The Design and Implementation of the Online Course Selection System based on Load Balancing

随着计算机的广泛应用和互联网技术的迅速发展，Web应用已经逐渐深入到人们工作和生活中的各个领域。网上选课系统作为高校教务管理系统的重要组成部分，已经从传统的手工模式脱离出来，成为高校选课的主要方式。本文以厦门大学嘉庚学院网上选课系统为例，由于其之前的系统功能相对简单，已无法满足当前学分制改革要求，构建满足学分制要求且同时支持选课环节高负载要求的网上选课系统已是当务之急。文中介绍了开发此系统所应用的技术和工具，主要包括：B/S架构、PHP编程、MySQL数据库、Apache和Nginx的Web服务器、HttpSQS队列服务器。运用面向对象的分析与设计方法，对选课系统的各个环节做了详细的需求分析、...With the wide application use of computers and the rapid development of Internet technology, the application of Web has gradually penetrated into all areas of people's work and life. Online course selection system as an important part of the college studying managerial system,which has run out of the manual mode,has become the main way of the college course selection.This paper takes Xiamen Univer...学位：工程硕士院系专业：信息科学与技术学院_工程硕士(计算机技术)学号：X201022102

中国南方地区罗非鱼无乳链球菌的分子流行病学研究

从广东省以及海南省等地区养殖的患病罗非鱼体内分离、收集到多株致病菌,经生化分析和分子生物学鉴定,均为无乳链球菌。对这些菌株分别进行了耐药谱测定、分子分型试验以及分子血清型分析。药敏试验结果表明,2007—2010年分离到的无乳链球菌耐药谱基本相似;多位点可变数目串联重复序列分析(MLVA)试验中,选择5个高变异指数的可变数目重复位点(VNTR)进行分子分型,结果表明,所有鱼源无乳链球菌菌株为同一MLVA型,而作为对照的牛源无乳链球菌则明显不同;为了对这些菌株进一步分型,分别进行了分子血清型和表面蛋白抗原基因的检测,结果表明,鱼源无乳链球菌的分子血清型均为Ⅰa型,表面蛋白抗原均为alpha-C蛋白。这进一步说明了不同年份和不同地区的鱼源无乳链球菌在基因水平上为同一分子类型,具有相同的起源或传染源。同时也说明,我国南方地区罗非鱼无乳链球菌在这几年中未发生明显的遗传变异。这些结果为罗非鱼无乳链球菌病疫苗研制,疫病监测及药物防治的研究提供理论依据

Overmodulation strategy for flux trajectory tracking PWM and analysis of its characteristics

结合磁链轨迹跟踪的PWM生成原理,讨论了一种过调制实现策略。根据实际磁链对期望磁链的跟踪特性,分析建立了相位和径向两类误差模型;结合两类误差模型,定义评价指标:跟踪能力,并由此确定了过调制Ⅰ区和过调制Ⅱ区的分界点;从理论上证明了实现过调制极限状态六阶梯波调制的可行性,并给出其实现条件。开展了仿真验证和样机试验,结果表明新策略能有效提高直流母线电压的利用率,保持从线性调制、过调制Ⅰ区、过调制Ⅱ区直至六阶梯模式的平滑过渡,并明显抑制调制过程中的输出电压总谐波畸变率(THd)。A overmodulation strategy was studied based on the flux trajectory tracking PWM.First,phase error and radial error were analyzed based on the flux trajectory model.Then,combining two types of error model,a new evaluation for tracking capability was defined,and the demarcation point of overmodulation was determined.Then,the feasibility of six-step operation was proved theoretically,and the achievement conditions of six-step operation was given.Finally,the overmodulation strategy was theoretically analyzed,simulated and experimented.The results show that the new strategy effectually enhance the utilization rate of DC bus voltage and keep smooth transition form linear modulation,overmodulation to six-step operation,and markedly reduce the total harmonic distortion( THD) of the output voltage.国家自然科学基金(51177141); 福建省自然科学基金(2010J01310); 中央高校基本科研业务项目(2010121041); 航空基金(2012ZD68003

中国社区为老服务及其对老年人生活满意度的影响

目的研究我国社区为老服务状况及其对老年人生活满意度的影响。方法依据2005年《中国老年人健康长寿调查数据库》居家养老样本15215例数据,8项社区服务指标,分析社区为老服务状况及其对老年人生活满意度的影响。结果超过30%的老年人所在社区开展了为老服务工作,但农村社区为老服务状况较城市差。有社区服务老年人的生活满意度显著高于无社区服务老年人。社区服务显著缩小了老年人由居住地(城

Advances in flower genetic engineering

近十余年来,花卉基因工程取得了较大的进展,许多种花都已获得转基因植株,有的已进入商品化生产阶段.本文就基因工程在花卉方面的研究和应用作一综述.Important progress in flower genetic engineering, including improvement of the color, shape, flowering time and so on, has been made in the past ten years. Some transgenic flowers have been commercially released. Advances in this field have been due to the isolation and cloning of many important regarding genes and the development of a range of plant transformation technology, along with appropriate tissue culture techniques for regenerating whole plants.福建省科委资助项目(99-Z-115)

甲硫氨酸亚砜还原酶A在肾透明细胞癌侵袭转移中的作用机制

目的本研究旨通过细胞学和动物实验验证甲硫氨酸亚砜还原酶A（MSRA）对肾透明细胞癌（ccRCC）增殖、凋亡、侵袭和转移的影响，揭示其潜在的生物学机制，为ccRCC的治疗提供新的分子靶点和策略。方法利用转染实验构建MSRA过表达细胞株；通过细胞增殖实验、平板克隆实验、凋亡实验、划痕实验、侵袭实验评估MSRA对ccRCC细胞增殖、凋亡、侵袭和转移的影响；并进一步通过ROS检测，RT-qPCR、Western blot实验探讨其作用机制及相关信号通路；随后，利用裸鼠皮下移植瘤模型在动物水平上验证MSRA对ccRCC肿瘤生长和转移的影响，并初步探索其潜在的分子机制。结果OS-RC-2和786-O细胞株MSRA mRNA水平和蛋白表达量较低（RT-qPCR：0.57±0.09，0.56±0.04；WB：0.26 ±0.13，0.24±0.09）；RT-qPCR和Western blot实验提示成功构建了OS-RC-2-pLVSO2-MSRA（RT-qPCR：108.04±1.80；WB：117.01±20.19）和786-O-pLVSO2-MSRA（973.45±51.37，WB：190.34±30.13）过表达细胞株，差异具有统计学意义（P＜0.001）；增殖实验提示OS-RC-2-pLVSO2-MSRA（72 h：1.246±0.003）和786-O-pLVSO2-MSRA（72 h：1.468±0.001）增殖活力降低，差异具有统计学意义（P＜0.001）；平板克隆实验提示OS-RC-2-pLVSO2-MSRA（0.090±0.002）和786-O-pLVSO2-MSRA（0.080±0.002）克隆数减少，差异具有统计学意义（P＜0.001）；凋亡实验提示OS-RC-2-pLVSO2-MSRA（2.013±0.116）和786-O-pLVSO2-MSRA（4.767±0.199）凋亡率增加，差异具有统计学意义（P＜0.001）；划痕实验提示OS-RC-2-pLVSO2-MSRA（0.643±0.028）和786-O-pLVSO2-MSRA（0.603±0.034）迁移距离较少，差异具有统计学意义（P＜0.001）；Transwell实验提示OS-RC-2-pLVSO2-MSRA（16.80 ±2.28）和786-O-pLVSO2-MSRA（21.40±4.78）穿透细胞数减少，差异具有统计学意义（P＜0.001）；荧光实验显示OS-RC-2-pLVSO2-MSRA（50.59±6.24）和786-O-pLVSO2-MSRA（62.87±5.35）活性氧含量降低，差异具有统计学意义（P＜0.001）；Western blot实验显示OS-RC-2-pLVSO2-MSRA和786-O-pLVSO2-MSRA中N-cadherin和Vimentin的表达量下降，而E-cadherin的表达量增加，差异具有统计学意义（P＜0.001）；Western blot实验显示OS-RC-2-pLVSO2-MSRA和786-O-pLVSO2-MSRA中p-ERK1/2和p-SMAD3的表达量下降，差异具有统计学意义（P＜0.001）；动物实验提示OS-RC-2-pLVSO2-MSRA肿瘤体积降低（155.00±50.46），差异具有统计学意义（P＜0.001）；动物组织Western blot实验提示N-cadherin和Vimentin的表达量下降，而E-cadherin的表达量增加，差异具有统计学意义（P＜0.001）；OS-RC-2-pLVSO2-MSRA中IHC实验提示Ki-67、N-cadherin和Vimentin的表达量下降，而E-cadherin的表达量增加，差异具有统计学意义（P＜0.001）。结论表达MSRA抑制ccRCCROS的表达，抑制EMT过程，进而抑制ccRCC的增殖、侵袭和转移

Research and implementation of underwater acoustic real-time voice communication prototype based on MELP

根据水声通信的复杂信道特性,对混合激励线性预测语音编码MElP算法和低密度奇偶校验码ldPC的结合进行了研究,设计了基于ArM+dSP的多载波水声实时语音通信样机。经水池实验测试,系统表现出良好的实时性和语音可懂度性能,可分辨出不同说话人的声音。Taking the complexity of the underwater acoustic communication channel characteristics into account,the combination of mixed excited linear prediction(MELP) and low density parity check(LDPC) were studied and a multi-carrier underwater acoustic real-time voice communication prototype based on ARM+DSP was designed.By the expreimental test in pool,the proposed system showed a good real-time and voice intelligibility performance,and could distinguish the voice of different speakers.中央高校基本科研业务费专项资金资助(2010121062

Advance in Red-emitting Mn⁴⁺-activated Oxyfluoride Phosphors

稳定可靠的高光子能量发光(620~650 nm)红光荧光粉, 对于构建低色温、高显指荧光粉转换型白光发光二极管(WLED)至关重要。Mn⁴⁺激活红光荧光粉是当前 WLED 用荧光粉研究热点之一。本文介绍了 Mn⁴⁺离子的能级跃迁与光致发光特性, 详细叙述了目前所报道的七种 Mn⁴⁺激活含 d⁰/d¹⁰/s⁰离子氧氟化物系列红色荧光粉(如Na₂WO₂F₄:Mn⁴⁺等)的制备方法、晶体结构及其发光特性。目前⁴⁺在氧氟化物结构中得到强 R 线(零声子线)发光的情况少, 微观配位体仍是[MnF₆]或[MnO₆], 其化学稳定性和量子效率研究也很缺乏。最后对 Mn⁴⁺激活氧氟化物红光荧光粉的研究进行了展望。The stable and reliable red phosphor with high-photon energy emission (620–650 nm) is critical for the fabrication of the phosphor-converted white light-emitting diode (WLED) with low correlated color temperature and high color rendering index. Mn⁴⁺-activated phosphor is an emerging kind of red-emitting phosphor for WLED. Herein, the energy levels transition and photoluminescence characteristics of the Mn⁴⁺ ion were introduced; then, the preparation, crystal structure and luminescent properties of as-far reported seven kinds of Mn⁴⁺-doped oxyfluoride red phosphors (such as Na₂WO₂F₄:Mn⁴⁺) containing d⁰/d¹⁰ or s⁰ cations were reviewed. Currently, only in quite rare case of oxyfluoride, Mn⁴⁺ was found to exhibit strong R-line emission, with local coordination remaining as either [MnF₆] or [MnO₆]. The studies on the chemical stability and quantum efficiency of Mn⁴⁺ -doped oxyfluoride phosphors are still insufficient. Finally, we prospected the future development of Mn⁴⁺-doped oxyfluoride phosphor

Preparation and Application of Soluble Human Squamous Cell Carcinoma Antigen Expressed by Escherichia coli

旨在建立基于大肠杆菌表达系统的高效可溶性表达人鳞状上皮细胞癌抗原(SCCAg)方法,获得具有较好活性的重组SCCAg抗原并应用于建立抗原检测方法; 。基于pGEX-6P-l载体和大肠杆菌E. coli; ER2566菌株开展重组SCCAg抗原可溶性表达纯化方法研究,评价纯化抗原活性,筛选特异性单克隆抗体,初步建立并评价SCCAg抗原检测方法。结果; 显示,pGEX-6P-l载体和E coli; ER2566菌株可用于建立较高效的可溶性表达和纯化SCCAg抗原的方法,获得了具有较高纯度和活性的重组SCCAg抗原,筛选获得特异性单克隆抗体并; 初步建立了 SCCAg管式化学发光检测方法。建立了有效的基于大肠杆菌表达系统的可溶性表达和纯化SCCAg的方法。The aims of this study are to establish a method for efficient soluble; expression of human squamous cell carcinoma antigen(SCCAg ) based on; Escherichia coli expression system and obtain the recombinant SCCAg; antigen in fine activity, then apply it in the detection method; establishment of antigen. The study on the method of soluble expression; and purification of recombinant SCCAg antigen was conducted based on; pGEX-6P-l vector and E. coli ER2566 strain. The activity of the purified; antigen was evaluated by Abbott Kit and the specific monoclonal antibody; was screened by indirect ELISA. It was proved that PGEX-6P-1 vector and; E. coli strain ER2566 could be used to establish efficient soluble; expression and purification method for recombinant SCCAg antigen.; Moreover, the recombinant SCCAg antigen was proved to be in high purity; and activity. Thus,the SCCAg detection method of chemical luminous tube; was established with the specific monoclonal antibodies. In conclusion,; an effective method for the expression and purification of SCCAg, which; is based on the E. coli expression system, is established.国家高技术研究发展计划(863计划

Comparison of Different Methods for Calculating Evapotranspiration of Crops in the Yellow River Delta

准确估算各地区的参考作物腾发量(ET_0)是农业灌溉设计和节水规划中必不可少的内容。利用黄河三角洲地区4个典型气候区的气象资料,选用5种计算方法(P-M, FAO-79Penman、Priestley-Taylor,FAO-24Penman和 Hargreaves-Samani)计算了 ET_0,并以P-M方法作为标准,对其他方法进行了评价。结果表明,在黄河三角洲各气候区FAO-Penman法估算的ET_0较Priestley-Taylor方法更接近于P-M法的计算结果,并且计算精度较高,误差在3%~10%之间。在缺少资料的湿润区,用Priestley-Taylor方法可以得到与P-M法估值相近的结果。</p