谈离子交换树脂的污染与处理

树脂被污染有两种情况,一种是树脂的中毒,另一种是树脂的老化.本文主要讲述阴离子交换树脂在不同水源情况下被污染的处理.     

实验史学:后现代主义在史学领域的诉求

效用、真实和时间构成了历史认识结构的基本要素 ,而历史认识史中的结构变迁经历了前现代 (从古代到 1 8世纪末职业化历史学产生之前 )、现代 (职业化历史学时期 ,即 1 8世纪末到 2 0世纪 70年代初 )和后现代 ( 2 0世纪 70年代后 )三个阶段 ,效用、真实、时间依次成为这三个阶段历史认识结构的中心。以时间为结构中心的后现代主义史学表现出历史主义的极端化 ,并进一步强调了时间、变化对于历史真实和历史意义的决定性作用 ,有鉴于此 ,历史叙述和阅读的私人化将促使历史学成为一种实验史学 ,即它不再是那种宣告历史真实的史学 ,而致力于在历史性情境下提供个体史学家认可的文本 ,并交由读者阅读、判断 ,随后通过该文本产生的效用来确认其是否真实。这样 ,任何一种史学实践都将是历史学家当下进行的一项追求历史真实的实验 ,而实验成功与否 ,完全取决于实验环境即阅读环境所提供的条件     

英国高校改革:学生资助与教育参与

英国工党上台后,奉行第三条道路的政治纲领.在高等教育领域,政府一方面延续了新自由主义的市场化政策,对大学生资助方式进行改革,进一步革除福利社会的弊端;另一方面又通过政府的管制,化解市场化造成的不良后果,扩大社会各界对高等教育的参与.本文从学生资助方式的改革和高等教育参与面的扩大两个方面介绍了英国高等教育改革的最新动向和措施.     

Fault detection of discrete-time delay Markovian jump systems with delay term modes partially available

This paper focuses on the fault detection problem for a class of discrete-time delay Markovian jump systems with delay term modes partially available. A crucial but general hypothesis considered here is there is a suitable and effective detector to provide a measurement signal of operation mode of delay term. The fault detection filter used as the residual generator could depend on the original system operation mode or the signal emitted from detector. Via minimizing the error between the residual and fault signal, the problem of fault detection and isolation (FDI) is converted into an H_∞ filtering problem and closely related to a probability representing the degree of dependence between the original and measurable signals. An improved Lyapunov function depending on such two operation modes is exploited to study the corresponding problems. Sufficient conditions for the existence of the desired FDI filter are presented in terms of LMIs. When such a probability is uncertain or partially unknown, similar problems are also considered. A practical example is used to demonstrate the effectiveness and superiority of the proposed methods.     

Output reachable set estimation for discrete-time switched systems with persistent dwell-time

This paper is concerned with the output reachable set estimation for discrete-time switched systems. The switching signal is considered as persistent dwell-time (PDT), which is more general and flexible compared with the common dwell-time and average dwell-time switching. The estimation of output reachable set is determined by a collection of bounding ellipsoids based on a family of quasi-time-dependent (QTD) Lyapunov functions. Furthermore, a set of non-fragile QTD controllers is designed. Finally, two examples are employed to illustrate the potentials of proposed methods.     

Ecological principle meets cancer treatment: treating children with acute myeloid leukemia with low-dose chemotherapy

Standard chemotherapy regimens for remission induction of pediatric acute myeloid leukemia (AML) are associated with significant morbidity and mortality. We performed a cohort study to determine the impact of reducing the intensity of remission induction chemotherapy on the outcomes of selected children with AML treated with a low-dose induction regimen plus granulocyte colony stimulating factor (G-CSF) (low-dose chemotherapy (LDC)/G-CSF). Complete response (CR) after two induction courses was attained in 87.0% (40/46) of patients receiving LDC/G-CSF. Post-remission therapy was offered to all patients, and included standard consolidation and/or stem cell transplantation. During the study period, an additional 94 consecutive children with AML treated with standard chemotherapy (SDC) for induction (80/94 (85.1%) of the patients attained CR after induction II, P = 0.953) and post-remission. In this non-randomized study, there were no significant differences in 4-year event-free (67.4 vs. 70.7%; P = 0.99) and overall (70.3 vs. 74.6%, P = 0.69) survival in the LDC/G-CSF and SDC cohorts, respectively. After the first course of induction, recovery of white blood cell (WBC) and platelet counts were significantly faster in patients receiving LDC/G-CSF than in those receiving SDC (11.5 vs. 18.5 d for WBCs (P < 0.001); 15.5 vs. 22.0 d for platelets (P < 0.001)). To examine the quality of molecular response, targeted deep sequencing was performed. Of 137 mutations detected at diagnosis in 20 children who attained hematological CR after two courses of LDC/G-CSF (n = 9) or SDC (n = 11), all of the mutations were below the reference value (variant allelic frequency <2.5%) after two courses, irrespective of the treatment group. In conclusion, children with AML receiving LDC/G-CSF appear to have similar outcomes and mutation clearance levels, but significantly lower toxicity than those receiving SDC. Thus, LDC/G-CSF should be further evaluated as an effective alternative to remission induction in pediatric AML.     

环渤海地区滴灌的资源与经济效应——政府与农户目标一致性检验

水资源是关系农村社会经济发展、农民增收的重要因素。本文从协调政府与农民关于增效与增收的目标出发,以2017年中国环渤海设施蔬菜主产地蔬菜专业村357个蔬菜种植户调研数据为例,运用联立方程组模型及条件混合过程（CMP）、倾向得分匹配方法（PSM）与工具变量分位数（IVQR）方法,对滴灌技术推广的约束因素与增效增收能力进行分析,探索促进中国农业可持续发展的路径。研究结果表明：①水资源稀缺程度较高的蔬菜主产地,种植年限较短,但家庭资本充裕且对节水知识了解程度越高的蔬菜种植户更倾向于采用滴灌技术;②滴灌技术具有明显的增效增收作用,蔬菜种植户采用滴灌技术后,每吨灌溉水产出可增加17.16 kg蔬菜,增收45.90 元,具有推广的长效动力;③滴灌技术的产出与经济效应存在“马太效应”,对于生产条件好的农户而言,滴灌技术的产出与经济效应更加明显;④技术供给层面的灌溉制度设计不健全、设备工程设计与质量较差、培训与售后服务不足,农户技术应用层面的专业知识与技术缺乏、与现代农业对接能力弱,以及政府层面的补贴不够科学、到位是影响农户滴灌技术采用积极性的重要因素,需要加以注意,此外,灌溉水价的适当提高,将有助于加快田间节水技术的推广。     

反恐怖主义情报信息工作关联资源及其配置研究

【目的/意义】全面梳理分析反恐怖主义情报信息工作关联资源,并进行有效配置有助于提升反恐情报信息 工作能力,有力打击恐怖活动。【方法/过程】本文分析反恐情报信息工作的关联资源分布态势,通过对近几年国内 外重大恐怖事件进行定性分析,总结相关部门及每项工作任务中职责主体所需要的资源,并提出关联资源的配置 方案。【结果/结论】反恐活动的各阶段均需要多种类型的资源来收集、处理、利用高质量的情报信息。结合反恐情 报信息工作内容与工作主体的资源配置方案可将反恐情报信息工作关联资源科学配置给相关主体,从而提高反恐 情报信息工作能力。     

多维视角的高质量专利识别及其应用研究

[目的/意义] 我国专利数量巨大,但质量高低不齐。高质量专利对技术追踪、技术引进和资产管理极其重要,低质劣质专利则会阻碍科技创新的评估。聚焦高质量专利并进行挖掘可以获取更加深层与核心的情报,但高质量专利筛选却如"大海捞针",目前尚无可行的识别筛选方法。探索适合中国专利的高质量专利评价模型及筛选方法迫在眉睫。[方法/过程] 通过文献调研法对当前专利质量及评价进行综合归纳的基础上,延伸并界定高质量专利的内涵,对专利质量评价维度及指标进行创新拓展,构建分级、分层的多维视角专利质量评价指标体系,并基于创新指标体系建立高质量专利识别方法流程模型,最后以上海市高质量专利分布现状为例验证了方法模型的实用性及可行性,并为创新主体提出相应建议。[结果/结论] 研究结果表明本文提出的高质量专利指标模型及识别方法具有较强的科学性和可操作性,利用该指标模型和识别方法可对某地区或某领域的大批量专利进行筛选识别,为实现专利技术情报的科学高效利用提供有价值的参考。