Mechanistic insights into an NHOAc-promoted imine dance in Rh-catalysed multicomponent double C-H annulations through an N-retention/exchange dual channel.

Developing new and understanding multicomponent reactions (MCRs) is an appealing but challenging task. Herein, Rh(iii)-catalyzed multicomponent double C-H annulations of cyclic diimines (or diketones and acetone), alkynes, and ammonium acetate to assemble functionalized 1,1'-biisoquinolines and C-bridged 1,1'-bisisoquinolines with controllable N/N editing in one shot has been developed. Through a combination of isotopic-labeling (H, O, and N) experiments, crystallography, and time-dependent ESI-MS, the reaction process was studied in detail.

Rh(III)-Catalyzed One-Pot Three-Component Diannulation of Benzils, Ammonium Acetate, and Alkynes to Build 1,1'-Biisoquinolines.

An efficient one-pot synthesis of 1,1'-biisoquinolines by a three-component reaction of commercially available raw materials (benzils, NHOAc, and alkynes) is disclosed. This complicated reaction involves in situ diimine formation via benzil-NHOAc condensation, Rh(III)-catalyzed 2-fold imine-directed C-H activation, and annulation with alkynes. Both symmetric and unsymmetric 1,1'-biisoquinolines could be assembled in moderate to high yields.

Study on sandstorm PM exposure assessment in the large-scale region: a case study in Inner Mongolia.

The current exposure-effect curves describing sandstorm PM exposure and the health effects are drawn roughly by the outdoor concentration (OC), which ignored the exposure levels of people's practical activity sites. The main objective of this work is to develop a novel approach to quantify human PM exposure by their socio-categorized micro-environment activities-time weighed (SCMEATW) in strong sandstorm period, which can be used to assess the exposure profiles in the large-scale region. Types of people's SCMEATW were obtained by questionnaire investigation.

Effects of Sediment Chemical Properties on Phosphorus Release Rates in the Sediment-Water Interface of the Steppe Wetlands.

Rising temperature causes a process of phosphorus release, which can be characterized well using phosphorus release rates (V). The objective of the present study was to investigate the major factors affecting sediment phosphorus release rates through a wetland habitat simulation experiment. The results showed that the V of different wetland sediments were different and changed with the order of W-R (river wetland) > W-L (lake wetland) > W-M (grassy marsh wetland) > W-A (reservoir wetland).

Analysis of factors controlling soil phosphorus loss with surface runoff in Huihe National Nature Reserve by principal component and path analysis methods.

Phosphorus (P) loss with surface runoff accounts for the P input to and acceleration of eutrophication of the freshwater. Many studies have focused on factors affecting P loss with surface runoff from soils, but rarely on the relationship among these factors. In the present study, rainfall simulation on P loss with surface runoff was conducted in Huihe National Nature Reserve, in Hulunbeier grassland, China, and the relationships between P loss with surface runoff, soil properties, and rainfall conditions were examined.

Analysis of factors controlling sediment phosphorus flux potential of wetlands in Hulun Buir grassland by principal component and path analysis method.

Phosphorus (P) flux potential can predict the trend of phosphorus release from wetland sediments to water and provide scientific parameters for further monitoring and management for phosphorus flux from wetland sediments to overlying water. Many studies have focused on factors affecting sediment P flux potential in sediment-water interface, but rarely on the relationship among these factors. In the present study, experiment on sediment P flux potential in sediment-water interface was conducted in six wetlands in Hulun Buir grassland, China and the relationships among sediment P flux potential in sediment-water interface, sediment physical properties, and sediment chemical characteristics were examined.

Responses of Biogeochemical Characteristics and Enzyme Activities in Sediment to Climate Warming under a Simulation Experiment in Geographically Isolated Wetlands of the Hulunbuir Grassland, China.

Climate warming generates a tremendous threat to the stability of geographically-isolated wetland (GIW) ecosystems and changes the type of evaporation and atmospheric precipitation in a region. The intrinsic balance of biogeochemical processes and enzyme activity in GIWs may be altered as well. In this paper, we sampled three types of GIWs exhibiting different kinds of flooding periods.

Dynamics of Phosphorus Content in the Water-Sediment Interface of Wetlands in a Mid-Temperature Steppe.

  In order to reveal dynamics changes in phosphorus release from the sediments of wetlands in a mid-temperature steppe without external phosphorus input, the relationship between phosphorus content in the overlying water, sediment, and interstitial water was studied using the variables control method. The results showed that, during the incubation period, the content of total phosphorus in the overlying water and the content of total phosphorus in interstitial water both presented in the order of August > September > July. Furthermore, the correlation relationships between phosphorus content in the overlying water, total phosphorus in the interstitial water, and the ratios of sediment Olsen-P to total phosphorus in the interstitial water, indicated that Olsen-P might be a kind of release form of phosphorus - from the sediment to the overlying water of the wetlands in Hulunbeier steppe, without external phosphorus input.

Regional risk assessment approaches to land planning for industrial polluted areas in China: the Hulunbeier region case study.

The rapid industrial development and urbanization processes that occurred in China over the past 30years has increased dramatically the consumption of natural resources and raw materials, thus exacerbating the human pressure on environmental ecosystems. In result, large scale environmental pollution of soil, natural waters and urban air were recorded. The development of effective industrial planning to support regional sustainable economy development has become an issue of serious concern for local authorities which need to select safe sites for new industrial settlements (i.

Study on the changes of urinary 8-hydroxydeoxyguanosine levels and burden of heavy metal around e-waste dismantling site.

To examine the relations between the burden of blood copper (B-Cu), blood ferrous (B-Fe), and the oxidative stress in people around electronic waste (e-waste) recycling sites, this study measured and analyzed the level of urinary 8-Hydroxy-2'-deoxyguanosine (8-OHDG) of these people. Exposed groups, consisted of female groups (directly exposed group n=100, indirectly exposed group n=54) and male groups (directly exposed group n=98, indirectly exposed group n=34), were chosen from e-waste recycling sites. Control group (female n=59, male=32) was selected from a green plantation.