高pH胁迫对“黄海1号”中国对虾免疫相关酶的影响

对高pH养殖水体中"黄海1号"中国对虾(Fenneropenaeus chinensis)群体和野生群体的存活率,血清中的溶菌酶(LSZ)、酚氧化酶(PO)、超氧化物歧化酶(SOD)、碱性磷酸酶(AKP)及酸性磷酸酶(ACP)活力变化进行了测定.经高pH胁迫72 h后检测发现,在pH8.2～8.6,"黄海1号"和野生群体存活率均高于90%,两群体机体表现出一定的应激能力;在pH8.8～9.0时,"黄海1号"及野生群体死亡率都急剧增加,几种免疫相关酶类较在pH 8.6时都有较高幅度的变化,"黄海1号"的死亡率及酶突变程度均小于野生群体;在pH 9.2时,2群体的死亡率及体内的几种免疫相关酶活性变化幅度继续增大,但2群体间差异减弱;在pH 9.4时,两群体中国对虾全部死亡.比较发现,当海水pH在一定的范围内升高时,"黄海1号"免疫能力要高于野生群体.     

月季干燥花护形护色的研究

以广州当地红色切花月季为试材,分别采用细沙、硅胶、硅胶+细沙这3种包埋剂,结合高火、中高火、中火这3种微波火力和5个不同干燥时间的试验处理组合,通过分析月季花朵在干燥过程中花色、花瓣质感、花瓣牢固性等指标的变化规律,研究了鲜花干制过程中的保色保形问题.结果表明:包埋剂结合微波处理能有效的降低干燥花花瓣的皱缩程度,提高干花的综合外观品质;其中硅胶+细沙包埋结合微波中高火4min处理的保色保形效果最佳.     

水泵机组状态监测与故障诊断系统研究

从20世纪60年代到21世纪,我国的泵站工程为输水、供水以及防洪减灾提供了有力保障。针对水泵机组的状态监测与故障诊断进行研究,建立水泵机组状态监测与诊断的软件及各分析模块与数据库,进行机组性能的预测研究,为水泵机组的状态维修提供支持。     

数字式蜂蜜含水率检测仪设计

对蜂蜜含水率的检测应提供便携、快速、精确、适于在线检测且能克服温度对测量结果影响的仪器。在实验基础上,基于蜂蜜电导率的检测原理,设计了数字式蜂蜜含水率检测仪。以洋槐蜂蜜为对象,通过实验建立了蜂蜜含水率（17%～43%）、温度（5～40℃）和电导率之间的数学模型。以8位单片机为控制器,DJS—1型电极为电导率传感器,DS18B20为温度传感器,设计了检测仪的硬件系统,利用单片机C语言编写程序。检测实验结果表明：每个样品的测量时间在3s内,测量精度为±0.5%。     

Effect of ensiling whole crop oat with lucerne in different ratios on fermentation quality,aerobic stability and in vitro digestibility on the Tibetan plateau

The objective of this study was to determine the effect of ensiling different ratios of whole crop oat to lucerne on fermentation quality, aerobic stability and in vitro digestibility of silage on the Tibetan plateau. Four experimental treatments were produced varying in the ratio of forages on a fresh matter (FM) basis: 1) 100% oat (control, dry matter (DM) content: 317 g/kg), 2) 90% oat + 10% lucerne (OL10, DM content: 316 g/kg), 3) 80% oat+ 20% lucerne (OL20, DM content: 317 g/kg) and 4) 70% oat+ 30% lucerne (OL30, DM content: 318 g/kg). All treatments were packed into laboratory‐scale silos and ensiled for 60 days and then subjected to an aerobic stability test for 15 days. Further, the four experimental treatments were incubated in vitro with buffered rumen fluid to study the nutrient digestibility. All silages were well preserved with low pH and NH₃‐N contents, and high lactic acid contents and V‐scores (evaluation of silage quality). Increasing the lucerne proportion increased (p < 0.05) crude protein (CP) content of silage, whereas neutral (NDF) and acid (ADF) detergent fibre contents were not affected. Under aerobic conditions, the control silage showed higher (p < 0.05) yeast counts (>10⁵ cfu/g FM) followed by OL10 silage, and OL10 silage improved aerobic stability for 74 h. OL20 and OL30 silages showed fewer (p < 0.05) yeasts (<10⁵ cfu/g FM) and markedly (p < 0.05) improved the aerobic stability (>360 h). After 48‐h incubation, OL30 silage increased (p < 0.05) in vitro dry matter digestibility (IVDMD) and neutral detergent fibre digestibility (IVNDFD) compared with the control silage. These results suggest that replacing oat with lucerne had no unfavourable effects on fermentation quality of silage, but improved CP content, aerobic stability IVDMD and IVNDFD. OL30 silage was the best among the three mixed silages.     

基于单片机的智能烤烟控制系统

为了提高烟叶的烘烤质量,实现烤房的智能化控制,设计了新型烟叶烘烤智能控制系统。系统采用AT89C51为核心,DS18B20和SHT11分别作为温、湿度检测参数的采集单元,由键盘与LCD显示器构成人机对话单元。结果表明,该智能控制系统能对烟叶烘烤过程中的分段、时间、温度、湿度等进行监测和显示,并能够依据设定的温、湿度曲线进行指导和报警;能使烤房内的温、湿度精确地按照烟叶最佳生化控制曲线而变化,从而提高了烤房内温、湿度的控制精度和烤烟质量。     

2010年通州区小麦条纹叶枯病原因及防治对策

介绍了通州区2010年小麦条纹叶枯病发生特点,分析其发生加重的原因,并提出合理的防治对策。     

一株梭鲈源无乳链球菌的分离、鉴定及分子分型分析

为查明梭鲈(Lucioperca lucioperca)凸眼病病原,从患病梭鲈病灶眼、肝、脾和肾分离纯化病原菌,进行了生理生化特性测定及16S rRNA基因序列分析,并开展人工感染试验,测定其血清型及MLST分型,并利用纸片扩散法进行药敏特性分析。结果显示:分离菌株(命名为SL1701株)为本次引发梭鲈病害的致病菌,Ib-ST261型。回归感染实验证实,分离得到的细菌SL1701对健康梭鲈具有非常强的致病性,4.5×105CFU/m L时可使80%受感染梭鲈死亡,并可复制出自然发病鱼的症状。菌株SL1701革兰氏染色为阳性链球菌,γ溶血,生理生化特性与普通无乳链球菌基本一致,16S rRNA基因序列与无乳链球菌(Streptococcus agalactiae)同源性最高,综合判定分离菌株为无乳链球菌(Streptococcus agalactiae)。药敏试验结果显示:分离菌株SL1701对氟苯尼考、氟罗沙星等17种抗生素高度敏感,对青霉素、磷霉素等8种抗生素耐药。结果表明,分离菌株SL1701为Ib-ST261型无乳链球菌,养殖时可选用氟苯尼考及氟罗沙星等药物进行防控。     

Dissecting Genetic Basis of Deep Rooting in Dongxiang Wild Rice

Deep rooting is an important trait in rice drought resistance. Genetic resources of deep-rooting varieties are valuable in breeding of water-saving and drought-resistant rice. In the present study, 234 BC₂F₇ backcross introgression lines were derived from a cross of Dongye 80 (an accession of Dongxiang wild rice as the donor parent) and R974 (an indica restorer line as the recurrent parent). A genetic linkage map containing 1 977 bin markers was constructed by ddRADSeq for QTL analysis. Thirty-one QTLs for four root traits (the number of deep roots, the number of shallow roots, the total number of deep roots and the ratio of deep roots) were assessed on six rice chromosomes in two environments (2020 Shanghai and 2021 Hainan). Two of the QTLs, qDR5.1 and qTR5.2, were located on chromosome 5 in a 70-kb interval. They were detected in both environments. qDR5.1 explained 13.35% of the phenotypic variance in 2020 Shanghai and 12.01% of the phenotypic variance in 2021 Hainan. qTR5.2 accounted for 10.88% and 10.93% of the phenotypic variance, respectively. One QTL (qRDR2.2) for the ratio of deep roots was detected on chromosome 2 in a 210-kb interval and accounted for 6.72% of the phenotypic variance in 2020. The positive effects of these three QTLs were all from Dongxiang wild rice. Furthermore, nine and four putative candidate genes were identified in qRDR2.2 and qDR5.1/qTR5.2, respectively. These findings added to our knowledge of the genetic control of root traits in rice. In addition, this study will facilitate the future isolation of candidate genes of the deep-rooting trait and the utilization of Dongxiang wild rice in the improvement of rice drought resistance.     

山羊痘病毒的分离鉴定及生物学特性的研究

本研究对2003年广西部分地区山羊群发生的疑似山羊痘进行了病毒分离鉴定及生物特性的研究。取疑似山羊痘病羊的皮肤丘疹、水泡或脓泡组织的病毒悬液，接种初生羔羊睾丸细胞观察到明显的细胞病变，免疫荧光试验结果显示，病毒能与山羊痘标准阳性血清反应，在感染的细胞浆内发出特异性的黄绿色荧光。病毒悬液接种乳鼠、小鼠、豚鼠、兔子都未发病，而接种3月龄山羊则出现典型的山羊痘症状和病理变化，接种9～10日龄鸡胚绒毛尿囊膜，未见出现痘斑，连传3代，均无异常变化。通过病理组织学观察可以看到在细胞浆内有大小不一圆形或椭圆形的包涵体，在电子显微镜下可以观察到150nm～300nm大小，卵圆形、砖形，有囊膜的病毒颗粒。利用一对山羊痘病毒P32基因引物进行了PCR扩增，将所得序列与GenBank收录的5株山羊痘病毒P32基因的核苷酸及氨基酸序列比较分析。结果与疫苗株的同源性分别为99．8％和99．4％。与国外其它毒株的同源性为99．6％和98、8％～99．4％。研究结果表明，所分离的病毒为山羊痘病毒，在生物学特性上与资料记载存在一定的差异，P32基因与疫苗毒和国外毒株之间同源性非常高。将该毒株命名为山羊痘病毒LiuJiang／2003株。