岩体初始地应力场边界模拟方式探讨

针对某水电站地下厂房地下洞室群的地形地质条件,在边界上施加分布位移与分布面力两类不同边界条件下,采用7种方案模拟构造应力场,对其初始地应力进行了多元回归计算,并对回归结果进行了比较分析.结果表明:相对于在边界上施加位移的方案,在边界上施加分布面力的方案对x、y向面力分布形式的变化较敏感;在边界上施加均布位移的方案操作简单,模拟效果较好比较适合于区域性地层较平缓、岩体状况较好的工程条件.     

软件可靠性模型研究进展

软件可靠性模型旨在根据软件失效数据,通过建模给出软件的可靠性估计值或预测值.它不仅是软件可靠性预计、分配、分析与评价的最强有力的工具,而且为改善软件质量提供了指南.对近年来提出的多种不同的软件可靠性模型进行分类剖析,讨论了部分模型的预测能力和适用性,分析了多个模型适用性差的原因,还对未来的研究趋势进行了展望.     

一种基于叶分量分析的带有监督信息的在线学习方法

在一些模式识别应用中,具有类属信息的样本数量较少,此时监督学习算法会遇到小样本问题,导致分类器的识别精度大幅低于预期水平.基于叶分量分析,提出一种带监督信息的在线学习方法.该方法在训练过程进行监督学习,而在模式识别阶段能够在对输入样本进行分类的同时基于这些样本进行非监督在线学习,因此实现了监督学习与非监督学习的结合.在小本量情况下,在线学习可以弥补训练阶段监督学习的不足,仍能保证获得较高的识别精度.实验证明,该方法能够有效克服小样本问题.     

Redox and pH Dual Responsive Polymer Based Nanoparticles for In Vivo Drug Delivery

Responsive nanomaterials have emerged as promising candidates as drug delivery vehicles in order to address biomedical diseases such as cancer. In this work, polymer‐based responsive nanoparticles prepared by a supramolecular approach are loaded with doxorubicin (DOX) for the cancer therapy. The nanoparticles contain disulfide bonds within the polymer network, allowing the release of the DOX payload in a reducing environment within the endoplasm of cancer cells. In addition, the loaded drug can also be released under acidic environment. In vitro anticancer studies using redox and pH dual responsive nanoparticles show excellent performance in inducing cell death and apoptosis. Zebrafish larvae treated with DOX‐loaded nanoparticles exhibit an improved viability as compared with the cases treated with free DOX by the end of a 3 d treatment. Confocal imaging is utilized to provide the daily assessment of tumor size on zebrafish larva models treated with DOX‐loaded nanoparticles, presenting sustainable reduction of tumor. This work demonstrates the development of functional nanoparticles with dual responsive properties for both in vitro and in vivo drug delivery in the cancer therapy.     

石墨烯/聚酰亚胺复合石墨纤维的结构与性能

采用干湿法纺丝工艺制备氧化石墨烯/聚酰亚胺复合纤维,然后将复合纤维进行炭化和石墨化处理得到石墨烯/聚酰亚胺复合碳纤维及石墨纤维。对复合碳纤维进行热重分析、Raman、力学性能、传导性能、形貌等测试分析。结果表明,氧化石墨烯添加量为0.3%(质量分数,下同)的复合纤维的耐热性能最佳;氧化石墨烯的加入,使石墨烯/聚酰亚胺复合碳纤维的力学性能和传导性能明显提高,石墨化程度增加。当复合碳纤维2800℃石墨化后,氧化石墨烯含量增加到2.0%时,复合石墨纤维的热导率达到435.57 W·m-1·K-1,结构更加致密。     

Chemotherapy in non-small cell lung cancer: a review

Lung cancer, of which non-small cell carcinoma is the most common, has been a significant therapeutic challenge for decades and will remain so for decades to come. Despite its prevalence, progress in the management of non-small cell lung cancer has been relatively slow. This is in part due to the pessimism of most physicians treating this disease, which has resulted in a relatively lackadaisical attitude with regards to clinical trials when compared to other solid tumours like breast or colorectal cancers. Nevertheless, the past decade has seen significant progress, specifically with regards to the management of locally advanced disease. Chemotherapy, though shown to be biologically active in non-small cell lung cancer, is considered an ineffective palliative tool in the setting of metastatic disease due to its toxicities and the "less than encouraging" response rates generated by the cisplatin-based combination regimen which is generally considered to be the most active currently available. The advent of new active agents such as paclitaxel and vinorelbine which are potentially less toxic may change this view. Conversely, the response rate of locally advanced disease to chemotherapy is significantly higher and this has resulted in numerous multimodality trials of neoadjuvant chemotherapy prior to surgery and/or radiation. To date, a number of randomised trials have shown that this approach can result in significant survival benefit for patients with locally advanced disease. An alternative approach makes use of the potential synergism between certain chemotherapeutic agents (such as cisplatin) and radiation when used concurrently. However, data on concurrent chemoradiotherapy in locally advanced disease have been largely based on single-arm studies and are inconclusive. Three randomised trials on concurrent chemoradiotherapy have been shown benefit for the use of combined modality in locally advanced disease. Hence, treatment of locally advanced disease should include chemotherapy as part of the combined modality approach. However, the optimal sequencing of these modalities would require well-designed randomised trials to determine.     

基于随机Petri网的柔性工作流可用性分析

提出一种基于随机Petri网的柔性工作流可用性分析方法。给出基本的异常处理模型,以电子商务配送系统(ELMS)为例,利用随机Petri网对系统进行SPN建模,分析ELMS系统的各种可用性参数。实验结果表明,该方法能准确、有效地对支持异常处理操作的柔性工作流进行可用性分析。     

新型锁相环在频率跟踪技术中的研究

在比较电力系统频率跟踪技术中软硬件同步优缺点的基础上,提出了一种基于FPGA的全数字锁相环(ADPLL)电路实现电力系统频率跟踪的技术;将FPGA技术运用于同步跟踪技术中,解决了软硬同步方法中的各个不足之处;全数字锁相环电路采用VHDL语言和FPGA设计,仿真波形和实验结果表明,该电路能够很好地跟踪电网频率的实时变化,相位误差仅为0.1%,频率测量误差仅为0.06%,实现了同频率同相位的锁定;速度快、精度高;对电网的谐波计算有较大的实际意义.     

菏泽民俗文化符号在旅游商品转化中的应用

本文从旅游商品的概念和山东菏泽地域文化资源现状出发,探讨了菏泽民俗文化旅游商品的现状,并针对菏泽旅游商品研发存在的问题,从菏泽地域文化的挖掘及其在旅游商品的转化方式上进行了分析,提出了民俗文化旅游纪念品开发的对策,以期推动民俗文化产业和旅游产业的健康发展。     

A proposal for student modeling based on ontologies and diagnosis rules

The advances in the educational field and the high complexity of student modeling have provoked it to be one of the aspects more investigated in Intelligent Tutoring Systems (ITSs). The Student Models (SMs) should not only represent the student’s knowledge, but rather they should reflect, as faithfully as possible, the student’s reasoning process. To facilitate this goal, in this article a new approach to student modeling is proposed that benefits from the advantages of Ontological Engineering, advancing in the pursue of a more granular and complete knowledge representation. It’s focused, mainly, on the SM cognitive diagnosis process, and we present a method providing a rich diagnosis about the student’s knowledge state – especially, about the state of learning objectives reached or not. The main goal is to achieve SMs with a good adaptability to the student’s features and a high flexibility for its integration in varied ITSs.