套作玉米产量与栽培密度及氮磷钾肥施用量的关系

采用二次回归通用旋转组合设计方法试验,以马铃薯套作玉米产量为目标,以套作的玉米密度、氮、磷、钾肥施用量为探讨对象,建立了套作玉米产量与密度、氮、磷、钾肥施用量间关系的数学模型(y=7396.05-536.7x1 129.0x2 135.6x3 104.7x4-19.65x1x2-5.4x1x3 147.75x1x4 165.15x2x3-86.55x2x4 113.7x3x4-478.8x12-407.7x22-446.25x32-450.3x42),通过模拟寻优,提出了玉米产量≥6750.00kg/hm2的综合农艺栽培方案(玉米密度44856-51135株/hm2,平均48000株/hm2;N279.30-350.70kg/hm2,平均315.00kg/hm2;P2O5189.00-231.00kg/hm2,平均210.00kg/hm2;K2O167.70-222.30kg/hm2,平均195.00kg/hm2。N:P:K=1:0.667:0.619)。     

Buddenbrockia is a cnidarian worm

A major evolutionary divide occurs in the animal kingdom between the so-called radially symmetric animals, which includes the cnidarians, and the bilaterally symmetric animals, which includes all worm phyla. Buddenbrockia plumatellae is an active, muscular, parasitic worm that belongs to the phylum Myxozoa, a group of morphologically simplified microscopic endoparasites that has proved difficult to place phylogenetically. Phylogenetic analyses of multiple protein-coding genes demonstrate that Buddenbrockia is a cnidarian. This active muscular worm increases the known diversity in cnidarian body plans and demonstrates that a muscular, wormlike form can evolve in the absence of overt bilateral symmetry.     

台湾青枣在北方日光温室的试栽表现

台湾青枣是一种新兴的热带、亚热带水果。果实形似苹果,叶似梨,其风味独特、清脆香甜、爽口,营养丰富。突出特点是当年种植,当年结果。在北方利用日光温室栽培还是空白。在温室内通过对其丰产优质栽培技术进行专门研究,以开发这一极具前景的珍奇果树。     

Standards and corporate reconstruction in the Michigan dry bean industry

Since the turn of the lastcentury, Michigan farmers, elevators, and stategovernment have used production and processstandards to shape the dry bean industry totheir interests and set a worldwide standardfor quality dry beans. Over the last 20 years,however, multinational agro/food firms haveintroduced their market criteria into standardssetting, and recent changes in Michigan beanstandards largely accommodate the interests ofthese firms. A review of the changes in thesestandards over time allows us to explore howconcepts of accountability and control improveour understanding of changes in the structureand operation of food production and marketing.What is the measure of state governmentaccountability to corporate capital and to thestate's bean farmers? In what ways can farmersuse standards to re-assert their priorities andgain a greater measure of influence overmarketing? What challenges do changing qualitystandards pose for public research as well asfor the institutions representing Michiganfarmers and elevators?     

Three-dimensional orientation mapping in the transmission electron microscope

Over the past decade, efforts have been made to develop nondestructive techniques for three-dimensional (3D) grain-orientation mapping in crystalline materials. 3D x-ray diffraction microscopy and differential-aperture x-ray microscopy can now be used to generate 3D orientation maps with a spatial resolution of 200 nanometers (nm). We describe here a nondestructive technique that enables 3D orientation mapping in the transmission electron microscope of mono- and multiphase nanocrystalline materials with a spatial resolution reaching 1 nm. We demonstrate the technique by an experimental study of a nanocrystalline aluminum sample and use simulations to validate the principles involved.     

State-specific correlation of coincident product pairs in the F + CD4 reaction

When a chemical reaction forms two molecular products, even if the state-resolved differential cross section (DCS) for each product is obtained individually, the coincident attributes of the coproducts are still lacking. We exploit a method that provides coincidence information by measuring the state-resolved, pair-correlated DCS. Exemplified by the reaction F + CD4 --> DF + CD3, a time-sliced ion velocity imaging technique was used to measure the velocity distribution of a state-selected CD3 product and to reveal the information of the coincident DF in a state-correlated manner. The correlation of different product state pairs shows a striking difference, which opens up a new way to unravel the complexity of a polyatomic reaction.     

Guava fruit (Psidium guajava L.) as a new source of antioxidant dietary fiber.

Guava (Psidium guajava L.) is a tropical fruit, widely consumed fresh and also processed (beverages, syrup, ice cream, and jams). Pulp and peel fractions were tested, and both showed high content of dietary fiber (48.55-49.42%) and extractable polyphenols (2.62-7.79%). The antioxidant activity of polyphenol compounds was studied, using three complementary methods: (i) free radical DPPH* scavenging, (ii) ferric reducing antioxidant power assay (FRAP), and (iii) inhibition of copper-catalyzed in vitro human low-density lipoprotein (LDL) oxidation. All fractions tested showed a remarkable antioxidant capacity, and this activity was correlated with the corresponding total phenolic content. A 1-g (dry matter) portion of peel contained DPPH* activity, FRAP activity, and inhibition of copper-induced in vitro LDL oxidation, equivalent to 43 mg, 116 mg, and 176 mg of Trolox, respectively. These results indicate that guava could be a suitable source of natural antioxidants. Peel and pulp could also be used to obtain antioxidant dietary fiber (AODF), a new item which combines in a single natural product the properties of dietary fiber and antioxidant compounds.