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1.
A new method of simultaneous determining Cu(II), Zn(II), Fe(II), Mn(II), Co(II) and Ni(II) with a single sweep polarography was developed. The experiment condition was studied and the results show that the optimum base solution is that the residue got from evaporating 25 mL mixed solution, 2.5 mL 1.0 mol/L ethylenediamine, 3.0 mL 1.0 mol/L ammonia-ammonium chloride, 5.0 mL 10 % sodium sulfite and 0.5 mL 0.5 % gelatin were mixed and diluted to 25 mL with water. Under the condition of this base solution, the polarography wave shapes of the six cations are ideal and without overlap of the peaks. In this base solution, Cu(II), Zn(II), Fe(II), Mn(II), Co(II) and Ni(II) in synthetic samples were determined with relative errors 0.4–9.4% and relative standard deviations 0.8%-12.2%. Under this experiment condition, one fold of Pb(II), Cr(VI) and Mo(VI) do not interfere with the determination for Cu(II). This method has been used to the simultaneous determination of the amount of the six cations in the samples of soil and Beiqi Tea. The relative standard deviations were 0. l%-2.1% and recoveries were 93.5%-99.0 %.  相似文献   

2.
The eggs ofArgas reflexus were splashed with the LiCl and Na2Cr2O7 saturated solutions on the 2nd day after laying and were kept at 25° C and 30% RH.Both examined chemical compounds caused great disturbances in embryogenesis ofArgas reflexus. Under influence of Na2Cr2O7 24.8% eggs died. The LiCl solution appeared to be more harmful on larvae development. 21.8% dead eggs, 11.6% dead embryos, and 8.9% larvae hatched abnormally were observed in these experiments
Zusammenfassung Hemmende Faktoren bei der Embryonalentwicklung vonArgas (Argas) reflexus (Fab.) (Acari, Argasidae)Die Eier vonArgas reflexus wurden am 2. Tag der Embryonalentwicklung bei 25° C und 30% r. L. der. Wirkung gesättigter Lösungen von LiCl und Na2Cr2O7 unterzogen.Beide chemischen Verbindungen verursachten große Störungen der Embryogenesis vonArgas reflexus. Unter dem Einfluß von Na2Cr2O7 starben 24.8% der Eier ab. LiCl erwies sich als schädlicher für die Embryonalentwicklung dieser Zeckenart als Na2Cr2O7.Bei den Experimenten mit LiCl wurden 21.8% Eier, 11.6% Embryos und 8.9% (abnormal geschlüpfte) Larven getötet.


With one table  相似文献   

3.
Zusammenfassung Die Nachkommenzahl von einem Weibchen vonSitophilus oryzae oderSitotroga cerealella in Sorghum-Körnern nahm mit dem Ansteigen der ursprünglichen Elterndichte ab. Jedoch nahm die Gesamtzahl an Nachkommen beiS. oryzae bis zu einem Maximalwert zu und danach bei weiterem Anstieg der Elterndichte wieder ab (Crowding-Konkurrenz). BeiS. cerealella dagegen tendierte die Nachkommenzahl dazu, von einem Grenzwert ab—unabhängig von der Elterndichte—konstant zu bleiben (Wettkampf-Konkurrenz).
Intraspezific competition and progeny production inSitophilus oryzae (L.) (Coleopt.) andSitotroga cerealella (Oliv.) (Lepid.) in Sorghum grain
The number of progeny produced per femaleSitophilus oryzae (L.) orSitotroga cerealella (Oliv.), on sorghum grain, decreased as the initial parental density increased. However, the total number of progeny (off-springs) produced inS. oryzae increased to a peak then declined with further increases in parental density (Scramble competition). InS. cerealella the progeny produced tended to be fairly constant once a certain parental density was passed (Contest competition).


Mit einer Tabelle  相似文献   

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The eggs ofArgas (Argas) reflexus (Fab.) were exposed to 0.05% colchicine on 9th, 15th or 23rd–25th days of embryonic development at 25°C and 30% RH. The eggs on the 15th and 23rd–25th days of development were the most sensitive to colchicine. In these experiments 6.9% and 9.4% embryos died, respectively. The largest number of disturbances of egg hatch (11.5%) were observed after exposure of the eggs to colchicine on 23rd–25th days of embryogenesis.  相似文献   

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In a recent paper, V. Michelsen(1988, Systematic Entomology 13: 271–314) revised 18 world species of anthomyiid cone and seed pests and described a new genus,Strobilomyia gen. n. He consideredS. melaniola of Northeast China to be a synonym ofS. viaria of North America. That they are the same species is not accepted. We compared the morphological characters of male and femaleS. melaniola adults with the close relatives,S. viaria andS. sibirica. We conclude that they are not the same species and that S.melaniola is an independent species.  相似文献   

8.
秘诀(小说)     
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9.
板栗作为食药两用植物,富含蛋白质、淀粉、脂肪、B族维生素、维生素C、胡萝卜素等多种营养成分,其皮、叶、花、苞中含有黄酮、多酚、单宁等大量的活性成分。从板栗各部位的形貌结构、化学成分、主要产品以及加工现状进行综述,并对板栗综合利用研究提出了展望,以期完善板栗产业链建设,为板栗高值化开发方向提供参考依据。  相似文献   

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猎手(小说)     
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(6)则     
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(7)则     
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(8)则     
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17.
This study was carried out to determine the development, survival and reproduction responses of Adalia fasciatopunctata revelierei (Mulsant) (Coleoptera: Coccinellidae) feeding on Hyalopterus pruni (Geoffroy) (Homoptera: Aphididae), using 20, 40, 80, 160 and 250 prey densities. All experiments were conducted at 25±1°C, 60±5% relative humidity, 16:8 light:dark under laboratory conditions. The average daily prey consumption of A. fasciatopunctata revelierei immatures and adults increased with increasing prey densities. Predation was not different for the larval stages at 80, 160 and 250 prey densities. The longevities of adult females were 35.67, 35.33, 49.00, 58.33 and 57.16 days when 20, 40, 80, 160 and 250 H. pruni were provided, respectively. The mean daily and total fecundity of A. fasciatopunctata revelierei increased with increasing prey densities. Females of A. fasciatopunctata revelierei feeding on H. pruni laid 89 eggs at 20 prey density and 301.67 eggs at 160 prey density. The search rate of females was higher than that of all larval instars; and the search rate of the fourth-instar larvae was higher than that of younger instars. Handling time decreased with development from larval stages to adult.  相似文献   

18.
Terminalia arjuna (“Arjuna”) in the family Combretaceae is a well-known medicinal tree whose bark is extensively used in Ayurvedic medicine, particularly as a cardiac tonic. Demand for Arjuna bark, both in India and abroad, has been growing rapidly for over a decade. Litsea glutinosa (“Maida”) in the family Lauraceae is a medium size tree. Its bark is used to treat joint pain, fracture, sprain, arthritis, back pain, and indigestion. Presently the bark of Arjuna and Maida is being extracted through unscientific and destructive harvesting practices. This is the first study on development of sustainable harvesting practices of Arjuna and Maida bark. The stages of bark recovery varied from tree to tree. Age of tree, harvesting method, and season of harvest influenced bark regeneration. This study recommends that for sustainable harvest, mature bark from only one fourth to one third of the total girth of the tree should be stripped by removing only outer and middle bark, leaving the inner bark for regeneration. However, strip harvesting was found to be the best method in younger trees having a girth at breast height (GBH) of less than 60 cm. Sustainable bark harvesting can be done after every 2 yr for Arjuna and 1 yr for Maida by removing opposite quarters of trunk bark.  相似文献   

19.
The parasitoids of Saperda populnea (L.) (Col.: Cerambycidae) were studied in Bulgaria during the period 1997?–?2001. Galls with pest larvae were collected from young aspen trees at eight locations (Sofia, Kokaliane, Plana, Churek, Gorni Lom, Gintzi, Dolno Kamartzi and Klisura) and examined under laboratory conditions. Four species were reared from 1118 galls containing overwintering pest larvae: Iphiaulax impostor (Scop.) (Hym.: Braconidae), Dolichomitus populneus (Ratz.), Schreineria populnea (Gir.) (Hym.: Ichneumonidae) and Billaea irrorata (Meig.) (Dipt.: Tachinidae). All of the parasitoids were solitary. Schreineria populnea was found as a new parasitoid of the host in Bulgaria. B. irrorata emerged mainly from late-stage S. populnea larvae; the remaining species from both early- and mid-stage larvae. In the parasitoid complex of S. populnea, the most numerous were B. irrorata (59.8?%) and D. populneus (29.4?%). The percentage of host larval parasitism varied from 2.4 to 33.3, with an average of 9.7?%. B. irrorata was the most important in reducing the pest number. The average mortality of S. populnea caused by the tachinid was 5.8?%, and the highest mortality observed in individual study was 20.2?%.  相似文献   

20.
Cool and wet weather in some periods of the season generally supressed the RWA (Diuraphis noxia Kurdj.) populations in the Czech republic in 2001. However, some sites manifested population levels ranging out of the population mean stated per area, and these sites were also apparently responsible for respective peaks of alate aphids sampled by suction traps. An analysis of these sites determined them to be attributed to some poor quality barley fields in a warmer area of the state. RWA is known to vary in all-over populations in different years, and the year 2001 illustrated its capability of its surviving even unfavourable periods and seasons, remaining well-established in the area.  相似文献   

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