《Nature》杂志分析孟加拉麦瘟病来源,我国应对该病害引起重视

据4月28日出版的《Nature》杂志报道,今年2月份在亚洲孟加拉发现的麦瘟病,其病原菌系可能来源于南美的巴西。麦瘟病是小麦的一种毁灭性新病害,由Magnaporthe grisea引起。该病害1985年最早在巴西Parana州的北部被发现,并很快扩散到邻近的地区和国家。目前其发病区域主要集中在南美的热带和亚热带地区,包括巴西的中部和南部、玻利维亚中部、

从死亡使者到彷徨王子 哈姆莱特自格拉麦提库斯至科索诺瓦斯的旅程

克罗齐曾说,一切真历史都是当代史。同理,我们也可以说,所有好故事都是时事。莎士比亚知名度最高的剧作《哈姆莱特》取材于12世纪丹麦历史学家萨克索·格拉麦提库斯所写的丹麦史。莎士比亚赋予了哈姆莱特本事新的生命力,然而对这个故事的演绎并未止于莎士比亚。我们简单回顾一下这个故事从萨克索·格拉麦提库斯到莎士比亚的流转,并以立陶宛著名导演科索诺瓦斯的新作为例,说明旧典只有与时俱进,方能成为今典,继而成为经典。

Correlation between Milling Flour Quality of Xinjiang Spring Wheat and Processing Quality of Xinjiang Hand-stretched Noodle

In the research,36 spring wheat cultivars from Xinjiang were used to investigate flour yield,ash content,color,granularity,flour quality,paste quality and gelatinization property and to evaluate processing quality and characters of stretched noodle,in order to explore relationship of milling flour quality with quality property of Xinjiang spring wheat and with processing quality of Xinjiang hand-stretched noodle,which provides theoretical references for improvement of Xinjiang spring wheat cultivars,breeding of specific cultivars（for Xinjiang stretched noodles）,and advancement of stretched noodles.The results indicated that flour color is dominant among flour quality properties of Xinjiang spring wheat,which is of significant correlation with processing quality of stretched noodles.Therefore,in quality improvement of Xinjiang stretched noodles,flour yield of Xinjiang wheat should be enhanced and ash content and damaged starch should be reduced in order to improve quality of flour and stretched noodles from Xinjiang spring wheat.The indices of milling flours for Xinjiang stretched noodles are as follows：flour yield ≥60.77%,ash content ≤ 0.45%,damaged starch≤3.77%,granularity ≤108.14%,brightness（L^＊）≥ 90.86,redness（a^＊）≥-0.82,and yellowness（b^＊） ≤9.00.

浸入艰辛的乐趣——准噶尔恐龙化石发掘现场采访生活散记

当科技记者多年,不知外出采访多少次,要论经历之奇、印象之深、收获之丰,当属两年前那次准噶尔恐龙化石发掘现场之行。线索,是我偶然在乌鲁木齐昆仑宾馆一次新疆地质地貌研讨会上听说的。当时是1987年9月。新疆竟然业有恐龙化石,而且一支中国加拿大联合恐龙化石发掘队伍就在准噶尔!这消息真使我兴奋异常。不知是科技记者猎新探奇职业责任的驱使。

留守的女人不明白的心

如果你是个常年在外打工的男人,那就请你多关心体贴一下独自在家的妻子;如果你也是个留守的农家女,那就要勇敢地面对留守的一切…… 本文所记录的镜头,是三位女人的守家所遇。

一种高效广谱驱虫新药问世

由英国科学家研制一种高效、广谱驱虫新药道拉麦克丁(Doramectin)新近问世。该药属阿维菌素类药物,对牛体内线虫及节肢动物具有优良的驱杀效果。据初步试验,对多种线虫包括成虫及未成熟幼虫均有很好的驱杀作用,最低平均驱杀效力达99.6％。对肿孔库柏线虫、奥氏奥斯特线虫、胎生网尾线虫的驱杀效力分别达90.7％、99.9％及100％。

Phenotypic Variation within a Jordanian Landrace of Durum Wheat ＂Safra Ma＇an＂ （Triticum turgidum L, var, Durum）

Two hundred and eighty six lines were selected randomly from the tetraploid wheat （Tritieum turgidum L.var Durum） landrace ＂Safra Ma＇an＂. The whole population with three check cultivars （ACSAD 65, HOURANI 27 and AMRA） was evaluated at Maru Agriculture Research Station for 16 characters including grain yield per plant. The objectives were to assess the magnitude of phenotypic variations for the traits in ＂Safra Ma＇an＂ and to evaluate the potential usefulness of some of the traits identified. Results showed wide range of phenotypic variation for several traits. Monomorphism was common for juvenile growth habit, whereas, the rest of the characters exhibited polymorphism in varying degrees. Considering all characters, the average diversity （H＇） for ＂Safra Ma＇an＂ landrace was 0.65 ± 0.047. Ten lines were superior to the check （HOURANI 27） for grain yield per plant. Subsequently, the population lines were clustered into six distinct groups at a distance of about 0.55 based on their similarity for all traits, ACSAD 65 and AMRA located in separate clusters, whereas, HOURANI 27 cultivar was presented in cluster with the most lines of ＂Safra Ma＇an＂. Thirteen lines from the population showed a bluish green cast or glaucousness characters. Glaucous lines had greater kernels per spike. In contrast, this character showed no significant association with grain yield per plant despite the greater grain yield per plant obtained for the glaucous lines. The results are important for the breeding and selection in this land race.

Selected Mineral Contents in Wheat from Paraguay by X-ray Fluorescence

The two fold purpose of this paper is to determine the composition of selected elements in Paraguayan wheat and flour as well as to analyse the implications of the bromine/bromate content on bakery products： the use （malpractice） of KBrO3 as an additive in the bakery dough to improve the whiteness and other characteristics of bread is well known. Accordingly, selected minor and trace elements in eight varieties of wheat from the center and south areas of Eastern Paraguay as well as commercial flour samples and bakery products were analyzed by XRF （X-ray fluorescence） techniques. The examined elements were K, Ca, Ti, Mn, Fe, Cu, Zn, Br, Rb, Sr. The results on wheat and commercial flour were consistent with those found elsewhere. With regard to the bakery products, in about 35% of the samples, the bromine/bromate content exceeded the normal Br values of Paraguayan flour showing bromate malpractice. From dietary point of view, it should be emphasized that KBrO3 is a complete carcinogen and its use as food additive has been banned. The employment of XRF to analyze bromine is easy, simple and reliable.

Series Solution for Rotating Flow of an Upper Convected Maxwell Fluid over a Stretching Sheet

The equations for two-dimensional flow of an upper convected Maxwell （UCM） fluid in a rotating frame are modeled. The resulting equations are first simplified by a boundary layer approach and then solved by a homotopy analysis method （HAM）. Convergence of series solution is discussed through residual error curves. The results of the influence of viscoelastic and rotation parameters are plotted and discussed.

Convective heat and mass transfer effects in three-dimensional flow of Maxwell fluid over a stretching surface with heat source

Heat and mass transfer effects in three-dimensional flow of Maxwell fluid over a stretching surface were addressed.Analysis was performed in the presence of internal heat generation/absorption. Concentration and thermal buoyancy effects were accounted. Convective boundary conditions for heat and mass transfer analysis were explored. Series solutions of the resulting problem were developed. Effects of mixed convection, internal heat generation/absorption parameter and Biot numbers on the dimensionless velocity, temperature and concentration distributions were illustrated graphically. Numerical values of local Nusselt and Sherwood numbers were obtained and analyzed for all the physical parameters. It is found that both thermal and concentration boundary layer thicknesses are decreasing functions of stretching ratio. Variations of mixed convection parameter and concentration buoyancy parameter on the velocity profiles and associated boundary layer thicknesses are enhanced. Velocity profiles and temperature increase in the case of internal heat generation while they reduce for heat absorption. Heat transfer Biot number increases the thermal boundary layer thickness and temperature. Also concentration and its associated boundary layer are enhanced with an increase in mass transfer Biot number. The local Nusselt and Sherwood numbers have quite similar behaviors for increasing values of mixed convection parameter, concentration buoyancy parameter and Deborah number.

Double-Cropping Pinto Bean after Winter Barley in Western Colorado USA

A double-cropping field study was conducted at the Colorado State University, Fruita. Colorado USA to evaluate an irrigated, double-cropping system of winter barley （Hordeum vulgare L.） followed by pinto bean （Phaseolus vutgaris L.） for the valley areas of western Colorado USA and other similar environments. Double-cropping pinto bean after winter barley was successful, but to use our double-cropping technology in commercial agriculture in adapted locations will likely require identifying or developing a winter barley cultivar that matures earlier than current cultivars but does not head and flower so early that it is susceptible to freeze damage. Double-cropping was more profitable in all three years than growing either pinto bean or winter barley as a sole crop.

Detection of Total Phenols, Essential and Toxic Elements in Latvian Whole Grain Bread

A survey was carried out with the aim of assessing the level of the total phenolic compounds （TPC）, essential （Na, K, Ca, Mg, Cu, Zn） and toxic （Cd and Pb） elements in 10 Latvian whole grain rye and/or wheat flour bread samples, obtained from the local market. The quantities of the TPC were determined by spectrophotometry. Mineral content was determined by flame photometry, flame atom absorption spectrometry （FAAS） and electrothermal atomic absorption spectrometry （ETAA） after wet digestion in concentrated HNO3. The values were comparable to the literature data. The average content in all the samples was （on a basis of weight of the product） 547 ± 28 mg/100 g for Na; 280 ±20 mg/100 g for K; 32 ± 2 mg/100 g for Ca; 88 ±5 mg/100 g for Mg; 0.49 ± 0.09 mg/100 g for Cu; 1.6 ±0.2 mg/100 g for Zn. Both Pb and Cd were determined below the limit of detection （LOD 5 0.10 mg/100 g）. The LOD values were determined for each element. The TPC content in defatted samples was slightly lower than the non-defatted ones, showing the dependence on the sample preparation. The calculated average levels of the elements were compared with the maximum levels recommended or regulated by the national legislation.

Study on Microcapsulation of Onion Oil with Complex Coacervation and Spray Drying Method

[Objective] The aim was to study the microcapsulation of onion oil with double place separation-coacevation and spray drying. [Method] The effect of processing parameters which included the different wall material combination,the ratio between the wall material,the core material content and the feed concentration on the efficiency and yield of microencapsulated was evaluated by single factor experiments. [Result] Through orthogonal optimization experiments, the optimum condition was as follows: the ratio of Arabic gum and maltodextrin ration was 1∶1, the core content was 25%, feed composition was 18%, and the microencapsulation efficiency and yield can reach 80.7% and 95.3% respectively. [Conclusion] The microcapsulaiton of onion oil with complex coacervation spray drying method can increase membrane thickness, improve core stability and prolong shelf life of products.

Wheat Stripe Rust Virulence and Varietal Resistance in the Foot Hill Himalayas of Nepal

Stripe rust, caused by Puccinia striiformis f. sp. tritici （Pst） is an important disease of wheat （Triticum aestivum） in Nepal, which is a part of the Himalayas stretching over the North of Nepal, India, Pakistan, Bhutan and beyond. Wheat production plays a crucial role in food security of the marginal hill farmers of Nepal. Frequent epidemics of the rust have caused huge loss in farmer＇s field. Periodic monitoring during 1980-2008 showed that changes in virulence occurred during this period. The objective of this study was to evaluate Pst resistance and its effective genes in wheat genotypes. For this, trap nurseries, wheat stripe rust differentials, commercial cultivars and advanced breeding lines were tested under artificial epiphytotic and natural hot spots conditions during 2005 to 2010. Four genes （Yr5, Yr10, Yr15 and YrSp） consistently showed resistance to the prevailing races. The gene Yr9 and Yr27 in combinations with Yrl8 were found effective. Other lines with combination of minor genes were also found effective. The genotypes Amadina, Kukuna, Tukuru, Kakatsi and Buck Buck widely used in breeding program were resistant. The cultivation of varieties WK1204, Gautam, Gaura and Dhaulagiri have ensured genetic diversity for the rust resistance and slowed down frequent occurrence of epidemics. The findings of these studies could help in developing effective varietal resistance program in the sub-continent.

Elemental Content in Wheat Products of Asir Region, Saudi Arabia

Wheat is one of the most grown crops in Saudi Arabia. Accurate knowledge of the various elemental concentrations in wheat and its products （bran and flower） is of great importance from nutrition point of view. Wheat samples were obtained from Asir region, 900 Km southern of Riyadh, and analyzed. Up to 50 elements in wheat products were determined. It was observed that the mineral content of bran was much higher than white flour.

Relationship Between Classical and Quantum Physics

Schrfdinger＇s equation is one the equations that mark the beginnings of the systematic quantum physics. It was shown that it follows from the Dirac＇s equation and the relationship with classical physics, i.e. with classical field theory was established. The subject of this work is the relationship between classical relativistic physics and the quantum physics. Investigation carded out in this work, shows that the free electromagnetic field, spinor Dirac＇s field without mass, spinor Dirac＇s field with mass, and some other fields are described by the same vibrational formulation. The conditions that a field be described by Maxwell＇s equations of motion are given in this work, and some solutions of these conditions are also given. Non-relativistic approximation of the equations of the non-quantified field are the Schrōdinger＇s equations. Dirac＇s equation as a special case, contains Maxwell＇s equations and the Schrōdinger＇s equation.

麦收时节

待麦子晒干装仓入库,一年的口粮总算落实了,心才真正踏实了。回首这期间的疲惫和汗水,真是"谁知盘中餐,粒粒皆辛苦"啊!周末开车回家,路边一片一片的金黄,擦亮了我的视线,沉甸甸的麦穗在风中欢笑着,难以掩饰丰收的喜悦,麦子熟了,要收麦了!"麦黄,麦黄,赶紧抢粮"儿时的童谣,在耳边响起。

建国后:41年间与130多个国家建立外交关系

新中国成立以后,我国的国际地位不断提高,与我国建交的国家越来越多。截止到1990年8月8日,同我国建立正式外交关系的国家有137个。亚洲33个;朝鲜、蒙古、越南、印度、印度尼西亚、缅甸、巴基斯坦、阿富汗、尼泊尔、叙利亚。