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Search Results: 1 - 10 of 39000 matches for " 谢婷蜓 "
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基于颗粒流程序的真三轴应力状态下堆石体的变形和强度特性研究
周伟,,马刚,常晓林
岩土力学 , 2012,
Abstract: 采用三维颗粒流程序,模拟了堆石体的真三轴试验,不仅研究了堆石体在三维应力条件下的宏观应力变形特点,而且将细观与宏观参数联系起来,进一步完善了对堆石体的研究。试验过程采用等中主应力比路径加载。通过比较堆石体真三轴颗粒流模型试验和室内真三轴试验结果,表明颗粒流程序能较好地模拟堆石体的力学特性。颗粒流数值试验结果表明,中主应力对堆石体在三向应力状态下的强度和变形特性均有显著的影响。应力比参数b从0~1变化过程中,中主应力面先压缩后膨胀,小主应力面一直处于压缩状态;中主应力对内摩擦角、弹性模量和泊松比也均有影响。从细观上看,围压越高,b值越大,颗粒配位数越大,孔隙率越小,故从细观角度解释了堆石体的宏观应力变形现象。
试论建立完善的信息化信息系统

科技进步与对策 , 2001,
Abstract: 实现信息化体育的关键是建立完善的现代化体育系统。信息化系统是一个极其复杂的系统,根据现代体育的需要,应该从扩大信息源、提高信息处理质量、疏通信息传输通道以及重视信息的存储和检索等4个方面来完善它,促使现代体育跟上信息化社会发展的步伐。体育信息化现代体育信息化体育系统体育教育
指数补料发酵提高鲁氏酵母β-1,3-葡聚糖酶产量

- , 2015, DOI: 10.13982/j.mfst.1673-9078.2015.6.032
Abstract: 高耐盐鲁氏酵母A菌株(耐24%盐)10 L发酵罐产β-1,3-葡聚糖酶的过程中,葡萄糖(YEPD)是鲁氏酵母A生长和产酶的最适碳源,其发酵效率显著高于甘油(YEPG)和乙醇(YEPE),而乙酸钠的可利用性较差。YEPD批培养生长效率(生物量)、最大酶活力以及酶产率分别比YEPG和YEPE批培养提高了1.89%和29.88%、114%和19.65%以及188%和33%。与YEPD批培养相比,15~23 h开始指数流加YEPF培养基,达到最大生物量的周期缩短12 h,最大生物量提高19.29%,而且β-1,3葡聚糖酶几乎以对数增长的方式提前6 h合成到最大酶活力(44.99 U/mL),酶产率提高了76.86%,达到2.14 U/(mL?h),实现了指数补料发酵的目的。研究结果确定了有效提高鲁氏酵母A生物量和?-1,3-葡聚糖酶产量的指数补料模型,为高耐盐鲁氏酵母菌剂和β-1,3-葡聚糖酶产品有效生产以及其在高活性酿造功能食品行业的应用打下了基础。
High salt-tolerant Zygosaccharomyces rouxii A (tolerant of 24% NaCl) was used to produce ?-1,3-Glucanase in 10 L fermenter. Glucose (YEPD) is the optimum carbon source for yeast growth and enzyme production. Fermentation efficiency with YEPD batch culture is significantly higher than that with glycerol (YEPG) and ethanol (YEPE), respectively. Meanwhile, batch culture efficiency with acetate as carbon source was poor. The growth efficiency (biomass), the largest ?-1,3-Glucanase and enzyme productivity with YEPD batch cultivation was increased by 1.89% and 29.88%, 114% and 19.65%, 188% and 33% than that with YEPG and YEPE batch culture, respectively. Compared with the YEPD batch cultivation, exponential fed-batch with YEPF medium from 15 to 23 h, the time of maximum biomass was shorten by 12 h and the maximum biomass was increased by 19.29%. Moreover, ?-1,3-glucanase was nearly logarithmically synthesized to the largest enzyme activity (44.99 U/mL), the time of synthesis was shortened by 6 h and enzyme productivity was up to 2.14 U/(mL?h) that was increased by 76.86%. Exponential fed-batch model for effective enhancement of biomass and β-1,3-glucanase production by Z. Rouxii A was confirmed by the results above, which laid the foundations for the effective production of high salt-tolerant Z. Rouxii A, ?-1,3-glucanase products and the application of them in highly active fermentative function food industry.
孕妇孕期体重指数变化与妊娠结局的相关性研究 Relationship Between Body Mass Index and Pregnancy Outcome in Pregnant Women

- , 2017,
Abstract: 目的:探讨孕妇孕前体重指数(BMI)、孕期体重增重现状与妊娠结局的关系,为孕期体重管理提供科学依据。方法:选择2013年5月至2015年2月我院产科住院分娩的初产妇457例作为研究对象。收集研究对象的一般资料,按照标准进行孕前体重指数分组,孕期增重分组,比较不同组别妊娠结局的差异。结果:457名孕妇孕前超重与肥胖有177人(38.73%),孕期增重过多120人(26.26%);平均年龄(26.99±5.89)岁,平均孕周为(39.27±1.43)周,不同孕前体重指数分组的孕妇年龄、孕周差异无统计学意义,P>0.05;肥胖组的妊娠期高血压综合征发生率(15.79%)、巨大儿发生率(14.04%)最高,体重过低组的低出生体重儿发生率(8.33%)最高,不同孕前BMI孕妇妊娠期高血压综合征、巨大儿、低出生体重儿发生率差异具有统计学意义,P<0.05;增重过多组妊娠期高血压综合征发生率(16.28%)、巨大儿发生率(10.85%)、剖宫产发生率(20.16%)最高,增重不足组低出生体重儿发生率最高(6.20%),不同孕期增重孕妇妊娠期高血压综合征、巨大儿、低出生体重儿、剖宫产发生率差异具有统计学意义,P<0.05。结论:孕前及孕期体重与妊娠结局密切相关,控制孕前体重、孕期体重增重在合理的范围内,对减少不良妊娠有着重要的意义
科研团队潜规则对团队成员创新行为影响的实证研究
廖冰,侯青
科技进步与对策 , 2015, DOI: 10.6049/kjjbydc.2014120532
Abstract: 在东方文化科研团队背景下,运用国内外部分成熟量表,重点探讨和测量了科研团队潜规则结构维度及其对团队成员创新行为的影响。在对重庆、台湾209份科研团队初试问卷及重庆、上海、广州、北京、台湾486份正式问卷调查的基础上,经项目分析、CFA和EFA分析,得出了科研团队潜规则的5维度结构,即团队形象、团队规章制度、领导行为、心理安全感、绩效奖惩。运用相关回归分析对企业潜规则各维度与相关变量之间的关系进行了探讨。地域数据分析结果显示,领导行为和心理安全感与团队成员创新行为显著正相关;大陆数据模型中,绩效奖惩与科研团队成员创新行为相关性不显著,台湾地区科研团队成员创新行为更加关注绩效薪酬和晋升发展。科研团队潜规则创新行为地域差异分析
hiv非核苷类逆转录酶抑制剂研究进展
,
药学学报 , 2004,
Abstract:
鲢鱼放养密度对水体中浮游藻类的影响
Influence of Breeding Density of Hypophthalmichthys molitrix on Phytoplankton in Ponds
 [PDF]

, 丁建华, 冯佳, 树莲
Open Journal of Fisheries Research (OJFR) , 2014, DOI: 10.12677/ojfr.2014.11004
Abstract:
2013年4~9月调查了山西省永济市温流水良种繁育场鲢鱼放养密度对水体浮游藻类,特别是蓝藻细胞丰度以及溶氧量的影响。两组鱼塘,一组为低密度鲢鱼养殖(21.2 g/m3),一组为高密度鲢鱼养殖(42.4 g/m3)。调查结果显示:1) 高密度鲢鱼放养鱼塘溶氧高于低密度鲢鱼放养鱼塘;2) 初期水体的浮游藻类总细胞丰度差异不大,但后期鲢鱼高密度放养鱼塘浮游藻类总细胞丰度低于低密度放养鱼塘;3) 初期两种密度鲢鱼养殖池塘中的蓝藻细胞丰度差异不大,后期高密度鲢鱼养殖池塘比低密度鲢鱼养殖池塘中的蓝藻细胞丰度明显降低,在浮游藻类总细胞丰度中所占比例也有同样的变化趋势;4) 两种养殖密度下,后期高密度养殖池塘中优势种有由蓝藻门向其他门类变化的趋势。总体结论,高密度鲢鱼养殖较低密度鲢鱼养殖可以更有效地控制和减少水体中的浮游藻类细胞丰度,特别是蓝藻的细胞丰度,更有利于水质净化,同时也提高了渔产潜力。
An investigation was carried out that the breeding density of Hypophthalmichthys molitrix influenced the cell abundance of phytoplankton, especially Cyanobacteria in Wenliushui Excellent Fish Breeding Grounds, Yongji, Shanxi Province, North China, from April to September of 2013. Two experimental groups were set, which represented low and high breeding density of H. molitrix, and were 21.2 g/m3 and 42.4 g/m3 respectively. The results showed that: 1) the dissolved oxygen of high density breeding ponds was higher than that of low breeding density ponds; 2) the cell abundance of phytoplankton had little difference at first but distinct difference later, and it was obvious lower in high breeding density ponds of H. molitrix than that in low breeding density ponds; 3) the same trend was reflected in Cyanobacteria; 4) compared with the low breeding density ponds, the dominant species had the trend from Cyanobacteria to the other divisions in high density breeding ponds of H. molitrix. In conclusion, the high density breeding of H. molitrix can control the cell abundance of phytoplankton especially Cyanobacteria, and purify water body, and meanwhile, the aquatic productivities are increased.
放养密度对鲢鱼淀粉酶和脂肪酶活性的影响
Influence of Breeding Density on Amylase Activity and Lipase Activity of Hypophthalmichthys molitrix
 [PDF]

, 丁建华, 冯佳, 树莲
Open Journal of Fisheries Research (OJFR) , 2014, DOI: 10.12677/OJFR.2014.12006
Abstract:
本实验就高密度养殖与低密度养殖下对鱼体内淀粉酶和脂肪酶活性的影响进行了探究。2013年4月~10月,在山西省永济市温流水良种繁育场设置了两组池塘,每组三个,一组为低密度鲢鱼养殖(21.2 g?m?3),一组为高密度鲢鱼养殖(42.4 g?m?3)。对此两种密度养殖下鲢鱼肠道淀粉酶和脂肪酶活性进行了测定,结果表明:高密度养殖池塘中鲢鱼肠道的淀粉酶活力和脂肪酶活力均高于低密度养殖池塘,且鲢鱼前肠此两种消化酶活性高于后肠;高密度鲢鱼养殖池塘与低密度相比,蓝藻门的细胞丰度明显下降,绿藻门细胞丰度所占百分比明显增加;淀粉酶活力与蓝藻的细胞丰度呈负相关,与其余门类浮游植物细胞丰度呈正相关,脂肪酶活力与蓝藻和裸藻的细胞丰度呈负相关,与其余门类浮游植物细胞丰度呈正相关。
This experiment has carried on exploration including the influence on amylase and lipase activities in fish body under high and low breeding density. From April to October in 2013, the influence of different breeding densities on amylase activity and lipase activity in H. molitrix intestinal tract was investigated in Wenliushui excellent fish breeding grounds in Yongji, Shanxi province, North China. Two experimental groups (each including three ponds) were set, which represent low and high breeding of H. molitrix density of 21.2 g?m?3 and 42.4 g?m?3 respectively. The results showed that amylase activity of high density breeding ponds was higher than that of low density breeding ponds, and amylase activity in foregut is higher than that in hindgut, as is the same with the lipase activity. The cell abundance of Cyanophyta in high breeding density ponds was obviously lower, while the proportion of the cell abundance of Chlorophyta was higher than that in low breeding density ponds. The amylase activity had a negative correlation with the cell abundance of Cyanophyta but a positive correlation with the cell abundance of the other divisions. The lipase activity had a negative correlation with the cell abundance of Cyanophyta and Euglenophyta, but a positive correlation with the cell abundance of the other divisions.
五金产品的滞销风险定价模型构建
,刘阳
财会月刊 , 2010,
Abstract: 目前成本加成定价法是五金制造企业采用的产品定价的主要方法,但是该方法并没有考虑五金产品的滞销风险因素。本文纳入滞销风险因素,对原有的成本加成定价法进行修正,构建了适合五金产品定价的滞销风险定价模型。  【关键词】五金产品滞销风险定价模型成本加成定价法五金是指铁、钢、铝等金属经过锻造、压延、切割等物理加工制造而成的各种金属器件。五金行业的发展对我国经济的发展有着重要的影响。对于五金制造企业这种典型的工业企业而言,价格是产品营销最重要的影响要素,价格杠杆对促进五金产品的销售、获得良好经济效益起着十分有利的推动作用。五金制造企业的产品价格是否合理、生产技术水平的高低都对企业经营的成败有着决定性的影响。在很多情况下,很多企业的产品质量较好、生产技术水平较高,但由于价格制定得不够合理,结果出现灾难性的后果。因此,如何科学制定产品的销售价格非常重要,对于五金制造企业而言更是如此。当五金制造企业面临滞销危险的时候,更要合理地对产品进行定价,以尽快销售产品从而避免出现资金周转不灵、破产等危机。  一、影响五金产品价格的主要因素
北京奥运交通限行前后街道机动车污染的模拟
,绍东
环境科学 , 2010,
Abstract: 为评估北京市街道的机动车污染状况及奥运期间的改善程度,利用OSPM模型模拟计算了2008年7月奥运交通限行前后北京街道大气中PM10、CO、NO2和O3的浓度,得到其在限行前的日均浓度值分别为146μg/m33、3.83mg/m3、114.4μg/m3和4.71×10-9,限行后为112μg/m3、3.16mg/m3、102.4μg/m3和5.31×10-9,削减率分别是23.4%、20.5%、10.5%和-12.5%.对污染物在限行前后的浓度变化和日变化趋势的研究发现,PM10浓度受交通限行影响削减最大;CO浓度的日变化趋势与机动车流量的变化最为类似;NO2在限行后的削减幅度有限,表明其浓度还受到除交通排放外的其他因素影响;O3浓度在限行期间有所上升,说明限行措施不能降低街道中大气O3浓度.另外,比较不同类型街道的计算结果,发现街道车型构成与几何形状对污染物浓度变化有影响.总之,北京市在实施交通管制前,街道中PM10、CO和NO2的日均浓度均接近或超过国家空气质量二级标准限值,机动车污染状况较为严重;交通限行可有效降低一次污染物的浓度,但二次污染物的浓度有可能升高.
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