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Search Results: 1 - 10 of 218986 matches for " 刘冬? "
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Disposal of the Network Overtime in Java Programming
Java编程中网络超时的简单处理


计算机系统应用 , 2004,
Abstract: 本文分别就连接后和连接时两种情况,讨论了基于套接字的Java语言网络编程中网络超时的简单处理,提出了让Ja-va应用程序具有非阻塞模式I/O操作功能的方法,并且给出了一个简单的应用实例.
绿卡工程新型网络管理软件的开发

计算机系统应用 , 1998,
Abstract: 本文介绍了用于该工程的一种新型网络管理软件。它不仅具有SNMP网管协议中被管代理的全部功能,而且能主动采集本地网络主要设备的信息,弥补了原有软件只能完全被动地接受查询的缺陷。大大增强了网络管理功能。
基于高斯过程的精密卫星钟差加密

测绘学报 , 2011,
Abstract: 在GPS数据处理中,经常需要高采样率的精密星历钟差参数,通常将IGS提供的15min或5min的精密卫星钟差采用拟合或插值的方法来加密到用户需要的间隔。本文将高斯过程方法应用到精密卫星钟差加密中,通过选择合适的核函数,将5min间隔的钟差数据插值到30s间隔。将结果与IGS提供的30s精密钟差数据和四阶多项式拟合插值方法得到的结果进行了比较,结果表明,高斯过程方法具有较高的加密精度,适用于GPS所有在轨卫星的原子钟钟差的加密,达到了厘米级精度。
城市商业银行竞争力统计评价指标体系的构建与运用

财会月刊 , 2006,
Abstract:   本文根据统计学评价指标体系设计的原理,针对我国城市商业银行的特点,构建科学合理的城市商业银行竞争力统计评价指标体系,以期为增强城市商业银行的竞争力提供一些参考。  【关键词】城市商业银行竞争力统计评价指标体系构建运用  经历了萌芽、扩张、整合和规范四个阶段的发展,城市商业银行已经成为我国银行体系中不可或缺的重要组成部分。虽然我国现有的城市商业银行所占的市场绝对份额仍然较低,但其经济增长速度很快,体现了强大的发展潜力和良好的发展态势。  在倡导企业核心竞争力与综合实力的新世纪,竞争对手的改革与发展、市场竞争环境与竞争规则的变化、行业内竞争与合作的深化、监管政策的调整、城市商业银行与地方政府的相互影响、城市商业银行所在地区经济发展趋势等因素构成了城市商业银行面临的外部机遇与挑战。而如何提升自身的竞争力成为城市商业银行改革的核心问题。
树脂基碳纤维复合材料应变传感稳定性研究

武汉理工大学学报 , 2008,
Abstract: ?研究了碳纤维毡和树脂基碳纤维复合材料的应变传感特性,结果表明:虽然碳纤维毡应变传感灵敏度系数比树脂基碳纤维复合材料高1倍多,但是树脂基碳纤维复合材料比碳纤维毡应变传感稳定性高出好几倍,甚至几十倍。5层碳纤维毡树脂基复合材料的应变传感稳定性系数为12.1,远高于碳纤维毡的0.35,因为它除了有单层碳纤维毡本身的纤维搭接构成的导电网络,层间也有短切碳纤维的搭接,形成了一个新的导电性能更加完好的立体导电网络。
中国主要水果抑制肝癌HepG2细胞和结肠腺癌Caco-2细胞增殖活性评价

- , 2015, DOI: 10.13982/j.mfst.1673-9078.2015.4.005
Abstract: 分别采用Folin-Ciocalteu法测定了水果提取物的总酚含量,采用亚甲基蓝法测定了其抗人肝癌细胞HepG2和人结肠腺癌细胞Caco-2增殖的活性,分析了总酚含量与抗HepG2和Caco-2细胞增殖活性之间的相关性。结果显示,25种水果中李子的总酚含量最高(1686.08±96.94 ?mol GAE/100 鲜果),西瓜(83.54±2.10 ?mol GAE/100 g鲜果)和哈密瓜(79.35±0.76 ?mol GAE/100 g鲜果)的总酚含量最低;在可测出抗增殖EC50值的水果中,李子(18.99±0.06 mg/mL)和番石榴(20.94±0.09 mg/mL)抗HepG2细胞增殖的活性最强,梨的活性最弱(389.63±10.82 mg/mL)。李子抗Caco-2细胞增殖的活性最强(8.73±0.11 mg/mL),火龙果的活性最弱(388.07±7.04 mg/mL)。水果的抗HepG2和Caco-2细胞增殖活性与其总酚含量相关性显著(R2=0.4147,p<0.01;R2=0.4071,p<0.05),该相关性表明水果中的多酚具有良好的抗肿瘤细胞增值的活性。
The total phenolic content and the anti-proliferative activities of the phenolic extracts against HepG2 and Caco-2 cells were determined by the Folin-Ciocalteu method and the methylene blue assay, respectively; the correlation between the total phenolic content and the anti-proliferative activity of the extracts was analyzed. The results of these analyses revealed that plum (Prunus salicina Lindl.) had the highest total phenolic content (1686.08 ± 96.94 ?mol gallic acid equivalent (GAE)/100 g of fresh fruit), whereas watermelon (Citrullus lanatus) (83.54 ± 2.10 ?mol GAE/100 g of fresh fruit) and hami melon (Cucumis melo var. saccharinus) (79.35 ± 0.76 mol GAE/100g of fresh fruit) had the lowest phenolic content among the 25 tested species. Among the fruit species with quantifiable anti-proliferative activities (half maximal effective concentration (EC50)), plum and guava (Psidium guajava Linn.) showed the strongest anti-proliferative activities against HepG2 cells (EC50 values: 18.99 ± 0.06 and 20.94 ± 0.09 mg/mL, respectively), whereas pears (Pyrus spp.) showed the weakest anti-proliferative activity against these cells (EC50 value: 389.63 ± 10.82 mg/mL). Plum also demonstrated the strongest anti-proliferative activity against Caco-2 cells (EC50 value: 8.73 ± 0.11 mg/mL), while the activity of pitava (Hylocereus undulatus Britt.) was observed to be the weakest (EC50 value: 388.07 ± 7.04 mg/mL). The anti-proliferative activities of fruits on HepG2 and Caco-2 cells were significantly correlated to their total phenolic content (R2 = 0.4147, p < 0.01; R2 = 0.4071, p < 0.05, respectively). This correlation indicates the high anti-proliferative effect of fruit polyphenols on cancer cells.
小麦不同部位在体外模拟消化过程中抗氧化活性的变化规律

- , 2016, DOI: 10.13982/j.mfst.1673-9078.2016.4.016
Abstract: 采用体外模拟消化的方法对小麦不同部位(全麦、麸皮和精面)进行模拟胃肠消化实验,测定在模拟消化过程中抗氧化活性物质(以多酚表示)和黄酮释放量及总抗氧化活性的变化规律。结果显示:模拟胃消化过程中,与胃消化0 h相比,全麦、麸皮和精面的最大多酚释放量分别为其2.157、1.653和3.092倍,最大黄酮释放量分别为其1.825、1.574和3.179倍,最大ORAC值分别为其2.601、1.658和6.197倍。模拟肠消化过程中,与肠消化0 h和胃消化0 h相比,全麦、麸皮和精面的最大多酚释放量分别为其1.541、1.042、1.578和3.429、1.697、4.975倍,最大黄酮释放量分别为其1.428、1.026、1.688和2.421、1.570、4.913倍,最大ORAC值分别为其1.464、1.039、1.514和3.694、1.690、9.017倍。表明谷物结合多酚(如黄酮)在胃肠消化过程中,由于胃酸水解和胃肠蛋白酶酶解等消化作用由结合态转变成游离态多酚(黄酮),因而谷物结合多酚可以在胃肠道消化吸收。
Different parts of wheat (whole wheat flour, bran, and refined flour) were subjected to simulated gastrointestinal digestion in vitro, to determine changes in the release of active antioxidant substances (polyphenols) and flavonoids, as well as total antioxidant capacity. The results showed that the maximum quantities of polyphenols and flavonoids released from whole wheat, bran, and refined flour during gastric digestion were 2.157-, 1.653-, 3.092-, and 1.825-, 1.574-, 3.179-times the values at 0 h, respectively. Similarly, the maximum oxygen radical absorption capacity (ORAC) values for whole wheat, bran, and refined flour were 2.601-, 1.658-, and 6.197-times the values at 0 h, respectively. On the other hand, the maximum quantities of polyphenols released from whole wheat, bran, and refined flour during in vitro simulated intestinal digestion were 1.541-, 1.042-, and 1.578-times the values at 0 h of intestinal digestion, and 3.429-, 1.697-, and 4.975-times the values at 0 h of gastric digestion, respectively. Additionally, the maximum quantities of flavonoids released from whole wheat, bran, and refined flour were 1.428-, 1.026-, and 1.570-times the values at 0 h of intestinal digestion, and 2.421-, 1.570-, and 4.913-times the values at 0 h of gastric digestion, respectively. Similarly, the maximum ORAC values for whole wheat, bran, and refined flour were 1.464-, 1.039-, and 1.514-times the values at 0 h of intestinal digestion, and 3.694-, 1.690-, 9.017-times the values at 0 h of gastric digestion, respectively. The results show that the polyphenols (such as flavonoids) bound to grains were converted to free polyphenols from the bound form due to gastric acid and enzymatic hydrolysis via gastrointestinal protease during gastrointestinal digestion. Thus, polyphenols bound to grains can be digested and absorbed in the upper gastrointestinal tract.
不同品种荔枝果肉细胞抗氧化及抗增殖活性评价

- , 2018, DOI: 10.13982/j.mfst.1673-9078.2018.2.009
Abstract: 为明确荔枝果肉的生物抗氧化和抗肿瘤保健功能,采用HepG2人肝癌细胞模型对我国南方地区主要种植的10种代表性荔枝品种果肉的细胞抗氧化活性(CAA值)和抗肿瘤细胞增殖活性进行了评价。结果表明,10种荔枝品种中,妃子笑荔枝果肉具有最大的CAA值,淮枝则最小;妃子笑抗HepG2肿瘤细胞增殖活性最强,糯米糍则最弱。荔枝果肉的CAA值与总多酚含量、总黄酮含量、多酚化学抗氧化能力指数(ORAC值)之间都有极显著的正相关性(p<0.01),且与黄酮含量之间正相关性最大,说明荔枝果肉中起生物抗氧化作用的主要成分是黄酮类化合物;但荔枝果肉对HepG2肿瘤细胞的抗增殖活性与总多酚含量、总黄酮含量、ORAC和CAA值之间均呈现较弱的负相关性(p>0.05),提示某些特殊酚类单体或其协同作用在抗肿瘤细胞增殖过程中发挥主要作用。
The celluar antioxidant activity (CAA) and antiproliferative activitiy of 10 representative litchi (Litchi chinensis Sonn.) cultivars in southern China were evaluated by HepG2 model to investigate the bio-antioxidant and antineoplastic functions of different litchi cultivars in this study. The results showed that Feixixiao had the largest CAA value among the ten litchi cultivars and the Huaizhi was the smallest; Feizixiao had the strongest antiproliferative activity on HepG2 cells and the Nuomici was the weakest. The CAA value of litchi pulp exhibited a significant positive correlation with total polyphenols, total flavonoids and ORAC (oxygen radical absorption capacity) values (p<0.01), and had the highest correlation with total flavonoids, indicating that the main component of biological antioxidants in litchi pulp was flavonoids. However, there was a weak negative correlation between antiproliferative activity of litchi pulp and total polyphenols, total flavonoids, ORAC and CAA values, indicating that some special polyphenol individuals or their synergies played a key role in antiproliferation of tumor cells.
基于第一性原理的信息内容产业发展研究

- , 2018,
Abstract: 第一性原理是一种探究事物本质的理论,以第一性原理的方式进行思考在物理等多个自然科学领域获得了巨大的成功,马斯克将Tesla和Space X的成功都归因于这个原理。这一原理同样适用于信息内容产业,出版业的数字化转型升级以及知识付费的兴起都从不同的数字产品形态验证了这一原理的应用。本文从第一性原理谈起,将其与出版的本质相结合,以数值型数据库和知识付费产品为例,深入剖析将第一性原理融入信息内容的实践,并认为这种思考和实践方式将是数字化转型升级不可或缺的工作方法
氨水量对微波制备花状ZnO光催化性能的影响
Effect of Precursor Ammonia on Photocatalysis of Flower-Like ZnO Microstructures Prepared by Microwave Method
 [PDF]

, 马青兰, 黄远明
Optoelectronics (OE) , 2013, DOI: 10.12677/OE.2013.34008
Abstract: 通过一种简便高效的微波法在不同氨水量下制备了花状ZnO。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)及光致发光光谱仪(PL)对产物的结构、形貌以及光学特性进行表征。发现此种方法制备的ZnO为微米量级,花状结构是由一系列底部粗、顶部细的纳米棒组合而成,光致发光显示有很强的绿光发光峰。光催化测试表明ZnO对甲基橙有较强的降解作用,1小时的降解率约95%。氨水量对ZnO的结构形貌有影响,对光致发光和光催化效果无明显影响。
Flower-like ZnO was prepared by using a simple and efficient microwave method in different amount of ammonia. The structure, morphology and optical properties of the products were characterized by XRD, SEM and PL. It was found that ZnO prepared by this method was micro dimension. Flower-like structure was consisted of a series of the thick bottom and thin top nanorods; photoluminescence showed a strong green emission peak. Photocatalytic meas- ure showed that ZnO had a strong function of degradation on methyl orange, and the degradation rate is about 95% after 1 hour. The amount of ammonia had effects on structure and morphology of ZnO, but had no significant effects on pho- toluminescence and photocatalysis.
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