不同立地条件20年生杉木各器官大量营养元素的比较分析     

廖祖辉 《福建林业科技》1999,26(1):22-25

在不同立地营养胁迫下对２０年生杉木各器官Ｎ、Ｐ、Ｋ元素变化进行分析,结果表明各器官Ｎ、Ｐ元素随立地营养胁迫加深而下降率增大,Ｋ元素则相反。而且各器官这些元素的变化程度不一。  相似文献   

无缝线巩膜隧道切口在软性白内障手术中的应用     

詹卫群  廖武 《湛江医学院学报》1999,17(2):135-136

目的;报告无缝线巩膜隧道切口在软性白内障手术中的应用并评价其疗效。方法：２２例软性白内障,其中先天性５例,并发性３例,外伤性１４例,通过弦长３．５ｍｍ及５．５ｍｍ的眉状隧道切口摘除,然后植入光学面为６．０ｍｍ折叠式及ＰＭＭＡ一体式人工晶体,切口不缝合。  相似文献   

设施农业与中国农业现代化建设   总被引：27，自引：1，他引：26  

廖允成  王立祥 《农业现代化研究》1999,20(1):5-8

通过对世界及中国农业发展形势的分析得出：（１）中国特色的农业现代化－－控制入口,节约资源、集约经营、保护生态并重的现代持续农业;是中国农业生产发展的必然选择;（２）设施农业是中国农业资源集约高效利用的重要途径,必将成为中国特色农业现代化的重要组成部分,并最终促使中国农业实现由传统农业现代化农业的飞跃。  相似文献   

Preliminary Report of Callus Culture on Prunus mume     

刘青林  陈青华  陈俊愉 《北京林业大学学报》1999,(2)

该试验以腋芽和胚为外植体,进行了梅花愈伤组织的长期培养及其细胞学的初步观测．结果表明成年母株腋芽外植体启动培养的愈伤率和发芽率在不同品种和不同培养基之间稍有差异,３＃梅花品种和ＭＳ＋ＮＡＡ２．０＋ＢＡ１．０＋ＺＴ２．０ｍｇ·Ｌ－１培养基较高．胚在ＭＳ＋ＧＡ１０．０培养基上发芽率高,并形成正常无根苗．暗培养有利于愈伤组织的生长,光培养有利于愈伤组织的分化．水解酪蛋白（ＣＨ）既有利于愈伤组织的生长、增殖,也延长了愈伤组织的寿命．梅花愈伤组织在第四代达到生长高峰,附加ＣＨ之后在第七代又出现一次生长高峰;一代之内第四周生长最快．多次继代培养的结果还表明,ＭＳ＋ＮＡＡ５．０＋ＫＴ１．０＋ＣＨ１０００有利于梅花愈伤组织的长期培养．细胞学观测的结果表明,多次继代培养的梅花愈伤组织的细胞形状不规则,核物质相对稀少,并且分化出了很多导管．  相似文献   

木兰科华木莲属木材结构   总被引：7，自引：0，他引：7  

俞志雄  肖德兴  廖军  郑庆衍  张露  李志强 《江西农业大学学报》1999,21(1):91-94

首次报道我国特有单种属植物华木莲ＳｉｎｏｍａｎｇｌｉｅｔｉａｇｌａｕｃａＺ．Ｘ．ＹｕｅｔＱ．Ｙ．Ｚｈｅｎｇ木材的主要解剖特征：散孔材;管孔通常４８～１６８个／ｍｍ２;管孔单独或由２～３个稀６个成径列复管孔,间或出现管孔团;管孔略具棱角;主要为单管孔稀为梯状穿孔,具２～１３个横闩,通常３～８个。管间纹孔式梯状或梯状－对列;螺纹加厚缺如。导管分子长５４７～９７３μｍ,通常长７７５μｍ。木射线异形ⅡＡ及ⅡＢ型,少数Ⅰ型,具１～２有时３～４列细胞;单列射线高３～１１（偶至１８）个细胞,９９～３３７ｃｍ;多列射线宽２～３（～４）个细胞或３３．００～４０．３３μｍ,高４～５９（通常２１～４０）个细胞或１０９～１５５０（通常５４７～１０３４）μｍ;无油细胞;纤维管胞长８８６～１７６３μｍ,通常长１３０５μｍ;木薄壁组织轮界状,通常宽２～４有时可达５个细胞。本研究支持华木莲属的建立。  相似文献   

胡萝卜肾形肾状线虫病的发生及药剂控制试验     

廖金铃殷友琴  宾淑英周慧娟 《华中农业大学学报》1999

  相似文献   

纸盒无菌灌装包装材料灭菌工艺优化   总被引：1，自引：1，他引：0  

董玉杰  卢立新  潘嘹  林自东  厉夫满 《农业工程学报》2022,38(4):324-330

为解决屋顶纸盒无菌灌装中包装材料灭菌工艺和灭菌效率问题,该研究进行工艺优化及提出微生物挑战测试方法.通过单因素试验研究过氧化氢溶液浓度、汽化过氧化氢蒸汽温度、汽化热空气压力和紫外线照射时间对灭菌效率的影响;并在此基础上,依据Box-Behnken原理设计响应面试验,建立包装材料灭菌效率二次多项式回归模型,获得灭菌工艺优...  相似文献   

基于DSSAT-Canegro模型的广西来宾市甘蔗生长对气象干旱的响应   总被引：1，自引：1，他引：0  

杨云川  张会娅  程禹灏  廖丽萍  杨家祯  邓思敏  谢鑫昌 《农业工程学报》2022,38(2):119-130

旱灾是制约甘蔗高产高糖的主要自然灾害之一,研究甘蔗生长过程对气象干旱的响应机制是实现其旱灾风险智慧管理、提高中国蔗糖业发展的一个关键科学问题.该研究基于来宾市1979—2018年0.1°格点及地面气象站点的多源气象要素数据,计算逐日标准化降水蒸散指数(Standardized Precipitation Evapotr...  相似文献   

Quantifying the impact of temperature variation on birnavirus transmission dynamics in hard clams Meretrix lusoria     

Tien-Hsuan Lu  Ying-Fei Yang  Chi-Yun Chen  Wei-Ming Wang  Chung-Min Liao 《Journal of fish diseases》2020,43(1):57-68

Susceptibility of hard clams Meretrix lusoria to birnavirus (BV) infections caused by temperature variations, from a mechanistic perspective, has rarely been explored. We used a deterministic susceptible–infectious–mortality (SIM) model to derive temperature-dependent key epidemiologic parameters based on data sets of viral infections in hard clams subjected to acute temperature changes. To parameterize seasonal pattern dependence, we estimated monthly based cumulative mortality and basic reproduction numbers (R₀) between 1997 and 2017 by way of statistical analysis. Two alternative disease control models were also proposed to assess status of controlled temperature-mediated BV infection by using, respectively, control reproduction number (R_C)-control line criterion and removal strategy-based control measure. We showed that based on R_C-control strategy, when temperatures ranged from 15 to 26.8°C, proportion of susceptible hard clams removed should be at least 0.22%. Based on removal-control strategy, we found that by limiting pond water temperature to 25–30°C, together with increased removal rates and periods to remove hard clams, it is better to remove hard clams from June and August to reduce both mortality rate and spread of BV. Our results can be used to monitor BV transmission potential in hard clams that will contribute to government control strategy to eradicate future BV epidemics.  相似文献   

Effect of feeding stimulants on growth performance,feed intake and appetite regulation of mandarin fish,Siniperca chuatsi     

Liao Li  Jinguang Fang  Xu‐Fang Liang  Muhammad Shoaib Alam  Liwei Liu  Xiaochen Yuan 《Aquaculture Research》2019,50(12):3684-3691

Mandarin fish is a typical carnivorous fish, it can accept artificial diet after domestication, which is significantly essential to optimize its artificial diet. Nevertheless, only few studies were conducted on artificial diet of mandarin fish. Therefore, an 8‐week feeding trial was conducted to evaluate the influence of feeding stimulants on growth performance, feed intake and appetite regulation of mandarin fish. In this trial, six diets were formulated, a basal diet contained 80% of Fish Meal without feeding stimulants, named as Control, 0.4% inosinic acid meal, 0.4% L‐Alanine meal, 3% Yeast meal, 3% a commercial squid extract meal and 0.4% betaine meal were added into the basal diet to make five experimental diets, which were named as IM, AM, YM, SVO and BM respectively. At the end of feeding trial, SVO group showed higher feed intake, up‐regulated mRNA expression of neuropeptide Y (NPY) and down‐regulated mRNA expression of pro‐opiomelanocorticoid (POMC) significantly as compared to control group, which suggested that squid extract improved feed acceptability and promoted appetite in mandarin fish. Similarly, compared to control group, SVO group showed low food conversion ratio, high weight gain and SGR, indicated that squid extract enhanced the growth performance. Our results suggested that the appropriate level of squid extract addition could contribute to optimize artificial diet in mandarin fish.  相似文献