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Search Results: 1 - 10 of 341313 matches for " 王永前 "
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Detecting monthly hydrological signal variations of the Qinghai-Tibet Plateau by utilizing gravity satellite and validation by microwave data product
关于利用重力卫星对青藏高原水储量年际变化和季节性变化进行监测并用微波数据产品进行验证的研究


地球物理学进展 , 2009,
Abstract: The problem of mean monthly terrestrial water storage changes in the Qinghai-Tibet Plateau is discussed in this paper. The significance of this problem and the disadvantages of the current research methods are introduced firstly. Then the mean monthly terrestrial water storage changes in the Qinghai-Tibet Plateau is computed using GRACE data, and the results are explained by the data of rainfall and snow water equivalence which are the products of the microwave sensors TMI and AMSR-E. The explanation is meaningful and good. At last, the error is analyzed for the results.
定向共晶组织的熔化行为
徐达鸣,李庆春,
金属学报 , 1993,
Abstract: 应用定向凝固/重熔技术研究了Al-Cu,Al-Ni和Al-Si合金定向生长共晶组织的熔化行为实验结果表明共晶组织的熔化过程与其凝固生长过程之间不存在完全的互逆性无论是规则片状或棒状共晶组织,或是不规则片状共晶组织,其熔化过程都是共晶组织的两相首先在熔化界面上同时分解,形成各自的分散相,然后这些成分不同的分散相经过进一步溶解混合才形成成分均匀的单一液相
不同骨料固结粉胶结充填体强度试验与对比分析
Strength test on consolidation powder cementing filling body and comparison analysis for different aggregates

杨志强,高谦,,马龙,永定
- , 2016, DOI: 10.7511/dllgxb201605005
Abstract: 为了将固结粉新型胶凝材料在金川矿山推广应用,针对目前矿山采用的4种充填骨料,开展固结粉胶结充填体强度试验研究.首先,针对龙首矿充填系统以及工业技术参数,进行4种充填骨料、3种胶凝材料和5种充填料浆浓度的试验方案设计.然后,针对4种充填骨料开展不同料浆浓度的充填体强度试验,获得了不同配比条件下胶结充填体强度.最后,针对固结粉胶凝材料进行4种骨料胶结充填体强度分析和对比研究.结果显示,除了戈壁粗砂骨料的胶结充填体3 d和28 d强度低于矿山设计强度外,其他3种骨料胶结充填体强度均满足金川矿山充填体设计强度.由此可见,固结粉新型胶凝材料可以替代水泥在金川矿山推广应用.
In order to generalize a new consolidation powder (CP) cementing material in Jinchuan mine, aiming at four kinds of filling aggregates, the strength tests of cementing filling body for consolidation powder are carried out. Firstly, considering the filling system and industrial technical parameters in Longshou mine, the test schemes including four kinds of filling aggregates, three kinds of cementing materials and five kinds of filling slurry concentrations are designed. Then, the strength tests of filling body including four kinds of aggregates under different slurry concentrations are carried out and the cementing filling body strengths under different ratios are obtained. Finally, the comparative research on the strength of filling body for the consolidation powder cementing material of four kinds of filling aggregates is given. Experimental results show that the strength of filling body of consolidation powder for the other three kinds of filling aggregates meets the the needs of design strength in Jinchuan mine, except the 3 d and 28 d strength of Gobi coarse sand aggregate. Thus, the new consolidation powder cementing material can be used into mining by replacing cement in Jinchuan mine.
基于ERS散射计数据的土壤水分反演方法
孙瑞静,施建成,
国土资源遥感 , 2010, DOI: 10.6046/gtzyyg.2010.04.03
Abstract: 在全球能量与水循环研究中,地表土壤水分是非常关键的参数之一。ERS散射计因具有观测尺度大、重复周期短等优势而在地表土壤水分监测方面日益受到关注。采用目前最先进的理论模型AIEM(改进的积分方程模型),根据ERS散射计的参数设计模拟出一个涵盖较宽地表粗糙度和介电常数输入范围的数据库,利用这个数据库发展出一个参数化模型。该模型采用了一个综合均方根高度(RMSheight)与相关长度(Correlationlength)的粗糙度参数,该参数在每个入射角度下都可以用同一个函数来描述,解决了多角度数据情况下粗糙度参数的表达问题。应用新发展的参数化模型进行土壤水分的反演结果表明,该模型具有较高的精度。
长大深埋隧道工程区地应力状态预测与实例分析
成虎,邢博瑞,
岩石工程学报 , 2014,
Abstract: 深埋隧道工程区地应力场的预测一直是工程技术人员所需迫切解决的难题。针对此问题提出了解决方案,即利用世界应力图、中国大陆地壳应力环境数据库以及前人研究成果可获得工程区应力场方向的初步认识,同时还可以利用anderson断层力学理论分析工程区可能的主应力方向。在获得原地应力实测资料后,利用较为翔实的工程地质资料基于hoek-brown强度理论估算工程区范围内的岩体强度,然后利用修正sheorey模型和数值模拟手段开展工程区深埋区域的地应力状态的预测分析。某水电站工程区位于青藏高原西缘。3个钻孔的水压致裂原地应力实测数据显示三向主应力之间的关系为sh>sh>sv或sh>sv>sh,表明最大水平主应力占主导地位,水平构造作用力明显。实测所得到的测区最大水平主应力方向为nee向(n70.3°—89°e);而世界应力图给出的区域应力场方向为ne向。通过修正sheorey模型对深埋引水隧洞沿线的工程区应力状态进行了预测,结果显示,埋深最大的地方,最大最小水平应力值分别为56.70,40.14mpa。
大豆再生体系和遗传转化研究进展
晓春,刘尚,
大豆科学 , 2009, DOI: 10.11861/j.issn.1000-9841.2009.04.0731
Abstract: 尽管大豆再生与遗传转化取得了一定成果,但是再生率和转化率仍然很低,是公认的难转化作物。从大豆再生体系与遗传转化两个方面阐述其研究进展,并对目前转化中遇到的植株再生频率低和转化率低或得不到转化体的原因及解决方法提出一些看法。
基于协同粒子群算法的单元集成布局方法
,丁奎学,
计算机集成制造系统 , 2012,
Abstract: 为避免单元间布局和单元内设施布局分开孤立研究所导致的问题解空间损失,建立了多目标集成优化模型,对布局中涉及的单元间布局、单元内设施布置、设施摆放方向三个问题同时进行描述,扩大问题解的搜索空间。针对模型的复杂性和传统粒子群算法容易陷入局部最优的弱点,设计了基于结构化编码的多粒子群协同进化算法,在多个粒子群协同进化的同时,对各子群构建基因库,并对基因库粒子进行遗传操作,提高了算法的寻优能力。通过求解单元布局问题实例,验证了模型和算法的有效性。
钙离子对米根霉菌体形态及L-乳酸合成的影响
,洪璐,孙小龙,
过程工程学报 , 2014,
Abstract: 采用添加钙离子的方法,考察钙离子对米根霉菌体形态及L-乳酸发酵合成的影响.结果表明,添加钙离子有利于球状米根霉形成.可溶性钙CaCl2浓度越低,越有利于形成较小直径的菌球,利于L-乳酸生成;添加较高浓度的难溶性钙CaCO3(8.0g/L除外)能形成较大菌球(约1.5mm),更有利于L-乳酸合成,产量达58.6g/L,高于CaCl2的57.2g/L,平均生产强度为1.22g/(L×h),高于CaCl2的1.02g/(L×h).但过量的CaCO3会包裹菌球,影响L-乳酸合成.
稳定表达FLT3-ITD/FIV载体的急性髓细胞白血病细胞株的构建及鉴定
陈姣,晓冬,
- , 2017,
Abstract: 构建稳定表达FLT3-ITD/FIV载体的急性髓细胞白血病细胞(AML)株,为研究FLT3-ITD在急性髓细胞白血病中的作用和以FLIT3为靶点的治疗提供一种新的体外模型。筛选临床上FLT3-ITD突变的AML患者,选取mutant/wt比值最高的FLT3-ITD突变作为克隆对象,PCR扩增FLT3基因全长。然后通过同源重组的方法构建FLT3-ITD/FIV慢病毒载体并包病毒,收集病毒液上清液进行K562白血病细胞株感染,通过流式细胞分选术筛选阳性转染细胞。收集阳性转染细胞做Western blot验证阳性质粒的表达情况。207名AML患者中有42例FLT3-ITD突变,成功扩增出了mutant/wt比值最高的FLT3-ITD突变患者的FLT3基因全长。双酶切FIV载体和模板DNA,连接以及感受态细胞转化筛选出阳性重组子,双酶切鉴定和测序结果验证。慢病毒成功感染K562白血病细胞株,用流式细胞分选术筛选出了稳定感染的细胞,且该细胞可以传代、扩增。同时,稳定感染细胞的Western blot鉴定也证实了阳性质粒的表达情况。通过筛选FLT3-ITD突变的AML患者,成功构建了稳定表达FLT3-ITD/FIV载体的白血病细胞株,为研究FLT3-ITD在AML发病中的作用以及针对FLT3-ITD为靶点的药物筛选治疗等提供了一个稳定的体外细胞模型。
The aim of this study was to construct the lentivirus expression vector of human FLT3-ITD mutation and to screen the AML cells for stable expression of FLT3-ITD. We screened the AML patient with FLT3-ITD mutation by peripheral blood DNA extraction and PCR, and then the ORF of FLT3-ITD was constructed using the method of homologous recombination, which used the BamH I and Not I double enzyme digestion of the ORF and the FIV vector. Results were confirmed by restriction enzyme identification and PCR. The constructed recombinant vector was co-transfected with VSVG and g/p into HEK293T cells to produce the lentiviral particles by transfection reagent. The lentiviral particles were transduced into K562 cells and the infection efficiency was measured by fluorescence microscope. The cells were sorted by the Flow Cytometer. The expression of FLT3 in the stable cell lines was detected by Western blot. There were 42 patients with FLT3-ITD mutation among the 207 patients we collected. We successfully amplified the ORF of FLT3 of the patient with highest mutant/wt ration. Then constructed the lentivirus expression vector FLT3-ITD/FIV and overexpressed it in K562 cell lines. We screened the cells expressed FLT3-ITD/FIV by fluorescence activated cell sorting, and Western Blot results proved the expression of FLT3-ITD. The over-expression 1entiviral vector of human FLT3-ITD/FIV has been successfully constructed and cell lines for stable expression of FLT3-ITD have been successfully established. This will shed a light on the future study of FLT3 function in AML and provide a new in vitro model for AML
综采工作面煤矸频谱特征
张守祥,张艳丽,,张岩,刘伟,
煤炭学报 , 2007,
Abstract: 采用数字信号处理技术,实时计算煤矸放落量比例.数字滤波首先消除煤矸放落环境噪声,再应用短时窗技术将信号按10~30ms的短帧为单位来处理,根据信号特征加凯塞窗处理,提高信号的分辨率,利用快速傅里叶变换分析数据的频谱特征.实验结果给出了煤矸信号的时域波形、频域波形和三维谱图,表明落煤振动频率集中在0.8~2kHz附近,而落矸振动频率集中在3~4kHz附近,具体数值需要根据综采工作面的地质环境修正.
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