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Adsorption characteristic of supercritical CO2 on coal directly determines the CO2 geological storage capacity. Through volumetric method, this paper analyzed the manifestation effects of different models on the experimental data of various ranked coals and activated carbon. The results indicate that the variation rate of gaseous CO2 density reaches the peak around 8 MPa. Introduction of parameter k could improve the fitting quality and trap various experimental errors. The adsorption mechanism of coal samples from Tiefa and Wolonghu is micropore filling. As coal samples of Yaojie is collected from a CO2 -rich reservoir, the alteration effect by experimental CO2 adsorption is unobvious and its micropores develop quite well, thus the greatest absolute adsorption is higher than other samples. When the gas density increases gradually, the gap between excess adsorption and absolute adsorption widens, and the absolute adsorption determines the adsorption capacity of the coal samples. The fitting CO2 adsorbed phase density of the activated carbon by OK model is 1.004 g/cm3.

In order to effectively reduce the gas content of coal seam, realize the efficient utilization of gas resources and reduce the difficulty of underground gas management, combined with the geological characteristics of Shoushan I mine site, we built a surface well zoning gas extraction technology, aiming to realize the systemization of gas management in the mine area. Based on the spatial and temporal distribution characteristics of mining activities, the mine field was divided into unmined area, mined area and vacant area, and different surface wells were established for gas extraction in zoning, so as to realize the change from gas management to gas utilization. The systematic gas management technology includes four parts: scientific arrangement of surface wells, well structure and construction design, reservoir fracturing and permeability enhancement in unmined area, and drainage and gathering engineering. The selection of surface well locations is based on the spatial stratification, coal seam characteristics, surface location, coal seam recovery and gas storage conditions. In the mining area, based on the height of the collapse zone and fissure zone after coal seam retrieval, the straight wells and L-type wells in the mining area were designed to be located in the middle and upper part of the fissure zone, so that the gas can be extracted efficiently from multiple coal seams in the area with the effect of pressure relief of this coal seam retrieval. The L-shaped well body in the unmined area, the straight well body in the mined area, the L-shaped well body in the mined area and the straight well body in the mined area were designed. Hydraulic fracturing of the coal seam in the unmined area to achieve coal seam penetration increase, the composite fracturing process of directional injection & pumped bridge plug type light casing fracturing was selected to fracture the coal seam, deep penetration reinforcing bullet was used for injection operation, and 20/40 mesh quartz sand was used as proppant. In Shoushan No.1 Mine, the engineering practice of surface well zoned gas extraction technology was carried out, and the statistics of gas extraction from different types of surface wells in the mine area showed that: the maximum daily gas production from a single well in the mining area can exceed 40 000 m3, and the accumulated gas extraction from a single well is up to 2 597 000 m3, and 11 wells are currently being drilled for extraction in the well field area, with an accumulated extraction of up to 14 252 000 m3. Field effect test showed that the implementation of surface wells zoned gas extraction technology can achieve efficient gas extraction, forming a gas management model of “mining one layer to treat multiple layers”.

In order to solve the problem of gas overrun and low utilization rate caused by mining pressure relief gas pouring into mining working space in high gas outburst coal seam, this paper used numerical simulation and field application methods to study the efficient extraction of coal gas in front of the working face under the influence of dynamic pressure. The results show that according to the gas concentration monitoring data on site, the coal body in front of the working area was divided into high efficiency extraction zone, effective extraction zone and original extraction zone. The efficient extraction zone was within 20 m in front of the working face, with an average gas extraction concentration of 30% or more. Gas extraction in the effective extraction zone was affected by the dynamic pressure, and the extraction concentration decreased fluctuatingly with increasing distance from the working face. The range of the original extraction area is 50-60 m away, and the gas concentration of the borehole was stable below 10%, which was less influenced by the mining movement. The second extraction technology of dynamic pressure gas in the floor gas extraction roadway of high gas outburst coal seam through the crossing boreholes was better applied in the middle extraction roadway of 12110 working face, the number of extraction holes in the dynamic pressure area was 5%-10% of that in the non-dynamic pressure area, but the monthly extraction volume could reach up to 74.01% of the monthly extraction volume inthe non-dynamic pressure area.

The output of wind and solar power stations is intermittent and fluctuating,but their complementarity can be fully realized with reasonable wind-solar capacity ratio. The inaccurate theoretical power calculation of power station affects the extraction of true features of wind and solar,and then leads to large capacity matching error. The model-generator method commonly used in theoretical power calculation of new energy power stations is improved in this study. The abnormal data are firstly identified and reconstructed,and then the abnormal model-generators are identified and updated. Furthermore,according to the actual operation of non-model-generators,the dynamic information window is selected. By using the measured power of model-generator and non-model-generator in the dynamic information window,the non-model-generators are grouped and the scale coefficient of each group of non-model-generator is dynamically identified,and thus the theoretical power of new energy power stations is calculated. Based on the calculation of historical theoretical power for many years,the characteristics of new energy power stations are analyzed. The random output scenario is simulated accordingly,and the optimization method of wind-solar capacity ratio based on the risk of source-load mismatching is established. The accuracy of the improved model-generator method is verified by examples. By using this method,the improved theoretical power data of wind farm and photovoltaic power stations in a certain area of northwest China are obtained,and the optimal ratio of wind-solar capacity in this area is optimized. The improved model machine method proposed in this paper can effectively improve the calculation accuracy of theoretical power of new energy power stations,and the optimal ratio of wind-solar capacity calculated based on this method can provide reference for wind-solar power generation capacity of regional power grid.

Rationale: A novel laser ablation‐isotope ratio mass spectrometry (LA‐IRMS) method for in situ analysis of sulfur isotopes in sulfides has been developed. Instead of the in situ reaction applied by the traditional laser microprobe, the analyte gas preparation in this method is separated temporally and spatially from the LA, resulting in improved precision and accuracy. Methods: Our LA‐IRMS system combines an ultraviolet LA system, an elemental analyzer (EA), a custom‐built cryogenic concentration system, a continuous‐flow interface, and an IRMS. The sulfide aerosol particles generated from LA were transferred by a helium carrier gas from the ablation cell into the reaction tube and were then converted into SO2. Subsequently, SO2 was enriched in two cold traps and was finally introduced into the ion source of the IRMS through the continuous‐flow interface. Results: We measured three synthetic and four natural sulfide reference materials to test the performance of this method. Precisions of ±0.25‰–±0.48‰ and ±0.32‰–±0.64‰ (1SD, n = 5) for δ34S values of synthetic and natural sulfide standards can be obtained for spot sizes ranging from 64 to 80 μm. Measured values and their recommended values showed a good linear relationship (R2 within 0.998 and 0.9995) with the slope of approaching unity (within 1.0509 and 1.1313). Conclusions: Data from the measurement of reference materials showed that the precision and accuracy of our method were satisfactory. This method is a powerful tool for in situ sulfur isotope measurement of sulfides and can be further applied to in situ carbon and oxygen isotope analyses. [ABSTRACT FROM AUTHOR]

Affected by geology and mining, a certain number of low-yield wells will appear after a period of production in coalbed methane wells, and technical repairs are urgently needed to restore their production capacity to the maximum. Therefore, it is of great significance to establish a reasonable and feasible theoretical standard to evaluate the workover priority of CBM wells for the efficient utilization of CBM resources. From the perspectives of technical feasibility and economic rationality, eight key indicators that affect the cost performance of CBM well workover are screened. Combining the entropy value method and the TOPSIS comprehensive ranking method, the surface coalbed methane well repair priority entropy value-TOPSIS comprehensive evaluation model was constructed, and the surface coalbed methane well repair priority evaluation was carried out by taking 9 surface coalbed methane wells that urgently needed to be repaired in a mine as the evaluation objects. The evaluation results show that among the economic indicators, the average gas production per meter in the 30 days before the coal bed methane well was stopped and the cumulative gas production per meter before the stop had a relatively high weight, which were 29.68% and 13.83% respectively, This shows that in coalbed methane well workover operations, the long-term gas production potential of the coalbed methane well and the gas production capacity when disturbed by harmful factors are the decisive factors affecting the priority of coalbed methane well workover; Among the technical indicators, the degree of casing deformation and the depth of the coalbed methane well have a relatively high weight, accounting for 11.34% and 9.90% respectively, This shows that the smaller the deformation of the wellbore casing and the shallower the depth of the coalbed methane well, the higher the priority of the workover of the coalbed methane well; The ranking of the production recovery rates of the three coalbed methane wells in the Pingdingshan mining area after workover operations is consistent with the results output by the evaluation model, which proves that the evaluation model is reasonable for determining the priority of workovers for damaged wellbores; This evaluation model can provide a theoretical reference for small and medium-sized coalbed methane development companies to determine the priority of workovers. [ABSTRACT FROM AUTHOR]

Somatic cell nuclear transfer (SCNT) can reprogram differentiated somatic cells into totipotency. Although pre-implantation development of SCNT embryos has greatly improved, most SCNT blastocysts are still arrested at the peri-implantation stage, and the underlying mechanism remains elusive. Here, we develop a 3D in vitro culture system for SCNT peri-implantation embryos and discover that persistent Wnt signals block the naïve-to-primed pluripotency transition of epiblasts with aberrant H3K27me3 occupancy, which in turn leads to defects in epiblast transformation events and subsequent implantation failure. Strikingly, manipulating Wnt signals can attenuate the pluripotency transition and H3K27me3 deposition defects in epiblasts and achieve up to a 9-fold increase in cloning efficiency. Finally, single-cell RNA-seq analysis reveals that Wnt inhibition markedly enhances the lineage developmental trajectories of SCNT blastocysts during peri-implantation development. Overall, these findings reveal diminished potentials of SCNT blastocysts for lineage specification and validate a critical peri-implantation barrier for SCNT embryos. [ABSTRACT FROM AUTHOR]

Porphyry Mo deposits are the most important type of Mo resource. They result from a high oxygen fugacity of the parent magma, which acts as an effective indicator for evaluating the mineralization. In the ore-forming system of porphyry Mo deposits, sulfur exists mainly as sulfate in highly oxidized magma but as sulfide in ores. What triggers the reduction in the mineralization system that leads to sulfide precipitation has not yet been determined. Most of the previous studies have focused on the origin and evolution of the ore-forming parent magma, and the effects of reductive surrounding rocks on porphyry mineralization have been ignored. In this study, a comprehensive geological–geochemical investigation and review have been performed on the typical porphyry Mo deposits, the Nannihu-Sandaozhuang, Yuchiling, and Shapingou deposits in China, and the Mt. Emmons deposits in America. Black carbonaceous sedimentary layers commonly surround porphyry Mo ores, which are widely altered and discolored during mineralization. CH4 is commonly present in fluid inclusions in the main mineralization stage, and the δ13CV-PDB values of calcite and fluid inclusions from the altered surrounding rocks and ore minerals are generally low and significantly different from those of marine sedimentary carbonate rocks, indicating that the involvement of reductive components from carbonaceous surrounding rocks might be key to the redox state transformation leading to mineral precipitation. On the other hand, the CH4 produced by the thermal decomposition of organic matter or carbonaceous reaction with H2O can diffuse into the ore-forming system along the structural fractures and reduce the SO42− in the ore-forming hydrothermal fluids to form sulfide precipitation without direct contact between the intrusion and the carbonaceous surrounding rocks. Moreover, the CH4 content controls the location of the orebody formation with the high content producing orebodies mainly in the porphyry intrusion, while the low CH4 content results in the orebodies mainly occurring at the contact zone between the porphyry and carbonaceous surrounding rocks. Compared to the magmatic stage of mineralization, the involvement of reductive components in the carbonaceous surrounding rocks during the hydrothermal stage is more favorable for forming giant/large Mo deposits. The highly oxidized porphyry with reductive carbonaceous surrounding rocks or Fe-rich volcanic rocks offers a new indicator for efficiently evaluating porphyry Mo mineralization. [ABSTRACT FROM AUTHOR]

Self-organized blastoids from extended pluripotent stem (EPS) cells possess enormous potential for investigating postimplantation embryo development and related diseases. However, the limited ability of postimplantation development of EPS-blastoids hinders its further application. In this study, single-cell transcriptomic analysis indicated that the "trophectoderm (TE)-like structure" of EPS-blastoids was primarily composed of primitive endoderm (PrE)-related cells instead of TE-related cells. We further identified PrE-like cells in EPS cell culture that contribute to the blastoid formation with TE-like structure. Inhibition of PrE cell differentiation by inhibiting MEK signaling or knockout of Gata6 in EPS cells markedly suppressed EPS-blastoid formation. Furthermore, we demonstrated that blastocyst-like structures reconstituted by combining the EPS-derived bilineage embryo-like structure (BLES) with either tetraploid embryos or tetraploid TE cells could implant normally and develop into live fetuses. In summary, our study reveals that TE improvement is critical for constructing a functional embryo using stem cells in vitro. [ABSTRACT FROM AUTHOR]

The traditional method for sulfur isotope measurement using EA‐IRMS commonly requires sulfur content greater than 2 μmol. Such a large sample size limits its application to low‐S materials, the size mainly being due to ineffective utilization of sample gas, almost 99.7% of which is discarded with carrier gas through the split port of the continuous‐flow interface. A modified EA‐IRMS system with a gas chromatographic (GC) column and a custom‐built cryogenic concentration device is used in this study. We measured six reference materials to test the performance of this method. The results were consistent with those obtained through traditional EA‐IRMS. Precisions ranging from ±0.24‰ to ±0.76‰ (1σ) can be obtained with samples equivalent to ∼80 nmol sulfur, which were similar to results obtained from an alternative method using an absorption column. Our improved method is a powerful tool for sulfur isotope measurement in ultrasmall sulfide and sulfate samples, which can be further applied to carbon, nitrogen and oxygen isotope analyses of samples at about 100 nmol level. [ABSTRACT FROM AUTHOR]

Insulin-like androgenic gland factor (IAG) plays an important role in sex manipulation in decapods. Understanding the molecular regulation mechanism of IAG in Procambarus clarkii (PcIAG) is important for realizing its sex control. In this study, the promoter and gene structure of PcIAG, mRNA, and miRNA expression profiles after interfering with two siRNAs synthesized according to the two short repeats in the 5′ untranslated regions (5′UTR) of PcIAG were analyzed, and miRNAs of exosomes were investigated to explore the role of repeated sequences with tandem two short repeats located in the 5′UTR of PcIAG isolated from the androgenic gland (AG) in the regulation of IAG expression. The results showed that the repeated sequences of 5′UTR only occurred completely in the cDNA from AG, and the function of the two repeats was different in regulating the expression of PcIAG, in which the Wnt signaling pathway may be involved. Furthermore, we found that six miRNAs including miR-133, miR-193, miR-34, miR-1, miR-100, and let-7 might be involved in the regulation of the expression of PcIAG, wherein miR-133 might directly be related with the repeated sequences of 5′UTR. [ABSTRACT FROM AUTHOR]

As an important part of the northern Huaiyang tectonic belt, the Mesozoic Xiaotian basin hosts a series of gold and alunite deposits. However, the ages of these deposits remain unclear, constraining the further understanding of the genesis of these deposits. In this work, zircon LA–ICP-MS and alunite 39Ar/40Ar isotopic dating studies were carried out on the andesitic porphyrite and alunite of the Saozhouhe alunite deposit, respectively. LA–ICP-MS zircon U–Pb dating for the Saozhouhe andesitic porphyrite yields a weighted average age of 122.8 ± 0.9 Ma (MSWD = 1.8), indicating that these volcanic rocks were formed in the Early Cretaceous period. The alunite 39Ar/40Ar dating yields a plateau age of 121.0 ± 1.1 Ma (MSWD = 4.4) and an isochron age of 121.2 ±1.9 Ma (MSWD = 8.5), indicating that the alunite was also formed in the Early Cretaceous period. Our finding confirms that the formation of the Saozhouhe alunite deposit is genetically related to the Cretaceous volcanic magmatism, which has great significance in the metallogenetic regularity of and further ore prospecting in the Xiaotian basin. [ABSTRACT FROM AUTHOR]