缅甸莫西西玉——一种特殊的动力变质与交代玉石

以缅甸莫西西玉为研究对象,采用镜下分析、X射线粉晶衍射、电子探针、拉曼光谱、红外吸收光谱等分析测试方法,重点对该玉石的成分、玉相和振动光谱特征进行了研究。研究表明,莫西西玉主要由一组分布不均的富铬矿物组成,即铬硬玉[x(Kch)为15%～18%]、富铬氟镁钠闪石[w(Cr2O3)为4%左右]、钠长石、含铬钠长石[w(Cr2O3)为1%左右]、钠铬辉石[x(Kch)为62%～65%]及铬铁矿。玉石具典型的糜棱、交代网脉状及交代假象结构。在300～580cm-1拉曼位移范围内,钠铬辉石和铬硬玉中由Cr—O和Al—O弯曲振动致拉曼谱峰,其峰形、峰位、半高宽及振动频率均存在较明显的差异。研究结果初步证实,莫西西玉属一种典型的由不同期次动力变质与低温热液交代作用形成的玉石。

RFLP Detection of Genetic Variation of Maize Inbred Lines

Genetic similarities of 13 inbred lines of maize (Zea mays L.) were analyzed by restriction fragment length polymorphisms (RFLPs). The objectives of the study were to detect genetic similarities among 13 inbreds and to assign them to heterotic groups. By means of 24 probe_enzyme combinations (PECs) selected for locus specificity, clear patterns and reproducibility, 85 alleles were found with an average of 3.3 alleles per locus. The allelic frequency data were used to estimate genetic similarities among lines, and as a result the diversity index of 0.499 was obtained. Genetic similarities between the pairs of 13 lines ranged from 0.523 up to 0.802 with an average of 0.649. The UPGMA clustering algorithm analysis classified the 13 lines into five groups, which generally corresponded to known maize heterotic groups based on pedigree information. The authors concluded that RFLP_based markers could be used for investigating genetic relationships between maize inbred lines and assigning them to heterotic groups, but it seemed that a large number of PECs were needed to obtain reliable estimates of genetic similarity.

Comparison between Microwave Coherent and Incoherent Scattering Models in Corn Field

[Objective] The aim was to compare and analyze microwave coherent and incoherent scattering models in a corn field. [Method] In the research, based on a coherent scattering model （Stile）, we proposed a coherent scattering model exclusive for corn, in which, physical optics （PO） and infinite-length dielectric cylinder were used to calculate single-scattering matrices of corn leaves and stalks. In addition, coherent components produced from interaction among the scattering mechanisms were also considered and this coherent model was compared with the Michigan Mi- crowave Canopy Scattering （MIMICS） model. The measured data in a corn filed in Gongzhuling in Jilin Province were used as the input parameters of the coherent and incoherent models. We simulated backscattering coefficients of VV and HH po- larization at L and C bands and made a comparison between the simulation results. [Result] The simulation results at L-band were poor, which indicated that we could not find regularity at early growth stage of vegetation. In addition, comparisons be- tween coherent and incoherent scattering models proved that the coherence triggered by the scattering mechanism was small. [Conclusion] In the research, we analyzed differences between coherent and incoherent scattering models with change of incident angle, and further analysis on the differences with change of vegetation and soil needed to be made in future.

Stability and changes in astaxanthin ester composition from Haematococcus pluvialis during storage

In this paper,we investigated the effects of temperature,oxygen,antioxidants,and corn germ oil on the stability of astaxanthin from Haematococcus pluvialis under different storage conditions,and changes in the composition of astaxanthin esters during storage using high performance liquid chromatography and spectrophotometry.Oxygen and high temperatures(22–25°C) significantly reduced the stability of astaxanthin esters.Corn germ oil and antioxidants(ascorbic acid and vitamin E)failed to protect astaxanthin from oxidation,and actually significantly increased the instability of astaxanthin.A change in the relative composition of astaxanthin esters was observed after 96 weeks of long-term storage.During storage,the relative amounts of free astaxanthin and astaxanthin monoesters declined,while the relative amount of astaxanthin diesters increased.Thus,the ratio of astaxanthin diester to monoester increased,and this ratio could be used to indicate if astaxanthin esters have been properly preserved.If the ratio is greater than 0.2,it suggests that the decrease in astaxanthin content could be higher than 20%.Our results show that storing algal powder from H.pluvialis or other natural astaxanthin products under vacuum and in the dark below 4°C is the most economical and applicable storage method for the large-scale production of astaxanthin from H.pluvialis.This storage method can produce an astaxanthin preservation rate of at least 80%after 96 weeks of storage.

Production of bio-ethanol by consecutive hydrogenolysis of corn-stalk cellulose

Current bio-ethanol production entails the enzymatic depolymerization of cellulose,but this process shows low efficiency and poor economy.In this work,we developed a consecutive aqueous hydrogenolysis process for the conversion of corn-stalk cellulose to produce a relatively high concentration of bio-ethanol(6.1 wt%)without humin formation.A high yield of cellulose(ca.50 wt%)is extracted from corn stalk using a green solvent(80 wt%1,4-butanediol)without destroying the structure of the lignin.The first hydrothermal hydrogenolysis step uses a Ni–WO_(x)/SiO_(2)catalyst to convert the high cumulative concentration of cellulose(30 wt%)into a polyol mixture with a 56.5 C%yield of ethylene glycol(EG).The original polyol mixture is then subjected to subsequent selective aqueous-phase hydrogenolysis of the C–O bond to produce bioethanol(75%conversion,84 C%selectivity)over the modified hydrothermally stable Cu catalysts.The added Ni component favors the good dispersion of Cu nanoparticles,and the incorporated Au3+helps to stabilize the active Cu^(0)-Cu^(+)species.This multi-functional catalytic process provides an economically competitive route for the production of cellulosic ethanol from raw lignocellulose.

The Compatibility Effects of Biochar-Vermicompost Mixes on Crop Productivity

This study sought to establish the compatibility effects of biochar/vermin-compost application on growth and yield of maize and cabbages. Biochar application rate was at 3 to 4% of soil weight. Biochar was mixed in various proportions to come up with treatments which were 100% vermicompost, 50/50% biochar： vermicompost, 75/25% biochar： vermicompost and 100% biochar. The experiment was repeated twice and arranged as a completely randomized design and replicated five times. The study established that maize yield increased with application of biochar from 25% to 50%. In the cabbage trial, comparable results in plant height, leaf numbers and final yield was obtained with 100% vermicompost application, 50% and 75% biochar inclusion. When biochar was applied at 100%, noticeable reduction in plant performance was noted. It is recommended to use biochar as a bio-fertiliser at 50/50% biochar： vermicompost in maize and cabbage production.

Determination of fermentable sugar in wort made from degermed corn extruded at low temperature as beer adjunct by HPLC

[Objective] To accurately determine the components and content of fermentable sugars in wort. [Method] The components and content of fermentable sugars in wort made from degermed corn extruded at low temperature as beer adjunct were determined by HPLC. [Result] The contents of sugar components were shown as below: fructose was 3.8 g/L, glucose was 7.4 g/L, sucrose was 4.2 g/L, maltose was 53.8 g/L and maltotriose was 10.6 g/L.The content of the five fermentable sugars had good linear relation within their peak area in the determination range, the correlation coefficient was 0.977 6-0.990 7, the recoveries of samples were >96%, the standard deviation was 1.27%-3.26%. [Conclusion] The method is simple and rapid with high sensitivity and good reproducibility, it provides reliable and accurate analytic method for determining the components of fermentable sugars in wort made from degermed corn extruded at low temperature as beer adjunct.