小麦、豌豆混种栽培模式

小麦、豌豆是雁江区的主要小春粮食作物，常年种植面积分别为46万亩和4万亩左右，总产分别为9万t和0．3万t，其种植面积和总产分别占全年小春粮食总播种面积和总产量的80％和87％左右。     

小舂马铃薯高产栽培技术要点

近几年，小春马铃薯种植面积正在不断扩大，因其耐贮藏、品质优良（商品薯率高）、销路好等特点，许多种植农户从中已得到了较好的经济收益。但由于小春马铃薯播种正值高温多雨季节，由于秋季气候仍然炎热，冬季易受霜冻危害，往往造成烂种缺苗严重和不能正常成熟，易造成烂种死苗，产量低下，从而影响产量和品质。如果按照栽培大春马铃薯的方法栽培小春马铃薯非失败不可，甚至绝收，不少地方都有过沉痛的教训。     

小春马铃薯地膜覆盖栽培技术

小春马铃薯地膜栽培是指小春马铃薯种植的大田在播幅带的土壤表面覆盖一层聚乙烯薄膜,通过地膜覆盖产生物理隔阻作用,改变马铃薯生育期间的生态环境,以达到早熟、优质、高产的栽培目标,小春马铃薯地膜覆盖栽培是以提高经济效益为中心的栽培方式。根据雄壁镇近几年的种植经验,小春马铃薯地膜栽培是农业产业结构调整中,达到农业增效、农民增收的一个新举措,具有广阔的推广前景。从地块与整地,应用脱毒马铃薯优良品种,重施底肥,适时播种,合理密植,覆盖地膜,加强田间管理,病虫害防治等方面阐述小春马铃薯种植技术,以促进小春马铃薯高产、优质、高效。     

农民增收新亮点——啤大麦

在今年的小春生产中，永平县加大种植结构调整力度，着力发展特色农业，充分挖掘小春生产中潜在的增收效益。一改全县小春生产小麦、蚕豆一统天下的格局，进一步加快啤大麦新品种的示范推广，以样板引路，积极培植啤大麦产业。今年全县三万亩啤大麦估计产量可在4500吨以上，产值可达450多万元，成为了农民增收、财政增效的新亮点。……     

南方油菜开沟起垄种植配套机具发展现状

传统油菜种植习惯是沿用精耕细作的方式,包括翻地整地、开沟、育苗移栽等环节,介绍了近年来国内外油菜种植开沟起垄装置取得的技术进展,对现有油菜种植开沟起垄装置进行归类分析;通过对国内外油菜种植开沟起垄装置的研究,对比分析现有油菜种植开沟起垄装置的优缺点,并对存在的不足提出了建设性的改进建议,为推进油菜种植开沟起垄装置的研发进程提供一定的参考。     

四川省小春备耕情况较好

目前,全省秋冬种备耕、育苗、播栽逐渐进入高潮。小春生产是全年农业生产的重要开端和基础,在小春粮食"九连增"、油菜籽总产连续11年创历史新高的基础上,稳定粮油生产难度大、任务重。据35个农业经济运行监测网点县调查,各地高度重视2013年小春生产,全力抓好政策落实,千方百计稳定种植面积、优化调整种植结构,技术服务、抓点示范、农资调运等备耕情况均好于上年同期。一、播种面积稳定,种植结构优化《全省小春生产指导意见》印发后,     

冷凉地区烤烟地小春优质小杂粮多样性种植技术及应用效果分析

在永胜县海拨2000m以上地区种植烤烟,大小春两季种植热量不足,若只在大春季种植烤烟,则烤烟连作病虫害发生严重,不但增加生产成本,而且影响烤烟质量和效益。通过在小春季以间作方式种植生育期较短的优质小杂粮,可以达到提高大小春两季作物效益,减少生产成本、增加土壤有机质、培肥地力,解决大小春两季作物争季节、争热量的矛盾,取得了良好的效果。云南省烤烟种植在2000m以上地区较多,此方法可作借鉴。     

浅谈云南省油菜生产技术推广

油菜具有养地和能有效解决大、小春粮烟茬口矛盾的优势，已成为云南小春种植中除小麦、蚕豆外的第三大重要作物。经过多年发展。种植面积和产量增幅均居各作物之首。从1978年到2009年．面积由135．06万亩增加到380．4万亩。总产量由3．18万t增加到45．6万t，亩产由24kg提高到120kg。     

小春马铃薯地膜覆盖栽培技术

从地块的选择,精心整地,应用脱毒马铃薯优良品种,重施底肥,适时播种,合理密植,覆盖地膜、加强田间管理,病虫害防治等方面阐述小春马铃薯种植技术,以促进小春马铃薯高产、优质、高效。     

可调式开沟起垄机研制与试验

本文针对甘肃省果蔬种植开沟起垄作业,设计了1K-30×50型可调式开沟起垄机。该机具包括机架、限深轮,机架前端中部连接一所述的限深轮,机架后部下方设有开沟起垄铲,开沟起垄铲之间设一垄面整形板。结构简单、加工方便、起垄规范,集耕整、开沟、起垄、修垄于一体,能够高质量的完成果蔬种植开沟起垄作业。     

Transformation of a star into a planet in a millisecond pulsar binary

Millisecond pulsars are thought to be neutron stars that have been spun-up by accretion of matter from a binary companion. Although most are in binary systems, some 30% are solitary, and their origin is therefore mysterious. PSR J1719-1438, a 5.7-millisecond pulsar, was detected in a recent survey with the Parkes 64-meter radio telescope. We show that this pulsar is in a binary system with an orbital period of 2.2 hours. The mass of its companion is near that of Jupiter, but its minimum density of 23 grams per cubic centimeter suggests that it may be an ultralow-mass carbon white dwarf. This system may thus have once been an ultracompact low-mass x-ray binary, where the companion narrowly avoided complete destruction.     

Action at a distance along a DNA

A number of ways are known by which an event at one location on a DNA molecule can affect an event at a distant location on the same molecule. Three classes of mechanisms are described for such distal actions: tracking or translocation of a protein along a DNA, the association of two proteins bound at separate sites to form a DNA loop in between, and distal interactions that are affected by the topology of the DNA. The basic characteristics of each type of mechanism are discussed in terms of the known physicochemical properties of DNA. The various modes of action at a distance are often interrelated. Examples include the formation of positively and negatively supercoiled DNA loops by tracking and the strong effects of DNA topology on looping.     

Development of a receptor on a foreign nerve fiber in a Pacinian corpuscle

When the sensory fiber of a Pacinian corpuscle (in cat mesentery) is transected (at the inferior mesenteric nerve) transduction fails within 30 hours: the nerve ending produces no generator potentials in response to mechanical stimulation. Electrically elicited nerve impulse conduction continues for at least another 18 hours. A transducer mechanism develops on a regenerating nerve fiber when this fiber enters the denervated corpuscle. Such transducer development takes place on myelinated fibers from the inferior mesenteric nerve, which normally supplies corpuscles, as well as on myelinated hypogastric nerve fibers, which normally do not go to corpuscles, including fibers larger than the original corpuscle afferents.     

Conversion of a peroxiredoxin into a disulfide reductase by a triplet repeat expansion

Pathways for the reduction of protein disulfide bonds are found in all organisms and are required for the reductive recycling of certain enzymes including the essential protein ribonucleotide reductase. An Escherichia coli strain that lacks both thioredoxin reductase and glutathione reductase grows extremely poorly. Here, we show that a mutation occurring at high frequencies in the gene ahpC, encoding a peroxiredoxin, restores normal growth to this strain. This mutation is the result of a reversible expansion of a triplet nucleotide repeat sequence, leading to the addition of one amino acid that converts the AhpC protein from a peroxidase to a disulfide reductase. The ready mutational interconversion between the two activities could provide an evolutionary advantage to E. coli.     

离散型三维竞争系统中某群体竞争获胜的条件

研究了离散型三维竞争系统的模型结构与稳定性,得到了这类竞争系统中各类平衡点的坐标及其性质,获得了系统在某些边界上的平衡点渐近稳定的充分条件和不稳定的充分条件,并由此得到了系统中的某群体在竞争过程中竞争获胜淘汰所有对手的条件和参与竞争的各个群体永不和谐的充分条件.