干旱区土地盐渍化时空动态变化及影响因子分析

土壤是人类社会及一切社会活动的基本条件,而土壤盐渍化是土壤退化和土壤荒漠化的重要类型之一,是当今干旱区发展中面临的重要问题之一,也是影响干旱半干旱区农业生产的第一障碍性问题。土壤盐渍化时空动态变化研究是发展土壤监测研究及估算方法的重要基础工作。因此盐渍化治理工作的好坏也成了人们关注的问题。文章以新疆塔里木盆地北缘渭干河-库车河三角洲绿洲为研究区,采用1989年9月25日及2001年8月1日的遥感影像,通过计算盐分指数,得到盐分指数图像,进一步将盐分指数图像参与其它波段进行分类,通过统计分析,研究了渭干河-库车河三角洲盐渍地动态变化状况和变化趋势,并对变化影响因素进行了分析。结果表明：非盐渍地有所减少,轻、微盐渍地有所扩大,年均扩大率3.37%,中度盐渍地和重度盐渍地都相应减少,而中度盐渍地减少较多,年均减少率分别为1.96%和1.09%;盐渍地时空变化是同时受自然和人文因素影响的复杂过程,其中人为因素的影响最大。虽然盐渍化治理工作取得了一定的成就,但干旱区盐渍化防治工作需要进一步努力和加强。     

Study on the distribution and expression of a DNA vaccine against lymphocystis disease virus in Japanese flounder (Paralichthys olivaceus)

The distribution and expression of lymphocystis disease virus (LCDV) vaccine, on the basis of DNA vaccine (pEGFP-N2-LCDV0.6 kb) construction, were analyzed in tissues of the Japanese flounder by PCR, RT-PCR and fluorescent microscopy. Results from PCR studies indicated that the vaccine-containing plasmids were distributed in injected muscle, muscle located opposite the injection site, hind intestine, gill, spleen, head kidney, liver and gonad 7 days after vaccination. However, these vaccine-containing plasmids disappeared by 90 days following vaccination. Fluorescent microscopy observations revealed that green fluorescence appeared in muscle, muscle located at the opposite side of the injection site, hind intestine, gill, spleen, head kidney and liver of fish 36 h after vaccination, and that green fluorescence did not appear in control tissue. The green fluorescence became weaker at 60 days post-vaccination, however, it remained detectable in the spleen 90 days post-vaccination. Results from RT-PCR studies indicated that the Mcp gene is expressed in all tissues of vaccinated fish 7-20 days after vaccination. These results demonstrate that the DNA vaccine is distributed and expressed in different tissues of vaccinated fish, and therefore, may have provided an antigen producing specific immune response.     

粗鞘双条杉天牛林间死亡规律的研究

研究表明在四川省泸县林场粗鞘双条杉天牛卵越冬成虫的死亡率为８２．３５％，各虫期死亡率为卵１３．３３％，初期幼虫５５．３８％，中、后期幼虫５３．９０％，蛹及越冬成虫很少死亡，致死因子包括寄主抗性、捕食性天敌昆虫、寄生性天敌昆虫、病原微生物、种内竞争共５类１３种。分析主要致死因子为杉木树脂、两色刺足茧蜂、川硬皮肿腿蜂、病原菌对粗鞘双条杉天牛种群的自然和抑制作用及防治中的应用前景和意义     

中国北方主产地苹果始花期模拟及晚霜冻风险评估

建立中国北方苹果主产地苹果始花期模型，分析苹果花期晚霜冻气候风险，为有效防御晚霜冻灾害对当地苹果生产的影响提供科学指导。该研究选取中国新疆的伊宁、阿克苏、黄土高原的万荣、白水、礼泉、陕州区和渤海湾的福山、熊岳分别代表中国3大苹果产区，利用各区代表站的苹果始花期资料和同期气象数据，建立并检验了不同站点苹果始花期模型，并利用该模型重建了1962－2019年苹果始花期，分析其时空变化特征。结合晚霜冻气象指标，对苹果花期晚霜冻气候风险进行评估。结果表明：1）苹果始花期模型能够在数据独立的情况下较准确地模拟各区代表站的始花期变化，新疆、黄土高原和渤海湾苹果产区内部检验的均方根误差分别为2.5～4.8、2.4～5.0、2.3～3.0 d，交叉检验的均方根误差分别为5.0～6.6、3.4～6.0和3.6～4.1 d。2）模拟得到的苹果始花期均呈显著提前趋势，趋势系数分别为-1.84～-1.04、-3.09～-2.62和-2.37～-1.88 d/10 a。3）不同区域苹果晚霜冻气候风险有着明显的差异。新疆和黄土高原果区苹果晚霜冻气候风险指数相对较大，其中伊宁最大达2.38，其次是万荣达1.81，而渤海湾果区的福山苹果晚霜冻气候风险指数为0。新疆和黄土高原果区苹果遭受晚霜冻的影响较大，渤海湾果区受晚霜冻影响最小。     

企业品牌危机产生机理的综合模式研究

首先分析品牌危机产生的原因可分为急性因子、慢性因子及模糊因子；其次论证了品牌危机产生机理，急性因子在媒体的危机心理效应的释放下，对品牌产生的媒体报道与社会舆论压力经公众的危机心理与企业的危机心理效应释放后，便可能演变成巨大的品牌危机，客户流失引发财务危机与企业全面危机，最终导致企业停产、破产、拍卖或被收购等，品牌生存与发展的根基被架空，品牌危机产生过程受企业品牌与基础管理能力的影响；本文最后论述了品牌危机产生机理对品牌危机管理的启示。     

肉桂粉实病菌两型孢子的研究

肉桂粉实病病原菌的无性阶段是病菌生命的基础,通过室内外的调查研究发现,肉桂粉实病的病原菌是花生油盘孢菌[ElaeodemafloricolaKeis],该病菌的无性阶段,除有隔菌丝外,有两型孢子。孢子适宜温度24℃左右,相对湿度98%以上,节孢子形成先于分生孢子。所有孢子都能致病,引起病害多次而集中,造成肉桂生产巨大损失。     

Bacteriological evaluation of composted manure solids prepared from anaerobic digested slurry for hygienic recycled bedding materials for dairy cows

Changes in mastitis‐causing pathogens, pH and water content in composted manure solids (CMS) prepared from digested slurry were evaluated during turning at 2‐day intervals for 8 days (C1–C4). The numbers of streptococci, coagulase‐negative staphylococci and coliforms were 2.6 × 10¹, 1.7 × 10² and 1.0 × 10¹ colony‐forming units (cfu)/g in CMS (C4) (summer), and these counts were markedly lower (P < 0.05) than those in CMS (C0 and C1). The bacterial counts ranged from 10¹ to 1.7 × 10² cfu/g in CMS (C4) (summer) and were within approved levels, <1 × 10⁶ cfu/g, indicating a minimal mastitis risk. The temperatures in CMS (C1–C4) increased to 63°C–74°C in summer and 67°C–70°C in winter. The mean pH values in CMS (C0–C4) were 9.2 in summer and 8.7 in winter, and water contents ranged from 61.7% to 69.6% in summer and 73.2% to 66.2% in winter. The significant decrease of pathogenic bacteria in CMS appears to be closely related to temperature >63°C for 8 days, pH 8.7–9.2, and water content 62% to 73%. This study demonstrates that prepared CMS has value as a recycled material with the potential to alleviate udder health issues in dairy cows.     

泥凼石林成因分析

介绍了泥凼石林的特征,从地质构造、岩性基础、水文地质结构、气候条件、新构造运动等方面阐述了其成因,最后对其成景过程和演化进行分析。     

果蔬采后致腐病菌检测及防治

引起果蔬采后腐烂的病原菌主要分属于葡萄孢属（Botrytis）、曲霉属（Aspergillus）、青霉属（Penicillium）、根霉属（Rhizopus）和链格孢属（Alternaria）.其中A.sp.和R.sp.是果蔬常温运输过程中的主要致腐菌,B.sp.、A.sp.和P.sp.是果蔬低温贮运条件下的主要致腐菌.采用仲丁胺和二氧化氯2种药剂对采后蔬菜进行熏蒸和浸泡保鲜处理.结果表明：低温与保鲜剂处理相结合,可明显提高果蔬采后运输及货架期9～11d.     

甘薯茎线虫病发生原因分析及防治建议

九十年代以来,甘薯茎线虫病在我国甘薯产区严重发生,本文分析了其发生原因,并提出防治建议,警示各地及早预防,以免流行。