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Search Results: 1 - 10 of 242369 matches for " 张思维 "
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存在转移成本和网络效应的动态双头竞争—考虑技术输入和新进消费者的情形
A Dynamic Duopolistic Competition Model with Transfer Cost and Network Effect—The Case of Technology Import and New-Coming Consumers
 [PDF]

思维
World Economic Research (WER) , 2014, DOI: 10.12677/WER.2014.34008
Abstract:
本文在标准Hotelling横向差异化模型的基础上,引入技术输入和新进消费者研究两期动态博弈过程中转移成本和网络效应对动态均衡结果的影响。研究发现网络效应会提高需求价格弹性,同时增强厂商的价格竞争并且放大技术差距的影响;而转移成本会降低价格弹性、减少消费者剩余;技术输入不仅对消费者效用有影响,同时还会改变市场份额和均衡价格。最后,根据研究的结果本文从技术输入和转移成本的角度提出了控制市场力量、促进竞争的政策建议。
Based on the Hotelling horizontal differentiation model, this paper introduces both technology import and new-coming consumers to explore how the transfer cost and network effect influence the dynamic equilibrium of a two-stage game. We find that the network effect will increase the price elasticity of demand, enhance price competition among firms, and amplify the impact of technology gap, whereas the transfer cost will reduce the price elasticity and decrease consumer surplus. Moreover, technology import not only affects consumers’ utility, but also changes the market share and the equilibrium price. Finally, we put forward policy suggestions of controlling market power and promoting competition from the perspective of technology import and transfer cost.
棉花转基因体细胞胚胎的诱导及植株再生
Somatic Embryogenesis and Plant Regeneration in Cotton (Gossypium hirsutum L.) after Agrobacteria-Mediated Tranformation
 [PDF]

陈翠娜, 冯德玉, 张新, 思维, 代其林, 王劲
Botanical Research (BR) , 2013, DOI: 10.12677/BR.2013.21006
Abstract:

以陆地棉种质系Coker 312为材料,探讨了三种氨基酸对棉花转基因胚性愈伤生长、胚状体诱导、萌发及NAA对转基因再生植株生根的影响,建立一个高效的转基因体细胞胚萌发系统。结果表明:单独使用Pro、Glu时能提高转基因胚性愈伤增长、胚状体诱导及萌发能力,但以综合使用效果更为显著,Ala的附加没有显著影响;当生根培养基NAA的浓度为0.3 mg/L,根的诱导数量及质量都优于对照。但NAA的浓度不宜过高,过高则加重了根的褐化程度。对得到的转基因再生植株进行Kan涂抹实验,Kan抗性苗获得率可达到11.53%;PCR检测约83.78%的Kan抗性苗呈阳性。
In this paper, the effect of three amino acids on the growth of embryonic calli, embryo germination after transformation and the effect of Naphthlcetic acid (NAA) on rooting in cotton (Gossypium hirsutum L.) were investigated. The results showed that: embryogenic callus growth and embryo germination ability were effectively improved on the medium with Glu and Pro, especially with 0.5 mg/LGlu and 0.5 mg/L Pro at the same time. However, the additional of Alahad no significant impact; Using 0.3 mg/L NAA in the rooting medium could produce more strong roots, but too high NAA concentration increased the level of root browning. The percentage of Kan-resistant regenerated plantlets reached 11.53% according to the Kanamycin smear experiments and about 83.78% of the Kan-resistant plantlets were proven to be PCR-positive. The successful transformation and regeneration protocol established in this study can be used to improve cotton cultivars by genetic engineering.

农杆菌介导DR1372基因转化甘蓝型油菜
Preliminary Study on Agrobacterium-Mediated Transformation of DR1372 Gene into Brassica napus L.
 [PDF]

思维, 周文波, 张新, 陈翠娜, 代其林, 王劲
Botanical Research (BR) , 2013, DOI: 10.12677/BR.2013.21007
Abstract:

DR1372基因是在耐辐射奇球菌(Deinococcus radiodurans, DR)基因组中克隆得到的一个基因,其蛋白序列存在一个WHy功能域,此功能域可能参与油菜的抗旱过程。本研究首先构建植物DR1372- pBI121表达载体,然后利用农杆菌介导法将目的基因DR1372成功转入甘蓝型油菜中,并对影响油菜再生频率以及遗传转化效率的几个因素进行了探讨,初步建立了油菜转DR1372基因遗传转化体系,为DR1372基因的功能研究奠定了基础。
The DR1372 containing a special domain called WHy was cloned from Deinococcus radiodurans. This WHy domain may be involved in the mechanism of drought resistance. In this study, the plant expression vector DR1372-pBI121 was constructed and introduced into Brassica napus L. mediated by Agrobacteria. Several factors affecting genetic transformation efficiency were explored and the Agrobacterium-mediated genetic transformation system was set up in Brassica napus. This study provides essential materials for later research on DR1372 gene.

吴茱萸汤醇提各组分止呕活性的研究
,王敏伟,思维
中国中药杂志 , 2002,
Abstract: 目的:对吴茱萸汤醇提各组分止呕活性的研究和机制初步探讨。方法:采用硫酸铜诱导家鸽呕吐实验,小鼠胃排空实验,ACh和5-HT作用的离体大鼠胃条实验来确定其中具有止呕活性的组分,并观察有效组分对ACh,5-HT,组胺累积浓度效应曲线的影响。结果:50%醇洗脱液和70%醇洗脱液有十分显著性的止呕效应,且副作用较小,对ACh,5-HT,组胺累积浓度效应曲线均有一定的作用。结论:50%醇洗脱液和70%醇洗脱液含有的止呕活性成分较多,50%和70%醇可以从吴茱萸汤中提取较多止呕活性成分,止呕作用可能与拮抗ACh,5-HT,组胺受体有关。
14种植物对土壤重金属的分布、富集及转运特性
,彭重华,王莹雪,思维
草业科学 , 2014, DOI: 10.11829\j.issn.1001-0629.2013-0261
Abstract: ?以株洲市清水塘重金属污染工业区14种典型植物为研究对象,采用原子吸收分光光度法测定其Cu、Cd、Pb、Zn4种重金属含量,研究植物对重金属的分布、富集和转运特性。结果表明,14种植物对修复复合型土壤重金属污染有较好的应用前景。其中,马兜铃(Aristolochiadebilis)对Cu、Pb、Cd、Zn,臭牡丹(Clerodendrumbungei)、接骨草(Sambucuschinensis)对Pb、Cd、Zn,山莴苣(Lagediumsibiricum)对Pb、Zn,狗尾草(Setariaviridis)、牛皮消(Cynanchumauriculatum)对Cd,空心莲子草(Alternantheraphiloxeroides)对Cu的地上部分富集系数和转运系数都大于1。可将这些植物作为先锋植物用于相应重金属污染严重区域。
嗜热四膜虫自噬相关蛋白TtATG8调节细胞生长的机制研究
凌子惠,思维,吕晓腾,王树林
复旦学报(自然科学版) , 2015,
Abstract:
中国恶性肿瘤的动态变化
陈万青,郑荣寿,思维
科技导报 , 2014, DOI: 10.3981/j.issn.1000-7857.2014.26.009
Abstract: 随着中国人口老龄化趋势的加剧、环境及生活方式的改变,癌症已成为严重危害中国居民健康和社会发展的主要疾病之一。自20世纪70年代以来中国恶性肿瘤发病率和死亡率呈持续增长趋势。对目前恶性肿瘤发病和死亡数据的分析,了解其负担和变化趋势,可为制定有效的肿瘤控制规划和策略提供可靠依据。据全国肿瘤登记中心掌握的全国肿瘤登记数据及3次全国死因调查资料,对目前的恶性肿瘤发病和死亡及变化趋势进行汇总和分析发现,目前中国每年恶性肿瘤新发病例约309万,死亡196万,肺癌、女性乳腺癌、胃癌、肝癌和食管癌是常见的肿瘤。恶性肿瘤发病率在20年间呈明显上升趋势,特别是后10年变化尤其显著,其中人口老龄化是主要因素。肿瘤负担不断加剧,应采取积极有效的防控措施遏制肿瘤对中国居民健康的危害。
快速溶剂提取-高效液相色谱-二极管紫外阵列/荧光串联法同时测定土壤中18种多环芳烃
纯淳,思维,李钟瑜,林长青
环境化学 , 2015,
Abstract: 建立了快速溶剂(ASE)提取,高效液相色谱-二极管紫外阵列/荧光串联法测定土壤中18种多环芳烃.通过选择净化小柱和仪器条件的优化,实现了18种多环芳烃组分的完全分离及高灵敏度检测,该方法二极管紫外阵列(PDA)检测器和荧光(RF)检测器检出限分别为0.04—0.6μg·kg-1和0.002—0.07μg·kg-1;4种浓度水平(PDA检测器0.5μg、2μg;RF检测器0.02μg、0.05μg)土样加标回收率稳定在82.8%—122%之间,RSD为1%—5%之间.
杨木不同纹理方向介电特性初步探究
王佩,思维,,周定国
- , 2015, DOI: 10.13360/j.issn.1000-8101.2015.02.024
Abstract: 对杨木在室温下不同纹理方向、不同含水率及不同频率下的介电特性进行了测量。结果显示,杨木顺纹方向介电特性比横纹方向更为明显,介电常数和损耗因子都随含水率的增加而增大,且当含水率在0~5%时,木材介电常数随含水率的提高而增加得较为缓慢,介电常数随频率的增大逐渐变小,而介电损耗随频率增大而加大。研究结果为杨木高频加热、干燥及人造板胶合等工艺提供了理论依据。
The influence of grain direction, moisture content and electric field frequency on dielectric properties of poplar was investigated. The results indicated that the direction parallel to the grain exhibited more significant dielectric behavior than that along the transverse direction. The dielectric constant and loss factor increased with the rising of moisture content, while the increase of dielectric constant was slow when the moisture content was below 5%. Dielectric constant decreased with the rising of frequency while dielectric loss increased with it. These findings provided theoretical basis for high frequency heating, drying and gluing of wood-based panel
完全轮廓法计算液体表面张力的改进
Full-profile fit pendent drop method for surface tension measurements

周斌,思维,陈志勇,
- , 2016, DOI: 10.16511/j.cnki.qhdxxb.2016.25.047
Abstract: 为了提高液体表面张力测量的准确性和稳定性,该文基于悬滴法中完全轮廓法计算原理,改进了二维寻优算法中变量初值的选取方法,并利用权重因子对变量误差函数进行了修正,减小了液滴轮廓偏离点对表面张力测量结果的影响。在温度为25℃,常压条件下,利用改进后的完全轮廓法对水和无水乙醇表面张力进行了测量,结果表明:改进后的完全轮廓法相比原完全轮廓法测量标准差减小了40%,充分证明改进后的完全轮廓法具有更好的测量重复性和稳定性。
Abstract:The accuracy and stability of surface tension measurements are improved fitting the entire surface profile in the pendent drop method with an algorithm to determine the initial value for two-dimensional optimization. Moreover, the error function was modified by a weighting factor which reduced the influence of the droplet profile deviation point on the surface tension measurement. The full-profile fitting method was used to calculate the surface tension of water and ethanol at 25℃ and atmosphere. The final results show the standard deviation was reduced by 40% compared with the previous method, which verifies the stability and repeatability of this full-profile fitting pendent drop method.
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