DEVELOPMENT AND EXPERIMENTAL ANALYSIS OF HYDRAULIC LOCK OF THE THINNEST COAL SEAM SHEARER

The structure and work theory of a new type of hydraulic lock of the thinnest coal seam shearer is described in this paper. Its performance tests have been done the test results show that the performance of hydraulic lock is satisfactory and can be fit for the needs of locking and floating of the cutting drum of the thinnest coal seam shearer     

低温条件下组合式生态浮床系统净化微污染水体的特性研究

为研究低温对生态浮床水质净化效果的影响,引入陶粒作为浮床的基质,构筑了美人蕉-陶粒基质组合式生态浮床系统,研究在低温条件下其对微污染水体水质净化的效果特性。结果表明,在进水温度为0.5~15℃,进水DO浓度为4.94~6.65mg/L,水体交换时间为7d下,该生态浮床系统对水体中NH+4-N、NO-3-N、NO-2-N、TN、COD和色度的平均去除率为36.30%、77.37%、50.34%、52.56%、16.89%和70.99%。当水体的温度低于5.0℃,该生态浮床系统对水体中NH+4-N、NO-2-N、TN、COD和色度的去除效果均有所下降。     

Inheritance studies of characters associated with floating habit and their linkage relationship in rice

Summary Deep water rice varieties in general have certain peculiar characters which are associated with floating habit. These characters are (i) early nodal differentiation, (ii) nodal rooting, (iii) spreading habit, (iv) awned grains, (v) brown hull colour, (vi) red pericarp (red rice), and (vii) seed dormancy. Inheritance of these characters and linkage relationship of genes governing these characters were studied in a cross between Pankaj (non floating) and Nageribao (floating) rice varieties. Nageribao, a cultivar from Assam possesses these characters.Early nodal differentiation was observed to be controlled by a single dominant gene, designated as Nd. Nodal rooting was controlled by two dominant complementary genes, designated as Nr ₁ and Nr ₂. We found an inhibitory factor for spreading habit and one for brown hull colour in Pankaj; the operation of two dominant duplicate genes An ₁ and An ₂ for controlling awning characters, a single dominant gene Rd for red pericarp colour and a single dominant gene Gd for grain dormancy. Joint segregations between these characters resulted in the assignment of genes in the X linkage group of indica rices with estimated map distances based on the cross-over values. The genes An (awning), Es (spreading habit), Nr (nodal rooting) and Nd (nodal differentiation) were observed to be associated with each other. The gene for red pericarp (Rd) was observed to be linked with the grain dormaney gene Gd.     

THE WAYS FOR IMPROVING INDOOR ENVIRONMENT AND AIR-CONDITIONING SYSTEMS IN DANCLING HALLS

Since 1988, air temperature, humidity, air quality, noise level and intensity of illumination in lots of dancing halls in China have been investigated and tested. This paper introduces the present situation of indoor environment and air conditioning systems in dancing halls of China. The design indexes of cooling load for room and ontside air are recommended. The reasons for indoor environment deterioration have been found out. From the actual situation of China, the ways for imoroving indoor environment and approach of energy conservation in air conditioning systems are explored.     

Inheritance of plant elongation ability at seedling stage in rice

Summary In a comparison of methods to study inheritance of plant elongation ability, 15-, 20-, 25-, 30-, and 35-day-old F₂ populations of a cross between Baisbish (floating variety) and IR42 (nonelongating semidwarf modern variety) of rice, (Oryza sativa L.) were subjected to 65 cm water depth for 7 days. Frequency distribution of plant height before and after submergence was obtained. Bimodal curves in 15-, 20- and 25-day-old populations gave good fits to 9:7 elongating: nonelongating plants, suggesting that elongation was due to two dominant complementary genes. Segregation in the 30-day-old population was not clear-cut. A seedling age of 20 days was subsequently chosen for further studies.Two F₂'s involving floating rice and a nonelongating semidwarf; four F₂'s involving floating rice and an elongating semidwarf; and two F₂'s involving elongating and nonelongating semidwarf parents were studied with 20-day-old seedlings in the same way. Floating rice combinations with nonelongating semidwarf parents as well as with elongating semidwarf parents segregated into 9:7 elongating: nonelongating ratio. It is possible that because elongating and nonelongating dwarf parents did not differ much in elongation ability at seedling age, their combination with floating rice parents provided similar segregation. The F₂ distributions for height in elongating and nonelongating dwarf cross combinations were continuous with one peak.Genetic constitution of parents proposed are Sd1 Sd1 El El for floating parents, sd1 sd1 El El for semidwarf elongating, and sd1 sd1 el el for dwarf nonelongating.     

漂浮植物对富营养化景观水体的净化效果研究

利用软隔离小区试验研究了凤眼莲(Eichhornia crassipes)、黄花水龙(Jussiaen repens L.)、空心莲子草(Alternanthera philoxeroides(Mart.)Griseb.)、水鳖(Hydrocharis dubia(Bl.)Backer.)和四角菱(Trapaquadrispinosa Roxb.)5种不同漂浮植物对富营养化景观水体的净化效果,研究结果表明,经过100天植物处理,5种飘浮植物对水体中总氮的去除率为黄花水龙(63)%>凤眼莲(57%)>水鳖(46%)>四角菱(42%)>空心莲子草(34%),对总磷的去除率为凤眼莲(52%)>黄花水龙(50%)>水鳖(45%)>四角菱(31%)>空心莲子草(22%),其中凤眼莲、黄花水龙处理围区的水质净化效果最好,水体中总氮和总磷的去除率也最高,这与植物自身吸收同化污染水体中氮素、磷素的能力大小及植物根系微生物的作用都有关。凤眼莲、黄花水龙在提高水体透明度方面表现最佳,试验围区在处理40天后水质透明度即可达到1 m以上,而空心莲子草、水鳖和四角菱的试验围区则需要处理60天以后透明度才能达到1 m以上。5种漂浮植物对富营养化景观水体都有较好的净化效果,且易于成活,容易管理,可在今后的水质净化中推广应用。     

Suitability of foliar N applied to rainfed maize in permanent beds after 12 crop seasons of granular N application

Abstract

Yield and kernel quality of rainfed maize as affected by N fertilizer has been generally evaluated through the application of granular N sources at high rates. The purpose of this work was to estimate the response of maize yield and quality (kernel hardness—floating index, weight and test weight -, P uptake and protein) to foliar N application and preceding granular N. Data for this report were collected in 2014 and 2015 in a long-term experiment established in 2002 under permanent beds in a split plot arrangement. Main plot treatments were three foliar N rates (0, 4.5 and 9?kg ha^?1) laid out on the top of four preceding granular N rates (0, 20, 40 and 60?kg ha^?1) applied from 2002 to 2013 as subplots. Weather conditions were relatively wetter in 2014 than 2015. In 2014, test weight and floating index improved over that in 2015. Foliar application of 9?kg N ha^?1 enhanced yield and protein. In 2014, yield response to preceding N rates showed an increasing trend whereas in 2015 response was null. Kernel P uptake response to preceding N rates showed a differential reaction among foliar N rates; 9?kg ha^?1 showed the greatest uptake. Kernel floating index was associated to kernel P uptake. Apparently, this relationship has not been previously reported. Results suggests that the application of 9?kg N ha^?1 to foliage of rainfed maize grown in permanent beds has the potential to substitute the traditional fertilization practice of granular N sources.