创业网络从何而来?——决策逻辑视角下创业者结网研究回顾与展望

创业网络对于新创企业的存活和发展而言意义重大。伴随网络能动观的提出,创业网络研究开始关注创业者结网(Entrepreneurial Networking),探讨“创业网络从何而来”的问题,即创业者如何建立和发展创业网络。然而,既有研究未能清晰界定创业者结网的概念内涵及其背后的决策逻辑,对于创业网络来源多样性及其原因的体系化研究框架亟待整合。基于文献回顾,首先本文结合目标与行动先后顺序的不同理论假设,明晰创业者结网的概念内涵与策略类型;其次,梳理创业者“决策逻辑-结网模式”的逻辑链条,系统归纳创业网络“搜集”“汇集”“搜集+汇集”三条来源路径,并引入不确定性这一关键条件,从区域、企业和个体三个层次解构不同路径的适用边界;最后,从细化创业者结网概念、探索数字组织场景新议题、拓展研究方法三个角度提出未来研究方向。本文通过刻画创业者结网研究的“认知-行为”路径框架,为拓展能动观视角下创业网络来源研究以及推动创业网络微观机制研究提供了理论借鉴。

循环肿瘤DNA在结直肠癌精准诊疗中的应用

结直肠癌(colorectal cancer,CRC)是世界上最常见的恶性肿瘤之一,其发病率和死亡率居高不下,严重危害着人们的身体健康。传统的诊断模式已不能满足现如今人们对于肿瘤进行实时监测的需求。对比传统的检测手段,ctDNA检测不仅无创,而且能够实时检测肿瘤全面的基因组信息。随着检测技术的进步,逐渐凸显出其在CRC临床治疗中的潜在价值。本文就ctDNA在CRC患者中早期筛查、微小残留病变检测、指导个体化治疗的临床应用进展进行综述。

Feature extraction and learning approaches for cancellable biometrics:A survey

Biometric recognition is a widely used technology for user authentication.In the application of this technology,biometric security and recognition accuracy are two important issues that should be considered.In terms of biometric security,cancellable biometrics is an effective technique for protecting biometric data.Regarding recognition accuracy,feature representation plays a significant role in the performance and reliability of cancellable biometric systems.How to design good feature representations for cancellable biometrics is a challenging topic that has attracted a great deal of attention from the computer vision community,especially from researchers of cancellable biometrics.Feature extraction and learning in cancellable biometrics is to find suitable feature representations with a view to achieving satisfactory recognition performance,while the privacy of biometric data is protected.This survey informs the progress,trend and challenges of feature extraction and learning for cancellable biometrics,thus shedding light on the latest developments and future research of this area.

丁酸钠在反刍动物上的应用研究进展

丁酸钠在反刍动物上具有促进瘤胃等消化道上皮细胞生长、缓解炎症、抗氧化等多种生物学作用,能够提高反刍动物的营养物质消化率、生产性能,以及抗球虫等。本文综述了丁酸钠的生物学作用及其在反刍动物上的应用研究进展,以期为丁酸钠在反刍动物上的应用提供理论和实践参考。

突发公共事件对员工对上关系建构的影响:基于调节定向理论

现有突发公共事件的研究大多关注其负面影响,鲜有研究讨论个体如何积极应对。基于调节定向理论,本文关注在突发公共事件引发的损失情境下,员工如何通过对上关系建构应对损失的自我调节机制。研究1以我国华中地区某制造业企业266名员工为样本,检验突发公共事件对员工对上关系建构的主效应以及情境性预防定向的中介作用。研究2基于206名跨地区跨行业的员工数据,检验特质性预防定向的调节作用。研究发现:(1)突发公共事件和员工的对上关系建构行为正向相关;(2)情境性预防定向在突发公共事件和对上关系建构之间起到中介作用;(3)特质性预防定向正向调节情境性预防定向的中介作用。本文丰富了突发公共事件影响个体心理状态和对上关系建构行为的研究,从宏观事件和微观动机层面有效拓展了对上关系建构行为的前因变量,并将调节定向理论引入突发公共事件研究中,深化了该理论在损失情境下的解释机制。

医用聚乳酸材料性能及加工方法研究进展

与天然降解高分子材料相比,人工合成高分子材料具有更好的力学性能、可控的降解性能及良好的生物相容性,因此广泛用于生物材料制品。聚乳酸是研究最多的人工合成高分子材料之一。文中围绕医用聚乳酸材料的性能及加工方法,首先介绍了聚乳酸体内降解规律及生物安全性的研究现状,其次综述了组织工程支架领域多种加工方法(熔融沉积3D打印、静电纺丝、气体发泡、相分离、冷冻干燥等)的技术特点,并概述了药物传输微球常用加工方法(喷雾干燥法、溶剂挥发法、其他方法)的研究进展,最后对聚乳酸材料性质、加工方法及在生物医学领域的应用前景进行了展望。

一种全局供需感知的均值场多智能体强化学习订单分配算法

提出一种具备全局供需动态感知能力、基于均值场多智能体强化学习的网约车平台订单分配算法。该算法通过将多智能体强化学习与均值场理论相结合,提升了智能体在局部空间上相互之间的协作性;通过注入全局空间上供需的动态分布信息,提升了智能体对全局供需分布的感知和优化能力。本文构建了真实历史数据驱动的模拟器,用于算法的训练和评估。实验表明,在全天时段和高峰期时段两个不同场景下,本文提出的算法在网约车司机累计收益及订单应答率两个重要指标上均显著优于现有的订单分配算法。实验结果充分验证了本文提出算法的有效性。

Organic Optoelectronic Synapses for Sound Perception

The neuromorphic systems for sound perception is under highly demanding for the future bioinspired electronics and humanoid robots.However,the sound perception based on volume,tone and timbre remains unknown.Herein,organic optoelectronic synapses(OOSs)are constructed for unprecedented sound recognition.The volume,tone and timbre of sound can be regulated appropriately by the input signal of voltages,frequencies and light intensities of OOSs,according to the amplitude,frequency,and waveform of the sound.The quantitative relation between recognition factor(ζ)and postsynaptic current(I=I_(light)−I_(dark))is established to achieve sound perception.Interestingly,the bell sound for University of Chinese Academy of Sciences is recognized with an accuracy of 99.8%.The mechanism studies reveal that the impedance of the interfacial layers play a critical role in the synaptic performances.This contribution presents unprecedented artificial synapses for sound perception at hardware levels.

Simultaneous realization of high sulfur utilization and lithium dendrite-free via dual-effect kinetic regulation strategy toward lithium-sulfur batteries

With the high theoretical specific capacity and energy density,lithium-sulfur batteries(LSBs)have been intensively studied as promising candidates for energy storage devices.However,LSBs are largely hindered by inferior sulfur utilization and uncontrollable dendritic growth.Herein,a hierarchical functionalization strategy of stepwise catalytic-adsorption-conversion for sulfur species via the synergetic of the efficiently catalytic host cathode and light multifunctional interlayer has been proposed to concurrently address the issues arising on the dual sides of the LSBs.The multi-layer SnS_(2) micro-flowers embedded into the natural three-dimensional(3D)interconnected carbonized bacterial cellulose(CBC)nanofibers are fabricated as the sulfur host that provides numerous catalytic sites for the rapid catalytic conversion of sulfur species.Moreover,the distinctive CBC-based SnO_(2)-SnS_(2) heterostructure network accompanied high conductive carbon nanofibers as the multifunctional interlayer promotes the rapid anchoringdiffusion-conversion of lithium polysulfides,Li^(+)flux redistribution,and uniform Li deposition.LSBs equipped with our strategy exhibit a high reversible capacity of 1361.5 m A h g^(-1)at 0.2 C and superior cycling stability with an ultra-low capacity fading of 0.031%per cycle in 1000 cycles at 1.5 C and 0.046%at 3 C.A favorable specific capacity of 859.5 m A h g^(-1)at 0.3 C is achieved with a high sulfur mass loading of 5.2 mg cm^(-2),highlighting the potential of practical application.The rational design in this work can provide a feasible solution for high-performance LSBs and promote the development of advanced energy storage devices.

Screening hepatoprotective effective components of Lonicerae japonica Flos based on the spectrum-effect relationship and its mechanism exploring

Lonicerae japonicae Flos(LF)is a kind of healthcare food with hepatoprotective function.This study was designed to explore the spectrum-effect relationships between UPLC fingerprints and the hepatoprotective effects of LF.Fingerprints of ten batches of LF were established by UPLC-PDA.The inhibitory levels of AST and ALT were used as pharmacological indexes,and secoxyloganin,isochlorogenic acid A and isochlorogenic acid C were screened as hepatoprotective active compounds by grey relational analysis(GRA)and partial least squares regression analysis(PLSR).Caspase-3 was obtained by network pharmacology as a key target of hepatoprotective active compounds.Molecular docking is used to explore the interaction between small molecules and proteins.This work provided a general model of the combination of UPLC-PDA and hepatoprotective effect to study the spectrum-effect relationship of LF,which can be used to considerable methods and insight for the fundamental research of the material basis of similar healthcare food.

State of art on the mechanisms of laparoscopic sleeve gastrectomy in treating type 2 diabetes mellitus

Obesity and type-2 diabetes mellitus(T2DM)are metabolic disorders.Obesity increases the risk of T2DM,and as obesity is becoming increasingly common,more individuals suffer from T2DM,which poses a considerable burden on health systems.Traditionally,pharmaceutical therapy together with lifestyle changes is used to treat obesity and T2DM to decrease the incidence of comorbidities and allcause mortality and to increase life expectancy.Bariatric surgery is increasingly replacing other forms of treatment of morbid obesity,especially in patients with refractory obesity,owing to its many benefits including good long-term outcomes and almost no weight regain.The bariatric surgery options have markedly changed recently,and laparoscopic sleeve gastrectomy(LSG)is gradually gaining popularity.LSG has become an effective and safe treatment for type-2 diabetes and morbid obesity,with a high cost-benefit ratio.Here,we review the mechanism associated with LSG treatment of T2DM,and we discuss clinical studies and animal experiments with regard to gastrointestinal hormones,gut microbiota,bile acids,and adipokines to clarify current treatment modalities for patients with obesity and T2DM.

液相色谱串联质谱法同时测定凡纳滨对虾中的27种抗寄生虫药物残留

目的:规范凡纳滨对虾抗寄生虫药物的使用。方法:用80%乙腈水溶液提取凡纳滨对虾样品中的抗寄生虫药物,经C 18和中性氧化铝粉净化后,超高效液相色谱—串联质谱分析。药物经Thermo Hypersil Gold aQ色谱柱分离,0.1%甲酸—乙腈和10 mmol/L甲酸铵溶液(含0.1%甲酸)分别作为有机相和水相进行梯度洗脱,采用电喷雾离子源正负离子同步扫描,多反应监测模式,基质匹配标准溶液外标法定量分析。结果:27种抗寄生虫药物在一定浓度范围内皮尔森相关系数(r)大于0.9741,线性关系良好;检出限为0.5~2.0μg/kg,定量限为2~5μg/kg;空白样品在5,10,50μg/kg 3个添加水平下的方法加标回收率(n=6)为61.90%~118.54%,批内变异系数(n=6)为0.57%~12.56%,批间变异系数(n=3)为1.29%~16.47%。结论:该方法选择性好,回收率、精密度高,测定周期短,可满足实验室的检测需要。

Diagnosis of Disc Space Variation Fault Degree of Transformer Winding Based on K-Nearest Neighbor Algorithm

Winding is one of themost important components in power transformers.Ensuring the health state of the winding is of great importance to the stable operation of the power system.To efficiently and accurately diagnose the disc space variation(DSV)fault degree of transformer winding,this paper presents a diagnostic method of winding fault based on the K-Nearest Neighbor(KNN)algorithmand the frequency response analysis(FRA)method.First,a laboratory winding model is used,and DSV faults with four different degrees are achieved by changing disc space of the discs in the winding.Then,a series of FRA tests are conducted to obtain the FRA results and set up the FRA dataset.Second,ten different numerical indices are utilized to obtain features of FRA curves of faulted winding.Third,the 10-fold cross-validation method is employed to determine the optimal k-value of KNN.In addition,to improve the accuracy of the KNN model,a comparative analysis is made between the accuracy of the KNN algorithm and k-value under four distance functions.After getting the most appropriate distance metric and kvalue,the fault classificationmodel based on theKNN and FRA is constructed and it is used to classify the degrees of DSV faults.The identification accuracy rate of the proposed model is up to 98.30%.Finally,the performance of the model is presented by comparing with the support vector machine(SVM),SVM optimized by the particle swarmoptimization(PSO-SVM)method,and randomforest(RF).The results show that the diagnosis accuracy of the proposed model is the highest and the model can be used to accurately diagnose the DSV fault degrees of the winding.

Integrated percutaneous sclerotherapy and surgical intervention for giant cutaneomucosal venous malformation from TIE2 mutation:A case report

Cutaneomucosal venous malformations(VMCMs)can manifest as sporadic or familial forms,following an autosomal dominant inheritance pattern.This report highlights the case of a 5-year-old girl presenting with a substantial congenital VMCM attributed to a TIE2 mutation,who underwent percutaneous sclerotherapy followed by surgery.The clinical,three-dimensional computed tomographic angiography(3D-CTA),as well as pathological and genetic findings concerning a patient with an extensive VMCM in the left pro-axillary region,are elucidated.The genetic analysis in this patient verified a missense mutation(c.2545T>C)in TIE2,confirming familial VMCMs.The combined strategy integrating percutaneous sclerotherapy and surgical excision is the most efficacious approach for managing large VMCMs and can successfully attain therapeutic goals.

Effects of Astragalus membranaceus on Energy Metabolism and Expression of CNTF Protein in Skeletal Muscle of Exercise-induced Fatigue Rats

[Objectives]This study was conducted to investigate the effects of Astragalus membranaceus in different groups on energy metabolism and CNTF protein expression in skeletal muscle of exercise-induced fatigue rats.[Methods]Thirty-five clean male SD rats were randomly divided into a normal group,and low-,meddle-and high-dose groups of A.membranaceus aqueous solution,with 7 rats in each group.The low-dose,medium-dose and high-dose groups were given by gavage at 0.65,1.3 and 2.6 g/kg,respectively,while the normal group and the model group were given normal food and water.The weight of rats was observed.The contents of serum urea,lactate,muscle glycogen,liver glycogen and CNTF expression were detected.[Results]After modeling,compared with the normal group,the serum lactate and urea contents of rats in the model group significantly increased(P<0.01),while the muscle glycogen content(P<0.01)and liver glycogen content(P<0.05)of the skeletal muscle significantly decreased.Compared with the model group,the low-,meddle-and high-dose groups of A.membranaceus significantly reduced the levels of lactate and urea in serum(P<0.01),while the levels of muscle glycogen and liver glycogen in the skeletal muscle significantly increased(P<0.01,P<0.05).[Conclusions]This study provides a good research foundation for the treatment of exercise-induced fatigue using traditional Chinese herb A.membranaceus in modern clinical practice.

Person Re-Identification with Model-Contrastive Federated Learning in Edge-Cloud Environment

Person re-identification(ReID)aims to recognize the same person in multiple images from different camera views.Training person ReID models are time-consuming and resource-intensive;thus,cloud computing is an appropriate model training solution.However,the required massive personal data for training contain private information with a significant risk of data leakage in cloud environments,leading to significant communication overheads.This paper proposes a federated person ReID method with model-contrastive learning(MOON)in an edge-cloud environment,named FRM.Specifically,based on federated partial averaging,MOON warmup is added to correct the local training of individual edge servers and improve the model’s effectiveness by calculating and back-propagating a model-contrastive loss,which represents the similarity between local and global models.In addition,we propose a lightweight person ReID network,named multi-branch combined depth space network(MB-CDNet),to reduce the computing resource usage of the edge device when training and testing the person ReID model.MB-CDNet is a multi-branch version of combined depth space network(CDNet).We add a part branch and a global branch on the basis of CDNet and introduce an attention pyramid to improve the performance of the model.The experimental results on open-access person ReID datasets demonstrate that FRM achieves better performance than existing baseline.

艾草的应用基础研究及开发利用进展

主要针对艾草的化学成分及其作用机理、分子生物学等应用基础研究,以及在临床、食用、动物饲料添加、家纺和日用化学品等方面的应用进行了概述,旨在为艾草研究和产业发展提供信息。

Study on Ability of Ground Cover Plant of Taiyuan to Adsorb PM(2.5)

Four ground cover plant species of Taiyuan（ Iris,Hemerocallis,Sedum,Hosta） were selected to study their capacities in adsorbing PM（2.5）. Meanwhile,the concentration of PM（2.5） in Taiyuan between April 2017 and August 2017 was recorded,and the characteristics of PM（2.5） pollution in summer and autumn in Taiyuan were studied. The results showed that for the 4 plants,the ability to adsorb PM（2.5） was in the order from great to small of Hosta,Iris,Hemerocallis,Sedum,in which H. plantaginea had the best effect to adsorb PM（2.5）. The fresh weight and dry weight per gram of H. plantaginea were 4. 4 times and 2 times higher than those of S. spectabile,while the mass quality of dust adsorption was 2.8 times higher. The sorting result was the same as the ability to adsorb PM（2.5） of unit leaf area. The result of the coefficient of purification showed that the purification coefficients of 3 vegetation structure were positive,and the combination of trees and shrubs in university campus had strong PM（2.5） adsorption capacity. By comparing the seasonal variation of PM（2.5） concentration in Taiyuan city,it found that the PM（2.5） concentration was particularly high in late spring and early summer of Taiyuan,when most of the ground cover plants were not fully grown. Therefore,ground cover plants played an important role in the construction of landscape and the regulation of ecological environment in Taiyuan.

重症心脏瓣膜病的外科治疗

目的:探讨提高重症心脏瓣膜病外科治疗成功率、降低死亡率的方法。方法:回顾总结2015年1月-2018年12月我院重症瓣膜病手术治疗患者42例临床资料。结果:术后3例死亡,死亡率7.14%,2例死于多器官功能衰竭,1例死于肺部感染、急性肾功能衰竭,其余均好转出院。术后随访6-48个月,4例患者术后再发心衰,其中1例住院期间因华法林抗凝不足并发脑梗,经治疗后均好转出院,其余患者均恢复良好。结论:充分的术前准备,缩短手术时间,提高手术技术,精细化的术后管理,是重症瓣膜病治疗成功的关键。

Development and Performance Evaluation of a Deep Water Synthetic Based Drilling Fluid System

With the enhancement of environmental protection awareness, the requirements on drilling fluid are increasingly strict, and the use of ordinary oil-based drilling fluid has been strictly restricted. In order to solve the environmental protection and oil-gas reservoir protection problems of offshore oil drilling, a new synthetic basic drilling fluid system is developed. The basic formula is as follows: a basic fluid (80% Linear a-olefin + 20% Simulated seawater) + 2.5% nano organobentonite + 3.5% emulsifier RHJ-5# + 2.5% fluid loss agent SDJ-1 + 1.5% CaO + the right amount of oil wetting barite to adjust the density, and a multifunctional oil and gas formation protective agent YRZ has been developed. The performance was evaluated using a high-low-high-temperature rheometer, a high-temperature and high-pressure demulsification voltage tester, and a high-temperature and high-pressure dynamic fluid loss meter. The results show that the developed synthetic based drilling fluid has good rheological property, demulsification voltage ≥ 500 V, temperature resistance up to 160°C, high temperature and high pressure filtration loss < 3.5 mL. After adding 2% - 5% YRZ into the basic formula of synthetic based drilling fluid, the permeability recovery value exceeds 90% and the reservoir protection effect is excellent. The new synthetic deepwater drilling fluid is expected to have a good application prospect in offshore deepwater drilling.