[Ten-year Trend Analysis of Eutrophication Status and the Related Causes in Lake Hongze].

In order to propose pertinent suggestions regarding eutrophication control for Lake Hongze, we used monthly monitoring data from 2011 to 2020 to elucidate the spatiotemporal changing characteristics of eutrophic status and the relevant driving factors. As the main river entering Lake Hongze, River Huaihe experienced an increase in permanganate index and a decrease in TN in the last 10 years. Meanwhile, Secchi depth, TP, and permanganate index increased, whereas TN and Chl-a concentration decreased significantly in Lake Hongze. As a result, the eutrophic status TLI index of Lake Hongze declined over the past 10 years. The change trend of TLI in Lake Hongze differed spatially. As the main water passage of River Huaihe, the algal biomass was lower in the eastern region than that in the other two lake regions, regardless of the relatively high nutrient concentration, due to the short water retention time. Furthermore, the water quality of River Huaihe improved; thus, the TLI index decreased significantly in the eastern lake region. The northern region had a high coverage of aquatic vegetation, which not only reduced the concentration of water nutrients but also provided a habitat for zooplankton and fish, effectively inhibiting algal growth. Thus, the TLI index was lowest among the three lake areas and showed a downward trend over the last 10 years. In the western region, the algal biomass was the highest due to the intensification of phosphorus release from sediment in summer. Thus, the TLI index was the highest and had not improved in the past 10 years. There were also significant seasonal differences in the TLI of Lake Hongze, which was highest in summer, due to the relatively high algal biomass. Moreover, the algal biomass in summer was mainly affected by the concentration of nitrate. According to the spatiotemporal distribution characteristics of eutrophic status and the impacting factors in Lake Hongze, corresponding measures for eutrophication control should be taken for different seasons and lake areas.

Prenatal Perfluorooctyl Sulfonate Exposure and Alu DNA Hypomethylation in Cord Blood.

BACKGROUND: Perfluoroalkyl substances (PFASs) are stable and persistent in the environment, animals, and humans. PFASs can penetrate placenta and affect fetal growth. We investigated associations between prenatal exposure to perfluorooctanoic acid (PFOA), perfluorooctyl sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUA) and global methylation levels. Specific Aims and Methods: The study used the subjects from Taiwan Birth Panel birth cohort study, including all pregnant women who gave birth between July 2004 and June 2005 in four hospitals in Taipei city and New Taipei City. A total of 363 mother-infant pairs were included in the final analyses. PFOA, PFOS, PFNA, and PFUA were measured by UPLC-MS/MS in cord blood. LINE-1 and Alu repeated elements from cord blood was used to represent global DNA methylation levels. Multivariable regression models were used to adjust potential confounders. RESULTS: After controlling for potential confounders, each unit increase in the natural log-transformed PFOS exposure was associated with an adjusted OR of 1.72 (95% CI: 1.03, 2.88) for low Alu methylation level when dichotomized methylation level by medium. No significant effects between PFOA, PFNA, PFUA and methylation levels in the multivariable regression models were observed. CONCLUSIONS: Our findings suggest that prenatal PFOS exposure may be associated with low Alu methylation level.

[Analysis of Microfiber Knot Resonator Spectrum for Seawater Temperature].

As a sensing device, microfiber knot resonator (MKR) has been widely used in sensing field due to its advantages of high sensitivity and fast response. It is important to analyze the spectrum of MKR for detecting environmental parameters in that the spectrum can reflect the change of ambient environment. In this paper, the relationship between spectrum of MKR and seawater temperature has been studied theoretically and experimentally. Firstly, the dependences of the propagation constants of fundamental mode (HE11) on the fiber diameter and the probing wavelength are studied theoretically in this paper, including two orthogonal polarization states of fundamental mode. The calculated results show that the propagation constant increases with the increasing fiber diameter and the decreasing probing wavelength. Simultaneously, the dependence of propagation constant of fundamental mode on seawater temperature is studied. The results show that the larger propagation constant corresponds to the higher seawater temperature, which indicates that the seawater temperature affect the mode propagation constant. Thus, the seawater temperature can be obtained by detecting the resonant spectrum. Secondly, the experimental system for seawater temperature sensing is set up, with which the resonant spectrum of MKR for seawater temperature sensing are obtained. The experimental results show that two sets of resonant peak exist on the spectrum, which are corresponding to TE and TM modes of fundamental mode. The sensing sensitivities of the two polarization modes are 5.54 pm/°C and 5.24pm/°C, respectively. Finally, the reason for resonant spectrum of the two polarization states is discussed, which is that the separation of the two modes resulting from the twisted coupler of the knot zone, and the resonant intensity of the two polarization modes is analyzed. The resonant intensities of the two modes are different and one increases while the other one decreases with the increasing probing wavelength. It is determined by the coupling coefficients and attenuations of the two coupled states，which are affected by the probing wavelength. The experimental and theoretical results agree well.

[Near Infrared Spectroscopy of the Cretaceous Red Beds in Inner Mongolia Dongshengmiao].

Take the cores and surface weathered soil from the Cretaceous red beds in the western of Dongshengmiao mine of Inner Mongolia and analysis with near-infrared spectroscopy. The result shows that near-infrared spectroscopy can identify mineral quickly through the characteristic absorption peaks of each group. The Cretaceous red beds in the western of Dongshengmiao mine is argillaceous cementation, it is mainly composed of quartz, feldspar, montmorillonite, illite, chlorite, muscovite etc, the mineral composition is mainly affected by the upstream source area. The clay mineral like montmorillonite water swelling and uneven drying shrinkage expands the original crack and creates new cracks, reduces its strength, which is the mainly reason of its disintegration. According to the composition of clay mineral, we speculate its weathering process is mainly physical weathering, the climate during the weathering is cold and dry. The results can not only improve the geological feature of the mining area, but also show that the near-infrared spectroscopy technology can analyze the mineral composition of soil and rock effectively on the basis of Mineral spectroscopy, which demonstrates the feasibility of the near-infrared spectroscopy can analyze minerals in soil and rock quickly, that shows the feasibility in geology study, provides new ideas for the future research of soil and rock.

[Near infrared spectrum analysis and meaning of the soil in 512 earthquake surface rupture zone in Pingtong, Sichuan].

Through modern near infrared spectrum, the authors analyzed the yellow soil from the rupture zone located in Ping- tong town,Pingwu, Sichuan province. By rapid identification of the characteristic of peak absorption of mineral particles, the result shows that the soil samples mainly composed of calcite, dolomite, muscovite, sericite, illite, smectite; talc, tremolite, actinolite, chlorite, etc. And the mineral compositions of the soil is basically the same with the yellow soil in Sichuan region. By analyzing and comparing it was revealed that part of mineral compositions of the soil are in accordance with the characteristics of the rock mineral compositions below the rupture zone, indicating that part of the minerals of the soil's evolution is closely related to the rock compositions in this area; and the compositions of the clay mineral in the rupture zone is similar to the Ma Lan loess in the north of China, so it is presumed that the clay minerals in these two kinds of soil have the same genetic type. The characteristic of the mineral composition of the soil is in accordance with evolution characteristics of the rocks which is bellow the rupture zone, also it was demonstrated that the results of soil minerals near-infrared analysis can effectively analyze the mineral particles in the soil and indicate the pedogenic environment. Therefore, the result shows the feasibility of adopting modern near-infrared spectrum for rapid analysis of mineral particles of the soil and research of geology. Meanwhile, the results can be the foundation of this region's soil mineral analysis, and also provide new ideas and methods for the future research of soil minerals and the earthquake rupture zone.

[X-ray diffraction and infrared spectrum analysis of fault gouge in Wenchuan seismic belt].

Wenchuan earthquake produced a series of co-seismic surface ruptures in Leigu and Zhaojiagou, and we collected samples of co-seismic fault gouge in the surface ruptures as well as the old gouge in the fault of Nanba. Testing The new and old fault gouge was tested with X-ray diffraction and infrared absorption spectra, and its characteristics such as mineral compositions, clay mineral contents and combinations were comprehensively analyzed. The results display obvious differences between the new and old fault gouge, showing that the old fault gouge is mainly composed of wall rock debris or milled powders, while the main components of new fault gouge are clay minerals. The assemblage of clay minerals composition shows that the environment of the fault activity was mainly warm and humid, and the clay minerals were mainly transformed by low temperature and low pressure dynamic metamorphism. And this also partly indicates that the latest way of the fault activity in this area may be a creeping. However the previous researches on the fault gouge of Wenchuan earthquake fault zone are mainly focused on its mechanical properties as well as its texture and structure, the research in this paper is to determine the physical and chemical environment of fault activity through the mineral compositions and clay mineral contents in the fault gouge characteristics, and this research has important scientific significance to the researches on the evolution of the fault environment and the activity mechanism of the earthquake.