三农问题与社会稳定

三农问题是指农业、农村、农民问题,三者密不可分.近年来,由于体制、制度、思想等各方面的原因,三农问题凸现出来,对农村、城市和整个社会的稳定构成了威胁.要解决三农问题,必须重视农业、把农业摆在重要位置,改革基层政府组织,畅通利益表达渠道.     

两种高山杜鹃试管增殖和生根影响因子

目的为了解两种黄花高山杜鹃(Bob’s yellow和黄杯杜鹃)组织培养的不同阶段对光质需求的规律,从而提高种苗质量及生产效率,促进其推广应用和保护。方法以两种黄花高山杜鹃组培苗为材料,在8种LED光质和传统荧光灯下进行增殖和生根培养,比较其增殖系数、增殖苗和生根苗叶绿素含量、生根率及生根苗株高等5个指标。结果纯红光最适宜Bob’s yellow增殖和生根,增殖系数为8.53,生根率为93.33%;纯蓝光适宜黄杯杜鹃增殖,增殖系数为4.2;红蓝光(2RB)处理下黄杯杜鹃生根效果最好,生根率为83.33%;红蓝绿光对两种高山杜鹃增殖均有抑制作用,但促进叶绿素合成。结论不同光质对两种黄花高山杜鹃组培苗增殖和生根的影响不同,同一基因型增殖和生根所需的光质配比也不相同。针对高山杜鹃不同基因型及不同的生长阶段,探索适宜的光质类型,可提高种苗质量及生产效率。     

Successiveness discrimination as a two-state, quantal process

The duration of the "psychophysical time quantum" measured through the application of a two-state model of successiveness discrimination is equal in magnitude to the modal zero-crossing interval of the alpha rhythm. The two quantities have similar distributions and they are correlated over individuals.     

Epinephrine,norepinephrine, and acetylcholine as conditioned stimuli for avoidance behavior

Conditioned leg-flexion responses in dogs were developed with electric shock as an unconditioned stimulus and intestinal stimulation or the effects of injections of various drugs as conditioned stimuli. It is concluded that physiological effects can play a role in the development and maintenance of conditioned avoidance behavior.     

Boryllithium: isolation, characterization, and reactivity as a boryl anion

Nucleophilic, anionic boryl compounds are long-sought but elusive species. We report that reductive cleavage of the boron-bromine bond in N,N'-bis(2,6-diisopropylphenyl)-2-bromo-2,3-dihydro-1H-1,3,2-diazaborole by lithium naphthalenide afforded the corresponding boryllithium, which is isoelectronic with an N-heterocyclic carbene. The structure of the boryllithium determined by x-ray crystallography was consistent with sp(2) boron hybridization and revealed a boron-lithium bond length of 2.291 +/- 0.006 angstroms. The structural similarity between this compound and the calculated free boryl anion suggests that the boron atom has an anionic charge. The (11)B nuclear magnetic resonance spectrum also supports the boryl anion character. Moreover, the compound behaves as an efficient base and nucleophile in its reactions with electrophiles such as water, methyl trifluoromethanesulfonate, 1-chlorobutane, and benzaldehyde.     

发展中国家与中等收入国家大学教授职业情况、问题与启示

除少数国家外，发展中国家与中等收入国家大学教授职业的任职资格和工资待遇普遍较低，工作条件普遍较差，学术自由普遍受到严格限制，从而导致大学教授学术水平存在较大差异、学术发展面临危机等诸多问题。因此，调整大学教授任职资格、提高工资待遇、减轻教学任务、建设良好的学术自由制度环境，是改善发展中国家与中等收入国家大学教授职业状况、提高其职业竞争力的内在要求。     

聚乙烯、聚丙烯与木纤维复合制板工艺

通过聚乙烯、聚丙烯分别与木纤维复合制板工艺的实验，探讨了加入助剂和改变聚乙烯、聚丙烯用量对复合材料力学性能的影响，结果表明：对纤维进行改性处理，可以明显改善木塑复合材料力学功能；塑料越细且含量为30％时复合材料力学性能基本达到中密度板材的力学性能指标。     

以“项目为载体,任务为驱动”模式在花卉栽培课程教学中的应用

以"项目为载体,任务为驱动"的教学模式在结构上实现了"以学生为主体"的转变,在理论和实践相互融合联系企业实际需要方面体现了创新性,在推行项目与任务相结合的学习模式方面突出实践性,在结合实际应用,使学生在掌握理论知识的基础上体现科学性,有助于学生职业能力和社会能力的培养,使人才培养与企业岗位需求相适应。     

Faults in the mojave desert, california, as revealed on enhanced landsat images

Previously unknown strike-slip and normal faults in the central and eastern Mojave Desert have been revealed on Landsat Thematic Mapper images enhanced by four-component processing. This method provides color images on which lithologies are discriminated by their contrasting absorption and reflection, primarily at infrared wavelengths and particularly with regard to their ferric iron, ferrous iron, and hydroxyl contents, while retaining landform depiction. These discriminants represent a new type of geophysical display for geologic mapping in regions of well-exposed bedrock. Faults are revealed on the images by abrupt spectral and textural contrasts that coincide with aligned topographic features. The newly discovered faults form part of an extensive regional network of right shear that connects faults in the Death Valley region with the San Andreas fault system. They support a heterogeneous strain model for late Cenozoic tectonic evolution of the region. Regional structural relations indicate a westward migration of the locus of strain through time. Some of the newly identified faults bound blocks that have experienced contrasting rotational histories since early Miocene time.     

Identification of Bphs,an autoimmune disease locus,as histamine receptor H1

Bphs controls Bordetella pertussis toxin (PTX)-induced vasoactive amine sensitization elicited by histamine (VAASH) and has an established role in autoimmunity. We report that congenic mapping links Bphs to the histamine H1 receptor gene (Hrh1/H1R) and that H1R differs at three amino acid residues in VAASH-susceptible and -resistant mice. Hrh1-/- mice are protected from VAASH, which can be restored by genetic complementation with a susceptible Bphs/Hrh1 allele, and experimental allergic encephalomyelitis and autoimmune orchitis due to immune deviation. Thus, natural alleles of Hrh1 control both the autoimmune T cell and vascular responses regulated by histamine after PTX sensitization.     

添加凝结芽孢杆菌对生长猪生产性能的影响

目的在含有抗生素的肉鸡饲粮基础上,额外添加饲用益生菌凝结芽孢杆菌(Bacillus coagulans),研究凝结芽孢杆菌与抗生素组合使用对1~21日龄AA肉仔鸡生产性能的影响。方法98只1日龄AA肉鸡分为2个处理组：对照组,添加抗生素(50 mg/kg金霉素、60 mg/kg盐霉素钠);试验组,在对照组基础上额外添加3×10⁶ cfu/g (全价配合饲料)凝结芽孢杆菌。试验周期21 d,至肉鸡21日龄,屠宰试验鸡,重点分析生长性能、血液生化指标及免疫器官指数。结果试验组肉鸡的末体重和平均日增重分别比对照组增加约4.54%和4.84%,但差异不显著(P>0.05)。1~21日龄阶段,试验组与对照组肉鸡的料重比基本一致(P>0.05);然而,试验组肉鸡腹泻率约8.2%,低于对照组14.3%。21日龄试验组肉鸡血清的葡萄糖、甘油三酯、高密度脂蛋白胆固醇含量以及丙氨酸氨基转移酶活性等指标显著高于对照组(P<0.05)。此外,试验组与对照组之间的脾脏指数、胸腺指数、法氏囊指数等免疫器官指标无显著差异(P>0.05)。结论在含抗生素的肉鸡饲粮基础上额外增加3×10⁶ cfu/g凝结芽孢杆菌饲用益生菌,进一步提高了幼龄(1~21日龄) AA肉鸡的生产性能,主要表现在腹泻率、平均日增重的改善作用。血液生化指标结果也显示：凝结芽孢杆菌改善肉鸡生长性能与提高饲料碳水化合物和脂肪的消化、吸收效率有关。研究结果对促进凝结芽孢杆菌饲用益生菌产品在肉鸡实际养殖及饲料配方中的应用具有科学价值与生产指导的实际意义。     

优良的能源树种—沙棘

沙棘具有适应性强,分布范围广。生长快,产柴量高,火力旺的特点,是保持水士,改良土壤,适宜于荒地造林的优良树种。且繁殖容易,造林技术简单,易于推广。