A personal computer program for calculation of soil bulk density coefficient of linear extensibility,and linear shrinkage

Abstract

A computer program was developed to calculate bulk density(BD), coefficient of linear extenslbility(COLE), linear extensibility(LE), and linear shrinkage(LS) in the presence or absence of coarse fragments (>2mm). When coarse fragments are present in a soil clod, COLE and linear extensibility calculations become more complex, requiring additional equations and correction factors. The calculation of linear shrinkage is not sensitive to coarse fragments, thus requiring a single equation. This BASIC computer language program is accommodating to various parameter imputs and correction factors for fast calculation of BD, COLE, LE and LS in soil clods with and without coarse fragments.     

A METHOD TO IMPROVE DIMENSIONAL STABILITY OF PF PARTICLEBOARD

A method of alkaline pretreatment of particles was designed to produce threetypes of chips.The pretreatmentet of particles in 1% water solution of NaOH for 30minutes offered a possibility of producing PF bonded particleboards with minimal irrecover-able swell and a reduction in thickness swelling.The method used in this work could beused to produce more stable PF particeboard.     

Sorption Characteristics of Chromium and Its Phytotoxic Effect with or without City Compost on Maize and Spinach in a Vertisol of Central India

Abstract

Phytotoxicity, due to chromium [Cr (VI)] additions from low to very high levels in a swell–shrink clayey soil (Haplustert), in maize and spinach was studied in a pot culture experiment. Six levels of Cr (VI) (0, 5, 10, 25, 50, and 75 mg kg^?1 soil) for maize and five levels for spinach (0, 2, 5, 10, and 25 mg kg^?1 soil) were applied singly and in combination with two doses (0 and 20 t ha^?1) of city compost. At levels of more than 75 mg Cr (VI) kg^?1 soil for maize there was virtually no growth after germination, whereas 25 mg Cr (VI) kg^?1 soil hindered the germination of spinach crop. Initial symptoms of Cr (VI) toxicity appeared as severe wilting of the tops of treated plants. Maize plants suffering from severe Cr (VI) toxicity had smaller roots and narrow brownish red leaves covered with small necrotic spots. In spinach, severe chlorosis was observed in leaves. Higher levels of Cr (VI) inhibited the growth and dry‐matter yield of the crops. However, application of city compost alleviated the toxic effect of Cr (VI). The concentration of Cr (VI) in plant parts increased when Cr (VI) was applied singly but decreased considerably when used in combination with city compost. There was evidence of an antagonistic effect of Cr (VI) on other heavy‐metal (Mn, Cu, Zn, and Fe) concentrations in plant tops. Thus, when Cr (VI) concentration increases, the concentration of other beneficial metals decreases. Chromium (VI) concentration in maize roots ranged from traces (control) to 30 mg kg^?1and were directly related to soil Cr (VI) concentration. At 25 mg Cr (VI) kg^?1 soil, yield of maize was reduced to 41% of control plants, whereas in spinach, 10 mg Cr (VI) kg^?1 soil caused a 33% yield reduction. Experimental results revealed that the maize top (cereal) is less effective in accumulating Cr (VI) than spinach (leafy vegetables). Laboratory studies were also conducted to know Cr (VI) sorption capacity of a swell–shrink clayey soil with and without city compost, and it was found that Cr (VI) sorption reaction was endothermic and spontaneous in nature.     

禽呼肠孤病毒动物感染模型的建立简

The infection model of avian reovirus in chicken was established, which layed the ground for vaccine efficacy test.The 49-day-old chickens were inoculated with 10^2.0, 10^3.0, 10^3.5, 10^4.5and 10^5.5 ELD₅₀/0.2 mL of two strains of ARV, T98 and AV2311, respectively, in foot pad inoculation method. Clinical signs were observed ten days and recorded daily. 6 days after inoculation, serum samples were taken. 10 days after inoculation, chickens were sacrificed for necropsy. Serum antibody was detected by ELISA. The results indicated that the morbidity of 10^5.5and 10^4.5 ELD₅₀/0.2 mL were 100%, and the foot pads of chicken were swelled severely, which were dark red or purple. Symptoms of AV2311 set was a bit lighter than that of T98 strain. The morbidity of 10^3.5 ELD₅₀/0.2 mL was 90% and the morbidity of 10^3.0and 10^2.0 ELD₅₀/0.2 mL were 80%. The ELISA result indicated that only the serum efficacy of 10^4.5and 10^5.5 ELD₅₀/0.2 mL set of two strains of ARV were positive.The experiment proved that the virulence of ARV T98 strain was strong, and had good immunogenicity. The best inoculated dose of ARV T98 strain was 10^4.0 ELD₅₀/0.2 mL, which provided the important basis for researching the quality standard of chicken viral arthrilis vaccine.     

百合不同离体授粉方法的杂交结实研究

为克服百合(Lilium ssp.)杂交受精前障碍,以5个杂种系品种和1个野生种为试材,采用离体柱头授粉、高体切割花柱授粉和离体子房授粉方法进行离体授粉杂交.结果显示,对于近缘杂交,离体柱头授粉的子房膨大率和结实率分别为30%和15%,高体切割花柱授粉的为15%和5%,离体子房授粉的为25%和5%;不同杂种系间杂交组合3种授粉方法的子房膨大率和结实率分别为17%和13%、3%和3%、10%和3%.百合杂交组合类型对高体授粉杂交结实率有明显影响;近缘杂交或系内杂交组合的子房膨大率和结实率高于远缘杂交(系间杂交)组合.在3种离体授粉方法中以高体柱头授粉的效果最好,其余2种方法的效果基本相同.采用胚培救方法获得了部分杂交组合的幼苗,经ISSR分子标记鉴定了杂种的真实性,表明通过离体授粉方法可以获得百合远缘杂交的真实杂种.     

壳聚糖/聚乙烯醇复合膜的研究 Ⅰ.溶胀、吸湿和力学性能

研究了壳聚糖与聚乙烯醇混合制膜，测定了膜的溶胀、吸湿和力学性能．实验结果表明，与壳聚糖膜相比，复合膜的吸水性降低，吸湿性能提高，膜的力学性能有很大的改善     

湘南红砂岩崩解机理研究

在红砂岩室内崩解试验和大气条件模拟的渐进崩解试验中,对崩解过程碎屑物的颗粒级别质量变化进行了跟踪.采用分形方法对颗粒级别的质量变化进行了处理,发现红砂岩膨胀崩解过程是一个分数维不断变化的过程.在崩解达到一定程度后,崩解碎屑物的颗粒级别不再发生变化,红砂岩类的吸水膨胀崩解也停止,此时崩解物的分数维亦达到一个不再变化的临界值.该临界值可用来定量表征其崩解的机理,解决了红砂岩的崩解过程一直无法采用定量指标进行刻画的难题.     

刨花碱液预处理对酚醛刨花板尺寸稳定性的影响

采用氢氧化钠水溶液预处理刨花，并用这些刨花压制单层酚醛刨花板。经１％碱液处理刨花３０ｍｉｎ，可提高板材尺寸稳定性，尤其是可将板材的不可逆厚度膨胀降至极小。     

茎瘤芥PHYA基因与茎瘤芥茎膨大关系的初步研究

从茎瘤芥基因组中克隆了全长PHYA基因,构建了植物超表达载体,通过农杆菌GV3101转化茎瘤芥——永安小叶,得到PCR反应呈阳性的转基因株系.结果发现,在自然生长环境下,转基因植株发生了多种形态变异,如植株矮化、花期提前、叶片变大且色泽浓绿、转基因植株茎膨大延缓等.初步推断PHYA基因参与调控茎瘤芥植物茎膨大过程,过量表达PHYA基因可能会抑制茎膨大过程.