丘陵山区果园机械化装备发展现状分析与展望

水果产业已成为我国继粮食和蔬菜之后的第三大农业种植产业, 2019年,我国果园种植面积为1204万hm2,水果产量为2.74亿吨,居世界首位.但国内优质果园多分布于川中、两广、陕甘等以丘陵山地为主的地区,受地理条件限制与传统种植模式影响,果园机械化程度长期处于较低水平,果园生产管理多以人工作业为主,工作强度大、生产效率...     

试论我国棉花育种现状,问题与发展对策

优良品种的种子是棉花生产的基础，种子不行其他现代技术就无法充分发挥作用。因而不断培育出适应生产需要的棉花新品种是实现棉花生产持续发展的重要战略途径。40多年来我国主要棉区进行了6次大规模的品种更换或更新，每次都使棉花单产提高10％以上，其作用是其它技术所不可替代的。下面就我国棉花育种的现状、存在问题及发展对策进行探讨。一、现状我国棉花年种植面积目前在600万hm2左右，皮棉总产450万t上下，单产大约为750kg／hm2。1995年棉田面积为5288万hm2，皮棉总产476．8万t，较1949年增长近11倍，约占世界棉花总产的1／4，居世界…     

高山蔬菜——一个大有可为的农业新产业

随着人民生活水平的不断提高,大众对蔬菜产品的需求数量和质量都发生了巨大的变化。我国1997年蔬菜总面积1126.7万公顷(其中设施栽培面积84万公顷),年人均蔬菜占有量260公斤。蔬菜产业已发展成种植业中的第二大产业。我省和县、砀山已成为全国有名的大棚商品蔬菜基地。在蔬菜全年生产和供应环节中,每年10月到次年7月,蔬菜市场货源充足品种丰富;而每年7月中     

国家咖啡检测重点实验室在普洱诞生

由于咖啡产品既无行业标准、部颁标准,也无国家标准,我国咖啡产业的发展并不顺利。目前,国家质检总局正式行文批准成立国家咖啡检测重点实验室,全国唯一的国家咖啡产品专业检测实验室在地级市普洱诞生。普洱市咖啡种植面积占全国的61.44%,产量占全国的58.6%。按普洱市政府的发展规划,2016年种植面积将达100万亩,产量10万吨,普洱市已成为     

宁夏南部山区马铃薯脱毒种薯繁育技术

马铃薯是宁夏南部山区的主要粮菜兼用和传统种植的优势作物,社会、经济效益十分显著。全区2011年种植面积达15万hm2,占到粮食作物播种面积的49.0%,年产鲜薯达432.9万吨,其中脱毒薯面积达65%,70%的用于淀粉加工,种植面积不断扩大,加快了马铃薯产业的发展,但也存在一定的问题,现根据马铃薯的生产情况及宁南山区所处的地理位置和自然环境,在马铃薯栽培区划上,该区属于北方一季作区。大多在四月中下旬播种,五月底出苗,九月底成熟收获。制定宁夏南部山区马铃薯脱毒种薯繁育技术,供参考。     

鄢陵县工商联以花为媒结良缘

<正> 鄢陵县花卉种植历史悠久,是中国北方花卉苗木的主要生产基地。近几年来,鄢陵县工商联深入调查研究,摸清了全县花卉生产企业的现状,筛选、分析有关资料,向政府提合理化建议20多条,为鄢陵县党委、政府大力发展花卉产业提供了可靠依据,并积极引导会员大力发展特色花卉产业。目前,鄢陵县工商联会员共有花卉企业100多家,拥有各类花木400多个品类,2000多个品种,从业人员达5000多人,种植花卉面积达10万多亩,花卉苗木生产能力近3亿株(盆),年产值达1亿元,为国家上缴税金200多万元,花卉产业已成为会员企     

元胡无公害生产技术操作规程

元胡为婴粟科多年生草本植物延胡索的块茎,是传统的配伍中药和医药工业原料,具有镇痛、平喘、止咳等多种功效,药用范围十分广泛。城固是继浙江,四川之后的全国第三大产区,年种植面积达5万亩,年产总量2．2万吨,产值超过1．1亿元,已成为具有活力的县域优势产业之一。为做大做强元胡产业,使其在城固率先突破发展中起排头兵作用,县农技中心经多年生产实践,制订元胡标准化生产技术规程。     

山东菏泽牡丹促成栽培品种筛选

牡丹是我国的传统名花,已有1600多年的栽培历史,以其富丽堂皇、雍容华贵而深受各族人民的喜爱。菏泽是我国牡丹生产、观赏和栽培中心,牡丹品种1156个,种植规模大,品种资源丰富,花色花型较多。栽培面积达3334公顷,约占全国牡丹种植面积的60%以上,每年牡丹促成栽培数量为100万株。选择牡丹促成栽培品种是成功与否的关键,结合菏泽地区的实际情况,筛选出符合其自然气候条件、市场需求的牡丹品种,有利于牡丹促成栽培技术的推广和牡丹产业的发展。     

院士工作站助蔬菜产业发展

<正>安徽省农科院园艺所自两年前设立院士工作站以来,共筛选出适宜安徽省栽培的蔬菜新品种30个,引进中国农科院蔬菜花卉所十字花科蔬菜品种33个,有力地推动了安徽省蔬菜产业的发展。安徽省是蔬菜种植大省,全省蔬菜种植面积1700万亩,产值达400亿元,但长期以来存在着蔬菜品种选育技术单一、种质创新不够、抗多种病害的优     

甜糯玉米优质高产配套栽培模式的示范推广

用＂两精四适宜＂即铺膜精细播种、精细管理;适宜播种期、适宜密度、适宜采收期、适宜绿色病虫害防治的综合集成栽培技术,种植迪糯278、京科糯2000、迪甜6号、迪甜10号、鲜糯1号5个甜糯玉米品种,两年来种植推广面积达1966.667hm2,平均增产2550kg/hm2,平均增收4500元/hm2以上,新增经济效益1068万元。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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