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1.
本文对太阳能的起源、传播、与物质的相互作用以及储存和利用等各个方面所涉及的物理学定律,特别是对太阳能热利用所涉及的热力学定律进行了概括和归纳。根据热力学定律指出太阳能热利用的真正适用范围。  相似文献   
2.
The lack of protective action of oestrogens which appears during menopausal period may be the reason of serious metabolic disturbances including oxidative stress. The hypothesis was stated that ovariectomy may induce the variations of antioxidant/oxidant status which can be detected in rat liver. A total of 102 healthy Wistar female rats were included in the experiment and divided into control (CON; n = 6), sham-operated (SHO; n = 48) and ovariectomized (OVX; n = 48) groups. Animals from SHO (n = 6) and OVX (n = 6) groups were killed every week during 8 weeks of experiment to detect dynamic changes in examined parameters. Anti-oxidative enzyme activities [glutathione peroxidase (GSH-Px); superoxide dismutase (SOD)] as well as total antioxidant capacity (TAC) and the intensity of lipid peroxidation, measured by the concentration of N,N,diethyl-p-phenylene diamine (DEPPD) radical, were determined in liver homogenates by the use of spectrophotometric methods. Wave-like patterns of examined parameters within 8 weeks of experiment were detected. GSH-Px activity tended to be higher in OVX animals and was significantly lower at 8th week when compared with 1st week of experiment. SOD activity was higher in SHO animals and showed significant differences between 3rd, 4th, 7th and 1st week. TAC values were significantly higher in OVX when compared with SHO groups in 2nd, 4th, 5th week and significantly lower in 3rd, 6th and 7th week of the experiment. The concentration of DEPPD radicals tended to increase in OVX group. In conclusion, ovariectomy which leads to oestrogen insufficiency is reflected as well in variation of anti-oxidative/oxidative parameters in rat liver homogenates.  相似文献   
3.
杂交棉A—92的高产生理特点与配套栽培技术探讨   总被引:3,自引:0,他引:3  
就杂交棉A-92生长发育特点、干物质生产与分配,产量形成规律及配套栽培等方面进行探讨。结果表明:杂交棉A-92干物质生产与积累、籽皮棉产量、单株成铃数、铃重、总果节数、节枝比、铃枝比、叶面积系数、根系活力等均高于对照种鄂荆1号,具有明显地竞争优势。杂种主要来源于单株叶面积扩大,特别是果枝叶面积增长速度较快;产量优势主要表现为早发明显、伏明桃增多和单铃重增加。结合多年示范、试验结果,栽培技术上在适当  相似文献   
4.
针对盘刀式铡草机存在的生产率低、功耗大、易堵塞等问题,以玉米秸秆为试验材料,选取不同的主轴转速、叶片倾角和秸秆含水率作为试验因素进行抛送性能试验研究。试验结果表明:各因素对抛送过程生产率影响的主次顺序为主轴转速>叶片倾角>秸秆含水率;对抛送过程功耗影响的主次顺序为主轴转速>秸秆含水率>叶片倾角。当叶片倾角为7°、主轴转速为650r/min、秸秆含水率为22.1%时,抛送过程生产率最高;当叶片倾角为11°、铡草机主轴转速为510r/min、秸秆含水率为27.3%时,抛送过程功率消耗最低;同时,得到了可用于预测铡草机抛送过程生产率和功率消耗的线性回归模型。  相似文献   
5.
Waxy (Wx) protein is a key enzyme for synthesis of amylose in endosperm. Amylose content in wheat grain influences the quality of end‐use products. Seven alleles have been described at the Wx‐D1 locus, but only two of them (Wx‐D1b, Wx‐D1e) were genotyped with codominant markers. The waxy wheat line K107Wx1 developed by treating ‘Kanto 107’ seeds with ethyl methanesulphonate carries the Wx‐D1d allele. However, no molecular basis supports this nomenclature. In the present study, DNA sequence analysis confirmed that a single nucleotide polymorphism in the sixth exon of Wx‐D1 changed tryptophan at position 301 into a termination codon. Based on this sequence variation, a PCR‐based KASP marker was developed to detect this point mutation using 68 BC8F1 plants and 297 BC8F2 lines derived from the cross ‘Ningmai 14’*9/K107Wx1. Combined with codominant markers for the Wx‐A1 and Wx‐B1 alleles, waxy and non‐waxy near‐isogenic lines were distinguished. The KASP marker was efficient in identifying the mutant allele and can be used to transfer waxiness to elite lines.  相似文献   
6.
不同氮素形态配比对网纹甜瓜干物质分配和氮代谢的影响   总被引:4,自引:0,他引:4  
该文研究了4种氮素形态配比(NO3--N∶NH4 -N分别为100∶0,75∶25,50∶50和25∶75)对基质栽培网纹甜瓜(品种为“春丽”和“蜜玲珑”)干物质积累和氮代谢的影响。结果表明,不同氮素形态配比影响了植株各器官干重占全株干重的百分比。随氮素形态中氨态氮比例的增加,叶片中硝酸还原酶、硝酸盐含量和可溶性蛋白质含量逐渐降低,而游离氨基酸含量则在NO3--N∶NH4 -N为50∶50的处理中最高。  相似文献   
7.
选用山楂,胡萝卜,沙棘,穗醋粟,姜5种果蔬作为复合汁的材料,对复合汁Vc的稳定性及其在贮藏过程中的变化进行了研究。试验表明,果蔬复合汁在贮藏过程的前期,Vc损失迅速,以后Vc的变化趋于缓慢,在5种果蔬原料中,沙棘汁对Vc具有明显的保护作用,姜汁对Vc具有一定的破坏作用。  相似文献   
8.
Wheat‐Dasypyrum villosum translocations T6V#2S·6AL and T6V#4S·6DL, carriers of Pm21 and PmV, respectively, confer high resistance to wheat powdery mildew. For better understanding of the difference in genetic effect between them, a RIL population was constructed based on the cross between “Yangmai 18” carrying T6V#2S·6AL and “Yangmai 22” carrying T6V#4S·6DL. Analysis of distribution of the translocations showed that T6V#2S·6AL is much more transmittable than T6V#4S·6DL. By comparing their effects on main agronomic traits, we firstly found that T6V#2S·6AL contributes greatly to top spikelet fecundity, but causes a decrease of 6.7%–10.5% of spike number. No stable effects of T6V#4S·6DL on agronomic traits were found, except for positive effect on plant height. Excitingly, a new recombinant, T6V#4S‐6V#2S·6AL carrying PmV, was screened and proved to have a higher transmission rate than the original translocation T6V#4S·6DL, which will greatly promote the utilization of PmV. The above conclusions of this research will provide important guidance for utilization of Pm21 and PmV more effectively, in wheat powdery mildew resistance breeding.  相似文献   
9.
继代培养基再利用研究   总被引:10,自引:0,他引:10  
利用组织培养法繁育三倍体山杨继代丛生无根苗过程中,为降低育苗成本,利用回收转换后废弃的继代培养基,进行再利用试验研究,分别加入了原继代培养基10%,20%,30%,40%,50%的母液,不加琼脂和糖,用原继代培养基做对照。  相似文献   
10.
不同腌制方法对蕨菜主要化学指标的影响   总被引:2,自引:0,他引:2  
蕨菜腌制过程中若干化学指标的变化,结果表明:经过腌制,蕨菜中VC和叶绿素含量显著下降,饱和盐水法腌制蕨菜两项指标高于干腌法;饱和盐水法和干腌法的亚硝峰出现分别在腌制后的105d和120d,峰值为4.0μg.g-1和21.4μg.g-1,两种腌制方法的蕨菜pH值在7月份均因轻微发酵作用有所下降,但并未影响蕨菜的风味;饱和盐水法腌制的蕨菜食盐含量在前15d迅速增加,60d达到平衡。从感官状态看,饱和盐水法的蕨菜组织较饱满,色泽黄绿,而干腌法的蕨菜表面皱缩,色泽褐绿;综合感官和化学指标以饱和盐水法腌制的蕨菜品质好于干腌法。  相似文献   
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