基于产业链的企业知识治理结构与要素研究

以产业链为连接的企业知识活动,是产业知识结构的重要组成部分.对企业知识治理要素的分析,可借助产业链知识转移理论从产业层面进行研究.通过借助产业链结构框架,分析企业知识活动特征,构建知识转移SECI模型,研究企业知识治理的结构,探究影响企业知识治理的要素构成.     

Ag/Ag2SO3 plasmonic catalysts with high activity and stability for CO2 reduction with water vapor under visible light

Environmental Science and Pollution Research - The conversion of CO2 into useful raw materials for fuels and chemicals by solar energy is described using a plasmonic photocatalyst comprised of Ag...     

Atmospheric oxidation capacity in the summer of Houston 2006: Comparison with summer measurements in other metropolitan studies

Both similarities and differences in summertime atmospheric photochemical oxidation appear in the comparison of four field studies: TEXAQS2000 (Houston, 2000), NYC2001 (New York City, 2001), MCMA2003 (Mexico City, 2003), and TRAMP2006 (Houston, 2006). The compared photochemical indicators are OH and HO₂ abundances, OH reactivity (the inverse of the OH lifetime), HO_x budget, OH chain length (ratio of OH cycling to OH loss), calculated ozone production, and ozone sensitivity. In terms of photochemical activity, Houston is much more like Mexico City than New York City. These relationships result from the ratio of volatile organic compounds (VOCs) to nitrogen oxides (NO_x), which are comparable in Houston and Mexico City, but much lower in New York City. Compared to New York City, Houston and Mexico City also have higher levels of OH and HO₂, longer OH chain lengths, a smaller contribution of reactions with NO_x to the OH reactivity, and NO_x-sensitivity for ozone production during the day. In all four studies, the photolysis of nitrous acid (HONO) and formaldehyde (HCHO) are significant, if not dominant, HO_x sources. A problematic result in all four studies is the greater OH production than OH loss during morning rush hour, even though OH production and loss are expected to always be in balance because of the short OH lifetime. The cause of this discrepancy is not understood, but may be related to the under-predicted HO₂ in high NO_x conditions, which could have implications for ozone production. Three photochemical indicators show particularly high photochemical activity in Houston during the TRAMP2006 study: the long portion of the day for which ozone production was NO_x-sensitive, the calculated ozone production rate that was second only to Mexico City's, and the OH chain length that was twice that of any other location. These results on photochemical activity provide additional support for regulatory actions to reduce reactive VOCs in Houston in order to reduce ozone and other pollutants.     

Nitrous oxide generation in denitrifying phosphorus removal process: main causes and control measures

Despite the many benefits of denitrifying phosphorus removal process, the significant generation of nitrous oxide (N₂O), a potent greenhouse gas, remains a problem for this innovative and promising process. To better understand and more effectively control N₂O generation in denitrifying phosphorus removal process, batch experiments were carried out to investigate the main causes of N₂O generation, based on which the control measures were subsequently proposed. The results showed that N₂O generation accounted for 0.41 % of the total nitrogen removal in denitrifying phosphorus removal process, whereas, in contrast, almost no N₂O was generated in conventional denitrification process. It was further demonstrated that the weak competition of N₂O reductase for electrons and the high nitrite accumulation were the two main causes for N₂O generation, evidenced by N₂O production and reduction rates under different conditions. Accordingly, the reduction of N₂O generation was successfully achieved via two control measures: (1) the use of continuous nitrate addition reducing N₂O generation by around 91.4 % and (2) the use of propionate as the carbon source reducing N₂O generation by around 69.8 %.     

《自然资源学报》1986—2015年零被引论文分析

为达到减少零被引论文发表数量、提高期刊质量与影响力的目的,在中国知网中检索了《自然资源学报》1986—2015年发表的论文作为研究的源数据,从刊文量及零被引率的变化、下载频次分布、作者情况、基金资助情况、所属学科领域等5个方面对零被引论文进行了详细的分析。研究结果表明：1）从季刊到双月刊和月刊,刊文量增加了,但零被引论文比例却没有随刊文量的增加而增加;2）零被引论文虽暂未被引用,但仍然存在一定程度的下载量,将来有可能被引,但也是低被引论文;3）作者分布方面,学生占比较大,因博士研究生是发文主流导致零被引论文中博士研究生人数多于硕士研究生,初、中级职称多于副高级、高级职称,由于高等院校和研究院所是投稿主力,因发文基数大导致零被引论文中高等院校和研究院所多于地方机构,作者群人数以1人为主,机构数量以1个为主;4）论文被引与否和基金资助数量和类别相关性不大;5）零被引论文学科分布以土壤学、地学、气象学和环境生物学为主。最后提出相应对策,建议通过“作者-审稿专家-编辑协同控制”过程,减少科技期刊零被引论文的产生,从而提高科技期刊的学术水平和影响力。     

自然保护区社区发展存在的问题、挑战及对策研究

我国自然保护区保护与社区发展关系紧密,如何统筹协调处理好二者之间的关系成为广受关注的问题。本文在总结自然保护区社区发展存在的问题与面临的挑战基础上,从建立社区沟通与参与机制、构建生态补偿机制、改善社区社会服务水平、弘扬传统文化、带动区域协调发展五个方面为自然保护区的社区发展提出了具体对策。本研究旨在推动自然保护区健康可持续发展,促进保护区社区发展与自然和谐共生。     

纳米羟基磷灰石对小麦植物酶及土壤酶活性的影响研究

采用土培方式研究纳米羟基磷灰石(NHAP)在不同质量分数下,小麦幼苗植株中3种植物酶及3种土壤酶活性的变化,并探讨添加不同质量分数NHAP对植物及土壤的影响.研究结果表明,添加NHAP后在初期(第7 d)能显著(p＜0.05)提高土壤pH值,但随着培养时间的推移,在第21 d时,对照处理(CK)与添加不同质量分数NHAP的处理1(T1)、处理2(T2)、处理3(T3)各处理间差异不显著(p＞0.05).添加NHAP可提高植物超氧化物歧化酶(SOD)活性,处理21 d后,与CK相比,除T1处理外,T2、T3处理SOD酶活性均显著提高.添加NHAP降低可过氧化物酶(POD)活性,在21 d处理时,T3处理POD酶活性显著降低,而T1、T2处理不明显.与CK相比,添加NHAP对植物过氧化氢酶(CAT)酶活性影响不显著.添加NHAP能提高小麦根际土壤过氧化氢酶活性,在第21 d,T1、T2、T3处理的土壤中过氧化氢酶活性显著增强,比CK分别提高19.5％、29.0％、49.8％.小麦根际土壤脲酶活性随时间延长变化不同,前14 d随NHAP质量分数升高而增加,之后随NHAP质量分数升高变化不明显.施加NHAP对土壤碱性磷酸酶活性影响不明显.综合考虑NHAP对小麦植物酶活性及土壤酶活性的影响以及经济成本等因素,确定添加纳米羟基磷灰石的适宜质量分数为1％.     

区域差异下农业用水效率对农业用水量的影响

基于全国30个省份1998~2015年面板数据,采用Super-SBM模型测算农业用水效率,并在观察农业用水量、农业用水效率动静态演进特征的基础上,利用门槛面板回归模型探究农业用水效率对农业用水量的影响。结果表明,全国农业用水量和农业用水效率均呈阶段性下降。农业用水效率对降低农业用水量具有显著的门槛效应,提高农业用水效率是降低农业用水量的有效途径;东部农业用水效率促进农业用水量下降,但须警惕"回弹效应";中部农业用水效率抑制农业用水量增长,且作用逐渐增强;西部农业用水效率提高能够快速降低农业用水量,但作用逐渐减弱。另外,提升农民受教育水平、增加绿水足迹、扩大农业劳动人口能够降低农业用水量,而丰富的水资源禀赋促进农业用水量增加。     

基于机制分解法长江口南汇潮滩悬移质泥沙通量研究

基于实测资料以长江河口南汇潮滩为例，对传统机制分解法进行改进，将机制分解计算中的含沙量项按悬沙粒径进行分组处理，分为63～250、16～63、4～16、05～4 μm 4个粒径组，对各粒径组泥沙的净输移通量分别进行机制分解计算，分析不同粒径组泥沙的各机制分解项对悬沙净输移通量的贡献。研究表明不同粒级的泥沙其控制输沙的潮滩动力因子不同。相当于粘土类（0.5～3.9 μm）和细粉砂类（3.9～16 μm）粒级的悬移质泥沙，平均流项T1+T2及潮泵项T3+T4+T5对其输移起控制作用；相当于粗粉砂类（16～62.5 μm）和细砂类（62.5～250 μm）粒级的悬移质泥沙，潮泵项T3～T5、潮振荡项T6～T8起控制作用。同时，对不同水深条件下同粒级悬沙净输移通量的机制分解项的比较，当悬沙输移过程由深水进入浅水时，潮泵项的贡献急剧减小，且不受大小潮汛、悬沙颗粒粒级粗细的影响