Study on Pulp Grade of Iron Ore Concentrate by Monte Carlo

When energy distribution X-ray fluorescence analysis method (EDXRF) is used to measure the pulp grade of iron concentrate, the parameters such as the location of radioactive source, detector, the particle size of the iron concentrate, and the concentration of the iron concentrate slurry, etc. have a greater influence on the measurement results. In order to more accurately measure the grade of iron ore pulp, the Monte Carlo method was used to study the different pulp grades of samples of the iron ore concentrate under different conditions such as the location of radioactive source, detector, the particle size of the iron concentrate, and the concentration of the iron concentrate slurry. By studying the relationship between different influencing factors and counting rate, the error of the actual measurement time and the pulp grade of iron concentrate can be reduced. The pulp grade of iron concentrate is improved, and the in-situ EDXRF analysis of iron concentrate slurry is more in line with the actual grade.

Paleoproterozoic volcanic rocks in the southern margin of the North China Craton, central China:Implications for the Columbia supercontinent

The volcanic rocks of the Xiong’er Group are situated in the southern margin of the North China Craton(NCC).Research on the Xiong er Group is important to understand the tectonic evolution of the NCC and the Columbia supercontinent during the Paleoproterozoic.In this study,to constrain the age of the Xiong’er volcanic rocks and identify its tectonic environment,we report zircon LA-ICP-MS data with Hf isotope,whole-rock major and trace element compositions and Sr-Nd-Pb-Hf isotopes of the volcanic rocks of the Xiong’er Group.The Xiong’er volcanic rocks mainly consist of basaltic andesite,andesite.dacite and rhyolite,with minor basalt.Our new sets of data combined with those from previous studies indicate that Xiong’er volcanism should have lasted from 1827 Ma to 1746 Ma as the major phase of the volcanism.These volcanics have extremely low MgO.Cr and Ni contents,are enriched in LREEs and LILEs but depleted in HFSEs(Nb,Ta,and Ti),similar to arc-related volcanic rocks.They are characterized by negative zirconεHft values of-17.4 to 8.8,whole-rock initial 87Sr/86Sr values of 0.7023 to 0.7177 andεNd(t)values of-10.9 to 6.4.and Pb isotopes(206Pb/204Pb=14.366-16.431,207Pb/204Pb=15.106-15.371,208Pb/204Pb=32.455-37.422).The available elemental and Sr-Nd-Pb-Hf isotope data suggest that the Xiong’er volcanic rocks were sourced from a mantle contaminated by continental crust.The volcanic rocks of the Xiong’er Group might have been generated by high-degree partial melting of a lithospheric mantle that was originally modified by oceanic subduction in the Archean.Thus,we suggest that the subduction-modified lithospheric mantle occurred in an extensional setting during the breakup of the Columbia supercontinent in the Late Paleoproterozoic,rather than in an arc setting.

EEG Source Localization Using Spatio-Temporal Neural Network

Source localization of focal electrical activity from scalp electroencephalogram (sEEG) signal is generally modeled as an inverse problem that is highly ill-posed. In this paper, a novel source localization method is proposed to model the EEG inverse problem using spatio-temporal long-short term memory recurrent neural networks (LSTM). The network model consists of two parts, sEEG encoding and source decoding, to model the sEEG signal and receive the regression of source location. As there does not exist enough annotated sEEG signals correspond to specific source locations, simulated data is generated with forward model using finite element method (FEM) to act as a part of training signals. A framework for source localization is proposed to estimate the source position based on simulated training data. Experiments are done on simulated testing data. The results on simulated data exhibit good robustness on noise signal, and the proposed network solves the EEG inverse problem with spatio-temporal deep network. The result show that the proposed method overcomes the highly ill-posed linear inverse problem with data driven learning.

精神分裂症听觉稳态诱发电位中Gamma振荡的缺陷（英文）

背景:精神分裂症患者存在多种认知功能缺陷。Gamma振荡存在人脑中,与神经认知关系密切。听觉稳态反应(Auditory Steady-State Responses, ASSRs)是一种反映gamma振荡的神经电生理指标,既往研究发现精神分裂症患者40 Hz ASSRs诱发能量较健康者明显降低,不过ASSRs的相位指标与临床症状及神经认知缺陷的相关性尚有待系统研究。本研究旨在深入探索精神分裂症患者gamma节律神经活动缺陷及其与临床症状和神经认知间的相关性。目的:比较并验证精神分裂症与健康人群20 Hz和40Hz ASSRs能量和相位一致性的差异,探索精神分裂症ASSRs与神经认知缺陷的相关性。方法:记录24名精神分裂症患者和30名健康对照重复听觉刺激引起的听觉稳态诱发电位,采用阳性与阴性症状量表(PANSS)评估患者的临床症状,采用认知功能成套测验-共识版(MATRICS Consensus Cognitive Battery, MCCB)评估神经认知功能,计算ASSRs能量、锁相因子和相位一致性等指标与临床和认知评估的相关性。结果:病例组在信息处理速度(t=-2.39, p=0.021)、注意/警觉(t=-2.36, p=0.023)、词语学习(t=-3.11,p=0.003)、推理和问题解决(t=-2.60, p=0.012)等认知领域与对照组比较存在差异,40 Hz ASSRs能量比对照组明显降低(t=-2.291, p=0.032),锁相因子和试次间相位一致性指标均弱于健康对照(t=-3.017, p=0.004和t=3.131, p=0.003),且与推理和问题解决功能缺陷显著相关。结论:精神分裂症患者在多个认知领域存在缺陷且40Hz ASSRs能量偏低,特别是相位锁定特性和相位一致性较差,与推理能力和思维障碍存在一定关联。

Avoiding revascularization strategy versus revascularization with drug-coated balloon for the treatment of superficial femoral artery occlusive disease

Objective:The aim of this study was to compare the efficacy,safety and treatment costs of superficial femoral artery revascularization(SFA)with drug-coated balloon(DCB)versus avoiding revascularization strategy for the treatment of symptomatic SFA disease.Methods:This retrospective single-center study reviewed 96 patients(113 limbs)with severe stenosis and occlusive SFA disease.All patients underwent either DCB(Group 1:n=55 limbs)or nonrevascularization(Group2:n=58 limbs)between March 2015 and June 2019.The improvement of Rutherford class,walking impairment questionnaire score(WIQ),target limb reintervention,perioperative major adverse events,the catheterization laboratory cost and length of hospital stay were compared.The limb salvage and survival rates were calculated using the Kaplan-Meier method.Univariate and multivariate logistic regression analysis were performed to assess the association between factors and the improvement of Rutherford category at 12 months.Results:The median follow-up time of Groups 1 and 2 was 17 and 33 months,respectively.At 12 months,the Rutherford category significantly decreased in both groups(P<0.001),with no significant difference(79.7%vs.64.3%,P=0.074).Furthermore,multivariate analysis showed that the selected therapeutic method was not an influential factor for the improvement of Rutherford class at 12 months.The WIQ overall score as well as three subscales scores(distance,speed and stair-climbing),the survival rate,limb salvage rate and the length of stay between the two groups were comparable.The perioperative adverse events rate and catheterization laboratory cost in Group 2 was significantly lower compared to Group 1[(34253.69±28172.87)yuan vs.(56936.76±41278.36)yuan,P=0.001].Conclusions:This study suggests that avoiding superficial femoral artery revascularization strategy has favorable efficacy and safety outcomes compared to combining revascularization with DCB in selected patients.

Dynamic Changes of Chemical and Mechanical Properties of Moso Bamboo (Phyllostachys edulis) Culms under Different Storage Conditions

The durability of bamboo based on its chemical and mechanical properties is a crucial consideration for the wood-based industry due to its vulnerability to insects and microorganisms.We investigated the dynamic changes of chemical and mechanical properties of Phyllostachys edulis under air-dry and water storage conditions for 3,6 and 12 months respectively.The chemical properties of P.edulis bamboo culms varied with culm age but insignificantly with culm height.The mechanical properties of P.edulis culms showed an increasing trend with culm age.Water storage condition decreased the ash,SiO2 and lignin content,but increased the ethanol-benzene extracts.It also created an anaerobic environment for bamboo culms in which only anaerobic respiration was possible contributing to reducing the content of soluble sugar and starch,thereby beneficial for decreasing the damage from insects and microorganisms.Moreover,the water storage conditions could maintain culm mechanical performance better.Therefore,the indigenous practice of local people to store bamboo culms in ponds has good science behind it and water storage practices of bamboo culms was recommended.

Overview of Industrial Materials Detection Based on Prompt Gamma Neutron Activation Analysis Technology

Prompt gamma neutron activation analysis (PGNAA) is a non-destructive online measurement nuclear analysis method. With its unique advantages, it has been widely used in online analysis of industrial materials such as coal, cement, and minerals in recent years. However, there are many kinds of literature on PGNAA in the field of industrial materials detection, and there are still a few concluding articles. To this end, based on the principle of PGNAA online analysis, the status quo and development of the real-time online detection of industrial material components in the field are reviewed and discussed by consulting a large number of domestic and foreign PGNAA related literature and data, to facilitate the reference of relevant scientific researchers.

Analysis on the Background of a Coalition Government Proposed by the Communist Party of China

It was under extremely complex background at home and abroad that the Communist Party of China proposed to form a coalition government. Domestically, the Kuomintang was faced with military defeat and political crisis while the strength of the Communist Party of China grew increasingly. Besides, the Constitutionalism Movement launched by democratic parties failed. Internationally, the proposal of a coalition government was inspired politically by some European countries and promoted by the US-Soviet policies towards China. It had a significant impact on domestic and international situation at that time and pointed out the direction of Chinese political model for Chinese people.

Critical Metals Ga,Ge and In in the Global Pb-Zn Deposits:Current Understanding,Challenges and Perspectives

BACKGROUND A spectrum of strategically critical metals, such as gallium(Ga), germanium(Ge) and indium(In), with promising applications in green and high-tech fields, are produced as byproducts of zinc ores in a variety of Pb-Zn deposits, such as magmatic-hydrothermal porphyry-skarn-vein type.