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1.
分别采用热风、真空、微波3种干燥方式处理铁棍山药,用静态称质量法测定铁棍山药在10,20,30,40℃下,水分活度为0.2~1.0的平衡含水率,并绘制等温吸附曲线。选用6种吸附模型对铁棍山药的吸湿数据进行拟合比较,以模型的均方差、残差平方和、相关系数、相关系数的平方为评价指标。结果表明,不同干燥方式处理后的铁棍山药,其平衡含水率均随水分活度的升高而升高,在相同水分活度时平衡含水率均随温度升高而升高。在相同水分活度下,热风干燥与真空干燥铁棍山药的平衡含水率均高于微波干燥铁棍山药的平衡含水率。GAB和Peleg模型适用于模拟热风干燥和真空干燥处理后铁棍山药的等温吸湿规律;Peleg模型适用于模拟微波干燥处理后铁棍山药的等温吸湿规律。  相似文献   

2.
为了研究带壳咖啡豆介电特性与含水率之间的关系,利用LCR测试仪研究频率信号(1~1 000 k Hz)、温度(20~45℃)和含水率(11.18%~43.69%)对带壳咖啡豆介电特性的影响。结果表明,在1~1 000 k Hz频段内,相对介电常数(ε')随着频率的增大单调减小,却随着含水率的升高而增大;温度对相对介电常数(ε')基本没有影响,介质损耗因数(ε')随频率增大先递减后增大;当温度和含水率升高,介质损耗因数(ε')呈增大趋势。在500 k Hz下建立相对介电常数(ε')预测带壳咖啡豆含水率(W,%)的模型,该模型R2=0.987 5;制作了20个样本,将测量值与模型计算值进行比较,发现其绝对误差范围为-3.07%~2.47%,说明所建立的模型可行。此项研究对了解带壳咖啡豆的介电特性,以及开发带壳咖啡豆含水率检测仪有一定的指导意义。  相似文献   

3.
基于Origin 7.0软件,非线性拟合热力学吸附过程不仅能够简单、准确得出热力学参数,且能将拟合效果直观表达出来。采用白浆土胡敏酸作为吸附剂,对Zn^2+进行了热力学吸附过程的研究,并结合Origin 7.0软件对吸附规律进行了2种方式的拟合描述。结果表明:3个温度(293、303、313 K)条件下,热力学等温线存在共性,较低Zn2+平衡浓度范围内,吸附曲线近似直线上升,而随浓度继续升高,吸附曲线上升程度减缓,随后渐趋平衡。相比较而言,随温度升高,胡敏酸对Zn^2+的吸附量逐渐增加,提升效果尤以高初始浓度条件下为最佳。运用Origin软件对热力学曲线进行拟合,可见Langmuir在描述两者间吸附规律的效果为最佳。同条件下,Origin自定义参数拟合的效果要优于软件自带方程。  相似文献   

4.
我国白果产量丰富,白果的营养价值很高,同时药用价值明显。利用网络分析仪和热特性分析仪对白果的物理特性进行研究。在1~3 000 MHz频率段内,当线路热源导热率探针测量的温度从30℃增加到80℃时,在一定的含水率下,白果的介电常数ε'从7.24增加到10.89,介电损耗因子ε'从1.77上升到7.8;当温度一定时,介电常数ε'和介电损耗因子ε'都随含水率的增大而增加。由此可见,白果的比热容和热传导系数随密度、含水率的增加而增大。  相似文献   

5.
水分胁迫对红麻生理特性和产量的影响   总被引:6,自引:0,他引:6  
王朝云  揭雨成 《作物学报》1995,21(6):746-751
水分胁迫下,红麻叶片水势降低,游离脯氨酸含量大幅度上升,过氧化物酶活性增强,蒸腾速率减慢,用水效率提高,绿叶面积和净同化率变小,生长受阻。以上变化随水分胁迫程度加重而加剧。复水后红麻各项生理功能恢复很快。反映了红麻是一种耐旱性很强的作物。在红麻旺长后期水分胁迫对营养生长及干茎和生麻产量的影响大于旺长前期。但旺长后期水分胁迫后有促进生殖生长的趋势。因此,根据红麻不同时期对水分胁迫的反应及收获对象不同而采取相应的水分管理技术是十分重要的。  相似文献   

6.
热风干燥过程中山药水分状态的变化研究   总被引:1,自引:0,他引:1  
为了解山药的水分赋存状态的变化,以襄阳道地山药为材料,分别在60、70、80、90、100 ℃条件下进行热风干燥,采用低场核磁共振(LF-NMR)和差式量热扫描(DSC)技术,每隔15 min测定山药在热风干燥过程中的水分状态及迁移规律。结果表明,在60~90 ℃条件下,温度越高,干基含水率的降速越快。山药的T2弛豫图谱有3个较为明显的吸收峰,随干燥进程的延续,各峰面积均明显减少,其中自由水所在峰的面积降幅最大,表明干燥过程中自由水散失最多,而且自由水逐渐向半结合水和结合水迁移,冷冻峰和解冻峰也随之变小。但在100 ℃下干燥时,样品可能因表面板结导致干基含水率、低场核磁吸收峰升高,冷冻和解冻峰面积增加。因此,在实际干燥过程中,山药的热风干燥温度不宜高至100 ℃。  相似文献   

7.
田永超  曹卫星  王绍华  朱艳 《作物学报》2004,30(11):1129-1134
本文研究了不同土壤水氮条件下,水稻不同叶位含水率、含氮率、叶色和光合速率的动态变化特征。结果表明,拔节至抽穗前后,不同叶位含水率为顶1叶<顶2叶<顶3叶<顶4叶;随胁迫时间的推移,灌浆期后不同叶位水分变化趋势随水分处理而异,W3和W5同拔节至抽穗期,而W1和W2表现相反(W1至W5为由低到高土壤水分处理)。不同叶位叶  相似文献   

8.
范君华  刘明  陈志林 《棉花学报》2008,20(2):154-157
 5个零型海岛棉品种棉铃发育过程中干物质积累、分配及铃壳生理指标的测定结果显示:(1)铃壳干物质随铃龄直线上升而后迅速下降,种子和子棉干物质积累直线上升。(2)铃壳率逐渐下降,种子率和子棉率逐步增加,最终达到峰值,而纤维重率呈先降后升的现象。(3)光合色素的含量随铃龄逐渐增长,类胡萝卜素、可溶性蛋白质含量、转化酶活性随铃龄增长而减弱。  相似文献   

9.
研究旨在通过添加外源微生物,加速屠宰废弃物堆肥的腐熟。[方法]本研究向加热烘干的屠宰废弃物添加浓度为0、5%、10%、15%、20%的史氏芽孢杆菌菌液获得堆肥原料,将原料置于60℃、65℃、70℃的环境中,保证通风并不断搅拌,堆肥10h后研究堆料的含水率、pH、电导率(EC)、全碳含量、全氮含量、碳氮比和发芽指数(GI)的变化。[结果]结果表明:添加菌剂后,随菌液浓度上升,在60℃环境下含水率下降,65℃和70℃时含水率上升;电导率在不同温度下均随菌液浓度上升呈上升趋势,最低为3.76mS/cm,最高为5.31mS/cm;全碳含量在60℃和70℃时随菌液浓度上升而上升,65℃时随菌液浓度上升而下降;pH、全氮含量受温度影响较大,菌液浓度影响不明显;碳氮比受温度和菌液浓度影响较大,变化范围为14-17;发芽指数在60℃和70℃时均随菌液浓度升高而升高,65℃时随菌液浓度升高而降低。[结论]以上结果表明,史氏芽孢杆菌可以促进屠宰废弃物堆肥腐熟,为屠宰废弃物综合利用提供理论基础。  相似文献   

10.
松辽平原玉米带高产土壤钾素状况研究   总被引:2,自引:1,他引:1  
为了弄清松辽平原玉米带的基本钾素状况,改良中低产土壤,提高粮食产量,选取位于吉林省梨树县胜利乡、泉眼岭、万发乡、公主岭市永发乡的不同剖面土壤作为供试土壤。通过测定其全钾、速效钾及缓效钾的含量,了解供试土壤的含钾状况及供钾潜力;并采用等温吸附试验和等温解吸试验测定土壤对钾素的吸附量和解吸率,以进一步掌握土壤的钾素状况。供试土壤的吸附特性以Freundlich等温吸附方程进行拟合。结果表明,松辽平原玉米带高产土壤钾素含量丰富,全钾与缓效钾含量较高,速效钾含量适中;高产土壤对钾的吸附强度明显大于其对照土壤,1/n最高为0.9575,最低为0.7341,说明高产土壤对K+的束缚力较弱,而对照土壤对K+的束缚力较强,不利于植物的吸收利用;高产土壤与对照土壤之间吸附钾的解吸率差异大,随着加入液中钾浓度的增加,两者间差异不断减小;当加入液含钾浓度大于0.56 g/L时,解吸率几近于相同。  相似文献   

11.
Jens Jensen 《Euphytica》1979,28(1):47-56
Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.  相似文献   

12.
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...  相似文献   

13.
T. Visser  E. H. Oost 《Euphytica》1981,30(1):65-70
Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.  相似文献   

14.
Richard N. Lester 《Euphytica》1989,44(1-2):125-132
Summary An hypothesis is developed that the rapid change from wild plants into domesticated crops principally involves the selection of alleles with non-functional gene products which leads to reduced control of the highly integrated metabolism and morphogenesis previously accumulated by lengthy natural selection. Such disturbance of the genome produces altered physiological and morphological development which, although deleterious in nature, serves mankind better and has been selected.  相似文献   

15.
Summary Twenty-five lucerne populations of the Medicago sativa complex, which were either diploid or tetraploid and wild or cultivated, were analysed for their resistance to four different fungal diseases and to stem nematode. Forage quality, including stem digestibility and saponin content, was also tested.Populations varied in susceptibility to the diseases caused by Colletotrichum trifolii, Verticillium albo-atrum, Sclerotinia trifoliorum and Pseudopezizza medicaginis, and to the nematode Ditylenchus dipsaci. Except for Sclerotinia rot, sativa and falcata subspecies differed in susceptibility, but this grouping of populations did not account for the full range of variation among them. However, the resistance to P. medicaginis was much lower in the sativa than in the falcata populations.Populations also varied significantly in stem fiber content and digestibility. Stem digestibility was negatively correlated to forage yield. Wild sativa and falcata populations had lower fiber content and higher digestibility than cultivated sativa populations. The medicagenic acid was the sapogenin responsible for the anti-nutritional effect of the lucerne measured by the yellow mealworm larvae Tenebrio molitor. The medicagenic acid content was lowest for the pure sativa populations, highest for the pure falcata populations, and intermediate for the French sativa varieties that have some traits originating from falcata germplasm. Some populations could be used in breeding programs to improve disease and nematode resistance, and forage quality.  相似文献   

16.
In order to explore the pharmacological effects of active components of Gastrodiae Rhizoma on the central nervous system,through consulting related literatures,...  相似文献   

17.
[Objectives]The purpose of this study was to investigate the effects of Pb on rhizosphere soil enzyme activity and chemical constituents of Achyranthes bidentat...  相似文献   

18.
不同P-Zn配比对小麦幼苗微量元素营养的影响   总被引:2,自引:0,他引:2  
采用了螯合-缓冲营养液培养方法对小麦进行了苗期培养试验,在3个P水平(0,0.6,3.0 mmol/L)和3个Zn水平(0,3,30 μmol/L)的完全组合下对小麦苗期生长及Zn、Fe、Cu、Mn营养进行了研究,旨在为小麦微肥施用提供理论依据.结果表明,P、Zn的正常供应促进了小麦生长,二者的缺乏与过量均会抑制小麦发育,且这种影响在冠部表现得更为明显.在小麦苗期,Zn与Cu的吸收存在明显的拮抗作用,但供Zn则促进了Zn和Cu的转运,而Mn转运则受到了抑制;过量供Zn时,大量Zn被转运到冠部,同时明显抑制了(Fe+Cu+Mn)的吸收总量;P的供应显著地抑制了Fe的吸收,但P的供应提高了Zn、Cu、Mn的转运率;P、Zn在对Zn与Fe、Cu、Mn间吸收竞争的影响中,Zn本身的影响要比P的影响更为明显,供Zn明显促进了小麦幼苗对Zn的吸收;在小麦幼苗冠部,Zn与Fe的竞争中,供P利于Zn的吸收,缺P则利于Fe的吸收;而Zn与Cu以及Zn与Mn间的竞争中,缺磷时利于Zn的吸收,供磷后则利于Cu和Mn的吸收.总之,小麦幼苗Zn、Fe、Cu、Mn营养中,P、Zn的不同配比会不同程度地改变Zn与Fe、Cu、Mn的协同或拮抗效应.  相似文献   

19.
Summary Glycine tabacina (Labill.) Benth. is a wild perennial species related to the cultivated soybean, G. max (L.) Merr. It is composed of diploid (2n=40) and tetraploid (2n=80) cytotypes. Currently, to differentiate the cytotypes, plants are grown out in the greenhouse and chromosome counts made on pollen mother cells. It is a laborious and time consuming process. The objective of this study was to determine whether electrophoretic techniques could be utilized to separate the cytotypes. Electrophoretic examination of seven isozyme systems from seed of 67 G. tabacina accessions revealed banding patterns that could be used to differentiate between diploid and tetraploid cytotypes in the species. Among the tetraploid accessions, the number of bands observed were always greater than the diploids. Some tetraploid banding patterns consisted of bands similar to the diploid tabacina and/or additional bands previously identified in other Glycine species. The patterns of isozyme multiplicity and variation in the tetraploid tabacinas suggests more than one mode of origin for the tetraploids.  相似文献   

20.
Summary Some photosynthetic characters as-leaf anatomy, leaf photosynthetic rate and CO2 compensation pointdistinguishing C3 and C4 plants and physiological characters as leaf area ratio, nitrogen content, leaf stem ratio and total shoot-to-root and deep root-to-shoot ratios have been studied in rice × sorghum and rice × wheat hybrids. Rice × sorghum 1. has lower values of photosynthetic rate, leaf nitrogen, total root and deep root-to-shoot ratio and CO2 compensation point as of rice parent where as, rice × sorghym 2. is superior in all these characters. Both hybrids lack kranz anatomy. Though both rice × sorghum hybrids show characters of C3 rice plant but rice × sorghum 2. has improved drought tolerance and leaf characters in relation to yield. Rice × wheat hybrid have higher assimilatory area and higher total root-to-shoot ratio. Grains of rice × wheat hybrids are identical to rice grain. However, as grains of rice × wheat hybrid does not contain seed coat, it could be exploited as novel rice germplasm after improvement.Abbreviations T CO2 compensation point - T21 CO2 compensation point at 21% O2 - T2 CO2 compensation point at 2% O2 - dR/sR deep Root-to-shoot Ratio - LAR Leaf Area Ratio - CER photosynthetic rate - TR/SR Total Root-to-Shoot Ratio  相似文献   

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