Traditional mining right evaluation method---DCF is widely used in projects with short period, low-level-risk, low-uncertain factors. But mining industry has characteristics such as large-scale investment, long period to recover, complicated technology and high-level risks. Method of DCF often underestimates the real values of mining investment project. It is better to use real options method in the investment and economic evaluation of mining projects with high-level risks and high- uncertain factors. As a new method of mining right evaluation, it changes people's traditional opinions to uncertain factors and make people no longer take the uncertain factors of a project as a negative factors. Instead of, the people pay more attention to research how to take the advantages of uncertain factors and get more profits. Real options method is introduced in practices of mining right evaluation, in fact it improves the traditional mining right evaluation method.
Based on the theory of energy dissipation, a numerical model of goaf excavation was established by FLAC3D based on the backflow channel of Heilong Coal Industry 2202. The dissipative energy distribution characteristics of coal pillars with different widths were studied, and the dissipative energy evolution law of surrounding rock of goaf roadway was analyzed. With the increase of the width of coal pillar, the width of elastic core zone is positively correlated with the bearing capacity. The peak value of dissipated energy density decreases with the increase of the width of coal pillar, and the concentration degree and region of dissipated energy density on the side of coal pillar are greater than that on the side of solid coal pillar. The project is applied to Heilong 2201 working face, and the optimum width of coal pillar and its supporting scheme are given. The practice results show that when the width of coal pillar is 5m, the deformation of surrounding rock can be effectively controlled and the demand for safe and efficient production can be met.
Rear-end collisions frequently occurred in the entrance zone of expressway tunnel, necessitating enhanced traffic safety through speed guidance. However, existing speed optimization models mainly focus on urban signal-controlled intersections or expressway weaving zones, neglecting research on speed optimization in expressway tunnel entrances. This paper addresses this gap by proposing a framework for a speed guidance model in the entrance zone of expressway tunnels under a mixed traffic environment, comprising both Connected and Autonomous Vehicles (CAVs) and Human-driven Vehicles (HVs). Firstly, a CAV speed optimization model is established based on a shooting heuristic algorithm. The model targets the minimization of the weighted sum of the speed difference between adjacent vehicles and the time taken to reach the tunnel entrance. The model's constraints incorporate safe following distances, speed, and acceleration limits. For HVs, speed trajectories are determined using the Intelligent Driver Model (IDM). The CAV speed optimization model, represented as a mixed-integer nonlinear optimization problem, is solved using A Mathematical Programming Language (AMPL) and the BONMIN solver. Safety performance is evaluated using Time-to-Collision (TTC) and speed standard deviation (SD) metrics. Case study results show a significant decrease in SD as the CAV penetration rate increases, with a 58.38% reduction from 0% to 100%. The impact on SD and mean TTC is most pronounced when the CAV penetration rate is between 0% and 40%, compared to rates above 40%. The minimum TTC values at different CAV penetration rates consistently exceed the safety threshold TTC*, confirming the effectiveness of the proposed control method in enhanced safety. Sensitivity analysis further supports these findings.
Non-destructive measurements of low-intensity charged particle beams are particularly challenging for beam diagnostics. At the Heavy Ion Accelerator Facility in Lanzhou (HIRFL), beams with weak currents below 1 µA are often provided for experiments. The detection of such low beam current is below the threshold of typical standard beam current transformers. Therefore, a low-intensity monitoring system is developed by using a sensitive capacitive pick-up (PU) and low-noise electronics. This device measures beam currents by digitally analyzing the amplitude of the PU signals using a homodyne detection scheme. During lab tests, the amplitude nonlinearity is <0.5% in the operational range of 1 nA–45 µA and the amplitude resolution is 0.94 nA. At present, four measurement systems for low beam currents are installed at HIRFL for the monitoring of standard operating conditions with low beam currents below 1 µA. After an absolute calibration with a Faraday cup, it can be used for accurate beam intensity measurement with a current resolution of about 1 nA.
An empirical study of the listed companies in mining industries shows that: R D expenditure growth of extractive industries has a significant positive impact on the growth of the company.Therefore,the minging industry companies should focus on R D activities,increase its investment,employ more high-level compound talents,and especially improve the relevance and practicality of R D activities,in order to better promote the company's technology and product innovation,which enable the company to stand out in the fierce market competition and global competition and achieve sustainable development.
Enhancers are cis-regulatory DNA elements that positively regulate the transcription of target genes in a tissue-specific manner and dysregulation in various diseases such as cancer. Recent studies showed that enhancers can regulate miRNAs and participate in the biological synthesis of miRNAs. However, the network of enhancer-regulated miRNAs across multiple cancers is still unclear. Here, a total of 2,418 proximal enhancer-miRNA interactions and 1,280 distal enhancer-miRNA interactions were identified through the integration of genomic distance, co-expression, and 3D genome data in 31 cancers. The results showed that both proximal and distal interactions exhibited significant tissue-specific feature trend at the tissue level rather than at the single-cell level, and there was a noteworthy positive correlation between the expression of miRNA and the number of regulated enhancers in most tissues. Furthermore, it was found that there was a high correlation between the formation of enhancer-miRNA pairs and the expression of eRNAs whether in distal or proximal regulation. The characteristics analysis showed that miRes (enhancers that regulated miRNAs) and non-miRes presented significant differences in sequence conservation, GC content and histone modification signatures. Notably, GC content, H3K4me1, H3K36me3 were presented differently between distal regulation and proximal regulation, suggesting they might participate in chromosome looping of enhancer-miRNA interactions. Finally, we introduced a case study, enhancer: chr1:1186391-1186507~miR-200a was highly relevant to the survival of thyroid cancer patients and a cis-eQTL SNP on enhancer affected the expression TNFRSF18 gene as a tumor suppressor.
Responsiveness to opioid analgesics differs among patients with acute postoperative pain.Our study presents the most recent evidence on the effect of genetic variations on postoperative pain, opioid consumption, nausea, and vomiting in patients treated with opioids.An updated systematic review and meta-analysis on the association between single-nucleotide polymorphisms and opioids administered to patients with acute postoperative pain.PubMed, Embase, ISI Web of Science, and the Cochrane Library databases were searched for articles published from February 1, 2014, through December 31, 2021.Added to the previous meta-analysis, 39 studies (a total of 7,455 patients) were included in the final meta-analysis. Highlights of the findings include: 1) human μ-opioid receptor gene 118G allele carriers required more opioids during the first postoperative 24 hours (standard mean difference [SMD] = -0.27; 95% CI,-0.40 to -0.14; P < 0.0001) and 48 hours (SMD = -0.52; 95% CI, -0.83 to -0.20; P = 0.001), and reported higher pain scores during the first 24 hours but not at the 48-hour postoperative period (SMD = -0.09, 95% CI, -0.15 to -0.03; P = 0.002) compared to homozygous 118AA patients. 2) patients with the CYP3A4 *1G allele required fewer opioids during the first 24-hour postoperative period (SMD = 0.59; 95% CI, 0.05 to 1.14; P = 0.03) compared to patients with the homozygous CYP3A4*1/*1 allele. 3) Adenosine triphosphate-binding cassette subfamily B member-1 (ABCB1) 3435T allele carriers required more opioids during the 48-hour postoperative period (SMD = -0.21; 95% CI, -0.38 to -0.04; P = 0.02) compared to homozygous CC carriers. 4) Catechol-O-methyl transferase 158A allele carriers required fewer opioids during the first 24-hour postoperative period (SMD = 0.33; 95% CI, 0.15 to 0.51; P = 0.0004) compared to homozygous GG carriers. No significant differences were observed in patients with CYP2D6*10 and ABCB1 G2677A/T genetic polymorphisms.Several loci were not analyzed in detail due to insufficient clinical data. Furthermore, nongenetic factors that affected analgesic efficacy and the clinical outcome of postoperative pain were not discussed and were not the aim of this meta-analysis.In combination with previous systematic reviews and meta-analyses, our results indicate that the A118G allele variant of OPRM1 and the *1*1G allele variant of CYP3A4 have a profound influence on individual differences in opioid reactivity in patients with postoperative pain. Our results, together with the identification of additional single nucleotide polymorphisms in future studies, may provide a theoretical basis for precise clinical analgesia.Single nucleotide polymorphism, postoperative pain, opioid, meta-analysis.
This paper assesses the allocation and cost efficiency of Scientific Technological Innovation(STI) between the Eastern and Western regions during 2001-2008 by using input-oriented DEA cost.Results show that the average technical efficiency,allocation efficiency and cost efficiency for eastern region is higher than that of western region.Optimizing the structure of input and collaborative innovation will help improve the allocation efficiency,innovation capabilities for both regions.
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