Development of Ba2Ti9O20 and (Zr0.8Sn0.2)TiO4 Microwave Ceramics

微波介质陶瓷是使用在微波频率下的陶瓷（300MHz～3000GHz），它主要应用于制作微波谐振器和滤波器，一般要求具有较高的相对介电常数εr、高的品质因子Q和趋于零的频率温度系数τf。为达到此目的，本论文对BaO-TiO2和(Zr,Sn)TiO4体系陶瓷进行研究，并对其介电极化机理进行初步的探讨。 在BaO-TiO2体系中,考察了不同原料配比、不同制备工艺和添加剂SnO2对Ba2Ti9O20相的形成及其微波性能的影响。实验表明：在不加任何添加剂的情况下也能形成Ba2Ti9O20；SnO2能促进Ba2Ti9O20相的形成；采用水热法制备的Ba2Ti9O20陶瓷微波性能比传统的固相法制备的Ba2...Microwave dielectric ceramic (MWDC) is usually applied in microwave frequency, 300MHz～3000GHz. It is mainly used as dielectric resonator and filters. It is expected for MWDC to have a high quality factor Q, a high dielectric constantεr and a low temperature coefficient of resonant frequency τf. The systems of BaO-TiO2 and (Zr,Sn)TiO4 ceramics and their polarization mechanisms are therefor studied ...学位：理学硕士院系专业：化学化工学院化学系_无机化学学号：20002500

响应面法提取公石松总黄酮工艺优化研究

目的:采用响应面法优化公石松总黄酮微波提取工艺。方法:先摸索液料比、反应时间、微波功率、反应温度四个微波提取条件,然后依据Box-Benhnken试验设计拟用四因素三水平方法,以公石松总黄酮提取率为响应值进行响应面试验,最后对不同公石松样品的总黄酮进行对比分析。结果:得出最佳提取工艺条件为:液料比30∶1(ml·g-1)、反应时间6.72 min,微波功率699.99 W,反应温度90℃,公石松总黄酮的提取率可达到1.02%。结论:微波提取工艺优化后公石松总黄酮的提取率可达1.02%;公石松叶子中的总黄酮含量高于茎,成熟期的总黄酮含量高于未成熟期。福建省教育厅中青年教师教育科研项目(编号:JAT171141);;漳州卫生职业学院课题项目(编号:ZYZ201701

Dividend Tax Cuts,Financial Market Heterogeneity and Corporate Capital Structure——Empirical Evidence from Chinese Listed Companies

文章基于2005年股利税改革,研究了股利税税率变动对我国上市公司资本结构的影响。研究发现,股利税税率总体上与企业资产负债率正相关,股利税减税政策降低了企业的资产负债率。但受所处环境金融市场化水平差异的影响,实施不同股利税政策的企业资产负债率的变化状况不同:一般而言,所处环境金融市场化水平越高,股利税减税带来的企业资产负债率下降程度越大;当所处环境金融市场化水平过低时,股利税率变动不会对企业的资本结构造成显著影响。此外,研究还发现股利税减税对非国企资本结构变化的影响强于国企。据此提出了相应的政策建议。Based on the dividend tax reform in 2005,this paper studies the impact of dividend tax rate change on capitalstructure of listed companies in China.The study shows that dividend tax rate is positively related to corporate asset-liabilityratio in general.The policy of dividend tax cuts reduces corporate asset-liability ratio.However,the degree of the impact var-ies according to the differences of financial markets' commercialized level.The corporate asset-liability ratio changes are dif-ferent in different dividend tax policies.Generally,the dividend tax rate change has a stronger impact on corporate capitalstructure when the financial market' commercialized level is higher whereas the dividend tax rate change has a weaker im-pact on corporate capital structure when the financial market' commercialized level is lower.Moreover,the degree of impactthat the policy of dividend tax cuts have on non state-owned enterprises is higher than that on state-owned enterprises.Final-ly,the paper puts forward the corresponding policy recommendations.国家自然科学基金面上项目(71473209

Least Square/Singular Value Decomposition Algorithm

针对预失真技术中存在记忆非线性放大器预失真的问题,分析数字预失真器的结构和常用预失真器的识别算法,对经典最小二乘/奇异值分解(lS/SVd)算法进行改进,以较少资源获得较高性能。仿真结果表明,改进的lS/SVd算法能实现记忆非线性放大器的快速、高效线性化,提高记忆非线性放大器的性能。Aiming at the problem of predistortion for memory nonlinear amplifier in predistortion technology,this paper analyzes the structure of digital predistortion and recognization algorithm of common predistortion,improves classical Least Square/Singular Value Decomposition(LS/SVD) algorithm.Improved LS/SVD algorithm can obtain better performance by less resource.Simulation results show the proposed algorithm can realize fast and effective linearization of memory nonlinear amplifier,and improve its performance

临床药师参与一例误诊为亚甲炎的急性甲状腺炎病人治疗的实践与体会

急性甲状腺炎又称急性化脓性甲状腺炎（acute suppurative thyroiditis,AST）或甲状腺脓肿,是一种十分罕见的疾病,仅占甲状腺疾病的0.1%0.7%[1]。AST是细菌或真菌经由血液、淋巴管或邻近化脓灶侵犯甲状腺组织引起的急性化脓性炎症,病人多表现为单侧甲状腺肿痛,吞咽时疼痛加剧,向齿部、两颊、耳后或枕部放射,局部肿胀导致颈部被动后伸,可有邻近组织感染征象。AST早期脓肿未形成

优质早籼南厦060的选育与应用

南厦 0 60是南平市农科所从厦大生物系育种组提供的株系中系统选育而成的优质、丰产、较抗稻瘟病的早籼新品种。 2 0 0 0年通过福建省品种审定委员会审定福建省“九五”水稻育种攻关项

Review and Prospect for Coastal Protection Forest Cultivating of Taiwan

从海岸防护林的主要树种、培育基础、营造技术及研究展望等方面,对台湾海岸防护林的保育与经营状况进行了概括总结,以期为海峡西岸防护林体系建设提供借鉴。From the main coastal protection forest species,nurturing base,creating technology and research prospects,this paper summarized the coastal protection forest conservation and operating conditions of Taiwan in order to provide a reference for the west coast protection forest system construction.国家“十一五”科技支撑计划(2009BADB2B0302);国家自然科学基金项目(41176092);国家林业局南方山地用材林培育重点实验室、福建省森林培育与林产品加工利用重点实验室资助项

Ecosystem Processes and Sustainable Management of Coastal Protection Forest of Casuarina equisetifolia

木麻黄为我国东南沿海防护林体系的主栽树种,如何维持和提高其环境调控功能成为当前沿海防护林经营的重要科学问题。文中概述了海岸带木麻黄林生态系统的物质循环、能量流动和防护功能以及育林措施对森林生态系统的影响等国内外研究成果,指出木麻黄人工林具有生产力高、光能利用率高和适应性强的特点;在探讨干扰与木麻黄林生态系统退化之间关系的基础上,提出加强木麻黄海岸防护林的恢复重建与生态系统管理等建议。Casuarina equisetifolia is a major species planted in protection forest along the coast of southeast China.At present,how to sustain and enhance its environmental regulation functions has become important science question for local protection forest management.This paper reviewed the research at home and abroad on nutrient cycling,energy flow and protective functions of C.equisetifolia ecosystem in coastal zone as well as on the effects of forest management measures on forest ecosystem,indicating that C.equisetifolia plantations have the characteristics of high production,high photosynthesis rate and better adaptive abilities.The relationship between disturbance and the degraded C.equisetifolia ecosystem was discussed.Then the suggestions were made for the restoration and reconstruction of the damaged C.equisetifolia protection forest and the management of its ecosystem.国家自然科学基金项目(41176092);国家“十一五”科技支撑计划(2009BADB2B0302);国家林业局南方山地用材林培育重点实验室、福建省森林培育与林产品加工利用重点实验室资助项

In situ Time-resolved FTIR and Raman Characterizations of the Partial Oxidation of Methane to Synthesis Gas over Ir/SiO_2 Catalyst

[中文文摘]采用原位时间分辨红外光谱和原位显微Raman光谱技术对Ir/SiO2 上甲烷部分氧化 (POM)制合成气反应的初级产物和反应条件下催化剂表面物种进行了跟踪考察 ,实验结果表明 ,在H2 预还原的新鲜Ir/SiO2 表面 ,CO是V(CH4)∶V(O2 )∶V(Ar) =2∶1∶45混合气反应的初级产物 ,因而甲烷的直接氧化过程是CO生成的主要途径 ;而在稳态反应条件下 ,CO生成的途径可能主要来自CO2 和H2 O与催化剂表面积碳物种 (CHx)和 /或CH4的反应 .催化剂上生成的积碳可能是导致稳态条件下Ir/SiO2 上POM反应机理不同于H2 预还原的新鲜催化剂的主要原因。[英文文摘]In situ time-resolved FTIR and in situ microprobe Raman spectroscopies were used to follow the primary products as well as the surface and gas phase species formed during the reaction of partial oxidation of methane (POM) to synthesis gas over Ir/SiO 2 catalyst. The results suggested that direct oxidation of CH 4 to CO is the dominant pathway of POM reaction over the freshly reduced Ir/SiO 2 catalyst, while the dominant schemes of CO formation over the catalyst under the steady state reaction condition are probably via the reactions of CO2 and H2O with the deposited carbon species (CHx) and/ or CH4 . The mechanistic difference between the POMto synthesis gas over freshly reduced Ir/ SiO2 catalyst and the catalyst under the steady state reaction may have resulted from the formation of significant amount of deposited carbon species in the latter system.国家重点基础研究发展规划 (No.G1999022408); 国家自然科学基金(No.20021002)资助项目

黔西北土法炼锌区水土流失的特点及防治对策

作者简介: 吴桂容( 1970- ) , 女, 广西贺州人, 博士研究生, 副教授, 主要从事污染生态学研究。E - mail: hzwgr510@ 163. com。通信作者: 敖子强, 博士研究生, 主要从事环境生态和污染生态学研究。E - m ai:l aoz iq iang628@ 163. com。通过对土法炼锌区的土壤、废渣、植物、地表水和沉积物进行实地调查和采样分析,发现土法炼锌区水土流失主要是由于含有SO2和重金属的废气导致植被严重破坏、土壤裸露造成的;水土流失同时导致了重金属的迁移扩散,污染土壤中重金属可溶态比重大,而废渣中重金属可溶态比重小,主要随废渣一起流失。减少土法炼锌区水土流失的主要途径是恢复植被和利用工程措施将废渣固定。对于污染土壤来说限制因子是土壤pH值低,可溶态重金属比重大,主要对策是增加土壤的pH值,选择耐酸性和耐重金属的树种恢复植被;对于废渣来说限制因子是废渣持水保肥能力差,重金属含量高,及废渣本身的结构疏松,主要对策是保持废渣的pH值不降低,利用工程措施将废渣固定,及改变土壤的结构来恢复植被;废渣和污染土壤上的先锋植物醉鱼草(Buddleja lindleyana)可作为首选来恢复植被。贵州省科学技术基金(编号:20062014);广西重点实验室研究基金(编号:桂科能0704K002