Discussion on the application prospect of the transient electromagnetic method based on the dual launcher and mine advanced detection

The dual transmitter implements the equivalent anti-magnetic flux transient electromagnetic method, which can effectively reduce the scope of the transient electromagnetic detection blind area. However, this method is rarely reported in the detection of pipelines in urban geophysical exploration and the application of coal mines. Based on this, this paper realizes the equivalent anti-magnetic flux transient electromagnetic method based on the dual launcher. The suppression effect of this method on the blind area is analyzed by physical simulation. And the detection experiment of underground pipelines is carried out outdoors. The results show that the dual launcher can significantly reduce the turn-off time, thereby effectively reducing the impact of the blind area on the detection results, and the pipeline detection results verify the device’s effectiveness. Finally, based on the ground experimental results, the application prospect of mine advanced detection is discussed. Compared with other detection fields, the formation of blind areas is mainly caused by the equipment. If the dual launcher can be used to reduce the blind area, the accuracy of advanced detection can be improved more effectively. The above research results are of great significance for improving the detection accuracy of the underground transient electromagnetic method.

非常规储层微纳米孔隙介质中流体相态研究进展

非常规油气储层具有岩石骨架颗粒小、比表面积大、微纳米孔隙发育的特点,流体与孔隙介质间存在着诸多复杂的界面效应问题,影响微纳米孔隙介质中流体的相态变化规律。对于受限域流体,经典油气相态理论方法忽略分子间相互作用及界面效应的影响,预测微纳米孔隙介质中流体相变特征存在偏差。为了更全面地揭示油气在受限空间中的相态特征及其微观作用机理,总结当前微纳米孔隙介质中流体相态研究技术现状,详细阐述微观实验测试、相态理论模型和分子模拟3种主流技术方法,指出3种技术各自的优缺点,并对未来流体相态研究技术提出展望。分析认为:微观实验测试方法可通过研究流体热力学参数的变化来确定流体相变点,由于实验误差、人为误差等原因,需与理论计算相结合;相态理论模型方法可通过改进临界参数场、考虑流体与孔壁界面作用、考虑相间毛管压力修正相平衡判据方程等方法建立纳米孔隙空间相态理论模型,但是由于没有综合考虑界面效应带来的影响且缺乏有力的实验数据支撑,难以推广应用;分子模拟方法能在分子尺度上揭示流体分子的相行为,但现有研究主要围绕小分子展开,并且与流体发生相变时的临界参数结合得较少。后续研究应以多界面效应耦合影响的微纳米孔隙介质中油气流体相变特征为研究对象,以微观实验、理论模型和分子模拟为技术手段,为描述微纳米孔隙介质中流体相态提供合理的实验测试手段和可靠的理论计算模型。

页岩矿物不同润湿性表征与吸附微观机理

无机矿物作为页岩气吸附的重要载体,其表面性质对甲烷吸附能力有着重要影响,而润湿性作为固体重要表面性质之一,对矿物气体吸附能力的影响不可忽视.文章以蒙脱石和石英作为研究对象,通过对矿物表面甲基化(-CH_(3))和羟基化(-OH)处理来改变其润湿性,以探究无机矿物表面润湿性对甲烷吸附能力的影响.采用分子动力学方法研究矿物体系的润湿性,用接触角对润湿性进行定量表征,并构建纳米狭缝,结合巨正则蒙特卡罗方法模拟润湿性改变前后,CH4在矿物中的吸附变化.研究结果表明,水滴在羟基化矿物表面迅速破裂并铺展在矿物表面,而在甲基化表面铺展程度较小,普遍呈半球形.羟基化蒙脱石和石英表面的润湿接触角分别为12.7°和26.5°,均小于其甲基化表面接触角62.5°和85.7°.甲基化矿物甲烷吸附量均高于其羟基化,气体几乎大都以吸附状态位于孔隙壁面,随着矿物亲水性的减弱,其对甲烷吸附能力增强.

Crosstalk among Oxidative Stress,Autophagy,and Apoptosis in the Protective Effects of Ginsenoside Rb1 on Brain Microvascular Endothelial Cells:A Mixed Computational and Experimental Study

Objective Brain microvascular endothelial cells (BMECs) were found to shift from their usually inactive state to an active state in ischemic stroke (IS) and cause neuronal damage. Ginsenoside Rb1 (GRb1),a component derived from medicinal plants,is known for its pharmacological benefits in IS,but its protective effects on BMECs have yet to be explored. This study aimed to investigate the potential protective effects of GRb1 on BMECs. Methods An in vitro oxygen-glucose deprivation/reperfusion (OGD/R) model was established to mimic ischemia-reperfusion (I/R) injury. Bulk RNA-sequencing data were analyzed by using the Human Autophagy Database and various bioinformatic tools,including gene set enrichment analysis (GSEA),Gene Ontology (GO) classification and enrichment analysis,Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis,protein-protein interaction network analysis,and molecular docking. Experimental validation was also performed to ensure the reliability of our findings. Results Rb1 had a protective effect on BMECs subjected to OGD/R injury. Specifically,GRb1 was found to modulate the interplay between oxidative stress,apoptosis,and autophagy in BMECs. Key targets such as sequestosome 1 (SQSTM1/p62),autophagy related 5 (ATG5),and hypoxia-inducible factor 1-alpha (HIF-1α) were identified,highlighting their potential roles in mediating the protective effects of GRb1 against IS-induced damage. Conclusion GRbl protects BMECs against OGD/R injury by influencing oxidative stress,apoptosis,and autophagy. The identification of SQSTM1/p62,ATG5,and HIF-1α as promising targets further supports the potential of GRb1 as a therapeutic agent for IS,providing a foundation for future research into its mechanisms and applications in IS treatment.

Aging Mongolian pine plantations face high risks of drought-induced growth decline:evidence from both individual tree and forest stand measurements

Discerning vulnerability differences among different aged trees to drought-driven growth decline or to mortality is critical to implement age-specific countermeasures for forest management in water-limited areas.An important species for afforestation in dry environments of northern China,Mongolian pine(Pinus sylvestris var.mongolica Litv.)has recently exhibited growth decline and dieback on many sites,particularly pronounced in old-growth plantations.However,changes in response to drought stress by this species with age as well as the underlying mechanisms are poorly understood.In this study,tree-ring data and remotely sensed vegetation data were combined to investigate variations in growth at individual tree and stand scales for young(9-13 years)and aging(35-52 years)plantations of Mongolian pine in a water-limited area of northern China.A recent decline in tree-ring width in the older plantation also had lower values in satellited-derived normalized difference vegetation indices and normalized difference water indices relative to the younger plantations.In addition,all measured growth-related metrics were strongly correlated with the self-calibrating Palmer drought severity index during the growing season in the older plantation.Sensitivity of growth to drought of the older plantation might be attributed to more severe hydraulic limitations,as reflected by their lower sapwood-and leaf-specific hydraulic conductivities.Our study presents a comprehensive view on changes of growth with age by integrating multiple methods and provides an explanation from the perspective of plant hydraulics for growth decline with age.The results indicate that old-growth Mongolian pine plantations in water-limited environments may face increased growth declines under the context of climate warming and drying.

Uncertainties of landslide susceptibility prediction:influences of different study area scales and mapping unit scales

This study aims to investigate the effects of different mapping unit scales and study area scales on the uncertainty rules of landslide susceptibility prediction(LSP).To illustrate various study area scales,Ganzhou City in China,its eastern region(Ganzhou East),and Ruijin County in Ganzhou East were chosen.Different mapping unit scales are represented by grid units with spatial resolution of 30 and 60 m,as well as slope units that were extracted by multi-scale segmentation method.The 3855 landslide locations and 21 typical environmental factors in Ganzhou City are first determined to create spatial datasets with input-outputs.Then,landslide susceptibility maps(LSMs)of Ganzhou City,Ganzhou East and Ruijin County are pro-duced using a support vector machine(SVM)and random forest(RF),respectively.The LSMs of the above three regions are then extracted by mask from the LSM of Ganzhou City,along with the LSMs of Ruijin County from Ganzhou East.Additionally,LSMs of Ruijin at various mapping unit scales are generated in accordance.Accuracy and landslide suscepti-bility indexes(LSIs)distribution are used to express LSP uncertainties.The LSP uncertainties under grid units significantly decrease as study area scales decrease from Ganzhou City,Ganzhou East to Ruijin County,whereas those under slope units are less affected by study area scales.Of course,attentions should also be paid to the broader representativeness of large study areas.The LSP accuracy of slope units increases by about 6%–10%compared with those under grid units with 30 m and 60 m resolution in the same study area's scale.The significance of environmental factors exhibits an averaging trend as study area scale increases from small to large.The importance of environmental factors varies greatly with the 60 m grid unit,but it tends to be consistent to some extent in the 30 m grid unit and the slope unit.

Spatiotemporal variations of parameters of internal solitary waves in the northern South China Sea

The dynamic parameters for internal solitary waves(ISWs)derived from the extended Korteweg-de Vries(eKdV)equation play an important role in the understanding and prediction of ISWs.The spatiotemporal variations of the dynamic parameters of the ISWs in the northern South China Sea(SCS)were studied based on the reanalysis of long-term temperature and salinity datasets.The results for spectrum analysis show that there are definite geographical differences for the periodic variation of the parameters:in shallow water,all parameters vary with a wave period of one year,while in deep water wave components of the parameters at other frequencies exist.Using wavelet analysis,the wavelet power spectral densities in deep water exhibited an inter-annual variation pattern.For example,the wave component of the dispersion coefficient with a wave period of about half a year reached its power peak once every two years.Based on previous work,this inter-annual variation pattern was deduced to be caused by dynamic processes.In further work on the regulatory mechanisms,empirical orthogonal function(EOF)decomposition was performed.It was found that the modes of the dispersion coefficient have different geographical distributions,explaining the reason why the wave components in different frequencies appeared in different locations.The numerical simulation results confirm that the variations in the parameters of the ISWs derived from the eKdV equation could affect the waveforms significantly because of changes in the polarity of the ISWs.Therefore,the periodic variations of the dynamic parameters are related to the geographical location because of dynamic processes operating.

Hydrogen-bonded organic framework modified separator for simultaneously enhancing the safety and electrochemical performance of Ni-rich lithium-ion battery

Nickel-rich layered oxide cathode(LiNi_(x)Co_(y)Mn_(1−x−y)O_(2),x>0.5,NCM)shows substantial potential for applications in longer-range electrical vehicles.However,the rapid capacity decay and serious safety concerns impede its practical viability.This work provides a hydrogen-bonded organic framework(HOF)modification strategy to simultaneously improve the electrochemical performance,thermal stability and incombustibility of separator.Melamine cyanurate(MCA),as a low-cost and reliable flame-retardant HOF,was implemented in the separator modification layer,which can prevent the battery short circuit even at a high temperature.In addition,the supermolecule properties of MCA provide unique physical and chemical microenvironment for regulating ion-transport behavior in electrolyte.The MCA coating layer enabled the nickel-rich layered oxide cathode with a high-capacity retention of 90.3%after 300 cycles at 1.0 C.Collectively,the usage of MCA in lithium-ion batteries(LIBs)affords a simple,low-cost and efficient strategy to improve the security and service life of nickel-rich layered cathodes.

Cholesterol-induced deformation of the gramicidin A channel inhibiting potassium ion binding and transport

Gramicidin A(gA)is a kind of antibiotic peptide produced by bacillus brevis and it can dimerize across lipid bilayers to form a monovalent cation channel.In this work,we investigate the impact of cholesterol in the lipid bilayer on the binding of potassium ions with the gA channel and the transport of the ions across the channel.The results indicate that cholesterol can significantly influence the conformational stability of the gA channel and cause the channel deformation which inhibits the potassium ion binding with the channel and transport across the channel.The work provides some molecular insights into understanding of influence of lipids on the activity of gA channel in both model membranes and plasma membranes of intact cells.

L_(1)-Smooth SVM with Distributed Adaptive Proximal Stochastic Gradient Descent with Momentum for Fast Brain Tumor Detection

Brain tumors come in various types,each with distinct characteristics and treatment approaches,making manual detection a time-consuming and potentially ambiguous process.Brain tumor detection is a valuable tool for gaining a deeper understanding of tumors and improving treatment outcomes.Machine learning models have become key players in automating brain tumor detection.Gradient descent methods are the mainstream algorithms for solving machine learning models.In this paper,we propose a novel distributed proximal stochastic gradient descent approach to solve the L_(1)-Smooth Support Vector Machine(SVM)classifier for brain tumor detection.Firstly,the smooth hinge loss is introduced to be used as the loss function of SVM.It avoids the issue of nondifferentiability at the zero point encountered by the traditional hinge loss function during gradient descent optimization.Secondly,the L_(1) regularization method is employed to sparsify features and enhance the robustness of the model.Finally,adaptive proximal stochastic gradient descent(PGD)with momentum,and distributed adaptive PGDwithmomentum(DPGD)are proposed and applied to the L_(1)-Smooth SVM.Distributed computing is crucial in large-scale data analysis,with its value manifested in extending algorithms to distributed clusters,thus enabling more efficient processing ofmassive amounts of data.The DPGD algorithm leverages Spark,enabling full utilization of the computer’s multi-core resources.Due to its sparsity induced by L_(1) regularization on parameters,it exhibits significantly accelerated convergence speed.From the perspective of loss reduction,DPGD converges faster than PGD.The experimental results show that adaptive PGD withmomentumand its variants have achieved cutting-edge accuracy and efficiency in brain tumor detection.Frompre-trained models,both the PGD andDPGD outperform other models,boasting an accuracy of 95.21%.

Characteristics of gut microbiota in anastomotic leakage patients in cold zones post-colorectal cancer surgery: A high-throughput sequencing and propensity-score matching study

Objective:The study aimed to explore the association between gut microbiota and anastomotic leakage(AL)after surgery in colorectal cancer(CRC)patients from a frigid zone,based on high-throughput sequencing.Methods:A total of 98 CRC patients admitted to the Second Affiliated Hospital of Harbin Medical University from July 2018 to February 2019,who met the inclusion criteria,were included.Among these,10 patients were diagnosed as AL.After propensity-score matching of baseline characteristics,10 patients from the anastomotic leakage group(AG)and 10 patients from the normal group(NG)were finally included in this study.Fecal samples were collected,and total DNA was extracted for high-throughput sequencing and bioinformatic analysis.Results:Alpha diversity analysis showed no significant difference between the two groups,while beta diversity analysis revealed significant differences in principal components.Differential microbiota were classified as Proteobacteria at the phylum level(P=0.021).At the genus level,the abundances of Streptococcus(P=0.045),Citrobacter(P=0.008)and Klebsiella(P=0.002)were significantly different between the two groups.LEfSe analysis indicated that these genera contributed most to the differences between the groups.Conclusion:The characteristics of the gut microbiota in the AG and NG were significantly different,and these differences might be associated with AL in CRC patients from frigid zones.

Research on the Application of Helmet Detection Based on YOLOv4

Helmets are one of the important measures to ensure the safety of construction workers. Because the harm caused by not wearing safety helmets as required is great, the wearing of safety helmets has also attracted more and more people’s attention. At present, the main method of helmet detection is the YOLO series of algorithms. They often only focus on detection accuracy, ignoring the actual situation during deployment, that is, a balance between accuracy and speed is required. Therefore, this paper proposes a helmet detection application based on YOLOv4 algorithm, and combined with the MobileNet network, it has achieved good results in terms of detection accuracy and speed. Through transfer learning and tuning parameters, the mAP and FPS values detected in this paper on the public safety helmet datasets are 94.47% and 27.36%, which exceed the research work of some similar papers. This paper also combines YOLOv4 and MobileNetv3 networks to propose a mobileNet-based YOLOv4 helmet detection application. Its mAP and FPS values are 91.47% and 42.58%, respectively, which meet the accuracy and real-time requirements of current hardware deployment.

灰尘导致的光伏电站发电损失的对比实验

对地面光伏电站的2个采取不同清洁策略方阵的运行数据和辐照数据分成上午数据和下午数据,分别进行处理和分析。介绍去除数据集中的异常数据和不可信数据的预处理的方法。之后,对比组串的发电数据,发现了2个方阵中发电异常的2个组串。为了研究清洁增益的效果,计算不同太阳辐照度下2个方阵的功率比值。发现对于不同的辐照度,清洁增益的效果有较大差别。在该文实验条件下,在200 W/m^(2)以上的辐照度下,上午的清洁增益约3.3%±2.1%,下午为3.6%±2.0%。

程志清教授从脏腑气化论治高脂血症临床经验荟萃

[目的]介绍与总结程志清教授从脏腑气化论治高脂血症的经验。[方法]通过跟随程志清教授抄方侍诊,总结程志清教授运用辨证思维从脏腑气化论治高脂血症的病因病机、临床诊疗思路及用药经验,并列举一则典型医案加以佐证。[结果]程志清教授认为脏腑气化失司是高脂血症形成发生的核心病机,有肝胆失疏、脾胃失和、心脉受损、肾气亏虚、三焦气化失常诸端,故临证时固本清源并施、标本兼顾,尤重疏肝理气、健脾和胃、化湿祛痰、活血化瘀、畅达三焦,恢复脏腑气化功能。所选医案患者确诊为高脂血症,该患者性情急躁,头晕纳差,更衣时干时稀,舌红苔腻,舌下络脉瘀紫,脉细弦,故辨证为肝郁脾虚、肝胆失疏、湿郁化热、血凝成瘀,治以调肝理气、健脾利湿、清化湿热、和畅三焦,获满意疗效。[结论]程志清教授从脏腑气化论治高脂血症,病因病机常见脾胃失和、肝胆失疏、心脉受损、肾气亏虚、三焦不畅等,治疗上从恢复脏腑气化入手,精准合理选择药物,疗效确切,其治疗经验具有较高的临床参考价值,值得深入学习和推广运用。

离子液体中阳离子纤维素的制备及对酸性蓝40的吸附性能

以离子液体1-丁基-3-甲基咪唑氯盐(BMIMCl)为溶剂、丙烯酰氧乙基三甲基氯化铵(AETAC)为阳离子单体合成了高效的阳离子改性纤维素材料。将纤维素溶解于BMIMCl中,在溶液状态通过自由基聚合接枝阳离子单体,采用相分离法制得产物。红外光谱和元素分析表明单体已成功接枝到纤维素上,扫描电镜和X射线衍射仪分析表明阳离子纤维素的样品呈多孔结构,晶型从纤维素Ⅰ型变为纤维素Ⅱ型,结晶指数从80.33%降至53.81%。阳离子纤维素对酸性蓝40具有优良的吸附能力,在中性、无盐条件下吸附效果最好,理论平衡吸附量可达到448.43 mg/g。吸附类型属于化学吸附,吸附过程符合Langmuir吸附等温线模型和伪二阶吸附动力学方程。吸附剂可循环使用,NaOH溶液可作为解吸溶液。

手术治疗复发性胸壁结核的效果评价

目的评价手术治疗复发性胸壁结核的临床效果。方法回顾性分析我院2013年1月~2017年6月收治的96例复发性胸壁结核患者的历例资料,统计分析手术治疗后原切口和非原切口的愈合及复发情况,并将患者病灶表现与手术效果进行皮尔逊相关分析。结果从复发部位看,非原切口复发24例(25%),原切口复发72例(75%),两者差异有统计学意义(χ~2=65.68,P<0.001);从性别上看,原切口复发男性50例(69.44%),女性22例(30.56%),两者差异无统计学意义(χ~2=0.78,P>0.05)。96例复发性胸壁结核患者经手术治疗后,甲级切口愈合90例(93.75%),延期愈合6例(6.25%);术后随访1年,仅在原切口的结核病灶复发4例,6例切口延期愈合患者经再次手术治疗后均治愈。在手术治疗复发性胸壁结核的疗效中,术后近期及随访1年后为甲级愈合与胸壁结核CT分型为哑铃型的呈负相关,与原切口复发部位和疼痛呈负相关;延期愈合与胸壁结核CT分型为哑铃型呈正相关,与原切口复发部位和疼痛呈正相关。结论针对复发性胸壁结核,手术治疗能够直接清除病灶,同时采用抗痨及抗感染处理,治疗效果良好。

基于薛雪湿热三焦辨证对新型冠状病毒肺炎传变规律的探讨

[目的]研究外感湿热病的传变体系与治则治法,为新型冠状病毒肺炎(下称新冠肺炎)的防治提供思路。[方法]研究薛雪《湿热条辨》的内容,总结湿热病的传变规律,结合湿热疫的相关研究文献和指南,以及临床上新冠肺炎的典型症状,提出其可能的传变途径、分期证型和治则治法。[结果]新冠肺炎具有湿热病的性质,而湿热病的传变以三焦为主线,可以三焦为主体进行分期分治。邪始在上焦,则有犯太阴阳明之分,犯太阴之经则当辛温宣透、芳香化湿,犯阳明之经则当辛温宣透、渗湿泄热。进而在中焦,则有湿重于热、热重于湿之别,湿重于热则法当芳香开郁、苦温燥湿,热重于湿则主以甘寒清热、苦温燥湿。邪踞下焦,则又可见湿阻下焦、热邪下陷等证型,湿阻下焦则当清热淡渗利水,热邪下陷则当清热开窍、活血散瘀。又可以六经、卫气营血变证为支线,产生多种坏病。[结论]新冠肺炎的传变具有湿热病特点,故研究分析湿热三焦传变可以为诊疗新冠肺炎提供新的思路。

螺环磷-氮协同反应型阻燃剂的合成及在环氧树脂中的应用

以三丙酮二胺、季戊四醇和三氯氧磷为原料,通过一锅法制备出一种新型环氧树脂反应型阻燃固化剂SPDPT,通过傅里叶变换红外光谱、核磁共振氢谱和磷谱,证明SPDPT制备成功。以4’,4-二氨基二苯砜(DDS)为共固化剂,共同固化环氧树脂制备了本征型阻燃环氧固化物(EP/DDS/SPDPT)。热重分析结果表明,SPDPT的加入能提高EP热固性材料燃烧后的残炭量。当磷质量分数为1.0%时,EP/DDS/SPDPT-4样品的LOI值为26.4%,UL94达到V-0级。在环氧固化物中,其拉伸强度最高达到了37.2 MPa,弯曲强度最高达到了63.8 MPa,冲击强度最高达到了21.6 kJ/m^2。

体育强国背景下的线上线下融合式教学设计与实践

体育强国国家战略的实现需要兼具体育专项技能、自主学习、信息素养等综合素质人才的支持,普通高等体育院校肩负着培养体育人才的重要使命。《计算机应用基础》作为普通高等体育院校开设的计算机公共基础课程,是术科学生掌握信息技术应用能力、发展信息素养的重要课程。文章采用行动研究法和问卷调查法,以北京体育大学开设的《计算机应用基础》课程为例,在“立德树人”的教育根本任务引领下,以发展自主学习能力和信息素养为目标,基于学生发展需要的具有体育特色的实践任务为驱动,以多元化学习资源为基础,从课前自主学习、课中演示释疑、实践应用、课后巩固拓展四个环节进行《计算机应用基础》线上线下融合式教学设计与实践。通过问卷调查和实践教学数据分析,线上线下融合式教学设计能有效提升运动训练和体育教育专业学生信息素养,对学生自主学习能力的培养有积极影响。

疏水性增透聚酯薄膜的制备及应用

以聚苯乙烯为大分子引发剂,丙烯酸聚硅氧烷酯为单体,通过原子转移自由基聚合制备苯乙烯-丙烯酸聚二甲基硅氧烷酯共聚物。将所得聚合物旋涂于聚对苯二甲酸乙二醇酯(PET)薄膜表面,研究共聚物中不同硅氧烷含量对聚酯薄膜性能的影响。通过核磁共振和红外光谱表征了丙烯酸聚硅氧烷酯单体及与苯乙烯共聚产物的结构,结果表明实验成功制备出了苯乙烯共聚物;凝胶渗透色谱结果表明聚合物的相对分子质量与设计相对分子质量相接近,并且相对分子质量分布系数均小于1.4,说明反应具有一定可控性;紫外-可见光分光光度计结果表明聚合物的折射率随着嵌段聚合物中硅氧烷含量的降低而增加;通过场发射扫描电镜(FE-SEM)对改性前后的聚酯薄膜进行观察,结果显示聚酯薄膜表面形成了蜂窝状多孔结构,从而有效改善了薄膜的透光性。总体研究结果表明,随着共聚物中硅氧烷含量的增加,聚酯薄膜的水接触角和透光率均呈先增后减的趋势。当共聚物中硅氧烷含量为19.6%时,PS-PDMS嵌段共聚物折射率为1.38,涂覆在PET表面后薄膜透光率达到92.6%,水接触角为120°。