Fluorescence detection of malachite green and cations (Cr, Fe and Cu) by a europium-based coordination polymer.

Due to remarkable fluorescence characteristics, lanthanide coordination polymers (CP) have been widely employed in fluorescence detection, but it is rarely reported that they act as multifunctional luminescent probes dedicated to detecting malachite green (MG) and various metal ions. A europium-based CP fluorescent probe, Eu(PDCA)(HO) (PDCA = 2,6-pyridinedicarboxylic acid), has been synthesized and exhibited excellent recognition ability for malachite green and metal cations (Cr, Fe and Cu) among 11 metal cations, 13 anions and six other compounds. The recognition was achieved by fluorescence quenching when MG, Cr, Fe and Cu were added to a suspension of Eu(PDCA)(HO) respectively.

[Extracting method of tidal creek features under heterogeneous background at Yellow River Delta using remotely sensed imagery.].

The Yellow River Delta exhibits irregular tidal flat, with tidal creeks that vary in width and experience tidal creek current anisotropy. Given such characteristics, the GF-2 multi-spectral image was selected as the data source to characterize the details of tidal creeks. First, the normali-zed difference water index (NDWI) and OTSU classification were used to delineate the wide tidal creeks.

[Object-oriented aquatic vegetation extracting approach based on visible vegetation indices.].

Using the estimation of scale parameters (ESP) image segmentation tool to determine the ideal image segmentation scale, the optimal segmented image was created by the multi-scale segmentation method. Based on the visible vegetation indices derived from mini-UAV imaging data, we chose a set of optimal vegetation indices from a series of visible vegetation indices, and built up a decision tree rule. A membership function was used to automatically classify the study area and an aquatic vegetation map was generated.

Dustfall Heavy Metal Pollution During Winter in North China.

In order to study heavy metal pollution in dustfall during Winter in North China, forty-four dustfall samples were collected in North China Region from November 2013 to March 2014. Then forty trace elements content were measured for each sample by inductively coupled plasma-mass spectrometry. Finally, the contamination characteristics of the main heavy metals were studied through a multi-method analysis, including variability analysis, Pearson correlation analysis and principal component analysis.

[Estimating total nitrogen content in reclaimed water based on hyperspectral reflectance information from emergent plants: a case study of Mencheng Lake Wetland Park in Beijing, China].

Hyperspectral reflectance information is a crucial method to detect total nitrogen content in plant leaves, meanwhile, vegetation nitrogen content has a strong relationship with nitrogen in water. Taking Mencheng Lake Wetland Park supplied with reclaimed water as study area, the vegetation hyperspectral data (Phragmites australis and Typha angustifolia), and the content of total nitrogen in water were detected to investigate the feasibility of estimating total nitrogen content in reclaimed water based on hyperspectral reflectance information from emergent plants. We established simple linear regression model, stepwise multiple linear regression model and partial least square regression model based on four hyperspectral indices (spectral indices, normalized difference indices, trilateral parameters, absorption feature parameters), respectively.

[Study on influence of traffic and meteorological factors on inhalable particle matters of different size].

To study the effects of meteorological and traffic factors on the PM2.5 and PM10 concentrations, 28 samples were taken in the Third Ring Road of Beijing, and dust fall weight, velocity of vehicle, traffic volume, temperature, humidity, wind speed, PM2.5 and PM10 concentration data were collected for these samples.

[Spatial distribution of inhalable particulate and association with respiratory disease in Beijing City].

Inhalable particulate has become the premier pollutant of Beijing, which has enormous influence on the environmental quality of the city and health of the residents. Inhalable particle pollutants (particulate matter of 0.3, 0.

[Typical plant spectral characteristics analysis in wild duck lake along water environment gradient].

Typical submerged plants, floating plants, emerged plants, hygrophyte plants, and mesophyte plants were chosen, and derivative method and continuum removal method were used to analyze the spectral characteristics and changing trend of plants along water environment gradient. Emerged plants and hygrophyte plants have the highest reflectance value; floating plants have lower value, while submerged plants take the lowest reflectance value due to the effect of water surface. Derivative method could emphasize the changed trends of original spectral curve, thus more characteristic bands could take on.