帅枣系品种枝条果实生长发育动态

选用7年生密植园帅枣新品种为试材,对帅枣和对照枝条、果实生长发育动态、产量和品质进行比较研究,以期为帅枣优质丰产栽培提供理论依据.结果表明:年周期中,帅枣系品种枝条果实生长量大,生长曲线均服从logistic生长模型,斜率均高于对照;7月上旬至9月上中旬为子叶与果实快速生长期,帅枣1、2、3号果肉增长量(占总质量)分别...     

特用蚕品种天然丝胶蛋白的乳化活性研究

[目的]通过品种生产来直接获得大量、优质全天然丝胶蛋白质原料。[方法]对"绿S"和"白S"2种全天然丝胶茧品种及现行推广普通蚕品种"菁松×皓月"的丝胶蛋白乳化活性进行了比较分析。[结果]试验表明,"绿S"和"白S"2个丝胶茧品种的丝胶蛋白含量极高,达95%以上,分别是对照品种茧的3.47倍和3.53倍,可以称之为全天然丝胶蛋白质;研究还表明,"绿S"品种的乳化特性也明显高于"白S"和"菁松×皓月",在保健食品领域具有更为优越的利用价值。[结论]该研究可为家蚕特用品种大量生产全天然、纯丝胶在非绢丝产业的广泛应用提供依据。     

三元交互视角下风景园林设计课程教学改革研究

针对高职院校学生在学习设计课程时自我效能感低的特点,引入社会认知理论的三元交互决定模型,通过从高职院校学生的“个人认知”、“行为模式”和“环境因素”三元视角重新梳理风景园林设计课程体系,在教学设计中融入思政元素,使课程思政和专业教学相互融合,使学生“术”与“德”更好融合,以实现“三全育人”的目标。具体措施包括:通过挖掘教学目标和内容的思政元素,塑造学生产生高效能感的“个人认知”;通过组织“项目沉浸式”教学过程,促使学生产生互为榜样的“行为模式”;通过完善课堂教学评价,营造学生良性互动的学习环境。     

延庆县鲜食玉米品种比较试验

为筛选出适合延庆地区种植的鲜食玉米新品种,2013年对11个鲜食玉米品种的生育期、经济性状、抗性、品质、产量等各项指标进行分析,结果表明：糯玉米播种至采收95～96d,甜玉米播种至采收86～90d。糯玉米“京科糯569”和甜玉米“京科甜533”综合表现突出,“京科糯569”鲜穗产量20700㎏/ hm2,商品穗产量17250㎏/ hm2;“京科甜533”鲜穗产量13400㎏/ hm2,商品穗产量13070㎏/ hm2。“京科糯569”抗性、株型均较对照理想,“京科甜533”穗型一致、排列整齐,没有秃尖,籽粒鲜亮,二者品质综合得分均较高,优于目前常规种植的“京科糯2000”和“京科甜183”,可作为替代品种在今后示范种植。     

Defects in carbon nanostructures

Previous high-resolution electron microscopy (HREM) observations of the carbon nanotubes have led to a "Russian doll" structural model that is based on hollow concentric cylinders capped at both ends. The structures of the carbon nanotubes and particles were characterized here by bulk physical and chemical property measurements. The individual nanostructure is as compressible as graphite in the c axis, and such nanostructures can be intercalated with potassium and rubidium, leading to a saturation composition of "MC(8)." These results are counter to expectations that are based on a Russian doll structure. HREM after intercalation with potassium and deintercalation indicates that individual nanoparticles are a "paper-mache" of smaller graphite layers. Direct current magnetization and electron spin resonance measurements indicate that the electronic properties of the nanostructures are distinctly different from those of graphite. Although the nanostructures have distinct morphologies and electronic properties, they are highly defective and have a local structure similar to turbostratic graphite.     

“替代词ONE”的用法研究

笔者认为,我国某些辞书的编者和语法学家把“替代词one”归入不定代词类是不恰当的,用于定冠词和形容词后表指代关系的“one”应该叫替代词,其理由是表示某一类中的一个或数个的定冠词或形容词不能单独存在,而需要一个词来“支助”或“支垫”它们。根据其定义,象someone,8nyone等这些复合词中的“one”和象my sweet one,the Iittle ones等这些成语中的“one-ones”应该是“替代词one”。     

The Resonating Valence Bond State in La2CuO4 and Superconductivity

The oxide superconductors, particularly those recently discovered that are based on La(2)CuO(4), have a set of peculiarities that suggest a common, unique mechanism: they tend in every case to occur near a metal-insulator transition into an odd-electron insulator with peculiar magnetic properties. This insulating phase is proposed to be the long-sought "resonating-valence-bond" state or "quantum spin liquid" hypothesized in 1973. This insulating magnetic phase is favored by low spin, low dimensionality, and magnetic frustration. The preexisting magnetic singlet pairs of the insulating state become charged superconducting pairs when the insulator is doped sufficiently strongly. The mechanism for superconductivity is hence predominantly electronic and magnetic, although weak phonon interactions may favor the state. Many unusual properties are predicted, especially of the insulating state.     

The role of intuition

"Intuition," as used by the modern mathematician, means an accumulation of attitudes (including beliefs and opinions) derived from experience, both individual and cultural. It is closely associated with mathematical knowledge, which forms the basis of intuition. This knowledge contributes to the growth of intuition and is in turn increased by new conceptual materials suggested by intuition. The major role of intuition is to provide a conceptual foundation that suggests the directions which new research should take. The opinion of the individual mathematician regarding existence of mathematical concepts (number, geometric notions, and the like) are provided by this intuition; these opinions are frequently so firmly held as to merit the appellation "Platonic." The role of intuition in research is to provide the "educated guess," which may prove to be true or false; but in either case, progress cannot be made without it and even a false guess may lead to progress. Thus intuition also plays a major role in the evolution of mathematical concepts. The advance of mathematical knowledge periodically reveals flaws in cultural intuition; these result in "crises," the solution of which result in a more mature intuition. The ultimate basis of modern mathematics is thus mathematical intuition. and it is in this sense that the Intuitionistic doctrine of Brouwer and his followers is correct. Modern instructional methods recognize this role of intuition by replacing the "do this, do that" mode of teaching by a "what should be done next?" attitude which appeals to the intuitive background already developed. It is in this way that understanding and appreciation of new mathematical knowledge may be properly instilled in the student.     

湘潭市近30多年降水变化特征分析

利用湘潭市1971￣2004年逐月降水资料,分析了湘潭市近30多年降水变化特征。结果表明,湘潭地区年降水呈准20年周期变化,春季呈"多-少-持续偏多"的变化趋势;夏季呈"持续偏少-多-少"的变化趋势;秋季呈"少-多-正常-少"的变化趋势;冬季呈"少-多-正常-多"的变化趋势。从年内变化看,1971￣2004年30多年来平均降水量最大的是6月份,达到211.9mm,最少的是12月份,为40.8mm;大雨发生频次为9.3次/a,暴雨发生频次为3.8次/a。     

隐形网页资源产生原因与开发利用

隐形网页资源是因特网上重要的信息资源,充分高效地利用这些资源是广大网络用户非常重视和急需解决的问题。文章对隐形网页的现状、隐形网页产生的原因、研究隐形网页重要性等方面进行了多角度、全方位的论述。最后重点探讨了隐形网页资源开发利用的措施和途径。     

黑龙江省中药材—关黄柏的研究

关黄柏是我国名贵中药材之一,黑龙江省是其主产区。对黑龙江省关黄柏原植物,黄波罗和毛波罗进行了植物外部形态、花粉形态等观察和比较,结果毛波罗与黄波罗近缘。对不同产地黄波罗和胡波罗的药用成分小蘖碱含量分析及生药解剖研究表明:胡波罗与黄波罗不仅在植物外部形态上不易区分,而且两者小蘖碱含量和生药解剖特征也基本一致,关黄柏作为药原植物,两者可互相代替。不同产区的关黄柏小碱蘖含量却有显著差异,以桃山的关黄柏质量最佳,枝条小蘖碱含量也很高,可供药原。根据黑龙江省各林区关黄柏资源贮量和药用植物特点,提出黑龙江省关黄柏药原植物的护、育、用相结合,药、材、栓皮分段开发、综合利用的措施。     

Insights into phases of liquid water from study of its unusual glass-forming properties

The vitrification of pure water is compared with that of molecular solutions rich in water, and gross differences are noted. Thermodynamic reasoning and direct observations on noncrystallizing nanoconfined water indicate that the glass transition in ambient-pressure water is qualitatively distinct from that found in the usual molecular liquids. It belongs instead to the order-disorder class of transition seen in molecular and ionic crystalline materials. The distinctive "folding funnel" energy landscape for this type of system explains the extreme weakness of the glass transition of water as well as the consequent confusion that has characterized its scientific history; it also explains the very small excess entropy at the glass transition temperature. The relation of confined water behavior to that of bulk is discussed, and the "fragile-to-strong" transition for supercooled water is interpreted by adding a "critical point-free" scenario to the two competing scenarios for understanding supercooled bulk water.     

Retinoblastoma: clues to human oncogenesis

The retinoblastoma gene can be considered a model for a class of recessive human cancer genes that have a "suppressor" or "regulatory" function. The loss or inactivation of both alleles of this gene appears to be a primary mechanism in the development of retinoblastoma. Such a mechanism is in direct contrast to that of putative human oncogenes which are thought to induce tumorigenesis following activation or alteration. The high incidence of second primary tumors among patients who inherit one inactive retinoblastoma allele also suggests that this cancer gene plays a key role in the etiology of several other primary malignancies. Finally, the observation that extra nonrandom copies of specific chromosomal regions occur in some of these tumors provides circumstantial evidence that an "expressor" gene (possibly an oncogene) may be involved in retinoblastoma development.     

Noble gases in stratospheric dust particles: confirmation of extraterrestrial origin

Noble gas elemental and isotopic ratios were measured in a group of 13 "chondritic" stratospheric dust particles. Neon and argon are present in "solar" proportions; xenon appears to be dominated by contributions from "planetary" sources. The apparent xenon concentration is higher than that measured in any bulk meteorite, approaching the concentration found in the noble gas-rich, acid-insoluble residues from carbonaceous chondrites.     

瓯江彩鲤酪氨酸酶基因的克隆与序列分析

瓯江彩鲤(Cyprinus carpio var.color)是分布在我国瓯江流域的一种鲤科鱼类,色彩艳丽,体形优美,深受人们喜爱。瓯江彩鲤有5种基本体色:"全红"、"大花"、"麻花"、"粉玉"和"粉花",是研究鱼类体色遗传的良好材料和理想模型。酪氨酸酶(tyrosinase)是影响黑色素合成的关键酶,其转录的提前终止会导致黑色素无法合成。采用RACE技术从瓯江彩鲤皮肤转录本中克隆5种体色酪氨酸酶基因全序列,并对序列进行分析。发现在瓯江彩鲤的5种体色中,酪氨酸酶基因cDNA序列长度存在差异:"全红"为2 100 bp,"麻花"为2 107 bp,"大花"为2 073 bp,"粉玉"为1 976 bp,"粉花"为2 111 bp;且每种体色都存在两种类型酪氨酸酶基因(TYR-1,TYR-2)的转录。这两种酪氨酸酶基因mRNA所翻译成的氨基酸序列仅在一二级结构上有所差异,而在结构域和三级结构上不存在差异。但酪氨酸酶基因的这些差异是否与瓯江彩鲤体色相关还有待后续的证明。研究亮点:在国内外首次克隆了鲤的酪氨酸酶基因,发现不同体色瓯江彩鲤均转录完整的酪氨酸酶基因,且每种体色都存在两种酪氨酸酶的mRNA转录。揭示了5种体色瓯江彩鲤酪氨酸酶基因的序列差异,对进一步研究该基因与体色的关系提供了依据。     

无拍式羽毛球自动发球机控制系统设计

根据投资者情绪是股票价格形成重要影响因素这一研究观点,围绕投资者情绪是否构成系统性风险及其对不同类型股票的差异化影响,运用我国股市交易数据进行的实证研究结果表明,投资者情绪不构成股市的系统性风险,但对不同市值的股票有着差异化的影响,随着股票的“投机性”增加,投资者情绪对其影响也增大。此外,投资者情绪会削弱股票收益与其波动的正相关性,且对于“投机性”越高的股票,这一影响也越大。     

重茬和品种差异对豫西夏大豆“症青”现象的影响

豫西地区夏大豆发生"症青"现象可导致大豆严重减产甚至绝收,但引发这种现象的原因尚不明确,防治手段也缺乏针对性。为了有效防治豫西夏大豆"症青"现象,采用裂区试验,研究了大豆重茬和品种差异对夏大豆"症青"现象的影响。结果表明,重茬地块大豆"症青"株率平均为31.70%,正茬地块大豆"症青"株率平均为1.01%,且两者差异达极显著水平。在重茬条件下,25个大豆品种均有一定程度的"症青"现象发生,"症青"株率变幅为8.6%～58.7%,品种间差异极显著。在正茬条件下,所有大豆品种的"症青"现象均较轻,56%的品种"症青"发生率不足1%,且品种间差异不显著。由此可见,重茬导致大豆"症青"现象发生或者加重,生产上应进行合理的轮作倒茬防治大豆"症青"发生,同时选择对"症青"现象抗性较好的大豆品种。     

关于对"三个代表"重要思想的几个认识问题

“三个代表”重要思想,是基于对党和国家前途命运的深沉忧患,回应当代世界和中国新的发展变化,全面推进建设中国特色社会主义事业,实现中华民族伟大复兴的强大思想武器。作为与时俱进的理论创新成果,其在基本理论层面主要表现为综合创新;在政策措施层面,则主要表现为继发性创新。“三个代表”重要思想由理论精髓、思想内核、学说本体和政策展开4个层面构成了严谨的理论体系。     

How mantle slabs drive plate tectonics

The gravitational pull of subducted slabs is thought to drive the motions of Earth's tectonic plates, but the coupling between slabs and plates is not well established. If a slab is mechanically attached to a subducting plate, it can exert a direct pull on the plate. Alternatively, a detached slab may drive a plate by exciting flow in the mantle that exerts a shear traction on the base of the plate. From the geologic history of subduction, we estimated the relative importance of "pull" versus "suction" for the present-day plates. Observed plate motions are best predicted if slabs in the upper mantle are attached to plates and generate slab pull forces that account for about half of the total driving force on plates. Slabs in the lower mantle are supported by viscous mantle forces and drive plates through slab suction.