红外探测器组件中一定尺寸大小多余物的存在,容易造成探测器服役状态下其光路中产生衍射现象,并改变焦平面局部光场分布,导致像面上形成"黑斑"或"泊松亮斑"。为了减少此类异常图像的出现,根据菲涅耳衍射原理,计算了几种典型探测器组件内不同位置处的多余物颗粒满足衍射斑形成条件时的尺寸范围,并分析了多余物尺寸、杜瓦结构、波长以及衍射斑之间的关系,结果表明,波长越长、多余物距离焦平面越近,越容易发生衍射;对于不同的探测器杜瓦组件,容易产生衍射的位置为距离焦平面距离L C的区域。此外结合生产实践提出了控制多余物的相应措施,研究结果对于红外探测器组件的设计和工程应用具有一定指导意义。

The deep resources of the gold mines have great potential to be the leading area of the national gold industry. However, with the increase of mining depth in Jiaojia gold mine of Shandong province, China, the overburden stress is increasing, the spatial and temporal distribution of mining stress field is more complex to cause spatial structure of overlying strata seriously damaged, which often leads to mine water disaster. Therefore, the research on the law of surrounding rock stress and water-conducting fractured zone development has become an important topic for safe mining of gold mines. In this paper, based on the analysis of borehole data and profile map, three-dimensional geological model was established to predict the height of the water-conducting fracture zone by using Sufer17, Rhino 6, Griddle plug-in and FLAC3D software, and the mining process with the method of downward horizontal slice stoping-filling was simulated by using constitutive model. Results show that the maximum height of the water-conducting fractured zone is about 21.2 m during the whole mining at -700 level, the shape is from near horizontal to micro arch, the failure range of the plastic area near the fault is larger than that far away from the fault. The stress distribution on both sides of the fault is not continuous, which is larger in the hanging wall than that in the footwall. The stress concentration zone is formed in the front and back of the stope during mining process and increases with mining depth. This method can restore the original state of underground stress field to the greatest extent, and make up for the lack of empirical formula theory and the limitation of similar material method for deep mining, which is relatively more accurate and reliable.

The O-18/O-16 of lignin at bulk, molecular and positional levels can be used to extract valuable information about climate, plant growth environment, plant physiology, and plant metabolism. Access to the individual oxygen isotope compositions (delta O-18) in the lignin monomeric units is, however, challenging as depolymerization of lignin to release the monomeric units may cause isotope fractionation. We have developed a novel method to measure the delta O-18 of the three oxygens (O-3, O-4 and O-5) attached to the aromatic ring of the monomeric units (bearing no oxygen in their side chains) releasable by highly selective W2C/AC (tungsten carbide supported by activated carbon)-catalyzed hydrogenolysis of lignin. O-4 is obtained by measuring the delta O-18 of H-type monomeric unit, while O-3 and O-5 can be calculated following isotope mass balance between H, G and S-type monomeric units measurable simultaneously with GC/Py/IRMS (gas chromatography-pyrolysis-isotope ratio mass spectrometry). The measurement precisions are better than 1.15 mUr and 4.15 mUr at molecular and positional levels, respectively. It was shown that there were a delta O-18(H) > delta O-18(G) > delta O-18(S) isotopic order in the herbaceous plant lignin and an (inclusive) opposite order in woody plant lignin. Such differences in isotopic order is likely to be caused by the fact that both L-tyrosine, which carries an O-18-enriched leaf water signal, and L-phenylalanine, which carries mainly a molecular O-2 isotopic signal, serve as the precursors for lignin biosynthesis in herbaceous plants while only the latter serves as precursor for lignin biosynthesis in woody plants. We have highlighted the potential application of such molecular and positional levels isotopic signals in plant physiological, metabolic, lignin biosynthetic and climate studies. (C) 2021 Elsevier B.V. All rights reserved.

RationaleAlthough the 2H/1H ratio of the carbon‐bound hydrogens (C‐Hs) in α‐cellulose extracted from higher plants has long been used successfully for climate, environmental and metabolic studies, the assumption that bleaching with acidified NaClO2 to remove lignin before pure α‐cellulose can be obtained does not alter the 2H/1H ratio of α‐cellulose C‐Hs has nonetheless not been tested.MethodsFor reliable application of the 2H/1H ratio of α‐cellulose C‐H, we processed plant materials representing different phytochemistries and photosynthetic carbon assimilation modes in isotopically contrasting bleaching media (with an isotopic difference of 273 mUr). All the isotope ratios were measured by elemental analyzer/isotope ratio mass spectrometry (EA/IRMS).ResultsOur results show that H from the bleaching medium does appear in the final pure α‐cellulose product, although the isotopic alteration to the C‐H in α‐cellulose due to the incorporation of processing H from the medium is small if isotopically “natural” water is used to prepare the processing medium. However, under prolonged bleaching such an isotope effect can be significant, implying that standardizing the bleaching process is necessary for reliable 2H/1H measurement.ConclusionsThe currently adopted method for removing lignin for α‐cellulose extraction from higher plant materials with acidified NaClO2 bleaching is considered acceptable in terms of preserving the isotopic fidelity if isotopically “natural” water is used to prepare the bleaching solution.

Brain electrical activity in different spectral bands has been associated with diverse mechanisms underlying Brain function. Deeper reconnoitering of these mechanisms entails mapping in grayordinates (Gray Matter coordinates), the spectral features of electrophysiological Brain signals. Such mapping is possible through MEG/EEG signals, due to their wide Brain coverage and excellent temporal resolution in reflecting neural-electrical-activity. This process-coined Electrophysiological Source Imaging (ESI)-can only produce approximated images of Brain activity, which are severely distorted by leakage: a pervasive effect in almost any imaging technique. It has been proposed that leakage control to tolerable levels can be achived through using priors or regularization within ESI, but their implementation commonly yields meager statistical guaranties. We introduce bottom-up control of leakage: defined as maximum Bayesian evidence search braced with priors precisely on the spectral responses. This is feasible due to an instance of Bayesian learning of complex valued data: spectral Structured Sparse Bayesian Learning (sSSBL). “Spectral” refers to specific spatial topologies that are reflected by the MEG/EEG spectra. We also present a new validation benchmark based on the concurrency between high density MEG and its associated pseudo-EEG of lower density. This reveals that prevealing methods like eLORETA and LCMV can fall short of expectations whereas sSSBL exibits an exellent performance. A final qualitative assesment reveals that sSSBL can outline brain lessions using just low density EEG, according to the T2 MRI shine through of the affected areas.

Recent research has unearthed that blink rate variability (BRV) can be employed as a psychophysiological measure. However, its efficiency for mental state recognition (MSR) has not been investigated yet. Because BRV can indicate dynamics inherent in eye blinks, we conjectured that BRV might exhibit stronger abilities for the MSR if compared with blink rate (BR), known as the leading indicator derived from eye blinks for MSR. Therefore, in this paper, we attempted to differentiate between high and low cognitive loads of an individual through the analyses of BR and BRV, respectively, which could be viewed as a preliminary study for comparing their MSR abilities. First, an $n$ -back experiment was performed to collect data. Then, in order to characterize the phenomenon of BRV, the features were extracted from its time and frequency domains, respectively. Finally, the area under the curve (AUC) values of BRV and BR for MSR were estimated by the ten commonly used classifiers, respectively. The results indicated that BRV achieves significantly higher AUC values than BR, which suggests its strong potentiality for MSR. In sum, the BRV may prove to be a promising method for the MSR, which should be considered in the future.

North China–type coal field of deep coal seam mining in Shanxi formation often faces the threat of roof water inrush. In order to reduce or avoid the roof water disasters, on-site technical personnel usually carry out the release of roof water through the roadway drilling based on the electric prospecting data obtained before the working stope mining. In fact, it is difficult to effectively release roof water in sandstone aquifers before coal seam mining since the connectivity between roof aquifers is very poor. In order to solve this problem, taking Shandong Xinjulong Energy Co., LTD. the first mining face No. 1301N working stope as practice research background, we put forward to effectively release the roof water with roadway drilling according to the three-dimensional high-density resistivity method detection results during the process of working stope mining, because the roof strata can be destroyed under the action of ground pressure, which makes the hydraulic relationship between roof aquifers better. The results show that three-dimensional high-density resistivity method is reliable for roof water advanced detection during working stope mining, which can effectively guide the roof water in sandstone to be released through roadway drilling. Therefore, the safety mining of the first mining face No. 1301N working stope is ensured.

The dynamic evolution of mining-induced fractures in overlying strata caused by mining has non-ignorable effects on engineering safety and water loss from an overlying aquifer. To clarify the evolutionary patterns of fractures due to the first and periodic weighting induced by coal mining, W-shaped fracture arch models are developed to explain and prevent water leakage during the mining process. With the conceptual hypothesis of a lopsided W-shaped fracture arch that may or may not consider the subsequent consolidation process from caving of the overlying strata, this model shows the evolutionary process of the morphological tendency in fracture arches and characteristics in different directions. Mining-induced fractures are found to evolve in W-shaped mode and develop both upward and forward with the advance of the mining face. Based on these models, we can identify the best developed parts of the overall fracture evolution, which are the key fracture paths for water to leak after the closure phase of fractures. Combined with a creative simulation experiment on similar materials including two comparative mining models, the normal mining model and the model of prefabricated fracture arches, the dome-shaped morphological evolution of this conceptual model is reflected well in the range of 20~40 m away from the initial mining location. The present models may help settle conflicts related to the dynamic evolution of mining-induced fractures and the loss of water resources during the mining process.

Eucrites represent one of the major lithologies of the Vestan upper crust, which had experienced pervasive and intense thermal metamorphism. To better constrain the timing and mechanism of thermal metamorphism, we carried out in situ Pb-isotope analysis of an unbrecciated basaltic eucrite NWA 6594 on the basis of detailed mineralogical and petrographic investigations. Zircon Pb-Pb dating reveals that NWA 6594 emplaced before or at 4547 +/- 11 Ma (95% confidence, MSWD = 1.3). Studies of silica minerals indicate that NWA 6594 had experienced intense thermal metamorphism after emplacement, followed by a late impact reheating and rapid cooling. Apatite grains yield a weighted mean Pb-Pb age of 4523 +/- 2 Ma (95% confidence, MSWD = 0.76). This age could not be attributed to slow cooling after the initial crystallization, but most likely related to an independent thermal event that induced thermal metamorphism. The protracted time lag (~24 +/- 13 Myr) between zircon and apatite closure ages indicates that this thermal event is most probably induced by an intense impact event that was synchronous with the metal-silicate mixing event recorded by mesosiderites. HEDs may have experienced multiple stages of thermal metamorphism after emplacement. The late impact reheating occurred after thermal metamorphism, which caused crystallization of tridymite.

The Jiaojia Gold Mine area is located in the northeast of Shandong Province, Eastern China, and its hydrogeological and structural geological conditions are complex; consequently, the mining conditions are complicated. Based on the hydrogeological measured data of the Jiaojia Gold Mine area, we first analyzed its main aquifers, that is, the Quaternary pore aquifer and bedrock fracture aquifer, and the hydrogeological boundaries of the simulated area were defined. Then, after defining the boundary conditions, and generalizing the vertical structure of the aquifer, hydraulic properties of the fault zones and groundwater flow system, a conceptual numerical simulation model of the area was established using the groundwater modeling system (GMS). Finally, after space division, time discretization, setting of the initial values, partition of the hydrogeological parameters, disposal of the sources and sinks, we continuously adjusted the hydrogeological parameters to ensure that the fitting error of the long-time observation well was within the confidence interval. With these values, we used this model to study the groundwater flow field and predict the mine water inflow. Numerical simulation showed that the general direction of groundwater flow in the study area was from southeast to northwest towards the sea, and faults acted as barriers to groundwater runoff. The mine water inflow increased with increasing mining level, while the water inflow at similar mining levels tended to remain steady with increasing mining period; the seasonal variation in the water inflow was clear. A groundwater funnel was formed in the main gold mine area, in which the groundwater level would decline by 10–77 m; the funnel had a range of approximately 609–3255 m2. This model can determine the dynamic response mechanism of groundwater to multimine interferences in dewatering and drainage, which provides a foundation for mine water control and water resource evaluation.

The O-18/O-16 ratio at both molecular and positional levels in the carbohydrates of higher plants is a reliable proxy for the plant growth environment, and a potential indicator of the plant photosynthetic carbon assimilation mode, and its physiological, biochemical and metabolic status. The lack of exploitable nuclear resonance in O-18 and O-16 and the extremely low O-17 abundance make the NMR-based PSIA (position-specific isotopic analysis) a significant challenge. In this Article, an alternative three-step wet chemistry based method for accessing the O-18/O-16 of glucose O-3 is presented. The O atoms (OH groups) at positions 1, 2, 5, and 6 were first protected by acetonation (converting glucose to 1,2;5,6-di-O-isopropylidene-glucofuranose). The protected glucose was then esterified at O-3 by thionoformylation. Subsequent Barton-McCombie deoxygenation quantitatively removed the O-3 from the protected sugar. Mass balance was then applied to calculate the O-18/O-16 of O-3 using the isotopic values of the protected sugar before and after the deoxygenation step. The method is innovative in that (i) isolation and purification of individual compounds for O-18 by EA/Pyrolysis/IRMS analysis is unnecessary as the reaction mixture can be analyzed on a GC/Pyrolysis/IRMS; (ii) sample quantity is dramatically reduced; and (iii) the approach to access the O-3 isotopic signal can be easily expanded to other positions within glucose and other sugars. It was shown that O-3 is enriched by 12 mUr relative to the molecular average (O-2-O-6) for a glucose of C-4 photosynthetic origin. We highlighted the potential applications of the intramolecular O isotopic heterogeneity of glucose this method revealed.

Alcohol use disorders (AUDs) represent a severe, world-wide problem, and are usually comorbid with psychiatric disorders, comorbidity increases the risks associated with AUDs, and results in more serious consequences for patients. However, currently the underlying mechanisms of comorbid psychiatric disorders in AUDs are not clear. Studies investigating comorbidity could help us understand the neural mechanisms of AUDs. In this review, we explore three comorbidities in AUDs, including schizophrenia, major depressive disorder (MDD), and personality disorders (PDs). They are all co-morbidities of AUDs with rate of 33.7, 28, and 50-70%, respectively. The rate is significantly higher than other diseases. Therefore we review and analyze relevant literature to explore whether these three diseases are the risk factors of AUDs, focusing on studies assessing cognitive function and those using neural imaging. We found that memory deficits, impairment of cognitive control, negative emotion, and impulsivity may increase an individual's vulnerability to AUDs. This comorbidity may indicate the neural basis of AUDs and reveal characteristics associated with different types of comorbidity, leading to further development of new treatment approaches for AUDs.

Predicting the destroyed floor depth caused by the mining of coal seams is of great importance in judging whether the mining of a deep coal seam can be safely performed above a confined aquifer and to prevent the inrush of water from the floor. Thirty sets of coal mining data on destroyed floor depth were selected for study. A comprehensive analysis of the factors that influence the depth of destruction of coal seam floor strata was performed and combined with the ability of a BP neural network to address dynamic nonlinear information. Then, a set of test samples was assembled and used to construct a predictive model using a BP neural network. The model was then used to predict the destroyed floor depth of the 7105 working face of the Baizhuang Coal Mine in the Feicheng coal field. To verify the effectiveness of the model, the depth of the destroyed strata comprising the coal seam floor was measured using equipment called the “Double Sided Sealed Borehole Water Injection Device.” By comparing the predictions made by the BP neural network with actual measurements, the conclusion was reached that a BP neural network model can effectively be used to predict the destroyed floor depth caused by the mining of a coal seam.

A case study on the source separation of municipal solid waste (MSW) was performed in Changsha, the capital city of Hunan Province, China. The objective of this study is to analyze the effects of different separation methods and compare their effects with citizens' attitudes and inclination. An effect evaluation method based on accuracy rate and miscellany rate was proposed to study the performance of different separation methods. A large-scale questionnaire survey was conducted to determine citizens' attitudes and inclination toward source separation. Survey result shows that the vast majority of respondents hold consciously positive attitudes toward participation in source separation. Moreover, the respondents ignore the operability of separation methods and would rather choose the complex separation method involving four or more subclassed categories. For the effects of separation methods, the site experiment result demonstrates that the relatively simple separation method involving two categories (food waste and other waste) achieves the best effect with the highest accuracy rate (83.1%) and the lowest miscellany rate (16.9%) among the proposed experimental alternatives. The outcome reflects the inconsistency between people's environmental awareness and behavior. Such inconsistency and conflict may be attributed to the lack of environmental knowledge. Environmental education is assumed to be a fundamental solution to improve the effect of source separation of MSW in Changsha. Important management tips on source separation, including the reformation of the current pay-as-you-throw (PAYT) system, are presented in this work.IMPLICATIONS:A case study on the source separation of municipal solid waste was performed in Changsha. An effect evaluation method based on accuracy rate and miscellany rate was proposed to study the performance of different separation methods. The site experiment result demonstrates that the two-category (food waste and other waste) method achieves the best effect. The inconsistency between people's inclination and the effect of source separation exists. The proposed method can be expanded to other cities to determine the most effective separation method during planning stages or to evaluate the performance of running source separation systems.