A New Algorithm for VoIP Adaptive Buffer

网络延迟与缓冲的矛盾是VOIP应用中的一个重要问题。介绍了VOIP应用中几种当前主要的缓冲算法,分别分析了它们的优缺点,提出了新的自适应缓冲算法,称为fISd算法,对现有的代表性算法以及fISd算法分别进行了仿真实验。结果表明,在网络延迟抖动较大时,新算法可以有效地提高语音质量。The contradiction between network delay and the buffer is an important issue of the application of VoIP.Introduces several major current buffer algorithms in the application of VoIP,and analyses their advantages and disadvantages respectively.Then a new adaptive buffer algorithm is proposed,which is named FISD algorithm.The representation of the existing algorithms and FISD algorithm simulation experiments were carried out.The results show that when the network delay jitter is intense,the new algorithm can effectively improve voice quality.福建省2004年自然科学基金资助项目(A0410004);厦门大学院士基金资助项目(0630-E23011);厦门大学新世纪优秀人才支持基金(0000-X07116

Preparation of LiNi_(0.9)Co_(0.1)O_2 material and study on its electrochemical performance

成功采用掺杂和改变前驱体两种方式同时对传统lInIO2正极材料合成进行改进,即用掺杂10%WTCO的β-nIOOH作为前驱体,和lIOH·H2O在空气中进行固相烧结。通过正交方法优化出合成lInI0.9CO0.1O2的最佳烧结温度为600℃,烧结时间为24H;此条件下材料首次充放电效率高达86%,20次循环后可逆放电比容量为167MAH/g,容量保持率高达94%。It is a success for using both doping and changing precursor to improve the traditional cathode material LiNiO2 which is using 10%wt Co doped in the β-NiOOH as the precursor, then solid- phase Sintering with LiOH·H2O in the air.By orthogonal methods we optimize the best sintering temperature is 600 ℃ and sintering time is 24 h for synthesis of the LiNi0.9Co0.1O2; Under these conditions, the first charge and discharge efficiency can be as high as 86%, discharge capacity is to be 167 mAh/g after 20 cycles reversible, and the capacity rates can maintain as high as 94%

Synthesis,structure and electrochemical performance of Mg-doping nickel oxyhydroxide

首次以掺杂Mg的β-nI(OH)2为前驱体,采用k2S2O8为氧化剂,制备出β-羟基氧化镍镁,并应用X射线衍射光谱法(Xrd)、傅里叶变换红外光谱法(fTIr)、热重-差热分析(Tg-dTg)、CV和放电测试对样品的结构和电化学性能进行了表征。The Mg-doping β-NiOOH was firstly synthesized by using Mg-doping β-Ni(OH)2 as precursor,K2S2O8 as oxidizer.The crystal structure and electrochemical performance of the prepared samples were analyzed by XRD,FTIR,TG-DTG,CV and discharge test

Screening research on effective parts of Alisma orientalis( Samuel. ) Juzep. associated with blood glucose decrease in type 2 diabetic mice

目的初步探索泽泻[Alisma orientalis(Samuel.)Juzep.]降低2型糖尿病小鼠血糖的有效部位。方法采用超声提取法获得泽泻乙醇提取物,再分别用石油醚、乙酸乙酯、水饱和正丁醇和水相进行萃取分离,得到的泽泻乙醇提取物及其各溶剂萃取物应用于腹腔注射烟碱、链脲霉素诱导的2型糖尿病小鼠模型。造模成功后,将动物分组,其中空白对照组(未注射链脲霉素和烟碱的小鼠)和2型糖尿病模型组小鼠连续灌胃0.9%Na Cl溶液21 d(灌胃剂量为10μl/g),测试药物组分别连续灌胃泽泻乙醇提取物、泽泻石油醚萃取物、泽泻乙酸乙酯萃取物、泽泻正丁醇萃取物、泽泻水萃取物21 d(各测试药物灌胃高、中、低剂量分别为100μg/g、50μg/g、25μg/g),阳性对照组连续灌胃罗格列酮溶液21 d(灌胃剂量为10μg/g),每组8只小鼠,筛选具有降低2型糖尿病小鼠血糖的泽泻有效部位。用具有降低2型糖尿病小鼠血糖的有效部位处理3T3-L1前脂肪细胞,观察其对前脂肪细胞分化过程的影响。结果与2型糖尿病模型组比较,连续灌胃泽泻乙酸乙酯萃取物21 d(剂量为100μg/g)降低了2型糖尿病小鼠的血糖,改善了口服葡萄糖耐受试验(oral glucose tolerance test,OGTT)过程中的糖耐量(P<0.01)。1 mg/L和10 mg/L的泽泻乙酸乙酯萃取层均能促进前脂肪细胞的分化过程。结论泽泻乙酸乙酯萃取物降低了2型糖尿病小鼠血糖,促进了3T3-L1前脂肪细胞分化,但其具体作用机制尚需深入研究。Objective To explore the effective parts of Alisma orientalis( Samuel.) Juzep. associated with blood glucose decrease in type 2 diabetic mice.Methods Ethanol extracts from A. orientalis were obtained by ultrasonic extraction. Then,the ethanol extract was extracted and separated with petroleum ether,ethyl acetate,water saturated n-butanol and water respectively. After decompressing concentration,these solvent extractions were applied to type 2 diabetic mice model induced by intraperitoneal injection of streptozotocin and nicotine. After successful modeling,the mice were divided into the blank control group( without injection of streptozotocin and nicotine),model group of type 2 diabetes mellitus,positive control group and test drug groups,8 in each group. The blank control group and model group were treated with 0. 9% Na Cl at the dose of 10μl / g,the test drug groups were treated with corresponding extracts from different solvent extractions described above at the high-,mid-,low-dose of 100,50,25 μg / g respectively. The positive control group was treated with rosiglitazone at the dose of10μg / g. The treatment course was 21 days for intragastric administration. The effective parts of Alisma orientalis( Samuel.) Juzep. associated with blood glucose decrease in type 2 diabetic mice were screened and then the effect of the screened effective part on the differentiation of 3T3-L1 pre-adipocyte was observed.Results Compared with the model group,the blood glucose was decreased after the intragastric administration with ethyl acetate extract of A. orientalis at dose of100μg / g for 21 days and the glucose tolerance during the oral glucose tolerance test( OGTT) was improved( P < 0. 01). The differentiation of pre-adipocyte was promoted when the ethyl acetate extract of A. orientalis at the concentration of 1 mg / L and 10 mg / L. Conclusion The ethyl acetate extract of A. orientalis reduced the blood glucose in type 2 diabetic mice and promoted the differentiation of 3T3-L1 pre-adipocytes,but the specific mechanism still need to be further studied.福建省科技厅自然科学基金青年创新项目;; 厦门市卫计委资助项目(2014D008),厦门市卫计委资助项目(2015-ZQN-JC-45);; 福建省卫生系统中青年骨干人才培养项目基础项目;; 福建省科技厅自然科学基金(2015J01065);; 福建省教育厅中青年教师教育科研项目杰青项目(JA14421),福建省教育厅中青年教师教育科研项目(JA13425);; 厦门市科技局科技计划高校创新项目(3502Z20143026),厦门市科技局科技计划项目(3502Z20144031);; 厦门医学高等专科学校科研基金(Z2013-12,Z2013-25

太子参环肽类化合物Pseudostellarin E对3T3-L1前脂肪细胞分化和葡萄糖吸收的作用

目的探讨太子参环肽类化合物Pseudostellarin E是否具有治疗2型糖尿病的潜力。方法在3T3-L1前脂肪细胞中应用了葡萄糖吸收试验和分化模型。结果 Pseudostellarin E不仅加速3T3-L1前脂肪细胞分化进程,而且在高浓度(30m M)葡萄糖条件下增加了分化的脂肪细胞对胰岛素刺激的葡萄糖的吸收。结论上述结果表明,Pseudostellarin E可能具有治疗糖尿病的潜能。国家自然科学基金面上项目(81773601);;福建省教育厅2015年第二批高等学校优秀学科(专业)带头人赴海外访学研修资助项目(闽教人[2015]103号);;福建省自然科学基金计划资助项目(2015J01065);;福建省卫生系统中青年骨干人才培养项目2015年资助计划基础项目(2015-ZQN-JC-45);;福建省厦门市科技局科技计划高校创新项目(3502Z20143026);;厦门医学院科研项目(Z2013-12,Z2013-25

定量磁化率成像重建方法及其应用

磁共振成像(MRI)中,相位图像包含丰富的组织磁化率变化信息,获取相位图像不需要额外的扫描时间.组织中的顺磁性物质会影响组织磁化率差异,从而导致局部磁场不均匀.对组织内顺磁性物质的定量有利于许多脑血管疾病和神经系统疾病的诊断,但利用局部相位信息重建组织磁化率分布是一个不适定逆问题,目前仍然有许多问题亟待解决.该文着重介绍定量磁化率成像(QSM)的原理、重建方法及其在MRI中的应用.国家自然科学基金资助项目(81171331,11174239);中央高校基本业务费资助项目(2010121101

Studies on the Interactions between Bioactive Peroxovanadium Complexes Bearing Organic Ligands and Histidine

在合成和表征了 4种具有较强生物活性双过氧钒配合物K3 [VO(O2 ) 2 (ox) ]·2H2 O ,Na[VO(O2 ) 2 (bipy) ]·5H2 O ,K[VO(O2 ) 2 (phen) ]·3H2 O和K2 [VO(O2 ) 2 (pic) ]·2H2 O [分别缩写为pV(ox) ,pV(bipy) ,pV(phen)和pV(pic) ,其中ox为草酸根 ,bipy为 2 ,2′ 联吡啶 ,phen为邻菲咯啉 ,pic为 2 羧酸吡啶负离子 ]的基础上 ,利用多种NMR技术和电喷雾质谱 (ESI MS)研究了这 4种含有机配体双过氧钒配合物与组氨酸 (His)在溶液中的相互作用以及反应物浓度、时间、pH等对相互作用体系的影响 .51VNMR跟踪监测的结果表明 :双过氧钒配合物pV(ox)和pV(pic)与His在中性水溶液中存在强配位相互作用 ,而pV(bipy)和pV(phen)与His在中性水溶液中无明显作用 .我们还利用谱学方法确定了pV(ox)和His相互作用后所生成产物是pV(ox)分别与His咪唑基上的 3 N和 1 N配位的一对异构体. 　In order to explore the structure2activity relationship and molecular mechanism of the specific recognition between peroxovanadium (pV) complexes bearing organic ligands and the target enzymes of tyrosine phosphatase , several NMR techniques and ESI2MS were used to study the interactions of four pV complexes {pV(ox) , pV ( bipy) , pV (phen) and pV (pic) , where pV = [VO (O2 ) 2L ] n - , in which L = oxalic acid dianion (ox) , bipyridine (bipy) , 1 ,102phenanthroline (phen) , and pyridine222carboxylic acid (pic) } towards histidine. Strong coordination interactions between imidazole of histidine and vanadium of pV(ox) or pV(pic) were observed in neutral solution , while there are not obvious interactions between histidine and pV(bipy) or pV(phen) . All 13C and 1H NMR signals of 1∶1 stoichiometric mixture of pV(ox) and histidine were assigned. Spectroscopic studies demonstrated that new complexes in the mixture of pV(ox) and histidine are a pair of isomers in which the vanadium in pV(ox) binding to the 32N and 12N of the imidazole ring. Moreover , the results of effective factors on the interaction system indicated that the new isomers were stable under the condition of physiological pH and the structure2activity relationship of these pV complexes may be relevant to their specific recognition towards histidine residues in tyrosine phosphatase.国家自然科学基金 (Nos.2 0 172 0 42 ,2 9832 0 2 0 )资助项

磁共振成像中背景不均匀场去除方法研究

磁敏感加权成像(susceptibility weighted imaging,SWI)是近年来新开发的磁共振成像技术,最早由E.Mack Haacke等于1997发明[1],并最初被称作"高分辨率血氧水平依赖静脉成像"(high resolution blood oxygenation level dependent venographic imaging)。中央高校基本科研业务费专项资金(2010121101);国家自然科学基金(81171331