影响工程造价的相关因素及对策

随着经济的持续快速发展,工程造价也在持续变化,新的问题不断出现,如何在市场经济下把握工程造价发展方向,已成为众多造价从业人员关注的热点.文章介绍了工程造价的相关概念,分析了工程造价及计价的特征、影响造价的相关因素,并提出了相关措施,有一定的参考意义.     

基于多层耦合网络的科技馆知识传播实证研究

[目的/意义]旨在为促进科技知识传播提供参考。[方法/过程]构建了多层耦合网络的传播模型,根据目前全国科技馆的情况,研究了科技知识在多层网络中的传播情况,并对影响传播的多种因素进行了仿真实验。[结果/结论]网上虚拟科技馆在多层网络中能加速科技知识的传播;科技馆影响力影响科技信息传播速度;用户节点之间兴趣匹配关系直接影响知识传播的速度和范围。     

跨语言文献检索系统研究

[目的/意义]旨在探讨解决原英日文献检索分析中存在的不足,实现以中文为检索语言的中、英、日文献资源的统一检索。[方法/过程]介绍了一种通过机器翻译技术实现以中文为检索语言的中日英文献资源的统一检索系统。[结果/结论]该系统基于MASH-UP技术将检索结果整合进行统一的内容分析,帮助用户跨越语言的障碍,方便地查询和使用外文文献。     

A fast and versatile cross-linking strategy via o-phthalaldehyde condensation for mechanically strengthened and functional hydrogels

Fast and catalyst-free cross-linking strategy is of great significance for construction of covalently cross-linked hydrogels. Here, we report the condensation reaction between o-phthalaldehyde (OPA) and N-nucleophiles (primary amine, hydrazide and aminooxy) for hydrogel formation for the first time. When four-arm poly(ethylene glycol) (4aPEG) capped with OPA was mixed with various N-nucleophile-terminated 4aPEG as building blocks, hydrogels were formed with superfast gelation rate, higher mechanical strength and markedly lower critical gelation concentrations, compared to benzaldehyde-based counterparts. Small molecule model reactions indicate the key to these cross-links is the fast formation of heterocycle phthalimidine product or isoindole (bis)hemiaminal intermediates, depending on the N-nucleophiles. The second-order rate constant for the formation of phthalimidine linkage (4.3 M⁻¹ s⁻¹) is over 3000 times and 200 times higher than those for acylhydrazone and oxime formation from benzaldehyde, respectively, and comparable to many cycloaddition click reactions. Based on the versatile OPA chemistry, various hydrogels can be readily prepared from naturally derived polysaccharides, proteins or synthetic polymers without complicated chemical modification. Moreover, biofunctionality is facilely imparted to the hydrogels by introducing amine-bearing peptides via the reaction between OPA and amino group.     

贸易开放、城市制度改进与经济增长

"以开放促改革,以改革谋发展"是中国推进开放的一个重要依据,然而鲜有文献专门考察贸易通过制度渠道对经济增长的影响,本文以中国各城市为对象对这一问题进行了研究。本文首先构造城市出口制度密集度指标以衡量世界市场对城市的制度需求,接着本文利用多元回归模型和中介效应模型实证检验出口制度密集度对城市经济增长的影响及其机制。实证结果表明,城市对外贸易带来的外部制度需求会通过促使城市制度改进来促进城市经济增长,并且,本土公司的一般贸易在贸易通过制度渠道促进城市经济增长的过程中起着主要作用。     

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.     

医药冷链物流在物联网环境下的动态风险评估

首先运用流程图法分析造成物联网环境下医药冷链物流各环节风险的众多因素源,并运用熵权法对风险指标客观赋权建立风险因素评估指标体系,然后利用Ge NIe软件建立动态贝叶斯网络模型对风险环节的关键风险因素进行概率评估。结果显示在风险评估中运输环节风险的发生概率最高,同时企业关于设备的验证选型是影响物联网医药冷链的关键风险因素,这为企业和政府控制药品质量安全管理提供了依据。     

供给侧结构性因素对产业生态效率影响的实证研究——基于中国纺织业的DEA-Tobit分析

选取结构性污染较严重的产业——纺织业作为研究对象,采用DEA-Tobit两阶段模型对纺织业生态效率作评价并分析纺织业生态效率的结构性因素。实证结果表明,能源消费结构指标与纺织业生态效率显著正相关,产业结构指标和产业组织结构指标与之负相关,而对外贸易结构指标的影响不是很显著,环境规制指标也对其有显著影响。因此,应从能源结构、要素替代、产业集中和加强执法4个方面来促进纺织产业生态化的实现。     

股票期权激励计划实施中的研发支出行为研究

以2010-2012年宣告实施股票期权激励计划并进行行权的上市公司为研究对象,研究股票期权激励计划对公司研发支出行为的影响。发现,在基数期公司研发支出强度与是否实行股票期权激励计划呈显著正相关;而在行权等待期公司研发支出强度变化与是否实行股票期权激励计划呈显著负相关,说明经理人存在很强的动机利用研发支出进行盈余操纵,以获取由股票期权激励带来更大的经济利益;研究还发现,经理人管理权力加剧了这种操纵行为,作为嵌入公司治理结构保护中小股东利益的独立董事制度发挥了一定的治理作用。本研究结论为政策制定者调整相关股权激励政策提供了参考。     

动态可持续能力与企业可持续绩效的关系研究

企业的动态能力和可持续发展已是学术探讨的一个重要命题。可持续发展作为一种管理趋势,在现代组织战略管理中发挥着日益重要的作用。但现有文献对于如何将可持续发展更加动态化同时与企业战略相结合转化为企业绩效及其过程研究较为匮乏。本研究基于资源管理视角,通过收集163个企业管理人员调研数据并使用最小二乘结构方程模型进行建模（PLS-SEM）分析了动态可持续能力对企业可持续绩效的全面影响及其内在机制。研究结果显示：动态可持续能力由监控、捕获和重构能力构成,动态可持续能力对企业可持续绩效各维度具有显著正向影响,资源管理能力部分中介动态可持续能力与企业环境和社会绩效的关系,但对经济绩效没有中介效应。本研究丰富了动态能力和可持续发展理论,并为企业在面对可持续发展问题时提供有效的经营管理建议。