CO₂ is the main component of non-condensable gas in high-temperature geothermal fluid and its existence still have important impact on geothermal development. Determining its content in high-temperature geothermal fluid is of great significance for geothermal development. The conventional sampling and testing analysis of CO₂ content determination has some drawbacks, such as insufficient sampling representativeness，cumbersome implementation process and high sampling cost. Based on the pressure-temperature measurement in the wellbore during discharge tests and two-phase flow calculation, this paper proposed a new method to determine CO₂ content in the geothermal reservoirs. This method only uses a large number of relatively reliable measured data of temperature and pressure, it has low cost, strong practicability and good reliability. This paper first describes the pressure-temperature measurement during discharge tests. Then constructs a model that solves the two-phase flow in the geothermal wellbore, which was verified by comparison with the commercial software WELLSIM, and determine CO₂ content by using both the wellbore pressure-temperature measurement and model calculation data. Finally, the method was tested and verified by using the measured data from Gulu geothermal field in Tibet and the Ziledaer geothermal field in Turkey, and the CO₂ contents in the geothermal reservoir were determined to be 1.1 % and 3.2 % respectively.

To address the applicability challenges of geophysical water exploration methods in the Carboniferous Huangjin formation of carbonaceous-argillaceous limestone characterized by uneven development of dissolution fissure，complex hydraulic connectivity of argillaceous shale interlayers，concealed groundwater occurrence conditions，scant water resources，and improve the success rate of water well drilling, This paper adopts high-density resistivity and Audio-frequency Magnetotelluric Sounding (AMT) methods to detect low-resistivity anomalies in an area of Shaoshui town，Guilin. By applying the induced polarization (IP) secondary time difference method to analyze and delineate water-induced anomalies within these low-resistivity zones. the spatial distribution and occurrence characteristics of groundwater were identified. Results indicate that the AB/2 positions characterized by low-resistivity anomalies，positive induced polarization secondary time difference values with good continuity correspond to the actual aquifer locations. Meanwhile，areas with single-point values or values below 50 ms and poor continuity exhibit low water-bearing capacity.

Dalishu uranium deposit is a carbonate rock type uranium deposit located at the Lukan fault hanging wall in the southeast limb of Xiongwu anticline. Researches on this uranium deposits are still seldom reported. Based on the field geological survey and collection of uranium ore samples in trenches and boreholes, this paper conducted a study on mineralogy，geochemistry，and genesis of the deposit. The study show that the ore body is controlled by the northeast-trending faults and the secondary Si-Ca structural planes and closely related to organic matters. The main uranium minerals in the ore are pitchblende and uraninite，and the uraninite minerals,which are closely associated with pyrite and “black”organic matters. The trace elements such as V，Cr，Co，Ni，Cu，Zn，and Mo are enriched in the ore and the wall rocks.The rare earth element distribution pattern is“right-inclined” with the enrichment of LREE and negative δEu anomaly，indicating a certain genetic relationship with the Cambrian black rock series. It believed that the ore-forming materials maybe come from the Cambrian Niutitang and Laoba formation，the deposit was formed by deep hydrothermal action which extracted the uranium from the Cambrian basement ore-forming materials and carried to favorable areas under the orogenic background of Himalayan period.

The southern section of Zone No. 9 in Mianhuakeng deposit is located in the middle of the Zhuguang pluton,which is a rich in uranium. The fault zone has undergone multiple tectonic and hydrothermal action ，forming the favorable space for uranium mineralization and storage. Through secondary development and utilization of data from previous exploration projects，this paper analyzes the change patterns of the ore bodies at different elevations in the southern section of Zone 9 by the statistics on grade and thickness. The results indicate that the ore body trend to be rich in the depth but remain stable in thickness on the whole with local widening. The occurring frequency of moderate and high-grade ore segments are increasing in the deep, which may be caused by the reduction environment in the deep. This understanding provides clues and basis for the next uranium predicting and prospecting.

To accurately measure the oxidation-reduction potential of uranium ore geological samples, this study try to explore a better measurement method and experimental conditions by comparing and analyzing the application effects of the acidic potassium dichromate method and the alkaline potassium permanganate method in the measurement of the oxidation-reduction potential of uranium ore geological samples. The potential drop method was used to systematically conduct a multi-dimensional comparison between the acidic potassium dichromate method and the alkaline potassium permanganate method. The aspects of comparison included solution stability, optimal solution concentration, sample soaking time，solid - liquid ratio, and electrode equilibrium time. The sample soaking time and electrode equilibrium time of the alkaline potassium permanganate method are shorter than those of the acidic potassium dichromate method, allowing it to reach a stable and reliable potential value more quickly. For strongly reducing samples，the ΔEh value obtained by the acidic potassium dichromate method is larger. However, the evaluation conclusions of the two methods regarding the reduction ability of the samples are consistent. Nevertheless, the precision of the alkaline potassium permanganate method is better.The optimal experimental conditions for the alkaline potassium permanganate method are as follows: a concentration of 0.03 mol∙L^-1, a sample soaking time of 1.5 h，a solid-liquid ratio of 1:25, an electrode equilibrium time of 5 min, a reaction medium of 0.2 % potassium hydroxide solution, and a temperature of (25±1) °C. The ΔEh value measured by this method is basically consistent with the judgment results of the oxidation - reduction environment by the oxidation coefficient method (Fe²⁺/Fe³⁺), and is also basically consistent with the color of the samples.Based on comprehensive experimental indicators, the overall performance of the alkaline potassium permanganate method is superior to that of the acidic potassium dichromate method in the measurement of the oxidation - reduction potential of uranium ore geological samples. By adopting the optimal experimental conditions, the accurate measurement of the oxidation - reduction potential of uranium geological samples is achieved, providing reliable technical support for uranium ore geological research.

High-quality field seismic data are fundamental to the refined processing of seismic signals and the accurate interpretation of geological information. A scientifically designed observation system is essential to ensure data quality and imaging effectiveness. In complex geological settings，traditional acquisition systems are prone to insufficient energy coverage and imaging shadow zones，which hinder the identification of reflection signals and the detailed delineation of target structures. To enhance seismic imaging performance under such conditions，this study conducts a systematic investigation into acquisition parameter optimization for observation systems in structurally complex areas，based on an illumination analysis approach using the one-way wave equation. Forward illumination analysis is first employed to optimize the layout of sources and receivers, thereby improving energy coverage over target horizons. Subsequently，reverse illumination analysis is used to refine shot point densification，receiver array length，and channel spacing，aiming to enhance energy acquisition and wavefield coverage. A two-dimensional geological model is constructed，and forward modeling is performed to quantitatively compare the illumination energy distribution before and after optimization，leading to the determination of acquisition parameters that meet imaging requirements. Results show that the optimized observation system effectively reduces imaging shadows in complex structural zones，improves profile continuity and reflection energy response，and exhibits strong adaptability and engineering feasibility. The proposed optimization workflow has been applied and validated in an actual survey area，demonstrating consistent improvements in imaging performance. This work confirmed the practical value of illumination-based analysis in the acquisition design for complex geological conditions and established a parameter configuration methodology suitable for fault-intensive zones and sand body development areas，which will provide a replicable design reference and technical path for future seismic exploration.

The rock fragmentation mechanism of worn disc cutters provides theoretical guidance for TBM cutter changing. To investigate the correlation between cutter force and penetration depth，evaluate rock fragmentation efficiency，and elucidate the fragmentation mechanism of single worn cutter in extremely hard rock conditions，different blade widths were utilized to represent different wear levels. This study employed sequential indentation tests using both a new cutter with blade width of 17 mm and worn cutters with different blade widths on Beishan granite specimens with dimension of 420 mm×400 mm×500 mm. The penetration process，force characteristics，rock fragmentation volume，and specific energy were systematically analyzed. The key findings include：1）Both new and worn cutters exhibited consistent rock failure phases - initial compaction followed by linear deformation，with intermittent force drops during single penetration, 2）During sequential penetrations with the same depth for the new cutter，both the maximum penetration force and the force growth rate in linear-deformation stage demonstrated an initial increase then decrease, 3）Worn cutters with larger blade widths required higher average force per unit penetration depth. For each kind of worn cutter，the force-depth ratio of each penetration showed fluctuating tendency during the whole sequential penetration process，confirming the cyclic process of energy accumulation，release and then re-accumulation, 4）Specific energy increased linearly with blade width while the penetration capability decreased correspondingly. The 18 mm-blade cutter exhibited optimal rock fragmentation efficiency and penetration performance in sequential penetration.

Microwave plasma torch（MPT）is a new type of plasma excitation source developed by domestic research team. It is a soft ionization technology with atmospheric ionization characteristics and is mostly used for the analysis of organic matter. Compared with inductively coupled plasma（ICP）ionization sources，MPT has low ionization energy and is difficult to ionize the tested elements into metal ions，which limits its application in inorganic detection. In order to broaden the application range of MPT source，linear ion trap mass spectrometry（LTQ-MS）was used to establish a quantitative analysis method for zirconium，which was applied to environmental monitoring. The zirconium solution was introduced into the MPT-LTQ-MS experimental device，and the aerosol was produced by pneumatic atomization. After drying by concentrated sulfuric acid，the dried aerosol formed anions in the plasma flame generated by the microwave plasma moment，and was detected by LTQ-MS in the negative ion mode. The experimental results show that part of the excited zirconium ion can basically be confirmed to exist in the form of [ZrO(NO₃)₃]^-. This composite anion can be used as the characteristic signal to detect zirconium in water samples，and can be quantitatively analyzed by the characteristic spectral peak of multi-stage mass spectrometry. The characteristic signal of m/z 292 （⁹⁰Zr）showed a good linear correlation with the concentration of zirconium in the concentration range of 5~100 μg·L^-1(R²=0.998 8). The limit of detection (LOD) of the method was 2.6 μg·L^-1，and the precision (RSD) was better than 8.9 %. The content of zirconia in surface water was determined by MPT-LTQ-MS，ranging from 0.34 to 3.22 μg·L^-1，and the recovery of standard addition was 94 % to 105 %. The results show that MPT-LTQ-MS can be used as a simple method for the determination of zirconium，and can be used in environmental monitoring and drinking water testing.

Hyperspectral remote sensing technology has been widely used in many fields due to its high spectral resolution and rich spectral information. Object classification is one of the key techniques to fully use the hyperspectral data. Based on the investigation and summary of the research status of hyperspectral image classification technology，experiments were conducted in the mining area north of Jinchang，Gansu province. A comparative analysis was mainly carried out from two aspects：supervised classification and unsupervised classification. Taking the spectral Angle method as an example，the key factors affecting the classification performance of different methods were deeply discussed. The results show that the accuracy of supervised classification method is better than that of unsupervised classification for the areas with insufficient spatial characteristics like the experimental area, in which the Maximum Likelihood Classification is the best, and it also proves that unsupervised classification is not suitable for mineral classification in the similar areas.

To meet the requirements of thermoionization mass spectrometry (TIMS) for the determination of low-abundance isotopes，it is necessary to configure a secondary electron multiplier (SEM) or Daly detector ion counting detector on the TIMS. Compared to SEM，Daly offers high gain，low noise， good linearity，long service life, and the photomultiplier tube is located outside the instrument’s vacuum system and easy to replace，making it more cost-effective. The authors developed Daly detector consists of a detection chamber，an ion conversion pole，a plastic scintillator，a fast-response photomultiplier tube，a preamplifier，a single-photon counter，a power supply，and the measurement and control software. The response gating of the Daly detector can be adjusted between 0.1~2 V，the photomultiplier tube has a high voltage of 800~900 V，the ion counting background is less than 0.1 cps，and the highest count rate is 40 Mcps. In this paper，the performance of the Daly detector was verified by uranium isotope composition determination, and the results showed that the intra-test precision of Daly for the CRM0002 isotope abundance of ²³⁵U/²³⁸U was 0.073 %，and the intra-test precision of the isotope abundance of UTB500 was 0.139 %，0.056 % and 0.214 % respectively for ²³⁴U /²³⁸U，²³⁵U /²³⁸U and ²³⁶U /²³⁸U，which met the requirements of ASTM C1625—19.