中密度纤维板施胶过程伺服系统的设计与仿真

在中密度纤维板(MDF)施胶过程的要求下,为克服施胶过程中存在的滞后、非线性等问题,采用了提高系统控制精度的交流伺服驱动系统。设计了伺服系统的硬件部分,根据系统的控制原理建立了数学模型,并进行计算机数字仿真,分析了系统的稳定性。仿真结果表明采用伺服系统可以获得较好的控制效果。     

植物提取物生产过程中废水的治理

概述植物提取物生产过程中废水的来源、特点、分类以及废水治理的方法,并对各种治理方法的优缺点进行论述,对植物提取物加工过程中废水治理的一般流程进行阐述。针对目前植物提取物废水治理的现状,提出由于植物提取行业废水的多样化,应根据其水质的特异性,采用不同的治理方法或是不同治理方法组合的观点。     

砀山梨、苹果烟煤病防治研究

 采用以植物保护剂为主体,调节果树内部营养生理增加抗性为基础,结合农药复配等技术,进行烟煤病的综合防治。     

Reproductive strategies and seeds behavior ofBetula platyphylla Suk. population

By the methods of morphological anatomy and investigation in the sample fields, the main studies were carried out such as morphological anatomy of reproductive organs, birch population’s reproductive ages, reproductive allotment value and seed behavior. The relationship between birch population and their surroundings was studied. The results showed that birch’s flower organs and its seeds were suitable well for spreading by wind. The seeds by wind can fly far away in a short time. The quantity of seed spreading greatly varied with different communities. Birch’s reproduction age can be changed in different ecological surroundings. The reproductive allotment value of birch was obviously different at different reproductive stages. In the mesic habitat, birch can grow well. The lowest reproductive age of them was 12, average age 15. In most cases the age of branches to bearing fruits was more than 18. The order of reproductive allotment values was as follows: a flowering phase > flower bud phase > fruit phase.     

大约克猪和二花脸猪SLA-DRB基因外显子2的PCR-RFLP多态性分析

采用PCR-RFLP方法分析大约克猪和二花脸猪SLA-DRB外显子2的多态性.结果显示:Rsa Ⅰ酶切后得到3种等位基因条带,分别为A(141/93/11 bp)、B(111/69/54/11 bp)、D(93/48/39/54/11 bp).χ2检测表明:二花脸猪SLA-DRB基因外显子2处于Hardy-Weinberg平衡状态(P>005),而大约克猪处于非平衡状态(P<001).两品种A等位基因均为优势等位基因,AA型为主要基因型,其频率在品种间无显著差异.首次发现等位基因B、D分别出现在二花脸猪和大约克猪中,有望用于区分两品种.     

铅对昆明小鼠肾脏毒性的病理学观察

采用醋酸铅灌胃于成年昆明小鼠,观察铅致小鼠肾脏的病理形态变化。取小鼠分为4组,分别为醋酸铅高、中、低剂量组(40、20、10mg/kg)、生理盐水阴性对照组,经口灌胃每天定时定量连续给药40d。取小鼠肾脏经甲醛固定,常规石蜡包埋切片,HE染色,显微镜下观察小鼠肾脏的组织形态。结果表明,各试验组肾皮质部小管上皮细胞肿胀,胞质疏松,染色浅,空泡变性,发生广泛性颗粒变性,部分肾小管上皮细胞嗜酸性坏死;高剂量组肾皮质部肾小管周围大量淋巴细胞浸润,肾小管上皮细胞表现明显的颗粒变性和嗜酸性坏死,肾小球体积萎缩,结构破坏,出现局灶性硬化;部分肾小管管腔内可见嗜酸性凝固物,肾小球毛细血管扩张充血;中剂量组病变相对较轻;而低剂量组无明显形态学异常。结果提示铅对小鼠肾脏有毒性作用,且随剂量增加损伤加重。     

不同位点结构修饰的喜树碱新衍生物内酯环稳定性

从构效关系角度考察了不同位点结构修饰对喜树碱母核内酯环稳定性的影响.利用高效液相色谱手段,对喜树碱母核10位与20位修饰后所得的新衍生物的内酯环稳定性进行分析;并采用ODS色谱柱(4.6 mm×260 mm),以乙腈-超纯水为流动相体积比35∶ 65;UV检测波长为360 nm;流速1.0 mL/min.在喜树碱母核的10位与20位引入含氮杂环,所得的受试喜树碱衍生物均能提高母核上内酯环的稳定性,而在所连接的取代基团中,以吡唑和羟基修饰的喜树碱内酯环最为稳定.     

甜菜（Beta vulgaris L）物质生产与碳水化合物代谢的生理生态学研究──第Ⅴ报可溶性糖分的分配动态与蔗糖积累遗传差异的研究

利用１４Ｃ标记研究了不同类型品种甜菜生育期间主要糖分的运转分配动态与蔗糖积累遗传差异．结果表明，在生育期间，叶片中葡萄糖和果糖占叶片和根内３种糖（葡萄糖、果糖和蔗糖）的百分比分别呈先下降后上升趋势，而根中两种糖的百分比呈下降趋势．叶片中蔗糖占叶片和根内３种糖（葡萄糖、果糖和蔗糖）的百分比呈先上升后下降趋势，但根中蔗糖的百分比始终保持上升趋势，甜菜糖分代谢强度随生育期而改变．高糖型品种叶片中葡萄糖、果糖和蔗糖的百分比都分别低于其它类型甜菜３种糖的百分比，而根中３种糖的百分比分别高于其它类型甜菜３种糖的百分比．说明高糖型品种叶片蔗糖合成和运转分配能力强，根部具有优势的蔗糖贮藏能力，最终表现为根中高额蔗糖的积累．     

Gas exchange of Rhodiola sachalinensis transplanted from different habitats in Changbai Mountain

Introduction1RhodiolasachalinensiSA.Bor,aperennial,medicalherb,mainlydistributesinJapan,Korea,ChinaandRussia.InChina,itmainlydistributesinChangbaiMOuntain,JinnProvince,andZhangguangcaiMountain,HeilongjiangProvince.ThistypicalalpineplantgenerallydistributedinhighMountain,ataltitude1700-25o0m(Wuetsl1987,Qin19941Luetal1995).Rhodiolsplant(RhodiOlaroseschieflyinRussia)hasbeenextensivelystudiedbyscholarsfromRussia,Ukraine,JapanandChinasincethe1950's(Ming1988iKir'yanovetsl1991,OhbaandMid…     

Structural remodelling of the heart valves extracellular matrix during embryo development

Alterations in heart valve development represent more than 20% of congenital cardiovascular malformations. Most of the functional properties of heart valves depend on extracellular matrix. Despite its relevance, little is known about fibrillar components on developing stages. Our objective is to define histological changes on valves fibrillar components in late embryonic development of Mus musculus. We found type III collagen as the predominant fibre type in the ECM in prenatal stages followed by a switch to a type I predominance for postnatal ages. The change in fibrillar components is necessary to support the normal mechanical function of adult heart valves.