD,等电点9.45。同源性分析表明,它们的核苷酸序列与其他木本植物的AP1同源基因的一致性达70%以上,推测它们具有相似功能。试验分析表明,XxAP1第1至第60个氨基酸为MADS盒结构域,说明XxAP1蛋白以序列特异方式与DNA结合,具有转录调节因子功能,第75至174个为K盒结构域,它负责蛋白质与蛋白质间的相互作用,其大多数氨基酸具有亲水性,使XxAP1蛋白具有较好的水溶性,促进蛋白的流动性有利于基因的转录。采用半定量RT-PCR技术检测XxAP1在雄花芽发育过程中的表达模式,结果显...     

Influence of environmental pH modulation on efficiency of apoplastic PR proteins during Fusarium culmorum– wheat seedling interaction

Variation of apoplastic pH by Fusarium culmorum and its influence on the production, activity and isoenzymes patterns of the pathogenesis‐related (PR) proteins β1,3‐glucanase, chitinase and peroxidase enzymes were detected in apoplastic fluids (AFs) from infected wheat seedlings. The time course in the 24–48 h interval post infection was characterized by an increase in activity and isoenzymatic differential induction of the selected PR proteins and by a concomitant rise of apoplastic pH. Chitinase attained maximum activity at pH 8·0 in the case of inoculated seedlings. Optimal β1,3‐glucanase activity in the pH range 6·0–8·0, was observed at pH 7·0. Peroxidase was strongly affected by pH, with enzyme activity having a maximum rate at pH 6·0 and thereafter rapidly declining at higher pH. Maximum peroxidase activity paralleled the appearance of the complete isoenzymatic pattern. In order to investigate the biological role of PR proteins in AFs, the in vitro antifungal activity was evaluated. In the interval 0–6 h, pH of macroconidia suspensions rose up to 7·2. AFs revealed inhibitory activity against germinating macroconidia of F. culmorum by decreasing the germination efficiency of macroconidia apical compartments, while this effect was compensated by an increased germination capacity of middle compartments. Present results suggest that during infection of wheat seedlings by F. culmorum the pH modulation favours host colonization by enhancing the activity of pectin lyase, and simultaneously inhibits the capacity of the host to oppose the pathogen by interfering with peroxidases which represent an important component of the defence arsenal.     

改进原位循环灌流法分离小鼠肝细胞研究

【目的】建立小鼠肝细胞分离原位循环灌流方法,为肝脏细胞蛋白质组研究提供技术技持。【方法】参考Seglen胶原酶两步原位灌流法,对其进行改进,建立原位循环灌流分离小鼠肝细胞方法,对小鼠肝脏进行原位循环灌流,离体消化肝脏组织,差速离心获得纯化小鼠肝细胞;台盼蓝拒染试验检测肝细胞活性,常规血球计数法计算肝细胞得率;利用显微形态观察、HE、PAS及免疫细胞化学等检测方法鉴定所获得的肝细胞纯度;用含体积分数20%FBS的RPMI-1640细胞营养液对原代小鼠肝细胞进行培养。【结果】建立了原位循环灌流分离小鼠肝细胞的方法,采用该方法可从每只小鼠肝脏中成功分选到细胞活性大于90%、纯度在95%以上的(4.2×107)～(6.5×107)个肝细胞。原代分离的小鼠肝细胞培养4h后,大多数细胞可贴壁,12h后贴壁完全,细胞呈伸张状态,该原代肝细胞可持续培养7d以上,且细胞形态状况良好。【结论】成功建立了小鼠肝脏原位循环灌流试验体系,获得了纯度和活性均较高的小鼠肝细胞,分选所得的小鼠肝细胞完全满足构建肝细胞蛋白质组表达谱试验的需要。     

农林仿形对靶喷雾及其控制技术研究进展

仿形对靶喷雾是实现农林精确施药的一种重要技术方式,近年来在理论发展和技术应用中取得重要进展。文中从仿形喷雾目标探测技术、常用仿形机构、仿形对靶控制及算法、仿形变量喷雾测试技术和典型农林仿形喷雾机方面评述现有仿形对靶喷雾技术,归纳包括红外线、超声波、图像和LIDAR等仿形喷雾目标探测方法与技术;分析常用仿形机构的仿形原理和各自设计的优缺点,强调轻量化是仿形机构设计的趋势;综述仿形对靶喷雾控制系统硬件和软件方面的发展,强调智能算法的应用能有效提高仿形喷雾控制系统的鲁棒性;分析评述仿形变量喷雾测试装置、喷雾系统数学模型和PWM变量喷雾技术的进展;介绍几种典型的农林仿形喷雾机,并提出农林仿形对靶喷雾的研究建议。     

高架栽培配套基质自动移动摊铺机设计与试验

针对现有高架栽培中的基质摊铺作业仅靠人工完成、劳动量极大等现状,设计了集基质运送、箱内出料、双侧分料落料和均匀摊填为一体的高架栽培配套基质自动移动摊铺机。根据栽培高架设施结构参数和基质流动特性测定结果,提出了基于少量人工操控介入的自动作业式基质架间双侧浮动移动摊铺方案,并设计了箱内折弯出料机构、双侧落料与架上摊平机构等关键部件,解决了箱内基质向上均匀出料及出料-排料协调难题,并实现了对高架竖直方向较大尺寸误差的补偿。完成了参数定型和样机开发,并进行了性能试验验证。试验结果表明,该机实现了330 m2/h的双侧4槽基质精量摊铺作业,能满足100 mm高度误差的仿形作业,4个槽内基质深度相对误差仅分别为7.72%、6.75%、9.33%和9.66%,各槽内基质深度平均误差仅2.01 mm,达到较好的4槽基质平均和均匀摊铺效果。该机为实现高架栽培的机械化配套作业提供了装备支持。     

南疆不同品种绵羊MSTN基因克隆及其组织表达谱分析

本研究旨在对山区型和田羊、平原型和田羊、卡拉库尔羊的MSTN基因进行组织表达谱分析。参考GenBank上（登录号：NM_001009428.1）绵羊MSTN基因序列设计引物,采用RT-PCR技术克隆绵羊MSTN基因序列,进行组织表达谱分析。结果表明：MSTN基因在各品种绵羊不同组织中表达的差异较大,MSTN在各品种绵羊的肌肉、肾脏和脾脏中都有表达,其中肌肉中表达量最高,其次是肾脏和脾脏;MSTN在山区型、平原型和田羊的心脏中表达丰度较低,而在卡拉库尔羊心脏中则几乎无表达;MSTN在山区型、平原型和田羊的肝脏中几乎无表达,而在卡拉库尔羊肝脏中则有一定量表达;MSTN在山区型和田羊、平原型和田羊与卡拉库尔羊的肺脏中则都无表达。     

Study of dynamic accumulation of secondary metabolites in three subspecies of Hypericum perforatum

St. John's Wort extracts are used for the treatment of mild to moderately severe depression, and their composition and standardization have been thoroughly investigated. Standardization of St. John's Wort extracts has to cope with several factors that affect the phytochemical profile of the plant, with geographic location, seasonal variations and subspecies all being important. To address this issue, three different subspecies of Hypericum perforatum L. were profiled in relation to different maturation phases, evaluating the variations in the context of the major secondary metabolites from this plant. HPLC analysis indicated that H. perforatum subsp. perforatum is richer in secondary metabolites than the other subspecies, and that the three subspecies show a different profile during the developmental stages. Hypericins, hyperforins and flavonoids peak at quite different stages, and the standardization of Hyperici extracts based only on the contents of hypericin is not adequate to guarantee batch reproducibility of the extracts.