[Spatial-temporal Distribution and Source Analysis of Polycyclic Aromatic Hydrocarbons in the Sediments of Poyang Lake].

The concentrations, spatial-temporal distribution, and influencing factors of 16 polycyclic aromatic hydrocarbons (PAHs) in the sediments of Poyang Lake were studied, and a quantitative source analysis of PAHs in different areas of the lake was conducted. PAHs were widespread within the sediments. The concentrations of ∑PAHs in the surface sediments of all sites ranged from 203 to 2 318 μg·kg.

[Augmenting locking plate with autologous bone graft for the treatment of nonunion of long bone fracture in the lower extremity with retaining of the original intramedullary nail].

Objective: To explore clinical effect of attaching locking plate with bone grafting based on retaining the original intramedullary nail in treating non-union after intramedullary nail fixation of long shaft fractures of lower limbs.

Methods: A retrospective study was conducted on 20 patients treated with non-union fractures after intramedullary nailing of long shaft fractures of lower limbs from June 2015 to June 2020. All patients were treated with the original intramedullary nailing and bone grafting from the iliac bone, and were underwent open reduction plate internal fixation and bone grafting for old fractures.

Nonadiabatic Derivative Couplings Calculated Using Information of Potential Energy Surfaces without Wavefunctions: Ab Initio and Machine Learning Implementations.

In this work, we implemented an approximate algorithm for calculating nonadiabatic coupling matrix elements (NACMEs) of a polyatomic system with ab initio methods and machine learning (ML) models. Utilizing this algorithm, one can calculate NACMEs using only the information of potential energy surfaces (PESs), i.e.

[Spatio-Temporal Variation of Release Flux of Sediment Nitrogen and Phosphorus in High-Risk Period of Algal Bloom in Lake Erhai].

Spatial and temporal characteristics of release fluxes of sediment nitrogen (N) and phosphorus (P) were investigated in the high-risk period of algal blooms in Lake Erhai. Moreover, the influence factors were examined. Results show that the release flux of N and P increased in recent years, exhibiting a clear increase in the period from 2009 to 2013, and a slight increase in the period since 2013.

[Effects and Differences of the Release of Dissolved Organic and Inorganic Phosphorus in Different Sediments Covered by Different Materials of Erhai Lake].

In this work, the effects of four covering materials on the release of total dissolved phosphorus (DTP), dissolved organic phosphorus (DOP), and soluble reactive P (SRP) in different sediments of Erhai Lake were simulated. The results showed that the max release of DTP was reduced in covering material, which attributed to the changes of pH, Eh and characteristics of dissolved organic matter (DOM) by the effect of covering material. The application of iron oxide material significant reduced the release of DTP in the northern and southern part of the lake, with decrease rate of 44.

[Temporal and Spatial Variation Characteristics of Nitrogen and Phosphorus in Sediment Pore Water and Overlying Water of Dianchi Caohai Lake].

The vertical variation in the contents of nitrogen and phosphorus with different forms in pore water and overlying water was continuously measured for twelve months in Dianchi Caohai Lake. The research revealed the difference of N or P concentration between pore water and overlying water and the contribution of nitrogen and phosphorus forms. It is significant to understand the formation of N and P and the ratio of N/P in pore water in the fields of lake eutrophication and the control of internal nutrient-loading.

[Characteristics of Water Extractable Organic Nitrogen from Erhai Lake Sediment and Its Differences with Other Sources].

The 47 samples from Erhai Lake surface sediments were collected in different seasons. The distribution and structure characteristics of sediment water extractable organic nitrogen(WEON) were investigated by using the combined techniques of UV-Vis absorption and three-dimensional excitation-emission matrix spectra(3DEEMs). The differences in DON of various sources(overlying water, pore water, inflow Rivers and wet deposition) were explored to analyze its effects on sediment.

[Gas Transfer Velocity of CH at Extremely Low Wind Speeds].

Thin boundary theory equation (TBL) is widely used to determine gas fluxes across water-air interfaces, and the gas transfer velocity () is the key environmental factor in the equation. A monthly field campaign was carried out during one year to measure CH flux and to probe its exchange rate across the air-water interface in a drinking reservoir and 5 adjacent ponds. The ranges of wind speed and surface water temperature were 0-0.

[Compositional Characteristics of Sediment Dissolved Organic Nitrogen in Typical Lakes and Its Relationship on Water Trophic Status].

UV-Vis absorbance, fluorescence, and Gas Chromatography Mass Spectrometry (GC-MS) were applied to the comparative study on sediment dissolved organic nitrogen (DON) in five typical lakes (Erhai lake, Dianchilake, Poyang lake, Wuhan Dong lake, and Taihu lake) in different lake regions with different nutrition status, revealing the relationship between structural and compositional characteristics of sediment DON and trophic level of lakes. The obtained results showed that: ①Structure of lake sediment DON in Yungui Plateau region is more stable, compared with those in Eastern Plain region, indicating its lower bioavailability. ②In Yungui Plateau region, the source and compositional characteristics of sediment DON weremore complex in Dianchi lake (a seriously polluted lake), and its sediment DON bioavailabilitywas relatively higher.

[Concentration of Phosphorus in Sediments Interstitial Water as Affected by Distribution of Aquatic Plants in Dianchi Lake].

In order to reveal the effect of aquatic plants distribution on the mass concentration of phosphorus in sediment interstitial water, the mass concentrations of Dissolved Total Phosphorus (DTP), Soluble Reactive Phosphorus (SRP) and Dissolved Organic Phosphorus (DOP) in the sediment interstitial water and overlying water from areas with or without plants in the same site of Dianchi were studied. The vertical variation characteristics of phosphorus forms in sediment interstitial water were analyzed to explore the effect of aquatic plants on the phosphorus forms in sediment interstitial water. The results showed: ①Aquatic plants had an significant effect on the phosphorus mass concentration of the sediment interstitial water in different Dianchi lakes.

[Vertical Variation of Phosphorus Forms in Lake Dianchi and Contribution to Release].

Columnar sediment samples were collected from the Waihai of Lake Dianchi in northern, central and southern sediment, combined with the data of phosphorus in the overlying water and sediment organic matter, the effects of organic matter and particle size on sediment release were studied, and the influence of different forms of phosphorus release from sediments and their contributions were discussed. The results showed:Sediment pore water (DTP) and (SRP) was negatively correlated with contents of OM, clay (<4.00 μm) and silt (4.

[Characteristics of nitrogen pollution and the potential mineralization in surface sediments of Dianchi Lake].

The nitrogen content, its different forms and their spatial distribution were studied by using the 53 sediment samples from different sites in Dianchi Lake. Thereafter, the potential nitrogen mineralization ability of the sediments and their pollution characteristics were also explored to understand the influencing factors of nitrogen pollution and its release risk from the sediment surface to the overlying water of Dianchi. The results showed: (1) the average total nitrogen content of surface sediment in Dianchi Lake was 3 515.

[Characteristics and bioavailability of organic phosphorus from different sources of sediments in Dianchi Lake].

The content and vertical distribution characteristics of organic phosphorus were studied by collecting core sediments of Dianchi Lake, characterizing the bioavailability of different organic phosphorus species of these sediments by enzymatic hydrolysis. The results indicated that, (1) The inorganic phosphorus represented primary portions of extractable phosphorus of sediments in Dianchi Lake, except for the H2O extractable organic phosphorus (H2O-P(o)). The rank of order of organic phosphorus fractionation in sediments was NaOH extractable organic phosphorus (NaOH-P(o)) > NaHCO3 extractable organic phosphorus (NaHCO3-P(o)) > H2O-P(o) > HCl extractable organic phosphorus (HCl-P(o)).

[Optical signatures of chromophoric dissolved organic matter in water body of Tien Lake].

The water samples of the Tien Lake were collected for the three-dimensional fluorescence spectrum detected. And parallel factor analysis (PARAFAC) and principal component analysis (PCA) were used for the spectra analyzing to know the main factor and relative contribution of the chromophoric dissolved organic matter (CDOM). PARAFAC decomposed CDOM into four components, the humic-like: C1 (240, 415), C3 (265, 525), C4 (255, 505) and the protein-like: C2(230/280, 330).

[Influence of the river-lake relation change on the distribution of heavy metal and ecological risk assessment in the surface sediment of Poyang Lake].

Effects of river (Yangtze River)-lake (Poyang Lake) relation on the distribution and potential ecological risk of Cu, Pb, Zn, Cr and Cd were investigated in surface sediment of Poyang Lake under different waterregimens. The results indicated: (1) the sediments of Poyang Lake were polluted by various concentrations of heavy metals mainly originated from particulates of Yangtze River, and Cu and Pb were the main pollution factors. The pollution level of determined heavy metals followed the order of Cu > Pb > Zn > Cr >Cd.

[Bioavailability of dissolved organic nitrogen components in the lake sediment to alage].

Samples in the sediments of Wuliangsuhai and Erhai Lake were selected, and the technologies of XAD-8 resins separation and three dimensional fluorescence excitation-emission matrix (3DEEM) spectra were applied, in order to study the bioavailability of dissolved organic nitrogen components to alage under the room cultivation. The obtained results showed that: (1) Average loss of DON and DOC from sediments was below 5% after dividing DON into different groups, which means the technology of XAD- 8 resins separation could be used in the study of DON components in the lake sediment. (2) Through 3DEEM analysis, hydrophilic and hydrophobic DON was dominated by protein-like and humic-like materials in the lake sediment, respectively.

[Tissue distribution and bioconcentration factors of tetrabromobisphenol A in five fishes in Lake Chaohu].

Tissue distribution and bioconcentration factors of tetrabromobisphenol A (TBBPA) in five economic fishes in Chaohu Lake were measured with SPE-HPLC. The results showed that, the average concentration of TBBPA was 4.70-11.

Development of freshwater aquatic life criteria for tetrabromobisphenol A in China.

Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant. It has been detected in the environment and has shown to high toxicity to aquatic organisms. To date no aquatic life criteria for TBBPA have been proposed.

[Relationship between the DO and the environmental factors of the water body in Lake Erhai].

The contents of DO and nitrogen (N), phosphorus (P), chlorophyll a in water from Lake Erhai were analysed by combining the nitrogen and phosphorus forms in sediment. The results indicated that the DO contents of the water from Lake Erhai varied from 6.61 to 7.

[Effect of different type sediments on transformation of phosphorus forms and growth of Myriophyllum spicatum].

The changes of the different phosphorus (P) forms in sediments, overlying water and the diversity of dry weight and root forms of Myriophyllum spicatum were studied using different type sediments under simulating condition. The characteristic of transformation of P forms and growth of submerged plant Myriophyllum spicatum were illustrated. The results indicated that the P release was promoted by adding the silver sand in sediment, and their P concentrations in the overlying water were increased.

[Physiological responses of Myriophyllum spicatum to ammonium nitrogen].

With the sediment applied with 0, 0.24%, and 0.48% NH4Cl (treatments CK, SN1, and SN2) as the substrate, a greenhouse experiment was conducted to study the physiological responses of Myriophyllum spicatum to ammonium nitrogen.