The ion-absorbed rare earth deposit occurred in the South of China is unique all over the world. Since the 1970s, rare earth in Longnan, South China has begun to be mined with leaching methods using oxalates and ammonium sulfate. Although this kind of methods is simple and economic, its presence in the environmental causes a growing environmental problems, especially changes in regional hydrochemical environment. In this paper typical ion-absorbed rare earth deposit——the Longnan rare earth mine, Jiangxi Provence, South China was selected as the study object, where the surface water and groundwater samples were collected. Analytic results show that the mining activities have affected the regional hydrochemical environment, which are expressed in the decreased pH（pH 3-4）, the enrichment of REE and heavy metal Pb in water with the maximum of 44760.1 μgL-1 and 1550 μgL-1 respectively, and the sulfate（214-1121 mgL-1）, ammonium（33.7-268 mgL-1） and nitrate ions（90-468 mgL-1） far beyond the background value. The impaction of the mining area surface hydrochemical environment is severest, then around the mining area, and the main rivers and groundwater in the study area have not been affected yet.

Badain Jaran Desert is the third largest desert of China. The research on aeolian geomorphology resources will be beneficial to the sustainable development of tourist industry and environment in the Badain Jaran Desert. This paper uses these basic geographical data, such as ETM+, 1:50,000 topographic map, GDEM, Google Earth data and so on. Then we integrate geological surveys in the field and summarize the characteristics of aeolian geomorphology resources. By combining with tourism projects of aeolian geomorphology resources set in other scenic area, the tourism development projects of aeolian geomorphology resources and desert environment in the study are put forward with the purpose of offering practical advice for tourism development of aeolian geomorphology resources and the control and utilization of desert environment in the Badain Jaran Desert.

A conventional method for identifying sediment-supply directions is to characterize the seismic progradational reflection configuration, which is based mainly on qualitative observation of numerous seismic profiles. We have developed a more quantitative and practical way to determine the major sediment-supply direction (MSSD) using a new type of rose diagram based on seismic progradational sequence angles. In accordance with similar principles of the rose diagram used in structural geology, we have developed an analytical method and a workflow for a new rose diagram of seismic-based progradational sequence angles to determine MSSD. The Bozhong sag, a subbasin of the Bohai Bay Basin with two typical progradational sequences (I and II), provides a suitable example to analyze MSSD and test the new method. Our result indicates that the MSSD of the two progradational sequences (I and II) corresponds to azimuths of 10°–20° and 340°–350°, respectively, intuitively indicating two sequences derived from different provenance-transport systems. The new rose diagram of seismic progradational angles offers a powerful and quantitative method for seismic-based sedimentary provenance and paleocurrent analysis.

Two frequency combs emitting from a single cavity are of great potential in the field of dual-comb spectroscopy because they are mutually coherent and therefore the common mode noise can be suppressed naturally. However, it is difficult to fully and flexibly control the repetition frequency difference in most of the all-optical schemes. In this paper, a birefringence-compensation Kerr resonator is proposed for the mutual dual-comb generation. It is shown that by offset aligning the fast and slow axis with appropriate fiber length, the total birefringence of the cavity can be equalized while the local one keeps at a high level. Theoretical investigations reveal that the polarization decoupled mutual dual-comb can be generated with nearly the same power level and arbitrary repetition frequency difference. Additionally, a numerical model of polarization-maintaining fiber (PMF) with near-zero dispersion is proposed for the proof of the concept. Based on this fiber, the coherent polarization-decoupled dual-comb with 10-dB bandwidth of 33 nm can be obtained. And the repetition frequency difference can be flexibly tuned compared to the cavity without offset alignment.