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Since its economic reform and opening-up, China has undergone unprecedented urbanization, where massive areas of rural land have been converted into urban use. Urban land development plays an important role in dynamic urban economic development. This study aims to contribute to the understanding of urban land development and its mechanisms in China. We conceptualized the mechanism of urban land development from multiple perspectives based on a case study in Jiangsu Province. We employed the methods of global and local spatial auto-correlation detection and spatial lag model to analyze the provincial land use conveyance and survey data from 2004 to 2008 and 2009 to 2012 to understand the dynamics of urban land development. The results show that urban land development varies significantly across different time periods, spatial scales, and regions in Jiangsu. Higher absolute urban land development mainly occurred in Sunan, expanding to Subei and Suzhong, while faster development occurred mainly in Subei, where the initial bases were lower but had strong economic growth potential. The regression analysis shows that market activities and administrative levels had played a more critical role in driving urban land development, which suggests that rapid urban land development has institutional and market foundations. Urban land development was not only a consequence of economic development but also a strategy of local governments to stimulate and govern the urban economy. This study enriches the literature on urban dynamics by providing an institutional understanding of rapid urban land development in a transitional economy.

This paper presents a spatial analysis of likely/potential hotspots of sustainability issues in Mainland China through an empirical investigation of patterns of ecological vulnerability in and of China’s megaregions. To be specific, this paper assesses the level of patterns of the ecological vulnerability of 16 megaregions through an indicator system, which includes soil erosion, desertification, ecosystem vulnerability, key ecological areas, and water and land resources. Empirical results reveal that while most megaregions are located in the less vulnerable areas, there are a couple of megaregions with a vulnerable basis of ecological environment. These megaregions consist of Chengdu-Chongqing, Guanzhong Tianshui Economic Zone, Shandong Peninsula, Wuhan City Circle, Beijing-Tianjin-Hebei, and Liaoning Coastal Belt. Furthermore, a typology of these megaregions is identified based on their development level and ecological vulnerability.

In this work, pyrolysis characteristics and kinetics of microalgae Diplosphaera sp. MM1 cultivated in different mediums were investigated by TG-FTIR and Py-GC/MS. Harvested MM1s biomass varied with the changing in proximate and ultimate analyses presented different weight loss behaviors. The weight loss of MM1s cultivated in dairy and winery wastewater in main pyrolysis region was ~48.4 wt% and ~52.9 wt%, respectively, and both showed secondary weight loss after 570 °C. However, MM1 harvested from BG-11 medium exhibited maximum weight loss of ~63.5 wt% and no secondary weight loss. Further, the activation energies of MM1s harvested from dairy and winery wastewater (176.3 kJ/mol and 130.4 kJ/mol, respectively) were lower than that of BG-11medium (189.4 kJ/mol). The best mechanism function for MM1s pyrolysis was third-order f(α) = (1-α)3. Py-GC/MS results of MM1 cultivated in winery wastewater showed highest contents of C4–C10 and C11–C21 that characterized the carbon level of gasoline and diesel, respectively, which are the major components of bio-oils.

Human activities do not only change the land use/land cover (LULC), but also release a large amount of anthropogenic heat through intensive activities above ground, which drives the formation of urban heat island (UHI). This study used the Nanjing metropolitan area as the research area and taken 2017 as the observation time and chosen land surface characteristic parameters, point of interest (POI) density and urban functional area data to quantify the driving mechanism of human activities at a grid scale. The results indicated as follows: i) The response relationships between the LST and its driving factors have a clear scale effect at the grid scale. The driving factors had the highest explanatory power at the 300 m grid; ii) LULC had a significant effect on LST, impervious layers and bare soil increased the LST, vegetation and water relieved it; iii) In different urban functional areas, the relationship between LST and POI density was piecewise. In addition to density, the types of human activities also have a significant impact on the UHI, in which industrial heat release has the most significant effect on the local temperature of the city, followed by daily heat production and transportation heat release.

The deteriorating water quality in the Taihu Lake Basin has attracted widespread attention for many years, and is correlated with a sharp increase in the quantity of pollutant discharge such as agricultural fertilizers and industrial wastewater. In this study, several factors were selected for evaluating and regionalizing the water environmental capacity by ArcGIS spatial analysis, including geomorphologic characteristics, water quality goals, water body accessibility, water-dilution channels, and current water quality. Then, the spatial optimization of agriculture and industry was adjusted through overlay analysis, based on the balance between industrial space and water environmental capacity. The results show that the water environmental capacity gradually decreases from the west to the east, in contrast, the pollution caused by industrial and agricultural clustering is distributes along Taihu Lake, Gehu Lake and urban districts. The analysis of the agricultural space focuses on optimizing key protected areas of the Taihu Lake Basin, and the shores of Gehu Lake, optimally adjusting the second protected areas of the Taihu Lake Basin, and generally adjusting the urban areas of Changzhou and Wuxi cities. The analysis of industrial space focuses on optimizing the downtowns of Changzhou and Wuxi cities, optimally adjusting key protected areas and second protected areas of the Taihu Lake Basin, and generally adjusting the south and southwest of Gehu Lake. Lastly, some schemes of industrial and agricultural layouts and policies for the direction of industrial and agricultural development were proposed, reflecting a correlation between industry and agriculture and the water environment.

This paper explores the urban-geographical potential of simulation approaches combining spatial and topological processes. Drawing on Vértes et al.'s (2012) economical clustering model, we propose a generative network model integrating factors captured in traditional spatial models (e.g., gravity models) and more recently developed topological models (e.g., actor-oriented stochastic models) into a single framework. In our urban network-implementation of the generative network model, it is assumed that the emergence of inter-city linkages can be approximated through probabilistic processes that speak to a series of contradictory forces. Our exploratory study focuses on the outline of the infrastructure networks connecting prefecture-level cities in the highly urbanized Yangtze River Delta (China). Possible hampering factors in the emergence of these networks include distance and administrative boundaries, while stimulating factors include a measure of city size (population, gross domestic product) and a topological rule stating that the formation of connections between cities sharing nearest neighbors is more likely (i.e., a transitive effect). Based on our results, two wider implications of our research are discussed: (1) it confirms the potential of the proposed method in urban network simulation in that the inclusion of a topological factor alongside geographical factors generates an urban network that better approximates the observed network; (2) it allows exploring the differential extent to which driving forces influence the structure of different urban networks. For instance, in the Yangtze River Delta, transitivity plays a less important role in the Internet-network formation; GDP and boundaries more strongly affect the rail network; and distance decay effects play a more prominent role in the road network. Dit artikel analyseert het potentieel binnen stadsgeografisch onderzoek van simulatiebenaderingen die zowel ruimtelijke als topologische processen in rekening brengen. Op basis van Vértes et al.'s (2012) economisch clustering-model stellen we een generatief netwerk-model voor dat factoren samenbrengt die doorgaans apart worden geanalyseerd in meer traditionele ruimtelijke modellen (bvb. zwaartekrachtmodellen) en in meer recente topologische modellen (bvb. actor-georiënteerde stochastische modellen). In onze stedelijke netwerk-implementatie van het generatief netwerk-model wordt aangenomen dat de totstandkoming van inter-stedelijke verbindingen kan ingeschat worden door middel van stochastische processen die analyseren hoe bepaalde krachten in variërende mate de vorming van die verbindingen versterken of afzwakken. Onze verkennende studie focust op de geografische structuur van de infrastructuurnetwerken die de voornaamste steden in de sterk geurbaniseerde Yangtze River Delta (China) met elkaar verbinden. Mogelijke afremmende factoren in de totstandkoming van deze netwerken zijn afstand en administratieve grenzen. Mogelijke stimulerende factoren zijn het belang van de stad (bevolkingsomvang of bruto regionaal product) en een topologische regel die aangeeft dat de vorming van connecties tussen steden waarschijnlijker is wanneer zij een ‘dichtste buur’ delen (m.n. een transitief effect). Twee bredere implicaties van ons onderzoek worden besproken aan de hand van de resultaten: (1) de resultaten bevestigen het potentieel van de voorgestelde methode voor de simulatie van stedelijke netwerken in de zin dat het opnemen van een topologische factor naast geografische factoren een stedelijk netwerk genereert dat een betere inschatting geeft van het geobserveerde netwerk; (2) de methode laat toe om de differentiële impact te meten van de verschillende stuwende factoren. In de Yangtze River Delta speelt transitiviteit bijvoorbeeld een minder belangrijke rol in de totstandkoming van het Internet-netwoerk; economische output en grenzen spelen een belangrijkere rol in de totstandkoming van het spoorweg-netwerk; en afstandsverval speelt een prominentere rol in de totstandkoming van het wegennetwerk.

Silicon nanoparticles (Si NPs) with sizes in the order of bulk exciton Bohr radius [1, 2] present interesting optical properties for fl uorescent labeling in biological imaging applications with their potential nontoxicity [3 – 6] . However, the origin of their photoluminescence has been subjected to intense debate for almost two decades. This debate has been focused on whether quantum confi nement effects or atomic scale defects at the surface of the nanocrystals are responsible for the light emission [7] . There have been reports of Si NPs produced by electrochemical etching of Si wafer, laser pyrolysis, plasma deposition and solution phase synthesis [8] . The last approach seems to be the most promising method because the size of nanoparticles can be controlled by the use of inverse micelles as nanoreactors in solution phase [3, 4] . Moreover, these synthesis methods allow chemical functionalization of Si NPs surfaces with relative ease, to offer numerous stabilization, solubility and bioconjugation options [4, 8 – 13] . In recent years, Wilcoxon ’ s and Tilley ’ s groups have synthesized water dispersible Si NPs by using LiAlH 4 reduction of silicon halide [3] , and then modifi ed the nanoparticles ’ surface with allylamine by using a platinum catalyst [4] . However, we have found that reproducibility and scalability of these reported methods of synthesis have not been completely controlled yet due to many factors, such as kinetics, oxidation, contamination, etc. For example, since LiAlH 4 is a very strong reducing agent, it is diffi cult to control the speed of the reducing reaction required for good reproducibility. It has also been previously reported that H 2 PtCl 6 can be reduced to platinum nanoparticles by methanol or other reducing agent [14] . The presence of other types of nanoparticles as impurities could introduce uncertainties in the origin of the fl uorescence. A possible solution for this problem could be the use of UV irradiation instead of H 2 PtCl 6 to functionalize the nanoparticle surface. Since all these methods involve the evaporation of the initial nonpolar solvent before redispersing in water, the possibility of contamination due to noneliminated toluene must be taken into account, as the optical properties of this solvent have been previously mistaken in the literature with those of Si NPs [15] .

A new water‐soluble polymeric fluorescent probe, poly[allylamine‐co‐N‐4‐chloro‐6‐(4‐methylcoumarin‐7‐oxy)‐1,3,5‐triazinylallylamine] (PA‐TMC), has been designed and characterized for near neutral pH measurement in dual‐excitation ratio application. The probe was synthesized by using cyanuric chloride as a linker, 7‐hydroxy‐4‐methylcoumarin as a fluorophore, and polyallylamine as a water‐soluble molecular scaffold. It showed a large pH‐dependent shift of excitation peak from 320 to 360 nm with no change of emission wavelength of 448 nm. The pKa value of the probe was 7.56, and the ratio R (I360/I320) of fluorescence intensities at the two excitation wavelengths of 360 nm and 320 nm was directly proportional to pH values over the range 6.8–8.5, which may be suitable for the pH monitoring of near‐neutral systems. Spectroscopic properties of the probe were also compared with the corresponding low molecular weight 7‐(4,6‐dichloro‐1,3,5‐triazinoxy)‐4‐methyl‐coumarin (TMC). The results showed that the i...

Oxidation of landfill leachate wastewater was studied in a transpiring-wall SCWO reactor, operated under varied temperature and pressure 320–430 °C, 18–30 MPa. Effect of temperature and pressure on COD and BOD removal efficiency was investigated. COD and BOD removal efficiency being 99.23%, 98.06% were achieved at 430 °C, 30 MPa, which increased with temperature and pressure. The modified pseudo first-order rate model was regressed from experimental data, taking into account the induction time ( t ind ) effect. The resulting pre-exponential factor A and activation energy E a were 34.86 s −1 and 32.1 kJ mol −1 , respectively, assuming that the reaction order for feed wastewater (based on COD) and oxidant were first order and zero order, respectively.

To detect the local polarity such as the N-terminal domain of a protein molecule, 3-(4-chloro-6-hydrazino-1,3,5-triazinylamino)-7-(dimethylamino)-2-methylphenazine has been designed and synthesized as a polarity-sensitive fluorescent probe by using an s-triazine ring as a backbone, neutral red and hydrazine as a polarity-sensitive fluorophore, and a labeling group, respectively. The fluorescence properties of the probe have been characterized. The probe has the following features: (1) stable in various solvents; (2) the long-wavelength emission of550 nm that can avoid the interferences of the background fluorescence shorter than 500 nm from common biomacromolecules; and (3) the maximum emission wavelength (lambda(em)) sensitive to solvent polarity only but not to pH and temperature. The hydrazino group in such a probe reacts readily with an active carbonyl produced by transamination of a protein molecule, leading to N-terminal specific attachment of the fluorophore and thereby allowing the monitoring of local polarity. With this probe, the polarity of the N-terminal domain in both native and heat-denatured alpha-lactalbumin has been first determined, which corresponds to that with a dielectric constant of about 16, and the hydrophobic core near the N-terminus is found to be conservative for heating. The present strategy may provide a general method to study the local environmental changes of a protein molecule under different denaturation conditions.

The synthesis of a novel fluorescent probe, 3-epoxypropoxy fluorescein (EPF), and its properties for labeling of histidine are described. The probe contained a fluorescein fluorophore with long-wavelength response and an active epoxy labeling group. In alkaline media EPF reacted selectively with histidine, rather than with other amino acids, causing a large increase in fluorescence intensity and thereby allowing a selective detection of histidine. This fluorescence increase resembled that of the fluorescein diaion with the increase of the media basicity, suggesting that the addition reaction of histidine with the epoxy group provides the fluorophore moiety with a basic molecular environment. As an application of this probe, fluorescent labeling of histidine in human serum was attempted and the obtained results were in agreement with those given by using histidine–nickel complex adsorptive voltammetry. Further, the relative S.D. of the method was 1.8% for 10 replicate determinations of 0.55 μM histidine. When 10 μM of EPF was used, the linear range for histidine was 0.007–10 μM with a detection limit (S/N=3) of 0.001 μM.