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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.
Seedling of Norway spruce (Picea abies L.) were grown under three different light qualities in fluid-roof growth chambers. Blue light with a high red/far-red ratio decreased shoot length as well as total plant dry weight compared to natural light. Yellow light with a low blue/red ratio did not significantly affect the plants. The effects of light quality were generally the same at 18, 24 and 28 °C day temperature. Plant growth was reduced at temperatures above 24 °C.  相似文献   

3.
经对元江县芒果成熟期的虫害芒果实蝇 2年的系统观察 ,掌握了该虫害的完整生活史和为害特点。元江芒果实蝇 1年发生 6代 ,每年 2个高峰期 ,第 1个高峰期在 4月下旬 ,第 2个高峰期在 7月初至 8月初。成虫产卵于成熟果实的果皮下 ,幼虫在果内取食果肉。在大田上进行果实套袋 ,农药和性诱剂诱杀 ,化学药剂防治试验 ,取得了一定防治效果。在芒果近成熟期连续施诱杀剂 12次 ,可有效地控制芒果实蝇的为害 ,诱杀剂以甲基丁香酚效果为好。  相似文献   

4.
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   

5.
Ectinogonia buquetti (Spin.) (Coleoptera, Buprestidae) was identified as the agent causing damage on a Eucalyptus camaldulensis (Dehnh.) bioenergy plantation. Damage affected the principal apex and upper lateral branches and loss of lateral branches on E. camaldulensis due to complete ring-barking. E. buquetti is a coleopteron native to Chile, it preferably feeds on the wood of native species. A total of 205 individuals, all adults were found; 45% of the plants presented some type of damage.  相似文献   

6.
7.
Host plant preference of the Russian wheat aphid Diuraphis noxia (Kurdj.) was studied on 11 cultivars of 9 plant species: winter barley, spring barley, winter wheat, spring wheat, rye, oat, Triticale, canary grass, red millet yellow millet and maize. Seeds of the host plants were sown in a circle near the edge of pots. The host plant choice was evaluated 24 hours after releasing 55 Diuraphis noxia female adults in the middle of each pot. The suitability of different hosts for aphid development was evaluated 2, 7 and 14 days after infestation based on the mean number of Russian wheat aphid individuals per plant. Red millet, yellow millet and maize were chosen by significantly fewer aphids than grain crops. Winter and spring barley were chosen as hosts most frequently, and the progeny production was also the highest on these plants. The growth rate of D. noxia was significantly affected by the host plants and the date of assessment and their interaction.  相似文献   

8.
胭脂虫实验种群研究   总被引:8,自引:2,他引:8       下载免费PDF全文
利用人工气候箱,按照正交设计方法,设置了8种不同温度、湿度、光照条件组合,运用生命表技术,对胭脂虫进行了种群动态研究。研究结果表明:15℃以下,胭脂虫卵有少量孵化,但不能完成世代;2D、25、30℃条件下胭脂虫能完成世代。从培育的胭脂虫的怀卵量、种群趋势指数及大小方面比较,以温度25℃、相对湿度60%和80%、光照强度980lx和601x的组合条件为好;胭脂虫的雌雄性比远大于1:1,环境因子对性比具有较大的影响;胭脂虫的种群趋势指数一般大于20,平均约40,对培育十分有利;发育起点温度为9.0℃,世代有效积温为822.9日度;多因素方差分析结果显示,温度为影响胭脂虫发育的最显著因素,而湿度和光照的影响相对较小。  相似文献   

9.
《占用征用林地审核审批管理办法》 ,已于 2 0 0 0年 1 1月 2日国家林业局第 3次局务会议审议通过 ,现予发布 ,自发布之日起施行。  国家林业局局长   周生贤 二○○一年一月四日国家林业局令 第2号  相似文献   

10.
《林木和林地权属登记管理办法》 ,已于 2 0 0 0年 1 1月 2日国家林业局第 3次局务会议审议通过 ,现予发布 ,自发布之日起施行。国家林业局局长   周生贤 二○○○年十二月三十一日国家林业局令 第1号  相似文献   

11.
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   

12.
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   

13.
采用定点观测方法研究栗大蚜生物学特性。调查了栗大蚜在不同树龄危害情况;基本弄清楚了栗大蚜危害规律。结合多年防治实践,提出了综合防治技术措施,使栗大蚜的危害得到了有效的控制。  相似文献   

14.
以羟丙基纤维素-聚丙烯酸(HPC-PAA)高分子复合物微粒为模板,通过自由基聚合反应在模板表面聚合单体N-异丙基丙烯酰胺(NIPAm),形成HPC-PAA-PNIPAm复合物纳米微粒,平均粒径约为130 nm.调节体系的pH值至8.0去除HPC模板后,获得中空结构的PNIPAm-PAA纳米胶囊,粒径约为500 nm.以盐酸阿霉素(Dox)作为模型药物,考察了PNIPAm-PAA纳米胶囊作为药物载体的相关性能.研究表明:PNIPAm-PAA纳米胶囊和Dox分子通过正负电荷的相互吸引实现有效结合,载药量高达130%;同时,载药纳米胶囊表现出很好的药物缓释效果.  相似文献   

15.
Bean-weevil (Bruchus chinensis L.) is commonly found in Sind region of Pakistan and it severely damages Mong seeds (Phaseolus mungo L.), and some other pulses in storage conditions. The parasitoidApanteles flavipes (Cam.), a gregarious Braconid parasite of Bean-weevil was reared under laboratory conditions with a view to exploiting it for the biological control techniques to be reported for the first time in Pakistan. This parasite completes its whole life cycle inside the body of the host by completing a number of generations in a year, and it successfully parasitisesBruchus spp. larvae inside the seed body; and its life cycle entirely depends upon the environmental factors like temperature and humidity as well as on the physiological condition of the host. It parasitised upto 45% in field population and 83% under laboratory conditions.  相似文献   

16.
We compared shade tolerance of maple, ash and beech in the saplingstage from two sites with rich soils differing in water supply,growing in dense thickets underneath a beech shelterwood ofvarying canopy densities. Shade tolerance was described by twocomponents: mortality in shade and height growth in high light.At low light, beech showed the least mortality, maple the highestand ash in between on both sites. The decline with increasinglight was steepest in beech and more gradual with ash and maple.At 15 per cent above canopy light, all three species approachedzero mortality. Beech as the most shade-tolerant species hadthe highest survival rate under low light and the least lengthgrowth rate under high light (>17 per cent). Ash had a lowersurvival rate at low light than beech and a highest growth rateat high light. Maple showed a bit weaker trade-off with thelowest survival rate but a growth rate inferior to ash. On thebetter water-supplied site, height growth was significantlysuperior in all three species only under high light. On thebasis of these results, silvicultural conclusions are drawnwith respect to appropriate light levels and cutting types.  相似文献   

17.
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   

18.
以高效液相色谱法检测方法,对橙皮甙的稳定性进行了初步研究。结果表明:橙皮甙的耐光、耐热性能好,在碱性较强的条件下稳定存在,pH值为12时,其在溶液中的溶解度最大。  相似文献   

19.
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   

20.
以戊二醛为交联剂,壳聚糖为聚合物基质,固化余甘子单宁制备一种固体吸附材料余甘子固定化单宁(PEIT),并采用FT-IR、DSC、TG对PEIT的结构和热性质进行了表征。研究结果表明:余甘子单宁通过戊二醛与壳聚糖基质产生了交联,最佳制备条件为2 g余甘子单宁,m(戊二醛)∶m(余甘子单宁)1∶4,m(壳聚糖)∶m(余甘子单宁)1.5∶1,反应液初始pH值4,55℃反应3 h。将制备的PEIT用于吸附金属离子,结果显示其对Ge(Ⅳ)、Ga(Ⅲ)和In(Ⅲ)有良好的吸附效果,当pH值为4时,In(Ⅲ)吸附量最大;当pH值为3时,Ge(Ⅳ)和Ga(Ⅲ)吸附量最大;对这3种金属离子的吸附符合准二级动力学方程,说明其吸附机理为化学吸附;吸附过程对温度并不敏感,且最佳吸附温度为30℃。吸附等温线符合Langmuir等温线模型,证明其表面存在均匀的吸附位点,且主要是单分子层吸附,Ga(Ⅲ)、In(Ⅲ)和Ge(Ⅳ)的最大吸附量分别为67.65、70.00和54.11 mg/g。  相似文献   

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