Efficacy and Safety of Iron Isomaltoside Compared with an Oral Iron Supplement in the Management of Patients with Iron Deficiency Anemia

Objective: To evaluate the treatment outcome of iron isomaltoside compared with an oral iron supplement in the management of iron deficiency anemia (IDA). Methods: The study included patients with IDA who visited the Outpatient Clinic of the Department of Hematology, the Affiliated Hospital of Qingdao University from October 2021 to August 2022 and met the inclusion and exclusion criteria. According to the actual application of iron supplementation, the patients were divided into two groups: iron isomaltoside treatment group and oral iron treatment group. Baseline measurements were collected before the start of treatment, and measurements were collected subsequently at intervals of 1 week, 1 month, and 3 months. The hematological parameters analyzed included Hemoglobin (Hb), Mean corpuscular hemoglobin (MCH), Mean Hemoglobin content (MCH), Mean corpuscular Hemoglobin concentration (MCHC), and Platelet (Plt). Safety data and adverse event profiles were recorded. Results: Intra-group comparisons: After 1 month of treatment, the Hb significantly improved (P 0.05). Inter-group comparisons: The biochemical parameters were significantly improved (P 0.05) in the iron isomaltoside group compared with those in the oral iron group after 1 month of iron supplementation in patients with mild and moderate anemia. Adverse reactions were tolerable for the patients in both iron isomaltoside group and oral iron group. Only 1 patient in iron isomaltoside group developed anaphylactic shock during medication and recovered after aggressive rescue. Conclusions: Iron isomaltoside which increases Hb more rapidly compared with the oral iron supplementation has few adverse reactions and good acceptance.

类乙二胺四乙酸螯合纤维素及其对水中重金属离子的吸附性能

为了改善纤维素对重金属的吸附去除性能,文中采用高碘酸钠选择性氧化纤维制得双醛纤维素,通过Schiff碱反应,将乙二胺接枝到纤维素骨架,再将溴乙酸取代到氨基上,获得含有氮和氧配位原子的类乙二胺四乙酸螯合纤维素(EDTA-CL)。表征了其形貌和结构,考察了其对水中Cd^(2+)和Pb^(2+)的吸附性能。EDTA-CL吸附Cd^(2+)和Pb^(2+)的最佳pH范围为4.5~6;EDTA-CL对Cd^(2+)和Pb^(2+)的吸附在20 min内达到了平衡;EDTA-CL对Cd^(2+)和Pb^(2+)的吸附容量分别为236.1 mg/g和382.6 mg/g,氮和氧配位原子的引入大大提高了对Cd^(2+)和Pb^(2+)的吸附容量;EDTA-CL对Cd^(2+)和Pb^(2+)的吸附过程符合Langmuir和准二级动力学模型;EDTA-CL可以重复多次使用。

大口径单井注抽试验求参过程中井底流和混溶效应的综合影响

单井注抽(single-well push-pull,SWPP)试验因其成本低、周期短以及操作简单的优点,被广泛用于求取含水层弥散度等水文地质参数。依托干旱半干旱区常用的大口径井开展SWPP试验,常面临井底流渗漏和井筒混溶效应共同的影响。为此,本研究构建了同时考虑井底流和混溶效应的SWPP试验三阶段溶质运移模型,利用有限差分法对模型进行求解,并利用前人的渗流和溶质运移模型解析解验证其准确性,随后依托该模型探究大口径井附近渗流特征及井尺寸对SWPP试验的影响机制。研究结果表明:(1)新提出的考虑井底流的SWPP试验模型对抽水过程降深以及井壁处溶质运移过程的刻画,同前人解析解匹配良好,表明了该模型构建及求解的准确性;(2)随着井筛长度的逐渐减小,井底流对含水层整体流场的影响程度逐渐增大,流场从径向逐渐转变为球形流场;(3)粗井径相比细井径,注入阶段井中的溶质BTC(Breakthrough curve,穿透曲线)值更小,但抽出阶段的溶质BTC更大,井中混溶过程相比井底渗漏过程对SWPP试验的影响更为显著;(4)当井深小到井径的一半左右时产生类球形流场,井底的渗漏过程相比混溶过程对SWPP试验可能存在更为显著的影响;(5)对于本研究设置的模拟场景,即使不存在井底流,前人的解析解由于忽略井筒混溶,对弥散度的解译仍存在152.5%的误差,而随着井底埋深逐渐减小,井底流导致前人解析解的误差也逐渐增大。

基于切片采样-马尔科夫链蒙特卡洛模拟的高比例新能源电力系统等效惯量概率评估

风电、光伏新能源发电功率的不确定性给高比例新能源电力系统的等效惯量评估带来了新的挑战。基于确定性的惯量评估方法不能有效反映全分析时段高比例新能源电力系统惯量的时序变化态势。为了评估新能源波动所引起的系统惯量不确定性,该文提出了一种基于切片采样–马尔科夫链蒙特卡洛模拟(slice sample Markov chain Monte Carlo,S-MCMC)的系统等效惯量概率评估方法。首先,对高比例新能源电力系统惯量组成及特性进行了分析,并对同步旋转设备的有效机械惯量、风电光伏电源的有效虚拟惯量进行量化计算。然后,基于Copula函数建立风速和光照强度之间的相关性模型,利用S-MCMC对系统等效惯量进行概率评估,从而得到系统等效惯量时序变化区间。最后,以改进的IEEE 39节点系统进行仿真分析,验证了所提出方法及分析结果的有效性。

HBV相关肝病患者外周血T细胞及细胞因子水平研究

背景乙型肝炎病毒(hepatitis B virus,HBV)相关慢性肝病患者外周血T细胞及细胞因子水平与患者免疫功能状态密切相关,不同疾病程度的HBV相关肝病患者的T细胞、细胞因子水平及与肝病阶段的相关性值得进一步探究.目的探究不同阶段HBV相关慢性肝病患者外周血T细胞亚群计数、细胞因子变化特点及关联性.方法本研究为一项观察性研究,共纳入慢性乙型肝炎(chronic hepatitis B,CHB)患者65例,肝硬化失代偿期(decompensated cirrhosis,DCC)患者122例,肝细胞癌(hepatocellular carcinoma,HCC)患者109例,收集患者一般信息、病史、治疗情况及实验室检查结果、Child-Paugh分级及HCC患者肿瘤巴塞罗那分期,分析各项指标,尤其是T细胞亚群计数及细胞因子的组间差异及特征.结果HBV相关肝硬化、HCC患者外周血CD8^(+)T细胞水平与Child分级A到C呈负相关.HCC患者CD8^(+)T细胞绝对计数显著低于DCC[240(150-379)cells/μLvs 277(154-435)cells/μL,P<0.05]及CHB[240(150-379)cells/μL vs 452(269-706)cells/μL,P<0.001]患者.白细胞介素(interleukin,IL)-6、IL-8、肿瘤坏死因子(tumor necrosis factor,TNF)-α在HCC组均最高.DCC、HCC患者Child-Paugh分级越差,CD3^(+)、CD8^(+)T细胞水平越低,IL-6水平越高.HCC患者CD3^(+)、CD8^(+)T细胞水平随着肿瘤巴塞罗那分期由A到D呈下降趋势,IL-6呈上升趋势.且肝硬化、HCC患者CD3^(+)(r=-0.340,P<0.001)、CD8^(+)(r=-0.353,P<0.001)T细胞水平与IL-6升高水平呈显著负相关.结论HBV相关肝硬化、HCC患者外周血CD8^(+)T细胞计数与Child分级(由A到C)呈负相关,且IL-6水平与CD8^(+)T细胞计数存在负相关关系.

Discontinuity development patterns and the challenges for 3D discrete fracture network modeling on complicated exposed rock surfaces

Natural slopes usually display complicated exposed rock surfaces that are characterized by complex and substantial terrain undulation and ubiquitous undesirable phenomena such as vegetation cover and rockfalls.This study presents a systematic outcrop research of fracture pattern variations in a complicated rock slope,and the qualitative and quantitative study of the complex phenomena impact on threedimensional(3D)discrete fracture network(DFN)modeling.As the studies of the outcrop fracture pattern have been so far focused on local variations,thus,we put forward a statistical analysis of global variations.The entire outcrop is partitioned into several subzones,and the subzone-scale variability of fracture geometric properties is analyzed(including the orientation,the density,and the trace length).The results reveal significant variations in fracture characteristics(such as the concentrative degree,the average orientation,the density,and the trace length)among different subzones.Moreover,the density of fracture sets,which is approximately parallel to the slope surface,exhibits a notably higher value compared to other fracture sets across all subzones.To improve the accuracy of the DFN modeling,the effects of three common phenomena resulting from vegetation and rockfalls are qualitatively analyzed and the corresponding quantitative data processing solutions are proposed.Subsequently,the 3D fracture geometric parameters are determined for different areas of the high-steep rock slope in terms of the subzone dimensions.The results show significant variations in the same set of 3D fracture parameters across different regions with density differing by up to tenfold and mean trace length exhibiting differences of 3e4 times.The study results present precise geological structural information,improve modeling accuracy,and provide practical solutions for addressing complex outcrop issues.

多尺度特征与注意力检测头的轻量化FOD检测

针对现阶段机场跑道异物碎片(FOD)目标检测算法存在的缺陷,进行了降低参数量和提高精度的改进。以你只看一次(YOLO)v5s目标检测算法为基础,提出多尺度特征与注意力检测头的轻量化FOD检测算法。首先,提出一种全新的轻量化网络结构。该结构使用深度可分离卷积和逐点卷积,并设计大卷积核架构,使模型感受野提升,从而解决大量特征图冗余问题。接着,融合多尺度特征图。通过移除大目标检测层、增加小目标检测层,在提升小目标检测能力的同时降低网络参数量。最后,提出一种动态头部框架来统一目标检测头和注意力,通过连贯地结合多个自注意力机制,进一步提升了网络检测精度。试验结果表明:所提出的使用鬼影卷积大卷积核架构下的多尺度特征注意力检测头的YOLOv5s(GRD-YOLOv5s)网络的参数量减少为3.39 MB,仅为原网络的48%;平均检测精度从98.40%提升至99.45%;检测速度为53.42帧/秒。该网络的提出为实现对小目标的准确检测提供了新思路。

基于轻量级卷积神经网络的转子碰摩故障诊断

随着非平稳信号的时频故障特征表示技术的优势以及卷积神经网络(CNN)的出现,转子碰摩故障诊断已经达到了高精度。然而,基于CNN的故障诊断方法有许多缺点,提出了一种基于轻量级卷积神经网络(GHSQNet)与时频图相结合的转子碰摩故障诊断方法。该方法能够在保证故障诊断精度的同时占用更小的内存。实验结果表明,与其他轻量级卷积神经网络相比,提出的模型性能表现更加优越。识别准确率达到了99.39%,而模型大小只有1.07 MB,在移动端有很高的实用价值。

辐射防护系统就地处理显示单元调试及评价

中国先进研究堆(CARR)辐射监测系统运行多年,运行可靠性降低,通过升级改造提高了CARR辐射监测系统的可靠性和维护维修的便利性。文章通过对改造后的就地处理显示单元和调试方法进行介绍,评价其调试结果,为其他反应堆辐射监测系统改造、调试提供参考。

A LiDAR Point Clouds Dataset of Ships in a Maritime Environment

For the first time, this article introduces a LiDAR Point Clouds Dataset of Ships composed of both collected and simulated data to address the scarcity of LiDAR data in maritime applications. The collected data are acquired using specialized maritime LiDAR sensors in both inland waterways and wide-open ocean environments. The simulated data is generated by placing a ship in the LiDAR coordinate system and scanning it with a redeveloped Blensor that emulates the operation of a LiDAR sensor equipped with various laser beams. Furthermore,we also render point clouds for foggy and rainy weather conditions. To describe a realistic shipping environment, a dynamic tail wave is modeled by iterating the wave elevation of each point in a time series. Finally, networks serving small objects are migrated to ship applications by feeding our dataset. The positive effect of simulated data is described in object detection experiments, and the negative impact of tail waves as noise is verified in single-object tracking experiments. The Dataset is available at https://github.com/zqy411470859/ship_dataset.

Correlation of personality with individual reproductive success in shrub-nesting birds depends on their life history style

Two questions in the research of animal personality—whether there is a correlation between a personality trait and individual reproductive success,and what is the genetic basis underlying a personality trait—remain unresolved.We addressed these two questions in three shrub-nesting birds,the Azure-winged Magpie(Cyanopica cyanus,AM),White-collared Blackbird(Turdus albocinctus,WB),and Brown-cheeked Laughingthrush(Trochalopteron henrici,BL).The personality type of an individual was first identified according to its response to a territorial intruder.Then,we compared the fleeing distance,breeding parameters,and differential expressed genes(DEGs) in the brain transcriptome between bold and shy breeders.In the three species,bold breeders exhibited more aggressiveness towards an intruder of their territory than did shy breeders.The reproductive success of bold breeders was significantly higher than that of shy breeders in AM but not in WB and BL.The three species shared one DEG,crabp1,which was up-regulated in bold relative to in shy individuals.By regulating the expression of corticotropin-releasing hormone,higher crabp1 gene expression can decrease cellular response to retinoic acid.Therefore,bold individuals are insensitive to external stresses and able to exhibit more aggressiveness to intruders than their shier counterparts.Aggressiveness is beneficial to bold individuals in AM but not in WB and BL because the former could evoke neighbors to make the same response of defending against intruders but the latter could not.Although a personality trait may have the same genetic basis across species,its correlation with reproductive success depends largely on the life history style of a species.

Degradable magnesium alloy suture promotes fibrocartilaginous interface regeneration in a rat rotator cuff transosseous repair model

Despite transosseous rotator cuff tear repair using sutures is widely accepted for tendon-bone fixation,the fibrocartilaginous enthesis regeneration is still hardly achieved with the traditional sutures.In the present work,degradable magnesium(Mg)alloy wire was applied to suture supraspinatus tendon in a rat acute rotator cuff tear model with Vicryl Plus 4±0 absorbable suture as control.The shoulder joint humerus-supraspinatus tendon complex specimens were retrieved at 4,8,and 12 weeks after operation.The Mg alloy suture groups showed better biomechanical properties in terms of ultimate load to failure.Gross observation showed that hyperplastic response of the scar tissue at the tendon-bone interface is progressively alleviated over time in the both Mg alloy suture and Vicryl suture groups.In the histological analysis,for Mg alloy suture groups,chondrocytes appear to proliferate at 4 weeks postoperatively,and the tendon-bone interface showed an orderly structural transition zone at 8 weeks postoperatively.The collagenous fiber tended to be aligned and the tendon-bone interlocking structures apparently formed,where transitional structure from unmineralized fibrocartilage to mineralized fibrocartilage was closer to the native fibrocartilaginous enthesis.In vivo degradation of the magnesium alloy wire was completed within 12 weeks.The results indicated that Mg alloy wire was promising as degradable suture with the potential to promotes fibrocartilaginous interface regeneration in rotator cuff repair.

An improved TDE technique for derivation of 2D turbulence structures based on GPI data in toroidal plasma

This paper reports an improved time-delay estimation(TDE)technique for the derivation of turbulence structures based on gas-puff imaging data.The improved TDE technique,integrating an inverse timing search and hierarchical strategy,offers superior accuracy in calculating turbulent velocity field maps and analyzing blob dynamics,which has the power to obtain the radial profiles of equilibrium poloidal velocity,blob size and its radial velocity,even the fluctuation analysis,such as geodesic acoustic modes and quasi-coherent mode,etc.This improved technique could provide important 2D information for the study of edge turbulence and blob dynamics,advancing the understanding of edge turbulence physics in fusion plasmas.

Single-center retrospective study of the diagnostic value of doubleballoon enteroscopy in Meckel’s diverticulum with bleeding

BACKGROUND The study aimed to analyze the characteristic clinical manifestations of patients with intestinal disease Meckel’s diverticulum(MD)complicated by digestive tract hemorrhage.Moreover,we aimed to evaluate the value of double-balloon enteroscopy(DBE)in MD diagnosis and the prognosis after laparoscopic diverticula resection.AIM To evaluate the value of DBE in the diagnosis and the prognosis after laparoscopic diverticula resection for MD with bleeding.METHODS The study retrospectively analyzed relevant data from 84 MD patients treated between January 2015 and March 2022 and recorded their clinical manifestations,auxiliary examination,and follow-up after laparoscopic resection of diverticula.RESULTS(1)Among 84 MD patients complicated with hemorrhage,77 were male,and 7 were female with an average age of 31.31±10.75 years.The incidence was higher in men than in women of different ages;(2)Among the 84 MD patients,65(78.40%)had defecated dark red stools,and 50(58.80%)had no accompanying symptoms during bleeding,indicating that most MD bleeding appeared a dark red stool without accompanying symptoms;(3)The shock index of 71 patients(85.20%)was<1,suggesting that the blood loss of most MD patients was less than 20%–30%,and only a few patients had a blood loss of>30%;(4)The DBE-positive rate was 100%(54/54),99mTcpertechnetate-positive scanning rate was 78%(35/45)compared with capsule endoscopy(36%)and small intestine computed tomography(19%).These results suggest that DBE and 99mTc-pertechnetate scans had significant advantages in diagnosing MD and bleeding,especially DBE was a highly precise examination method in MD diagnosis;(5)A total of 54 MD patients with hemorrhage underwent DBE examination before surgery.DBE endoscopy revealed many mucosal manifestations including normal appearance,inflammatory changes,ulcerative changes,diverticulum inversion,and nodular hyperplasia,with ulcerative changes being the most common(53.70%).This suggests that diverticular mucosal ulcer was the main cause of MD and bleeding;and(6)Laparoscopic dissection of diverticulae was performed in 76 patients,The patients who underwent postoperative follow-up did not experience any further bleeding.Additionally,follow-up examination of the 8 cases who had declined surgery revealed that 3 of them experienced a recurrence of digestive tract bleeding.These findings indicate that laparoscopic diverticula resection in MD patients complicated by bleeding had a favorable prognosis.CONCLUSION Bleeding associated with MD was predominantly observed in male adolescents,particularly at a young age.DBE was a highly precise examination method in MD diagnosis.Laparoscopic diverticula resection effectively prevented MD bleeding and had a good prognosis.

Investigating the Influence of Digital Economy Growth on Industrial Structural Optimization and Upgrading

With the rapid development of the social economy,science and technology continue to upgrade and optimize,ushering in the digital era,which provides technical support for industrial innovation and development across all sectors.At this stage,vigorously developing the digital economy has gradually become the only means to optimize and upgrade the industrial structure.Therefore,local leaders and relevant departments need to enhance the importance of constructing the digital economy,enabling the local industrial structure to be optimized and upgraded under the impetus of the digital economy,ultimately promoting overall economic high-quality development.To this end,this paper,combined with existing research results,first elaborates on the positive impact of the digital economy on the optimization and upgrading of the industrial structure.It then analyzes the challenges hindering the process of industrial structure optimization and upgrading and proposes practical pathways to address them,benefiting relevant stakeholders.

迪那2凝析气田全生命开采周期纵横向出砂规律探索

塔里木油田迪那2凝析气田属于高温高压、低孔低渗、中—高胶结强度裂缝性砂岩气藏,具有低孔低渗特点,传统观点均认为该类型储层不存在出砂问题,但自2009年投产至今,21口井取到砂样,出砂情况普遍,已成为影响气田稳产的一个关键技术难题。为此,建立了多孔弹塑性3D出砂流固耦合模型,利用数值模拟方法,对迪那2气田开展全方位出砂量预测。研究表明:迪那2气田出砂过程可划分为少量出砂、出砂递增、出砂加剧及稳定出砂4个阶段;重度出砂区域在X-6、X-7、X-8井周围,出砂量从气田中部往四周逐步降低,重点出砂层位在库姆格列木群E_(1-2)km^(2)组。经现场实测数据验证,出砂量预测误差在15%以内,说明该出砂量预测方法具有实用性。该研究可为油田制订合理防砂对策和高效开发提供技术支持。

双向主客体作用促进水溶液中选择性光催化CO_(2)还原与醇氧化

CO_(2)还原与H_(2)O氧化耦合被认为是将太阳能转化为化学能的理想方法.然而,H_(2)O氧化反应的显著动力学障碍限制了该类反应的转化效率.此外,额外的电子牺牲剂的消耗不仅在经济上不可行,而且浪费了光生空穴的氧化能力.因此,将CO_(2)还原与有机物的有效氧化相结合将是有效利用太阳能和解决能源危机的有效途径之一.对于包含光敏剂、催化剂和反应底物的离散光催化体系来说,电子转移效率主要由离散组分之间的扩散过程控制.为了提高光反应组分之间的电子转移效率,研究人员尝试通过共价键在催化剂和光敏剂之间建立“桥梁”,从而获得更快的电子转移速率.然而,该类体系存在合成过程复杂、共价键断裂及使用贵金属等问题.与共价键相比,非共价体系更便于合成,且具有更好的稳定性.本文利用双向主客体相互作用构筑高效光催化体系,其中水溶性β-环糊精修饰的CdS纳米晶与CoTPP(助催化剂)和有机醇(反应底物)均通过非共价主客体作用连接,促使光生电子和光生空穴的同步快速消耗.核磁共振氢谱结果表明,环糊精作为主体分子可以识别客体分子四苯基卟啉钴与呋喃醇.利用Job曲线测得环糊精与四苯基卟啉钴以及呋喃醇的键合比分别为2:1和1:1.紫外-可见吸收光谱结果表明,环糊精与四苯基卟啉钴以及呋喃醇之间存在不同强度的主客体键合.光催化CO_(2)还原反应与呋喃醇氧化性能测试结果表明,与无配体的Cd S纳米晶(CdS-BF_(4))以及其它配体(油酸、2-巯基乙醇和硫代甘油)修饰的Cd S纳米晶相比,环糊精修饰的CdS-CD纳米晶在水相中表现出更高的CO_(2)还原为HCOOH的活性与选择性,同时,表现出最佳的呋喃醇氧化活性与选择性.相反,表面无配体的Cd S-BF4纳米晶活性较低,且有严重的析氢副反应发生.为了更好地理解双向主客体相互作用对光反应性能的贡献,利用一系列稳态和瞬态荧光光谱实验研究了三个组分之间的电子转移过程.结果表明,CdS-CD与Co TPP之间以及Cd S-CD与呋喃醇之间的双向主客体相互作用可以有效促进这些组分之间的电子转移过程.原位漫反射傅立叶变换红外光谱和密度泛函理论研究表明,随着光辐射时间的增加,HCOO*信号逐渐增强.电子顺磁共振波谱结果表明,在光催化呋喃醇氧化的过程中产生了呋喃醇苄基自由基.在以上光还原和光氧化的全反应过程中,双向主客体作用同时将助催化剂和反应物聚集在吸光物质Cd SNCs表面,这对于促进快速电子/空穴转移和随后的氧化还原反应发挥着关键作用.综上所述,选择合适的有机物不仅可以促进光还原反应的发生,还可以生产更高附加值的化学品.本文采用双向主客体策略构建新型的人工光合作用系统,为构建具有实际应用潜能的人工光合作用系统提供了新的思路.

等离激元催化反应动力学研究装置

等离激元催化是利用金属纳米颗粒的局域表面等离激元来驱动化学反应的现象,已经发展成为多相催化的一个新兴研究领域.然而,实验研究中温度测量不准和反应物吸附状态不明确导致等离激元催化反应的微观机制存在争议.为了研究等离激元催化反应动力学,本文设计搭建了一台基于在线质谱检测的装置,通过对反应器的改进来解决温度测量和吸附状态识别的问题.相比于传统设计中仅安装一个热偶,本文在反应器中安装了三个热偶.基于传热模型,这种多点测温技术可以定量计算出催化剂的有效温度以及热反应的贡献.此外,在装置中集成了程序升温脱附谱,用于测量反应物的吸附状态.通过对模型催化反应Au/TiO_(2)等离激元催化H_(2)+D_(2)→HD的定量测量,测试了该装置的性能,明确了H_(2)/D_(2)在Au/TiO_(2)界面的解离吸附和非热反应对HD生成的贡献,证明了该装置在等离激元催化反应动力学研究方面的能力.

基于扎根理论的北京市大学生外卖餐饮购买行为影响因素与干预关键点研究

目的构建北京市大学生外卖餐饮购买行为的影响因素理论模型,确定干预关键点,为促进北京高校学生健康餐饮提供建议。方法基于扎根理论,于2021年12月采用滚雪球法招募北京市8所高校24名学生进行半结构化访谈,对文本资料进行三级编码构建理论模型。结果共生成464个编码参考点,概括为67个子范畴,提炼为17个范畴,最终归纳为外卖因素(217参考点)、个人因素(101参考点)、环境因素(93参考点)和人际因素(53参考点)4个主范畴。餐饮质量与配送情况等外卖相关因素是影响学生外卖餐饮购买行为的最主要因素,点餐经历、健康认知等个人因素和校内食堂设置、课业压力、社会舆论等环境因素居于次位,而同学与家长对于外卖的态度倾向等人际因素则较少影响学生的外卖餐饮购买行为。结论外卖餐饮自身各方面因素对于学生的购买行为影响较大,且学生购买外卖的需求难以直接抑制;高校食堂水平发挥着十分重要的作用;大多数受访者对食品营养认识不足。对高校而言,环境因素中的学校食堂水平、个人因素中的健康认知可作为干预关键点。

A Survey on Negative Transfer

Transfer learning(TL)utilizes data or knowledge from one or more source domains to facilitate learning in a target domain.It is particularly useful when the target domain has very few or no labeled data,due to annotation expense,privacy concerns,etc.Unfortunately,the effectiveness of TL is not always guaranteed.Negative transfer(NT),i.e.,leveraging source domain data/knowledge undesirably reduces learning performance in the target domain,and has been a long-standing and challenging problem in TL.Various approaches have been proposed in the literature to address this issue.However,there does not exist a systematic survey.This paper fills this gap,by first introducing the definition of NT and its causes,and reviewing over fifty representative approaches for overcoming NT,which fall into three categories:domain similarity estimation,safe transfer,and NT mitigation.Many areas,including computer vision,bioinformatics,natural language processing,recommender systems,and robotics,that use NT mitigation strategies to facilitate positive transfers,are also reviewed.Finally,we give guidelines on NT task construction and baseline algorithms,benchmark existing TL and NT mitigation approaches on three NT-specific datasets,and point out challenges and future research directions.To ensure reproducibility,our code is publicized at https://github.com/chamwen/NT-Benchmark.