Polyurea coating for foamed concrete panel:An efficient way to resist explosion

Autoclaved aerated concrete(AAC) panels have ultra-light weight,excellent thermal insulation and energy absorption,so it is an ideal building material for protective structures.To improve the blast resistance of the AAC panels,three schemes are applied to strengthen the AAC panels through spraying 4 mm thick polyurea coating from top,bottom and double-sides.In three-point bending tests,the polyurea-coated AAC panels have much higher ultimate loads than the un-coated panels,but slightly lower than those strengthened by the carbon fiber reinforced plastics(CEFRPs).Close-in explosion experiments reveal the dynamic strengthening effect of the polyurea coating.Critical scaled distances of the strengthened AAC panels are acquired,which are valuable for the engineering application of the AAC panels in the extreme loading conditions.Polyurea coatings efficiently enhance the blast resistance of the bottom and double-sided polyurea-coated AAC panels.It is interesting that the polyurea-coated AAC panels have much more excellent blast resistance than the CFRP reinforced AAC panels,although the latter have better static mechanical properties.

Fabrication and Mechanical Testing of Ultralight Folded Lattice-CoreSandwich Cylinders

In this research,two novel folded lattice-core sandwich cylinders were designed,manufactured,and tested.The lattice core has periodic zigzag corrugations,whose ridges and valleys are directed axially or circumferentially.Free vibration and axial compression experiments were performed to reveal the fundamental frequency,free vibration modes,bearing capacity,and failure mode of the cylinder.A folded lattice core effectively restricts local buckling by reducing the dimension of the local skin periodic cell,and improves the global buckling resistance by enhancing the shear stiffness of the sandwich core.The cylinders fail at the mode of material failure and possess excellent load-carrying capacity.An axially directed folded sandwich cylinder has greater load-carrying capacity,while a circumferentially directed folded sandwich cylinder has higher fundamental frequencies.These two types of folded lattices provide a selection for engineers when designing a sandwich cylinder requiring strength or vibration.This research also presents a feasible way to fabricate a large-dimensional folded structure and promote its engineering application.

Intelligent Process Fault Diagnosis for Nonlinear Systems with Uncertain Plant Model via Extended State Observer and Soft Computing

There have been many studies on observer-based fault detection and isolation (FDI), such as using unknown input observer and generalized observer. Most of them require a nominal mathematical model of the system. Unlike sensor faults, actuator faults and process faults greatly affect the system dynamics. This paper presents a new process fault diagnosis technique without exact knowledge of the plant model via Extended State Observer (ESO) and soft computing. The ESO’s augmented or extended state is used to compute the system dynamics in real time, thereby provides foundation for real-time process fault detection. Based on the input and output data, the ESO identifies the un-modeled or incorrectly modeled dynamics combined with unknown external disturbances in real time and provides vital information for detecting faults with only partial information of the plant, which cannot be easily accomplished with any existing methods. Another advantage of the ESO is its simplicity in tuning only a single parameter. Without the knowledge of the exact plant model, fuzzy inference was developed to isolate faults. A strongly coupled three-tank nonlinear dynamic system was chosen as a case study. In a typical dynamic system, a process fault such as pipe blockage is likely incipient, which requires degree of fault identification at all time. Neural networks were trained to identify faults and also instantly determine degree of fault. The simulation results indicate that the proposed FDI technique effectively detected and isolated faults and also accurately determine the degree of fault. Soft computing (i.e. fuzzy logic and neural networks) makes fault diagnosis intelligent and fast because it provides intuitive logic to the system and real-time input-output mapping.

Site-directed Chemical Modification of Recombinant Human aFGF Mutant with Polyethylene Glycol

A new product PEGylated rhaFGF was obtained by site-directed chemical modification.When compared with unmodified rhaFGF, PEGylated rhaFGF showed comparable bioactivity and superior stability at 37℃ in mouse serum and the stronger resistant potency to trypsin. This was accompanied by a substantial decreasing tmmunogenicity.Site-specific PEGylation of rhaFGF may increase its therapeutic potency in humans.

Study of Test Flow Optimization Method in Radar Fault Isolation

In order to optimize test flow after the default flow is modified by a tester, a new software framework for the radar fault isolation is illustrated. This framework separates all mapping algorithms from test flows so as to modify flow and to insert mapping algorithm dynamically in testing process. Based on this framework, a kind of optimization method of test flow is proposed and studied. By defining an objective function, we can evaluate all candidate test flows so as to get an optimized flow. An example explains how to search the flow from candidate flows.

吴家宜烈士与桂东南抗日武装起义

70多年前,桂东南抗日武装起义领导人之一吴家宜,是一位优秀共产党员。其为了民族独立与解放,与敌人浴血奋战,用短暂的一生实践了自己'把一切献给党'的誓言,用自己的言行回答了什么是'革命初心,不辱使命'、'神圣爱情'、'克己奉公'和'为人民利益而勇于献身的人生观',永远是后辈学习的榜样。

Prediction of the local and total thermal insulations of a bedding system based on the 3D virtual simulation technology

The thermal insulation of a bedding system is one of the most critical factors affecting sleeping thermal comfort.This study reported a mathematical model to evaluate both local and total thermal insulations of a bedding system.To determine the geometric parameters in the model,the geometric model of the bedding system was developed using a 3D virtual simulation program.Its reliability was validated by comparing it with the 3D scanning model.The predicted local and total thermal insulations of bedding systems were compared with those measured by the thermal manikin obtained in a previous study.The bedding systems included six down quilts with different filling weights and involved three body postures.The results showed that the predicted thermal insulation values agreed well with the experimental values.The predicted local and total thermal insulations were with acceptable accuracy,whose errors were within 20%and 10%,respectively.Finally,the research discussed the effects of two main parameters(i.e.,the proportions and partial thermal resistances of heat transfer parts)on bedding thermal insulations and provided practical suggestions for regulating bedding thermal insulation.This study has important implications for evaluating the thermal comfort of the bedding system and contributes to improving the sleeping environment.

阻塞性睡眠呼吸暂停低通气综合征患者下丘脑-垂体-甲状腺轴激素水平与抑郁状态的相关性研究

目的通过检测OSAHS患者血清促甲状腺激素释放激素(TRH)、促甲状腺激素(TSH)、游离甲状腺素(FT4、FT3)水平的变化及评估其抑郁状态,探讨OSAHS患者下丘脑-垂体-甲状腺轴激素水平与抑郁状态的相关性.方法根据多导睡眠监测结果,选取2013年8月至2017年5月于中国医科大学附属第一医院呼吸与危重症医学科就诊的73例男性OSAHS患者[年龄20~58岁,平均(39±11)岁]及13例男性单纯鼾症对照组[年龄22~51岁,平均(36±8)岁],其中OSAHS组进一步根据呼吸暂停低通气指数(AHI)分为轻度、中度、重度OSAHS组,根据最低指端血氧饱和度(SpO2)分为正常血氧组、轻度低氧组、中度低氧组、重度低氧组,均行抑郁状态评估,在第2天清晨抽血并检测血清TRH、TSH、FT4与FT3水平.结果重度低氧组患者血清FT3水平[(5.4±0.7)ng/L]、抑郁评分(40±10)均高于对照组[分别为(4.5±0.6)ng/L、30±7](均P<0.05).将重度低氧OSAHS患者进一步分层发现,合并抑郁状态的患者血清FT3水平[(5.0±0.5)ng/L]、FT4水平[(16.2±1.9)ng/L]低于不合并抑郁状态患者[分别为(5.5±0.7)ng/L和(18.2±2.3)ng/L].结论重度低氧OSAHS患者血清FT3、FT4水平降低与抑郁的发生密切相关.

Active disturbance rejection control： between the formulation in time and the understanding in frequency

With the rapid deployments of the active disturbance rejection control （ADRC） as a bonafide industrial technology in the background, this paper summarizes some recent results in the analysis of linear ADRC and offers explanations in the frequency response language with which practicing engineers are familiar. Critical to this endeavor is the concept of bandwidth, which has been used in a more general sense. It is this concept that can serve as the link between the otherwise opaque state space formulation of the ADRC and the command design considerations and concerns shared by practicing engineers. The remarkable characteristics of a simple linear ADRC was first shown in the frequency domain, followed by the corresponding analysis in time domain, where the relationship between the tracking error and the ADRC bandwidth is established. It is shown that such insight is only possible by using the method of solving linear differential equations, instead of the more traditional techniques such as the Lyapunov methods, which tend to be more conservative and difficult to grasp by engineers. The insight obtained from such analysis is further demonstrated in the simulation validation.

Active disturbance rejection control： some recent experimental and industrial case studies

This paper presents a summary of some recent experimental and industrial case studies of active disturbance rejection control （ADRC）. ADRC is a novel disturbance estimation and rejection concept, leading to a new technology with a distinct advantage where, unlike most existing methods, disturbances, internal and external, are actively estimated and rejected. Applications of the new approach in solving industry-wide bench mark problems have led to a slew of innovative solutions. The scope of the applications shown in this paper includes motion control, robotic-enhanced limb rehabilitation trainings, fuel cell systems, and the two-mass-spring benchmark problem. Recent production line validation results obtained are also included.

Structural and magnetic properties of backward extruded Nd–Fe–B ring magnets made by different punch chamfer radius

Radially oriented Nd-Fe-B ring magnets were prepared by backward extrusion of MQ-C powder. The punch chamfer radius has a great impact on the microstructure and magnetic properties of the ring magnet. With the chamfer radius changing from 2, 5 to 8 mm, the cracks in the inner wall decrease obviously while the crystallographic alignment drops. Furthermore, the mechanism of caxis growth was suggested to be a combination of shear deformation in the corner and solution-precipitation under the stress parallel to radial direction. The alignment drops on the top of ring because the grains grow freely and some textured grains grow through nucleation and recrystallization. In the present work, the optimal punch chamfer radius is found to be 2 mm, and in this case, the remanence,coercivity, and maximum energy product of the ring magnet achieve 1.4 T, 670 kJám, and 342 kJám,respectively.

Desorption–recombination behavior of as-disproportionated NdFeCoB compacts by reactive deformation

The disproportionated phases of Nd Hx, Fe2B,and a-Fe from Nd2Fe14B were applied to prepare Nd Fe B magnets by two different routes. The results show that the route of annealing in horizontal vacuum sintering furnace cannot reach the purpose of complete recombination after the hot pressing and hot deformation process due to the lack of dehydrogenation channel. The route of applying low pressure of 4–25 MPa on the as-disproportionated green compact during the desorption recombination process in situ hot deformation in a spark plasma sintering（SPS）system can obtain completely recombined Nd Fe B magnet with good anisotropy and magnetic properties. The maximum magnetic properties,（BH）max= 201 kJ m^-3,Br= 1.142 T and Hcj= 469 k A m^-1, are obtained after being treated for 15 min at 750 ℃ under low pressure.

Mochi: Composing Data Services for High-Performance Computing Environments

Technology enhancements and the growing breadth of application workflows running on high-performance computing(HPC)platforms drive the development of new data services that provide high performance on these new platforms,provide capable and productive interfaces and abstractions for a variety of applications,and are readily adapted when new technologies are deployed.The Mochi framework enables composition of specialized distributed data services from a collection of connectable modules and subservices.Rather than forcing all applications to use a one-size-fits-all data staging and I/O software configuration,Mochi allows each application to use a data service specialized to its needs and access patterns.This paper introduces the Mochi framework and methodology.The Mochi core components and microservices are described.Examples of the application of the Mochi methodology to the development of four specialized services are detailed.Finally,a performance evaluation of a Mochi core component,a Mochi microservice,and a composed service providing an object model is performed.The paper concludes by positioning Mochi relative to related work in the HPC space and indicating directions for future work.

自组装单分子膜表面分子间氢键的电化学研究

分子间氢键是普遍存在于分子间的一种弱相互作用,在细胞膜表面的分子识别过程中起着基础且重要的作用.为简化细胞膜的复杂性,利用结构明确的自组装单分子膜构建模拟细胞膜体系,在分子水平上对自组装单分子膜表面的分子间氢键进行探究,为细胞膜表面分子识别的研究提供了新的视角.本文从电化学角度,结合扫描电化学显微镜方法的优势,介绍了关于自组装单分子膜表面分子间氢键的研究进展.

The enhanced electronic communication in ferrocenemethanol molecular cluster based on intermolecular hydrogen-bonding

This work presents an electrochemical study of enhanced electronic communication based on intermolecular hydrogen-bonding in ferrocenemethanol （described as FcCH2OH） molecular clusters. The enhanced electronic communication in FcCH2OH clusters is confirmed and further investigated by differential-pulse voltammetry and cyclic voltammetry. A key finding is that this enhanced electronic communication increases the standard rate constant of the electron transfer process. These results will provide us with a further understanding of the electronic communication within the ferrocenyl derivariv~ which it ha^pd nn rhp inr^rmnlpcldar hvdrn^en-hnndinct