牵引车载荷对NOx排放和排温影响的试验研究

在五轴动力总成试验台架上对牵引车在不同载荷下进行同一路谱的排放试验,研究牵引车在不同载荷下NOx排放和排温的变化,得到载荷与排放物和选择性催化还原(selective catalytic reduction,SCR)上游排温的变化关系。结果表明:载荷为标定载荷的60%以下时,NOx比排放值与载荷基本呈线性相关;载荷超过标定载荷的75%时,NOx比排放值与载荷呈二次项相关;载荷在为标定载荷的23%以上时,NOx比排放值与SCR上游排温基本呈线性相关。利用该试验结论可以通过只进行单一载荷排放试验,判断车辆在其他载荷下的排放水平是否满足国家标准要求,并可通过载荷对排温的影响规律预判排放水平。     

南海北部陆坡天然气水合物成藏特征研究进展分析

南海北部陆坡区域构造地质控制着气源、流体疏导体系、富集空间及储层物性特征,因此,东沙海域、神狐海域、西沙海槽和琼东南盆地的水合物成藏条件及控制因素具有明显差异性。东沙海域深部气体可沿断层、裂缝、不整合面、砂岩疏导层和气烟囱等通道向上运移,并形成天然气水合物,具有渗漏型水合物产出特征;神狐海域水合物成藏与规模巨大的泥底辟活动相关,并与布莱克海台天然气水合物产出特征具有相似性;琼东南盆地中央坳陷带内为天然气水合物发育的重点区,底辟、泥火山或麻坑构造与天然气水合物发育密切相关。     

异质性环境规制对绿色全要素生产率的影响机制——基于能源消费结构的调节作用

为探讨能源消费结构调节下异质性环境规制对绿色全要素生产率的影响机制，论文利用SBM方向距离函数测得全国各省市“经济-资源-环境-社会”四位一体的绿色全要素生产率，并将环境规制工具分为命令控制型、经济激励型、治理投入型和公众参与型4类，构建了空间杜宾模型以及门槛效应模型，进而得出在能源消费结构调节下，异质性环境规制对绿色全要素生产率的直接作用、间接作用以及空间溢出效应。研究结果表明：1）经济激励型和公众参与型环境规制通过调节能源消费结构对当地和邻地的绿色全要素生产率产生影响；2）在门槛检验方面，能源消费结构对命令控制型、经济激励型和公众参与型环境规制影响绿色全要素生产率存在门槛效应，同时在能源消费结构调节下，命令控制型和经济激励型环境规制对其本身对绿色全要素生产率的间接作用存在门槛效应。建议政府在制定环境规制时要考虑到其与能源消费结构的交互作用，并且在不同能源消费水平地区采用适宜的规制方法和强度，以更好地发挥环境规制作用。     

Matrilin-3-Primed Adipose-Derived Mesenchymal Stromal Cell Spheroids Prevent Mesenchymal Stromal-Cell-Derived Chondrocyte Hypertrophy

Adipose-derived mesenchymal stromal cells (Ad-MSCs) are a promising tool for articular cartilage repair and regeneration. However, the terminal hypertrophic differentiation of Ad-MSC-derived cartilage is a critical barrier during hyaline cartilage regeneration. In this study, we investigated the role of matrilin-3 in preventing Ad-MSC-derived chondrocyte hypertrophy in vitro and in an osteoarthritis (OA) destabilization of the medial meniscus (DMM) model. Methacrylated hyaluron (MAHA) (1%) was used to encapsulate and make scaffolds containing Ad-MSCs and matrilin-3. Subsequently, the encapsulated cells in the scaffolds were differentiated in chondrogenic medium (TGF-β, 1–14 days) and thyroid hormone hypertrophic medium (T3, 15–28 days). The presence of matrilin-3 with Ad-MSCs in the MAHA scaffold significantly increased the chondrogenic marker and decreased the hypertrophy marker mRNA and protein expression. Furthermore, matrilin-3 significantly modified the expression of TGF-β2, BMP-2, and BMP-4. Next, we prepared the OA model and transplanted Ad-MSCs primed with matrilin-3, either as a single-cell suspension or in spheroid form. Safranin-O staining and the OA score suggested that the regenerated cartilage morphology in the matrilin-3-primed Ad-MSC spheroids was similar to the positive control. Furthermore, matrilin-3-primed Ad-MSC spheroids prevented subchondral bone sclerosis in the mouse model. Here, we show that matrilin-3 plays a major role in modulating Ad-MSCs’ therapeutic effect on cartilage regeneration and hypertrophy suppression.     

中国省际绿色技术创新效率测度及影响因素研究

文章基于2011—2017年中国30个省份面板数据，运用super-SBM模型对绿色技术创新效率进行测算，并利用ML指数对绿色技术创新效率进行动态分析，最后通过空间滞后模型分析影响效率的关键因素。研究结果表明：中国绿色技术创新效率呈逐渐增长的趋势，但整体效率偏低，有较大进步空间；中国绿色技术创新效率存在明显区域差异，呈现由东部向西部递减的格局；绿色技术创新水平的提高是技术效率和技术进步共同贡献的结果；产业结构、区域开放程度和教育水平对绿色技术创新效率产生积极的正向影响，环境规制和研发投入强度对绿色技术创新效率影响不显著。     

Governance choices and policy outcomes in the Latin American and caribbean electricity sector

The paper first provides, for Latin America and the Caribbean, country-specific synthetic quantitative measures of the degree of adoption of governance reforms in the electricity sector, focusing on four key dimensions (market structure, private sector participation (PSP), regulatory autonomy and operational organization). These measures are then correlated with standard policy performance outcomes measures. The findings suggest that, the reforms, considered jointly, were statistically significantly associated with higher technical and process quality but not with social or service improvements. Considered individually, increased regulatory autonomy enjoyed the highest positive correlation with desirable outcomes, but PSP has no significant correlation with any of the outcomes. In sum, as of 2018, governance reforms, considered jointly, had still not delivered on some promised payoffs, notably in addressing energy poverty, although the sensitivity analysis suggests that, for some indicators, the relationships are stronger for larger than for smaller countries.     

广州市传统滨水动态人文景观的类型及空间格局

文章从风景园林学科的角度出发，对传统老广州曾经存在的地域人文景观里的典型——滨水动态人文景观进行了初步的全面整理，以日常型滨水动态人文景观和节庆型滨水动态人文景观为两种基本类型，总结梳理出超过25种滨水动态人文景观的主要类型，充分说明了广州市传统滨水动态人文景观的多样性和独特性。并以景观格局的理论视角分析了传统滨水动态人文景观在广州旧城的空间格局，分析得出其两个核心聚集区：以祭祀水神的仁威神庙为精神核心节点的呈圆形扩散的西关功能核心区和以长堤滨江段为中线的呈椭圆形扩散的珠江两岸功能核心区，并总结了促使这种人文景观发展与繁盛的历史经验，为广州地域文化景观的发扬及旧城更新工作提供借鉴。     

The control of paracetamol particle size and surface morphology through crystallisation in a spray dryer

The parameters governing the crystallisation of paracetamol using various conventional techniques has been extensively studied, however the factors influencing the drug crystallisation using spray drying is not as well understood. The aim of this work was to investigate the crystallisation of an active pharmaceutical ingredient through evaporative crystallisation using a spray dryer to study the physicochemical properties of the drug and to use semi-empirical equations to gain insight into the morphology and particle size of the dried powder. Paracetamol solutions were spray dried at various inlet temperatures ranging from 60 °C to 120 °C and also from a series of inlet feed solvent compositions ranging from 50/50% v/v ethanol/water to 100% ethanol and solid-state characterisation was done. The size and morphology of the dried materials were altered with a change in spray drying parameters, with an increase in inlet temperature leading to an increase in particle Sauter mean diameter (from 3.0 to 4.4 µm) and a decrease in the particle size with an increase in ethanol concentration in the feed (from 4.6 to 4.4 µm) as a result of changes in particle density and atomised droplet size. The morphology of the dried particles consisted of agglomerates of individual crystallites bound together into larger semi-spherical agglomerates with a higher tendency for particles having crystalline ridges to form at higher ethanol concentrations of the feed.     

高瓦斯矿井回采工作面瓦斯综合抽采技术实践

为了解决高瓦斯矿井工作面瓦斯涌出量大、瓦斯浓度高,制约工作面安全生产的问题,以亨元煤业为背景,结合矿井开采及瓦斯地质条件,确定了本煤层顺层钻孔抽采、穿层钻孔抽采邻近层和覆岩裂隙带瓦斯、以及对上隅角布置抽采管路进行抽采的综合治理方法。试验表明,工作面开采期间瓦斯涌出正常,上隅角瓦斯浓度保持在0.56%以下,实现了工作面安全高效开采。     

甘肃省陇东地区极端降水的时空特征

为阐明甘肃省陇东地区极端降水的变化规律,利用该地区13个气象台站1961~2015年的逐日降水资料,应用超门限峰值法、反距离加权法、线性倾向估计法、滑动平均法、Mann-Kendall突变分析法、复值Morlet小波分析法研究极端降水的时空变化特征。结果表明,陇东地区各站第95百分位极端降水阈值在27.8mm附近变化,即可以大雨事件作为极端降水事件进行监测;极端降水指数主要表现为从南向北递减的趋势,极端降水事件对环县和崆峒的影响较小;极端降水事件虽然在总量、强度上表现为减小趋势,但其发生频次及对总降水的贡献率逐渐增强;极端降水总量和极端降水强度周期变化均在21年左右能量最强,而极端降水频次和极端降水贡献率周期变化分别在28、5年左右能量最强。