海南岛18种野生蔬菜的成分测定及质量安全和价值分析

采集海南省琼中、五指山、保亭、乐东等市县的18种野生蔬菜样品,对其产地环境、制样方法及品种重金属含量差别等进行分析,用国家标准方法测试了样品中重金属和营养成分的含量,并依照有关标准,对试验样本的质量安全和营养价值进行分析。结果表明,所采野生蔬菜样品的产地环境相关技术指标达到无公害蔬菜产地环境标准要求。除枸杞菜(Lycium chinense)铬含量超标外,其余样品重金属含量均低于国家限量标准,有67%的样品重金属指标低于农产品安全质量无公害蔬菜安全要求。所测试的18个野生蔬菜样品营养成分较为丰富,个别野生蔬菜的营养成分指标高于普通蔬菜。     

西昌地区石榴叶霉病的病原鉴定

本文报道了四川西昌市发生的石榴叶霉病的症状及病原鉴定结果。叶霉病发生在石榴生长后期,一般危害石榴老叶,表现为黑褐色病斑,造成石榴提早落叶。病原分离采用组织分离法,通过分生孢子悬浮液接种,用柯赫氏法则对其致病性进行验证。显微镜下观察菌丝形态及产孢结构,测量孢子大小,根据形态特征鉴定为极细枝孢（Cladosporium tenuissimum Cooke）。     

单片机抗干扰技术研究

单片机以其超小型化、高可靠性和高性价比的特点,广泛地应用于现代社会的各个领域。实验室设计的符合要求的系统置于现场后,常常会受到现场各种各样复杂环境的干扰,对单片机系统的可靠性提出了更高的要求。对单片机的抗干扰技术进行了研究。     

基于USB2.0的多路高精度数据采集系统设计

设计了一种基于EZ-USB FX2和ADS1271的数据采集系统,对基于USB2.0的多路数据采集模块进行了深入的研究。微控制器采用的是STM32系列32位ARM7芯片STM32F103RB,USB接口部分采用的是Cypress公司EZ-USB FX2系列单片机CY7C68013,AD采用的是TI公司的24位ADC芯片ADS1271,应用软件采用图形化编程语言labview8.20。系统实现了最高采样率80ksps（单通道时）,18Bit分辨率的4通道数据实时采集,通过USB接口实现了数据传送和实时监控的功能。     

大黄鱼腐败菌腐败能力分析与特定腐败菌鉴别

探讨了分别接种腐败希瓦氏菌和假单胞菌的无菌大黄鱼鱼块在5℃贮藏中的生长速率和腐败代谢产物的生成速率,以产生异臭味时的腐败菌数和腐败代谢产物的产量因子作为腐败菌腐败能力的定量指标。接种鱼块腐败时(产生明显异臭味)腐败希瓦氏菌与假单胞菌的菌数即最小腐败菌数(N_s)的对数值分别为9.14lg cfu/g和9.25lgcfu/g。由Gompertz方程得到腐败希瓦氏菌和假单胞菌的生长动力学参数:最大比生长速率(μ_max)分别为0.0714和0.0700,最大菌数(N_max)的对数值分别为9.45lg cfu/g和9.37lg cfu/g。结果表明,两种腐败菌在无菌大黄鱼鱼块中的μ_max基本一致,且N_max都超过N_s,这两种腐败菌都能引起大黄鱼的腐败。接种鱼块中腐败希瓦氏菌的腐败代谢产物(TVBN和TMA)的产量因子Y_TVBN/cfu和Y_TMA/cfu分别为1.38×10^-10mg-N TVBN/cfu和1.31×10^-10mg-N TMA/cfu,假单胞菌的腐败代谢产物(TVBN)的产量因子Y_TVBN/cfu为1.18×10^-10mg-N TVBN/cfu,比较产量因子可得,两菌的腐败能力相当。因为大黄鱼低温贮藏中的优势腐败菌是腐败希瓦氏菌,其次是假单胞菌,根据特定腐败菌的概念,大黄鱼低温贮藏过程中的特定腐败菌是腐败希瓦氏菌,其次是假单胞菌。     

石河子地区鲜食葡萄烂果病病原鉴定

[目的]明确石河子地区鲜食葡萄果实烂果病的主要病原.[方法]通过田间调查及对具有典型烂果症状的病样进行分离纯化和培养,对病原进行常规形态学和分子生物学鉴定.[结果]通过鉴定查明引起石河子地区葡萄烂果的病原菌主要有三种:灰葡萄孢菌(Botrytis cinerea .Pers),黑曲霉(Aspergillus niger)和黑根霉(Rhizopus nigricans).[结论]石河子葡萄烂果的主要病原有3种,其诱因主要与8月上旬久旱遇雨和膨大剂用量较多有关.     

不同燕麦品种的镉毒害效应及耐镉性差异

为探讨不同燕麦品种耐Cd能力的差异,采用营养液培养,对10个燕麦品种的Cd毒害效应及耐Cd性差异进行了研究。结果表明,供试燕麦品种添加5 μmol·L^-1 Cd处理20 d后,幼苗生物产量均低于对照,不同品种间降幅差异显著,其中“品5号”生物产量下降幅度最小,耐Cd指数最高,而“坝莜6号”生物产量降幅最大,耐Cd指数最低。Cd胁迫条件下,供试燕麦品种叶绿素含量、根系活力均有不同程度降低;POD活性、Pro含量不同程度增加,并且这些指标的增减幅度品种之间差异显著。Cd胁迫下,各品种叶片POD活性增加率、Pro增加率与耐Cd性呈显著正相关,根系活力降低率与耐Cd性呈显著负相关,这三者可作为燕麦耐Cd性的生化指标。     

Identification of two haplotypes of cytochrome oxidase subunit II (COII) gene of the Formosan subterranean termite,Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), in southern Mississippi

BACKGROUND: Coptotermes formosanus Shiraki was accidentally introduced into the United States from Asia. The introduction of the pest has brought significant economic consequences. During the past decade, Mississippi has become a significantly infested state, partly due to the proximity to coastal port cities such as New Orleans. This study was initiated to investigate the origin and infestation route of C. formosanus in southern Mississippi. RESULTS: Twenty‐eight colonies (21 colonies from Mississippi, six from Louisiana, one from China) were collected. Sequencing and analysis of 112 sequences revealed 15 haplotypes of cytochrome oxidase subunit II (COII) gene in the world. Two haplotypes of COII were identified in Mississippi. In addition, specific primers were designed and tested differentially to amplify characteristic fragments for verifying and surveying different genotypes of C. formosanus in the future. CONCLUSION: Of the two haplotypes identified in Mississippi, the GA group was identical to those reported previously in Georgia, Louisiana, Alabama and other infested states. The second haplotype, the AT group, was identified for the first time in southeastern United States. Sequence identity of the AT‐group C. formosanus with those reported mainly in southeastern Asian countries provided evidence of at least two introductions of C. formosanus into the United States. Copyright © 2010 Society of Chemical Industry     

不同土壤含水量对根茎冰草幼苗生长发育的影响

本研究采用盆栽试验方法,研究了不同土壤含水量对根茎冰草种子萌发出苗和幼苗生长发育的影响。土壤含水量共设5个处理,分别为26%2、1%、17%、12%、7%。试验时间共60d。结果表明:土壤含水量17%为种子萌发出苗的最适含水量,出苗率可达96%,土壤含水量7%时,根茎冰草种子不能萌发出苗。土壤含水量对根茎冰草幼苗生长发育也有明显影响,土壤含水量21%时,最先达到分蘖期;土壤含水量12%时,基生叶片最长,可达31.0cm,生长速度最快,为0.52cm/d,地上生物量最高,达0.18g。随着土壤含水量的降低,根长度增加,根尖数增多,沙套粗度降低,其中土壤含水量12%时,各项指标的测定值达到最大,根系总体积为0.06cm3,表面积为4.98cm2,地下生物量为0.35g,占总体生物量的66%,根尖数达到1206个,是土壤饱和含水量26%的3倍。     

Environmental quality assessment model of urban soils based on improved BP algorithm

The input and output samples for the network are determined through random function and pre processed with scaling in interval (0.2, 0.8). The neutral units in the hidden layer is decided by the trial and error method and an a model of artificial neural network(ANN) with a structure of 7∶8∶1 are established for the assessment of environment quality of urban soils. BPANN model is simulated through programming in Matlab 6.0. It is found that the BPANN model is reliable for assessing accurately and objectively the environment quality of the urban soils. With Changchun as a case study, it is concluded that the environment quality of urban topsoil is generally good and about 81% of the area reached the first level of national environmental quality standard for soils. It should be mentioned that the heavy metals pollution in local area is serious and should not be neglected, and some effective control measures of reducing heavy metal pollutants discharges should be put forward to ensure the sustainable use of urban soil resources.