High photoelectric conversion efficiency and fast relaxation time of FA_(0.4)MA_(0.6)PbI_(3) applied in ultrafast modulation of terahertz waves

Active control of terahertz(THz)waves is attracting tremendous attentions in terahertz communications and active photonic devices.Perovskite,due to its excellent photoelectric conversion performance and simple manufacturing process,has emerged as a promising candidate for optoelectronic applications.However,the exploration of perovskites in optically controlled THz modulators is still limited.In this work,the photoelectric properties and carrier dynamics of FA_(0.4)MA_(0.6)PbI_(3)perovskite films were investigated by optical pumped terahertz probe(OPTP)system.The ultrafast carrier dynamics reveal that FA_(0.4)MA_(0.6)PbI_(3)thin film exhibits rapid switching and relaxation time within picosecond level,suggesting that FA_(0.4)MA_(0.6)PbI_(3)is an ideal candidate for active THz devices with ultrafast response.Furthermore,as a proof of concept,a FA_(0.4)MA_(0.6)PbI_(3)-based metadevice with integrating plasma-induced transparency(PIT)effect was fabricated to achieve ultrafast modulation of THz wave.The experimental results demonstrated that the switching time of FA_(0.4)MA_(0.6)PbI_(3)-based THz modulator is near to 3.5 ps,and the threshold of optical pump is as low as 12.7μJ cm^(-2).The simulation results attribute the mechanism of ultrafast THz modulation to photo-induced free carriers in the FA_(0.4)MA_(0.6)PbI_(3)layer,which progressively shorten the capacitive gap of PIT resonator.This study not only illuminates the potential of FA_(0.4)MA_(0.6)PbI_(3)in THz modulation,but also contributes to the field of ultrafast photonic devices.

近20年人参治疗失眠的研究:基于VOSviewer、CiteSpace和Bibliometrix的文献计量学分析

目的:通过文献计量学分析,研究人参治疗失眠的历史与未来趋势。方法:检索近20年来国家知识基础设施数据库(CNKI)和Web of Science数据库中关于人参治疗失眠的文献,使用可视化分析工具进行发文量、作者、机构、国家、期刊、资助基金、关键词和被引频次等方面的分析。结果:纳入434篇中英文文献,其中中文364篇,英文70篇;发文总量最高的年份是2021年;最多发文的作者是滕晶;发文最多的期刊是《中医临床研究》和《JOURNAL OF GINSENG RESEARCH》;发文最多的机构是山东中医药大学;热点关键词是“归脾汤”“心脾两虚证”“GABA受体”等;被引最多的文献是Zhao、Fang等发表的人参治疗失眠通路机制的研究。结论:人参治疗失眠的研究呈增长趋势,未来将重点研究临床观察、作用机制和相关通路,为该领域的研究提供方法和思路。

Research on Flexible Job Shop Scheduling Based on Improved Two-Layer Optimization Algorithm

To improve the productivity,the resource utilization and reduce the production cost of flexible job shops,this paper designs an improved two-layer optimization algorithm for the dual-resource scheduling optimization problem of flexible job shop considering workpiece batching.Firstly,a mathematical model is established to minimize the maximum completion time.Secondly,an improved two-layer optimization algorithm is designed:the outer layer algorithm uses an improved PSO(Particle Swarm Optimization)to solve the workpiece batching problem,and the inner layer algorithm uses an improved GA(Genetic Algorithm)to solve the dual-resource scheduling problem.Then,a rescheduling method is designed to solve the task disturbance problem,represented by machine failures,occurring in the workshop production process.Finally,the superiority and effectiveness of the improved two-layer optimization algorithm are verified by two typical cases.The case results show that the improved two-layer optimization algorithm increases the average productivity by 7.44% compared to the ordinary two-layer optimization algorithm.By setting the different numbers of AGVs(Automated Guided Vehicles)and analyzing the impact on the production cycle of the whole order,this paper uses two indicators,the maximum completion time decreasing rate and the average AGV load time,to obtain the optimal number of AGVs,which saves the cost of production while ensuring the production efficiency.This research combines the solved problem with the real production process,which improves the productivity and reduces the production cost of the flexible job shop,and provides new ideas for the subsequent research.

Research on Flexible Job Shop Scheduling Optimization Based on Segmented AGV

As a typical transportation tool in the intelligent manufacturing system,Automatic Guided Vehicle(AGV)plays an indispensable role in the automatic production process of the workshop.Therefore,integrating AGV resources into production scheduling has become a research hotspot.For the scheduling problem of the flexible job shop adopting segmented AGV,a dual-resource scheduling optimization mathematical model of machine tools and AGVs is established by minimizing the maximum completion time as the objective function,and an improved genetic algorithmis designed to solve the problem in this study.The algorithmdesigns a two-layer codingmethod based on process coding and machine tool coding and embeds the task allocation of AGV into the decoding process to realize the real dual resource integrated scheduling.When initializing the population,three strategies are designed to ensure the diversity of the population.In order to improve the local search ability and the quality of the solution of the genetic algorithm,three neighborhood structures are designed for variable neighborhood search.The superiority of the improved genetic algorithmand the influence of the location and number of transfer stations on scheduling results are verified in two cases.

The phased chromosome-scale genome of yellowhorn sheds light on the mechanism of petal color change

Yellowhorn(Xanthoceras sorbifolium), especially its varieties, is the red petal yellowhorn(X. sorbifolium var. purpurea), an important tree species with great ornamental value, and its flower petals change color throughout the flowering period. In this study, we mainly focused on the mechanism of the petal color change with transcriptomics and metabolomics data. A phased chromosome-scale assembly of the red petal yellowhorn genome was generated using the PacBio high-fidelity reads, Illumina short reads, and Phase genomics Proximo Hi-C data. The final de novo assembly yielded 533.67 Mb with a contig N50 of 5.42 Mb, and 27 501 protein-coding genes were predicted. Notably, an alternate haplotig assembly was also obtained. Furthermore, a variation database for the alleles within the genome was constructed. Subsequently, the expression pattern of flower pigmentation-related genes and allelic expression imbalance events were investigated. Apart from 6 genes involved in the anthocyanin biosynthesis pathway regulated by the activation of 15 MYB-bHLH-WD40s, the increased expression of senescencerelated gene 1(SRG1) and 2-oxoglutarate-dependent dioxygenase(DIOX5) might also result in decreasing content of lutein and increasing abundance of(E/Z)-phytoene, cyanidin-3-O-rutinoside, and cyanidin-3-O-sambubioside. These changes in genes and metabolites were most likely related to the petal color change in red petal yellowhorn. This phased chromosome-scale genome assembly provides more accurate genomic information for future molecular breeding and facilitates allele function studies of the red petal yellowhorn.

Identification of microbial metabolites that accelerate the ubiquitindependent degradation of c-Myc

Myc belongs to a family of proto-oncogenes that encode transcription factors.The overexpression of c-Myc causes many types of cancers.Recently,we established a system for screening c-Myc inhibitors and identified antimycin A by screening the RIKEN NPDepo chemical library.The specific mechanism of promoting tumor cell metastasis by high c-Myc expression remains to be explained.In this study,we screened approximately 5,600 microbial extracts using this system and identified a broth prepared from Streptomyces sp.RK19-A0402 strongly inhibits c-Myc transcriptional activity.After purification of the hit broth,we identified compounds closely related to the aglycone of cytovaricin and had a structure similar to that of oligomycin A.Similar to oligomycin A,the hit compounds inhibited mitochondrial complex V.The mitochondria dysfunction caused by the compounds induced the production of reactive oxygen species(ROS),and the ROS activated GSK3α/βthat phosphorylated c-Myc for ubiquitination.This study provides a successful screening strategy for identifying natural products as potential c-Myc inhibitors as potential anticancer agents.

癫痫对幼年小鼠大脑皮质和海马神经元突起及突触的影响

目的:探讨癫痫持续状态(SE)对幼年小鼠大脑皮质和海马区神经元突起及突触的影响。方法:利用腹腔注射氯化锂和匹罗卡品方法制备幼年SE小鼠模型,用Morris水迷宫实验检测小鼠行为学变化,免疫荧光染色法观察小鼠大脑皮质和海马区神经元轴突、树突及突触连接形态学变化,透射电镜观察小鼠海马区锥体神经元突触的超微结构变化。结果:小鼠Ⅳ级以上发作率为80%,死亡率为25%。SE小鼠逃逸潜伏期延长(P<0.05),探寻平台路程轨迹明显延长且复杂化,且目标象限停留时间和穿越平台次数均明显减少(P<0.05)。两组小鼠大脑皮质和海马区均发现轴突神经丝标记蛋白SMI312和微管相关蛋白2(MAP2)阳性表达,且SE组轴突神经丝和神经元树突长短不一,排列比较密集散乱。SE组小鼠大脑海马区突触素(SYP)阳性表达增多,且SYP阳性斑点数量明显增加(P<0.01)。SE组突触囊泡数量增加,且突触后致密带(PSD)厚度明显降低(P<0.01)。结论:SE可能导致幼年小鼠大脑皮质和海马区突触急性损伤,诱发突触囊泡循环障碍,进而引起轴突和树突网络广泛的破坏和紊乱,突触发生反应性或代偿性重建。

系统性红斑狼疮患者应用靶向B细胞治疗后发生中枢神经系统病变文献病例分析

目的探讨系统性红斑狼疮(SLE)患者经靶向B淋巴细胞生物制剂治疗后发生中枢神经系统不良反应的临床特征。方法检索国内外相关数据库(截至2023年5月),收集系统性红斑狼疮患者经贝利尤单抗、利妥昔单抗治疗后发生中枢神经系统病变的病例报告类文献,提取患者的基本信息、贝利尤单抗或利妥昔单抗用药情况(用法用量、单用或联用、联用方案等)、中枢神经系统病变发生时间、临床表现、影像学特征、临床治疗及转归等,并进行描述统计分析。结果检索到进行性多灶性脑白质病(PML)患者14例,发病年龄(50.71±11.45)岁;可逆性后部脑病综合征(PRES)患者24例,发病年龄(30.67±14.93)岁。纳入有详细病例报道的患者共7例,7例患者均未合并HIV感染、恶性肿瘤及其他自身免疫性疾病。7例患者均经磁共振检查确诊,均未行脑组织活检。临床表现:癫痫5例,视物模糊或视力丧失3例,构音障碍或失语2例,头痛2例,昏迷1例,血压升高4例。最终7例患者中1例死亡。结论应用靶向B细胞治疗后,SLE患者中枢神经系统副作用多发生在疾病活动期且合并使用其他免疫抑制剂时。患者的临床表现容易与神经精神狼疮混淆,导致病情延误,提示在使用靶向B细胞生物制剂治疗时,应评估SLE患者发生中枢神经系统副作用的潜在风险。

用于氚产生率在线测量的小型背靠背锂玻璃探测器

为了实现强伽马场环境下的造氚率在线测量,研制了小型“背靠背”6Li/7Li玻璃探测器。每块锂玻璃闪烁体的尺寸为3.0 mm×3.0 mm×0.4 mm,闪烁体之间及侧面采用0.5 mm二氧化钛作为反射层,整体尺寸为4.0 mm×4.0 mm×1.3 mm。7Li玻璃探测器测量伽马产生的信号作为6Li玻璃探测器的伽马本底扣除。通过对标准60Co源的伽马射线脉冲幅度谱测量,验证了两个闪烁体对伽马场响应的一致性;在反应堆热中子孔道处和252Cf中子源直照等强伽马环境下测量了脉冲幅度谱,获得的中子伽马信噪比都大于1,表明可以有效扣除伽马本底。验证实验研制的锂玻璃探测器在强伽马场环境下仍能有效甄别伽马,可用于聚变堆和聚变-裂变混合堆实验包层模块内造氚率高精度在线测量。

页岩气开发过程水资源管理及水环境保护对策探讨

水力压裂和水平钻井技术是页岩气高效经济开采的关键,随着页岩气大规模商业性开发,会带来水资源大量消耗、地表水与地下水污染风险等水环境问题,可能造成页岩气开发区域内水环境影响。为此,本文系统对比研究了中国、美国、加拿大的页岩气开发水资源管理、水环境保护、监管制度相关的环保法规与标准规范,在借鉴北美页岩气开发的环保经验基础上,结合我国页岩气开发过程面临的水资源管理问题,以及国内页岩气企业在水管理中的实践经验,分别从取水用水、废水处置、水污染预防和控制三个方向提出水资源管理及水环境保护措施建议,目的在于促进页岩气企业规范水资源保护措施,改进清洁生产工艺、采用先进的技术与设备、不断改善管理水平,源头削减新鲜水消耗,减少处置风险,提高水资源循环利用效率,最大限度缓解页岩气开发中的用水问题。

滨里海盆地东缘速度建模方法研究与应用

滨里海盆地东缘阿克若尔地区石炭系碳酸盐岩顶面低幅度构造具有较大的油气勘探潜力,由于上覆下二叠统地层分布复杂,横向速度变化大,使得石炭系低幅度构造成图存在很大难度;为了解决研究区构造快速成图的问题,通过3种速度建模方法对比,优选出分频层速度反演方法,建立研究区的速度模型,解决了分频层速度反演受常规层速度反演方法横向连续性的限制问题,对下二叠统碳酸盐岩异常体的速度刻画更为准确;同时,分频层速度反演方法与井—震速度谱协同速度建模方法和常规井约束层速度反演相对比,提高了研究区下伏石炭系低幅度构造的深度域成图精度,取得了较好的效果。

“知识-信念-行为”健康教育模式对妇女产后非意愿妊娠预防效果

目的:探讨“知识-信念-行为”(简称知-信-行)健康教育模式对妇女产后发生非意愿妊娠的预防效果。方法:选取2020年7月-2022年7月在医院住院分娩的产妇1500名为研究对象,采用自愿原则将其分为观察组及对照组,各750例,对照组开展医院常规产后健康宣教,观察组进行产后避孕咨询,并开展基于知-信-行健康教育模式的避孕宣教。于产后42d及产后3,6,12个月进行随访,了解产妇恢复同房、避孕、非意愿妊娠及人工流产情况,比较两组避孕知识掌握情况、健康行为情况(采用健康促进生活方式量表Ⅱ评估)及对产后服务的满意度。结果:除去失访病例,最终纳入观察组731人,对照组718人进行分析。健康宣教后观察组的产后避孕知识知晓情况得分及HPLP-Ⅱ总得分高于对照组(P<0.05);产后42d及产后3、6个月观察组恢复同房率均低于对照组,产后避孕率均高于对照组(均P<0.05);产后12月观察组的非意愿妊娠率3.3%,低于对照组的8.5%,观察组的人工流产率1.8%,低于对照组5.4%(均P<0.05);观察组对产后服务满意度高于对照组(P<0.05)。结论:在产后开展知-信-行健康教育模式的避孕宣教可以提升妇女对避孕知识的掌握度,提高产后避孕率,降低产后1年内的非意愿妊娠率及人工流产率。

血清PGC-1α水平与PCOS患者体外受精-胚胎移植妊娠结局的关系

目的探析血清过氧化物酶体增殖物激活受体γ共激活因子1α(PGC-1α)水平与多囊卵巢综合征(PCOS)患者体外受精-胚胎移植(IVF-ET)妊娠结局的关系。方法选取2021年1月至2022年12月于广西壮族自治区妇幼保健院接受IVF-ET治疗的99例PCOS患者作为研究对象,依据患者妊娠结局分为妊娠组(n=49)和未妊娠组(n=50)。收集并比较所有患者基线资料以及性激素、血清PGC-1α水平等。采用Logistic回归分析影响PCOS患者IVF-ET妊娠结局的危险因素;采用受试者工作特征(ROC)曲线评估血清PGC-1α水平对PCOS患者IVF-ET妊娠结局的预测价值。结果99例PCOS患者中有49例妊娠成功,妊娠成功率为49.49%。未妊娠组血清甘油三酯(TG)、睾酮(T)水平均高于妊娠组,且血清PGC-1α水平低于妊娠组,差异具有统计学意义(P<0.05)。Logistic回归分析显示,血清T、TG水平高是PCOS患者IVF-ET治疗后妊娠结局的危险因素(OR>1,P<0.05),PGC-1α水平高是PCOS患者IVF-ET治疗后妊娠结局的保护因素(OR<1,P<0.05)。绘制ROC曲线显示,血清PGC-1α水平预测PCOS患者IVF-ET妊娠结局的曲线下面积(AUC)为0.752(95%CI:0.654~0.850,P<0.05),具有一定的预测价值。当血清PGC-1α的Cut-off值为0.485 ng/mL时,预测PCOS患者IVF-ET妊娠结局的灵敏度和特异度分别为76%、67%。结论血清PGC-1α水平与PCOS患者IVF-ET妊娠结局有关,且当其水平达0.485 ng/mL时,妊娠失败风险明显增加,具有一定的预测价值,未来或可将其作为预测IVF-ET妊娠结局的辅助指标。

低幅构造识别技术研究与应用

针对滨里海盆地东缘阿克若尔构造带低幅度构造识别的问题,开发基于反演层速度法和构造趋势面拟合法的低幅构造识别方法。该方法适用于局部发育速度异常体、速度变化快、斜坡区目的层埋藏深度大且圈闭幅度小的情况;优选构造解释层位趋势和单井速度约束下的层速度反演的方法建立研究区速度模型,对地震层位进行标定,克服了常规层速度反演方法横向连续性的限制,对复杂地层具有更好的适应性;构造趋势面拟合法对研究区低幅构造进行有效识别,克服了因构造幅度低、同相轴平直并且变化幅度小而难以识别的问题,对滨里海东缘深度域构造图进行构造趋势面拟合,取得了较好的效果。

针药联合治疗气滞血瘀型子宫腺肌病痛经的临床观察

目的:观察牡丹散加减联合针刺治疗对气滞血瘀型子宫腺肌病痛经的临床疗效。方法:选取2022年2月-2023年6月在淮安市中医院就诊的子宫腺肌病痛经气滞血瘀型患者40例为研究对象,随机分为治疗组和对照组各20例。对照组给予牡丹散加减治疗,治疗组在对照组基础上联合针刺治疗。经治3个月经周期,比较两组患者的临床疗效、疼痛视觉模拟(VAS)评分及COX痛经症状评分、中医证候积分情况。结果:治疗组临床总有效率为100.0%(20/20),优于对照组的80.0%(16/20)(P<0.05);治疗组VAS评分及COX痛经症状评分均优于对照组(P<0.05);治疗组中医证候积分较对照组低(P<0.05)。结论:牡丹散加减联合针刺治疗子宫腺肌病痛经,可缓解痛经程度,缩短痛经时间,并改善伴随症状。

基于物联网技术的图书馆书籍自动定位系统

当前图书馆书籍自动定位系统存在误差大,实时性差等不足,为了获得更加理想的图书馆书籍自动定位结果,设计基于物联网技术的图书馆书籍自动定位系统。首先无线射频识别技术读取书籍位置信息,再传送到物联网汇聚节点进行信息融合和处理,然后通过物联网将信息发送到控制中心,用户通过控制中心可以查询书籍位置信息,从而实现图书馆书籍的智能定位,最后对系统性能进行仿真测试,结果表明,所提系统提升了图书馆书籍信息定位的精度,加快了图书馆书籍信息定位速度,具有较好的智能化程度,实际应用价值更高。

基于CEEMDAN-VSSLMS的滚动轴承故障诊断

针对传统机械轴承故障诊断模型易受系统噪声干扰、特征识别效率低等问题,提出一种基于信号固有模式深度建模分析的轴承故障诊断方法。首先,将采集到的轴承振动信号进行噪声自适应完全经验模态分解(CEEMDAN),获得不同时间尺度的局部特征信号,使用相关系数判别并去除虚假模态分量,再利用可变步长最小均方算法(VSSLMS)对剩余IMF分量降噪并进行重构;然后,将降噪后的振动信号进行离散小波变换(DWT)得到时频谱图,并利用形态学开运算进行特征增强;最后利用改进GoogLeNet网络模型对特征图进行训练,通过Softmax分类器完成特征归类,从而实现轴承故障诊断。将提出的故障诊断方法应用于不同工况下的轴承故障数据集,试验结果表明,所提方法在噪声干扰下具有较高的诊断精度。

基于深度学习的隧道火灾火源位置和热释放速率反演

火源位置和热释放速率(HRR)是指导隧道火灾消防应急救援的重要信息。但在实际中,得到的关于火场的信息十分有限,很难直接得到火源关键信息。提出了一种基于深度学习的隧道火灾火源位置和HRR的反演方法。首先,基于试验数据验证的数值模拟建立不同边界条件下的隧道火灾数据集。基于卷积神经网络(CNN)和长短期记忆网络(LSTM)建立有限的固定式传感器温度数据和火源位置及HRR之间的映射关系,评估了该模型对于火源位置和HRR的反演效果。评估了时间输入步长和传感器间距对该模型反演性能的影响。结果表明,该模型对HRR和火源位置都有较好的反演性能,当时间输入步长为20 s,传感器间距为30 m时,模型反演HRR和火源位置的R2值分别为0.97和0.99。

基于机器学习算法的滑坡土壤含水率预测方法研究

土壤含水率是影响坡体稳定性的决定因素之一。针对滑坡体内部土壤水分信息难以准确感知的问题,建立了一种基于机器学习算法树突神经网络的土壤含水率预测模型(DDNN),通过分析土壤水分垂向变化特征和数据相关性确定关键的影响因子后,将水分预测模型DDNN与GA-BP、RF、RBFNN三种算法进行对比试验。发现DDNN预测模型的拟合优度R2最高为0.998,均方根误差和平均绝对误差均最小,分别为0.091、0.059,其预测精度明显高于其他三种算法。并采用关系谱探究了相关影响因素对土壤含水率的敏感程度。结果表明,敏感度由高到低依次为气温、降水、初始水分、风速、地温,研究结果可为滑坡体稳定性分析提供技术方法支撑。

基于智能优化算法的边坡稳定性预测方法研究

针对边坡稳定性预测中数据分析片面、模型预测精度低的问题,基于302个边坡案例,选取6个变量特征,利用麻雀搜索算法(SSA)更新BP神经网络的敏感因子,建立SSA-BP边坡稳定性预测模型。采用混淆矩阵、受试者工作特征(ROC)曲线及曲线下面积A_(UC)值作为衡量指标,通过五折交叉验证法提高模型的泛化能力并与RF、BP、SVM、PSO-BP、GA-BP和LSTM 6种机器学习算法进行预测效果对比。结果表明,SSA-BP模型的A_(UC)值、准确率和F_1分数均最高,分别为91.90%、85.81%和85.87%,相较于优化前的BP网络A_(UC)值提高了23%。经典算例证明SSA-BP预测模型与ABAQUS计算的安全系数相近,并可给出可靠的预测结果,为岩土工程中边坡稳定性预测提供了一种新方法。