发泡剂对PVC木塑复合装饰板性能的影响

通过测试PVC基木塑装饰板的物理力学性能,研究复合发泡剂配比和发泡剂添加方式对PVC木塑装饰板的密度、抗弯强度、表面结合强度、板面握螺钉力和72 h吸水厚度膨胀率的影响。结果表明:添加当复合发泡剂AC、Zn O、Na HCO3配比为6∶1∶4时,PVC木塑复合装饰板的抗弯强度、表面结合强度、板面握螺钉力最大,分别为21.08 MPa、0.67 MPa、0.82 k N,达到GB/T 24137—2009《木塑装饰板》的要求;采用直接添加发泡剂的PVC木塑复合装饰板的力学性能优于采用先混合物料后添加发泡剂的PVC木塑复合装饰板的力学性能。     

比重分级对杂交水稻种子发芽、出苗和产量的影响

以杂交水稻品种陆两优996和两优培九的商品种子为试验材料,以盐水溶液将种子精选分级为比重1.0(T1)、1.0~1.09(T2)、1.1~1.19(T3)、≥1.2(T4)等不同等级,以未精选的种子为对照(CK),研究比重分级对种子发芽出苗、秧苗素质及产量的影响。结果表明,种子精选分级后,处理T2、T3、T4种子的发芽率、发芽指数、活力指数、出苗率、成秧率均不同程度高于CK,T1处理则显著低于CK;与未分级的商品种子对照相比,T2、T3、T4处理均增产显著,增产的原因是单位面积有效穗数和每穗总粒数增加。     

PWM整流器的模糊PI内模控制策略

PWM整流器模型中的非线性特性给控制器的设计带来一定的困难，且随着对整流器性能的要求日益提高，传统控制在性能上已难以令人满意。对此提出一种新的双闭环控制策略，电压外环采用模糊PI控制，电流内环采用内模控制。模糊PI控制使系统具有更快的动态响应和更小的超调，电流环内模控制解决控制器过分依赖精确数学模型的问题，提高电流环的抗扰性能，并简化了控制器设计。理论分析和仿真对比验证了所提控制策略的正确性和可行性。     

Effect of Alfalfa Flavonoids on Growth Performance and Serum Indexes of Sheep

This experiment was conducted to evaluate the effect of alfalfa flavonoids (Medicago sativa) on growth performance and serum indexes of sheep.This experiment was performed with hybrid F1 sheep of Suffolk sheep×Small-tailed Han sheep.Twenty-eight sheep with the body weight of (27.02±3.03) kg were randomly divided into 4 groups with 7 replicates in each group and 1 sheep per replicate.Sheep in different groups were fed diets with 0 (group Ⅰ), 0.1% (group Ⅱ), 0.2%(group Ⅲ) and 0.4% (group Ⅳ) alfalfa flavonoids, respectively.The experiment was cosisted of 7-day-preliminary trial and 41-day-formal trial.The results showed as follows:① Dietary supplementation of alfalfa flavonoids had no significant effects on growth performance of sheep(P>0.05).② Dietary supplementation of alfalfa flavonoids had significant effects on the contents of GLB, ASP, BUN, HDL and P in serum (P<0.05).Serum GLB content at the 1st day in group Ⅲ was significantly lower than that in groupsⅠand Ⅱ(P<0.05), serum ASP contents at the 1st and 21th days in group Ⅳ were significantly lower than those in group Ⅰ(P<0.05), serum BUN content at the 1st day in group Ⅳ was significantly lower than that in group Ⅰ(P<0.05), serum HDL content at the 21th day in group Ⅱ was significantly lower than that in groups Ⅰ and Ⅲ (P<0.05), serum P content in group Ⅳ at the 21th day was significantly lower than that in groups Ⅱ and Ⅲ (P<0.05).In conclusion, dietary supplementation of alfalfa flavonoids might modulate lipid metabolism, improve nitrogen utilization, maintain energy metabolic and balance Ca and P contents, and have the potential function for promoting growth and no adverse effect on liver.The results suggested that the appropriate supplemental level of alfalfa flavonoids for sheep was 0.2%.     

两种不同包装材料对扒鸡产品品质的影响

为研究两种不同包装材料对扒鸡产品品质的影响，分别对扒鸡贮存不同时间的微生物指标、质量损失进行检测分析，并进行感官评价。结果表明，不同包装材质对高温灭菌后扒鸡的微生物指标影响不大；包装B的氧气及水蒸气透过量明显低于包装A，并且在保护扒鸡色泽和香气、延缓脂肪氧化方面明显优于包装A。因此，高阻隔包装材料能够提高扒鸡的产品品质，延长保质期。      

苹果属无融合生殖SERKs基因家族的克隆和表达分析

本研究利用同源克隆法以苹果属平邑甜茶和杂种后代叶片为试验材料,克隆得到4个SERK基因家族片段,并分析了SERKs家族基因在平邑甜茶和杂种后代不同器官和组织中的表达情况。研究结果表明:分离获得的4个SERK基因家族片段的氨基酸序列与模式植物拟南芥、烟草等植物的同源性均在84%以上,同时与其他物种的氨基酸序列进行Blast比对都具有较高的同源性;RT-PCR定量分析结果表明SERK1、SERK2、SERK3、SERK4基因主要在生殖器官中表达。因此,推测SERKs基因在平邑甜茶和杂种后代生殖发育过程中起着重要的调控作用。本研究结果为进一步揭示无融合生殖的发生机理奠定了基础。     

生根处理和扦插时间对杉木容器扦插育苗效果的影响

以通过审定的广西杉木(Cunninghamia lanceolata)良种为扦插材料,探讨不同的生根处理方法和扦插月份对扦插生根效果及成活率的影响。结果表明:使用生根剂处理的穗条,其生根率、成活率、根系数量及整齐度均极显著高于对照,ABT1和IBA处理的穗条根系萌发最快,根系萌发时间均为22 d,比对照提前13 d;ABT1处理的穗条生根率(97.8%)和平均根系数(4.2)最高,整齐度最好,其次为IBA;ABT1、IBA和NAA处理的穗条成活率分别为97.8%、97.2%和93.1%,对照成活率为81.5%;杉木扦插苗培育的最佳扦插时间为3~5月。     

褚橙龙陵基地柑橘叶片DRIS图解法和指数法综合营养诊断分析

[目的]开展基于综合营养诊断施肥法(Diagnosis and Recommendation Integrate System,DRIS)的冰糖橙种植基地柑橘营养诊断,为柑橘园的营养诊断和平衡施肥提供参考依据.[方法]以云南褚橙龙陵基地500 ha冰糖橙为研究对象(柑橘园随机划分为8个区域),通过测定成熟秋梢叶片中氮(N)、磷(P)、钾(K)、钙(Ca)、镁(Mg)、铜(Cu)、锌(Zn)和铁(Fe)矿质营养的含量,运用DRIS图解法求得冰糖橙叶片各营养元素诊断参数最适比范围,依据DRIS指数法求得各区域冰糖橙需肥紧迫程度排序及养分不平衡指数(NII),初步制定冰糖橙树体营养元素DRIS指数分级标准.[结果]整个园区高产园(>22500 kg/ha)的各营养元素含量大多高于低产园(≤22500 kg/ha),高产园和低产园间N、Fe、N/Fe、P/Fe、Ca/Mg、Ca/Fe、Mg/Zn差异显著(P<0.05)或极显著(P<0.01).当N/P在2.27~2.57,N/K在1.58~1.91,P/K在0.66~0.79时冰糖橙叶片N、P和K养分含量平衡;当Ca/Mg、Ca/Fe、Mg/Fe、Cu/Zn、Cu/Fe和Zn/Fe分别在17.01~19.09、0.21~0.26、0.012~0.015、2.77~4.60、0.30~0.43和0.09~0.12时,冰糖橙叶片Ca、Mg、Fe、Zn和Cu养分处于平衡状态.综合诊断显示冰糖橙叶片养分需求顺序为Mg>N>K>P>Ca>Cu>Zn>Fe,不同区域冰糖橙养分需求顺序不同,高产园冰糖橙相对缺乏的养分有N、P,低产园相对缺乏的养分有N、Mg,相比之下,低产园营养比例失衡情况较严重.依据高产园叶片矿质营养元素含量范围确定冰糖橙叶片矿质营养元素的适宜值为N(11.66~13.30 g/kg)、P(4.74~5.61 g/kg)、K(6.23~8.23 g/kg)、Ca(13.67~19.33 g/kg)、Mg(0.86~0.97 g/kg)、Cu(14.49~37.71 mg/kg)、Zn(6.38~8.02 mg/kg)和Fe(55.91~85.74 mg/kg).[结论]根据DRIS诊断,褚橙龙陵基地冰糖橙园普遍存在N、P、K、Ca、Mg缺乏,Cu、Zn、Fe相对过剩问题.DRIS图解法和指标法综合诊断既可求得各元素最适比范围和需肥紧迫程度,同时,参照冰糖橙叶片养分含量分级标准能判断树体营养元素的平衡状况,可用于生产上指导下一年合理施肥.     

Identification and expression analysis of 11 MADS-box genes in peach (Prunus persica var. nectarina ‘Luxing’)

MADS-box genes play a central role in the development of flowers in plants. In this study, 11 PpMADSs were isolated from ‘Luxing’ peach, and the expression levels were detected in different tissues and fruit development. Eleven PpMADSs, designated as PpMADS13, 14, 18, 23, 24, 25, 32, 33, 34, 35, and 39 were isolated. Phylogenetic analysis revealed that PpMADS13, 14, and 18 belonged to SVP, AGL15, and MIKC* group respectively; PpMADS23, 24, 25, and 39 were in the Mα group; PpMADS32, 33, 34, and 35 belonged to the Mγ group. Predictions from subcellular localization showed that 10 PpMADS were located in the nucleus. RT-PCR revealed that PpMADS13 was expressed in stems, leaves, and during fruit development (70d); PpMADS14 was expressed in sepals, stamens, petals, and during flower development; PpMADS18 was expressed in roots, stems, leaves, sepals, ovaries, stamens, petals, and during flower and fruit development; all MADS-box genes (expect for PpMADS33) in the Mα and Mγ group were expressed in roots, stems, leaves, sepals, ovaries, stamens, petals, and during flower development; few genes were expressed during fruit development. These results indicated that PpMADS may play a crucial regulatory role in vegetative growth and development processes of flowers and fruits in peaches.