Clustering Analysis on Large Grained Brassica napus Materials Based on the Optimized ACGM Markers

[Objective] This study aimed to develop ACGM markers for the clustering analysis of large grained Brassica napus materials. [Method] A total of 44 pairs of ACGM primers were designed according to 18 genes related to Arabidopsis grain development and their homologous rape EST sequences. After electrophoresis, 18 pairs of ACGM primers were selected for the clustering analysis of 16 larger grained samples and four fine grained samples of rapeseed. [Result] PCR result showed that 2-6 specific bands were respectively amplified by each pair of primes, and all the bands were polymorphic and repeatable, suggesting that the optimized ACGM markers were useful for clustering analysis of B. napus species. Clustering analysis revealed that the 20 rapeseed samples were divided into three clusters A, B, and C at similarity coefficient 0.6. Then, the clusters A and B were further divided into five sub clusters A1, A2, A3, B1 and B2 at similarity coefficient 0.67. [Conclusion] This study will provide theoretical and practical values for rape breeding.

Factors Influencing Large-scale Operation of Large Grain Farmers in Northeast China

With the grain yield accounting for 20% of the whole country, the north- east China is a strategic region for ensuring national grain security and also a most centralized region of large grain farmers. Through a sampling survey of large grain farmers in 15 counties and cities of northeast China, with the aid of SPSS and AMOS software, using multiple regression analysis and structural equation modeling, this paper made a quantitative analysis on the influence of the subjective and ob- jective factors of large grain farmers on their large-scale management. The results showed that the age structure, educational level, family operating capital, yield ex- pectation and protective farming awareness of large grain farmers are the positive factors influencing their large scale operation due to agricultural subsidy policy. By comparison, the number of agricultural machinery and equipment owned by family, regional labor force, expectation for future income, and expectation for contractual scale become negative factors influencing large-scale operation of large grain farm- ers because of agricultural policies. When the future expectation, self conditions, family endowment, and operation conditions of large grain farmers increase one unit, their large scale operation motivation will increase by 0.692, 0.689, 0.487 and 0.363 units respectively. Thus, increasing the future expectation and self conditions of large grain farmers is a key factor for promoting large scale operation of farmland.

Analysis on Phenotypic, Physiological and Genetic Characteristics of Large Grain Rice Line lg1

In this study, phenotypic, physiological and genetic characteristics of large grain rice line Igl were investigated. The results showed that Igl exhibited tall plants, long spikes and large grains, with a 1 000-grain weight of 47.58 g. In addition, Igl had strong photosynthetic capacity, but the stomatal conductance-and intercellular CO2 concentration were 32.1% and 3.94% lower compared with 9311, respectively. Igl displayed synchronous grain filling, and there were no significant differences between the contribution rates of superior and inferior grains at the early, middle and late grain-filling stages, but the grain-filling duration of superior grains was longer than that of inferior grains. The genetic analysis indicated that grain length, grain width, length-width ratio, grain thickness and 1 000-grain weight of F2 population obeyed normal distribution, which were quantitative trait loci controlled by multiple genes. The correlation analysis showed that there was an extremely significant positive correlation between grain width and grain length; grain length, grain width and grain thickness exhibited extremely significant positive correlations with 1 000-grain weight and extremely significant negative correlations with length-width ratio, it might be concluded that grain width, grain length, length-width ratio, grain thickness and 1 000- grain weight were controlled by one or more common QTLs. These results provided theoretic basis for the application of large grain rice line Igl in super high-yielding rice breeding.

Experimental study on SC RF cavities by using China large grain niobium for ILC

Large grain niobium has the potential of simplifying the production sequence and consequently reducing the cost of the superconducting RF cavities for ILC. To investigate the feasibility of fabrication and the possibility to achieve high gradient by large grain cavities, two 1.3 GHz cavities were made of China large grain niobium and a series of vertical tests were carried out following several different surfaces treatment procedures. Two cavities have both reached the high gradient of more than 43 MV/m repeatedly and the maximum accelerating field of 47.9 MV/m has been achieved by China large grain niobium. This paper introduces the features of the fabrication and surface treatments on the large grain cavities and presents the preliminary results of the research.

SUPERPLASTICITY IN LARGE-GRAINED Fe_3Al ALLOYS

The superplasticity behavior of Fe-28Al, Fe-28Al-2Ti, Fe-28Al-4Ti (all composition reported in this paper are in atomic percent) alloys has been investigated by tensile testing.optical microscopy and transmission electron mocroscopy.Tensile test were performed at 700 to 900℃ under a strain rate range of about 10-5/s to 10-2/s. Maximum strain rate sensitivity index m was found to be 0.5 and the largest elongation reached 620%. The flow activation energy was measured to be 263kJ/mol for Fe-28Al and 191kJ/ mol for Fe-28Al-2Ti, which are much lower than the creep activation energy generally observed in Fe3Al alloys. After deformation grain size became much finer from about 100 μm to 20-30μm.As combined with TEM observations, we suggested that a continuous recrystallization process took place and superplasticity may arise from this process.

Effect of Effective Grain Size and Grain Boundary of Large Misorientation on Upper Shelf Energy in Pipeline Steels

X65, X70, and X80 belong to high grade pipeline steels. Toughness is one of the most important properties of pipeline steels when the pipeline transports the gas or oil, and the means to control toughness is very important for exploring even higher grade pipeline steels. We established the relationship between toughness and crystallographic parameters of high grade pipeline steels by studying the crystallographic parameters of X65, X70, and X80 using EBSD and analyzing Charpy CVN of X65, X70 and X80. The results show that the effective grain size, the frequency distribution of grain boundary misorientation and the ratio of high angle grain boundary to small angle grain boundary are important parameters. The finer the effective grain size, and the higher the frequency distribution of grain boundaries （〉 50~）, the more excellent toughness of high grade pipeline steels will be.

Enlarging grain sizes for efficient perovskite solar cells by methylamine chloride assisted recrystallization

The quality of MAPbI3 film prepared by solvent engineering process highly depends on environment and antisolvent control.Here,we provided a simple methylamine chloride(MACl)solution treatment using a two-step process to enlarge the perovskite crystal grain sizes to more than 1 lm.Other than treatment on the film surface,the MACl solution diffuses into the MAPbI_(3) films to assist the recrystallization of small crystal at the bottom of perovskite film.The imitative contact between perovskite and substrate is formed.Meanwhile,the enlargement of grain size and ten times enhancement of crystalline reduce trap-assisted recombination of perovskite films.Thus,the significant improvement of cell efficiency of 20.89%as well as device stability is obtained with the MACl treatment.

PROCESS AND PROPERTIES OF THE MODERN MULTIALKALI PHOTOCATHODE USED IN A CASCADE IMAGE INTENSIFIER

A new processing technology and the properties of multialkali antimonide photocathodesare described.The technique requires an initial antimony layer to be deposited on a fiber-optic window at asuitable temperature.After that.the layer is activated by multialkali and antimonide.Thus.the multialkaliphotocathodes named“The Modern Multialkali Photocathode”are obtained.It has been found that aphotocathode thus processed gives a sensitivity of 200 to 300μA/Im for white light at a color temperature of2854K.This paper shows the variation of photosensitivity during processing of a Modern MultialkaliPhotocathode and the variatioon of spectral sensitivity at different wavelengths.The author discusses theresults.gives a supposition of“photoemission center”,and discusses the role of Cs in multialkaliphotocathodes.

Study on the 1.3 GHz low loss shape superconducting cavities at IHEP

As part of the international research program on the superconducting cavity for the International Linear Collider （ILC） R＆D on the 1.3 GHz low loss superconducting cavities has been carried out at the Institute of High Energy Physics （IHEP） since 2005. A design of 1.3 GHz low loss cavity shape was proposed and six single-cell cavities of different niobium material were successfully fabricated with standard technology. In this study our priority was on large grain （LG） cavities. The two LG cavities were treated with complete procedures of surface treatments based on chemical polishing （CP） without electro polishing （EP） at IHEP. The two LG cavities and a fine grain cavity were sent to KEK for vertical testing. All the three cavities reached accelerating gradients higher than 35 MV/m and the maximum gradient of 40.27 MV/m was achieved in the LG cavity. This paper presents the process of the vertical RF tests and the comparison of the LG and fine grain cavities＇s performance.