Filtration performance and modeling of granular bed for dust removal from coal pyrolytic vapors

Dust removal from pyrolytic vapors at high temperatures is an obstacle to the industrialization of the coal pyrolysis process.In this work,a granular bed with expanded perlites as filtration media was designed and integrated into a 10 t·d^(–1)coal pyrolysis facility.The testing results showed that around 97.56%dust collection efficiency was achieved.As a result,dust content in tar was significantly lowered.The pressure drop of the granular bed maintained in the range of 356 Pa to 489 Pa.The dust size in the effluent after filtration exhibited a bimodal distribution,which was attributed to the heterogeneity of the dust components.The effects of filtration bed on pyrolytic product yields were also discussed.A modified filtration model based on the macroscopic phenomenological theory was proposed to describe the performance of the granular bed.The computation results were well agreed with the experimental data.

Methylprednisolone promotes recovery of neurological function after spinal cord injury： association with Wnt/β-catenin signaling pathway activation

Some studies have indicated that the Wnt/β-catenin signaling pathway is activated following spinal cord injury, and expression levels of specific proteins, including low-density lipoprotein receptor related protein-6 phosphorylation, β-catenin, and glycogen synthase kinase-3β, are significantly altered. We hypothesized that methylprednisolone treatment contributes to functional recovery after spinal cord injury by inhibiting apoptosis and activating the Wnt/β-catenin signaling pathway. In the current study, 30 mg/kg methylprednisolone was injected into rats with spinal cord injury immediately post-injury and at 1 and 2 days post-injury. Basso, Beattie, and Bresnahan scores showed that methylprednisolone treatment significantly promoted locomotor functional recovery between 2 and 6 weeks post-injury. The number of surviving motor neurons increased, whereas the lesion size significantly decreased following methylprednisolone treatment at 7 days post-injury. Additionally, caspase-3, caspase-9, and Bax protein expression levels and the number of apoptotic cells were reduced at 3 and 7 days post-injury, while Bcl-2 levels at 7 days post-injury were higher in methylprednisolone-treated rats compared with saline-treated rats. At 3 and 7 days post-injury, methylprednisolone up-regulated expression and activation of the Wnt/β-catenin signaling pathway, including low-density lipoprotein receptor related protein-6 phosphorylation, β-catenin, and glycogen synthase kinase-3β phosphorylation. These results indicate that methylprednisolone-induced neuroprotection may correlate with activation of the Wnt/β-catenin signaling pathway.

Experience in the diagnosis and treatment of mesenteric lymphangioma in adults:A case report and review of literature

BACKGROUND Mesenteric lymphangioma(ML) in adults is a very rare disease. We report six hospitalized adult patients with ML in our hospital between January 2013 and July 2018 to investigate the characteristics and prognosis of ML in adults.CASE SUMMARY The male-to-female ratio was 3:3, and the median age at diagnosis was 55.2 years. Clinical manifestations varied; however, most were acute cases(5/6). No history of trauma was reported. None(0/6) of the patients were accurately diagnosed with ML in the emergency and outpatient departments. Mesenteric cysts were identified in four patients(66.7%) by abdominal ultrasound and in five patients(83.3%) by computed tomography. ML was postoperatively confirmed by pathology. Most MLs(4/6) were associated with infection of other systems. ML was located in the mesentery of the small intestine(n = 4), ileum(n = 1) and rectum(n = 1). Cyst fluid was clear(n = 4), chylous(n = 1) and bloody(n = 1). Surgical procedures included complete tumor removal and partial intestinal excision(n = 6). Recurrence and adhesive intestinal obstruction were not observed during the 3-12 mo follow-up period.CONCLUSION ML in adults is a rare benign acquired disease that can be cured by surgical treatment. Infection may be a cause of ML.

Pomegranate peel polyphenols alleviate insulin resistance through the promotion of insulin signaling pathway in skeletal muscle of metabolic syndrome rats

Insulin resistance(IR) has been considered to be an important causative factor of metabolic syndrome(Met S). The present study investigated whether pomegranate peel polyphenols(PPPs) could prevent the development of Met S by improving IR in rats. Male Sprague-Dawley(SD) rats were fed high fat diet(HFD) to induce Met S and supplemented with different dosages of PPPs for 12 weeks. The results showed that HFD-induced insulin resistant rats had disordered metabolism of blood glucose, blood lipid, and terrible muscle fiber morphology when compared with normal diet-fed rats, but PPPs treatment at a dosage of 300 mg/kg·day significantly reversed these negative effects. Moreover, in skeletal muscle tissue of insulin resistant rats, PPPs treatments significantly increased the protein expressions of insulin receptor(Ins R) and phosphorylated insulin receptor substrate 1(IRS-1), stimulated peroxisome proliferator activated receptor gamma(PPARγ) and phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT/PKB) signaling pathway, and aggrandized the protein levels of phosphorylated glycogen synthase kinase-3β(GSK-3β) and glucose transporter 4(GLUT4). Our results suggest that PPPs possess of the beneficial effects on alleviating IR by enhancing insulin sensitivity and regulating glucose metabolism.

公安民警执法遇袭原因及对策

袭警行为阻碍警察依法履行职务,对警察生命健康构成严重威胁。根据袭警嫌疑人心理动机可将袭警行为分为拒捕逃脱型袭警、抗拒阻碍型袭警、泄愤报复型袭警等五种类型。警察执法遇袭伤亡的原因一方面源于嫌疑人的暴力袭击,另一方面原因则是警察应对不力。既往大量的实战案例表明,警察伤亡与自身安全意识、武力使用能力、现场处置战术水平和警用防护装备等一个或多个因素相关。加强安全防护意识、合理运用处置战术、提高武力使用能力、配备并使用警用防护装备、重塑警察执法权威以及加强法治宣传教育是降低袭警行为发生和减少警察执法遇袭伤亡的有效方法。

SOPA:Source Routing Based Packet-Level Multi-Path Routing in Data Center Networks

Many ＂rich - connected＂ topologies with multiple parallel paths between smwers have been proposed for data center networks recently to provide high bisection bandwidth, but it re mains challenging to fully utilize the high network capacity by appropriate multi- path routing algorithms. As flow-level path splitting may lead to trafl＇ic imbalance between paths due to flow- size difference, packet-level path splitting attracts more attention lately, which spreads packets from flows into multiple available paths and significantly improves link utilizations. However, it may cause packet reordering, confusing the TCP congestion control algorithm and lowering the throughput of flows. In this paper, we design a novel packetlevel multi-path routing scheme called SOPA, which leverag- es OpenFlow to perform packet-level path splitting in a round- robin fashion, and hence significantly mitigates the packet reordering problem and improves the network throughput. Moreover, SOPA leverages the topological feature of data center networks to encode a very small number of switches along the path into the packet header, resulting in very light overhead. Compared with random packet spraying （RPS）, Hedera and equal-cost multi-path routing （ECMP）, our simulations demonstrate that SOPA achieves 29.87%, 50.41% and 77.74% higher network throughput respectively under permutation workload, and reduces average data transfer completion time by 53.65%, 343.31% and 348.25% respectively under production workload.

BTBR T^(+)tf/J小鼠:孤独症谱系障碍理想的动物模型

孤独症谱系障碍(autism spectrum disorders, ASD)是一组起源于儿童早期的以社会交往交流障碍和重复刻板的行为和兴趣为主要症状的神经发育性障碍。目前研究表明,ASD存在遗传基础,并在一定的环境诱导下发病,包括母体免疫因素、自身免疫紊乱及自然环境因素等,且存在脑发育的异常。但ASD的病因及发病机制尚不完全明确,尚需我们进一步研究。动物模型是评价实验结果的重要依据,确立合适的ASD模型是实验的基础。由于ASD是多因素引起的、可能涉及多种病理机制的疾病,能否选择精准复制ASD病理特征和临床症状的动物模型对ASD的深入研究具有重大意义。BTBR T^(+)tf/J (简称BTBR)小鼠是一种近交系小鼠,它不仅具有ASD的核心症状:社交减少、社交场合中发出的超声波少、重度的重复理毛行为;同时还具备与ASD类似的脑发育异常以及免疫生化指标异常。因此,BTBR小鼠是目前研究自闭症的理想模型,本文就BTBR小鼠与ASD的关系进行总结。

Occurrence of HTO and NE-OBT in soil in the vicinity of the Qinshan Nuclear Power Plant

In this study, concentrations of tritiated water(HTO) and non-exchangeable organically bound tritium(NE-OBT) and the NE-OBT/HTO ratios were determined in soil around Qinshan Nuclear Power Plant(NPP), Zhejiang, China, and their vertical profile and spatial distribution were investigated. Results showed variations in both the HTO and NE-OBT concentrations in the vertical profile. The HTO concentrations generally decreased firstly and then increased with the increasing depths, but the trend was not significant. The NE-OBT concentrations in the surface soils(0–5 cm) were considerably lower than those in the deep soils(5–25 cm) at all the sites. The NE-OBT/HTO ratios also show a variable vertical profile, initially increasing and then decreasing with increasing soil depth.Both the HTO and NE-OBT concentrations decreased with the increasing distance to the HWRs in deep soil layers(5–25 cm), revealing that the released tritium from the NPP affected the spatial distribution.

左乙拉西坦和奥卡西平治疗伴中央颞区棘波儿童良性癫痫的对比研究

目的:为明确左乙拉西坦(Levetiracetam, LEV)单药治疗首发伴中央颞区儿童良性癫痫(benign child-hood epilepsy with centro-temporal spikes, BECT)患儿的疗效及对认知的影响,采用奥卡西平(Oxcar- bazepine, OXC)作为对照进行开放性、平行性研究。方法:在来我院门诊就诊符合BECT诊断标准的患儿中选取104例,随机分为2组。OXC组51例,LEV组53例。以实验前3个月的每月平均发作次数为基线发作水平,每2~4周电话或门诊回访,记录临床发作次数。服药前、服药后3个月、6个月、12个月进行认知功能评定(4~6岁采用韦氏学龄前及小学智力量表,6~16岁采用韦氏儿童智力量表)。结果:1) 疗效比较:3次回访二组有效率、各组组内不同回访时间有效率比较无差异。2) 认知功能比较:基线时及12个月治疗后两组儿童比较无统计学差异。两组患儿用药后自身对照比较均显示多项分测验得分有增高趋势,OXC组治疗前后得分改变无统计学意义,LEV组的词汇及数字广度分测验得分的提高幅度与治疗前相比有统计学意义。结论:首选LEV治疗儿童BECT疗效与OXC相似,对BECT患儿的认知无不良影响。

Particle swarm optimization-based algorithm of a symplectic method for robotic dynamics and control

Multibody system dynamics provides a strong tool for the estimation of dynamic performances and the optimization of multisystem robot design. It can be described with differential algebraic equations(DAEs). In this paper, a particle swarm optimization(PSO) method is introduced to solve and control a symplectic multibody system for the first time. It is first combined with the symplectic method to solve problems in uncontrolled and controlled robotic arm systems. It is shown that the results conserve the energy and keep the constraints of the chaotic motion, which demonstrates the efficiency, accuracy, and time-saving ability of the method. To make the system move along the pre-planned path, which is a functional extremum problem, a double-PSO-based instantaneous optimal control is introduced. Examples are performed to test the effectiveness of the double-PSO-based instantaneous optimal control. The results show that the method has high accuracy, a fast convergence speed, and a wide range of applications.All the above verify the immense potential applications of the PSO method in multibody system dynamics.

中国城市动画产业时空格局及其成因研究

以动画产品为研究对象,利用国家广电总局官方统计数据与新媒体网络数据,对中国城市动画产业发展的时空格局及其成因进行了分析与探讨。首先,从产业规模、产品质量、产品集中度3方面构建动画产业发展评价指标体系,运用熵值法、三角模型法与GIS技术分析中国城市动画产业时空格局,发现:中国动画城市不断增多、发展范围梯度扩散,动画城市多数处于萌芽阶段、整体发展水平较低,动画城市之间差距较大、“二元三核”格局逐渐形成,四大板块差距明显、东中西梯度发展;其次,运用主成分分析和相关分析方法,探讨中国动画产业空间格局成因,结果表明生活质量、包容度、创新精神等内生条件是中国城市动画产业发展的主要影响因素,文化资源、政策支持等外在条件也影响较大。

Thioperamide treats neonatal hypoxic-ischemic encephalopathy by postsynaptic H1 receptors

Thioperamide, a selective histamine H3 receptor antagonist, can increase histamine content in the brain, improve brain edema, and exert a neuroprotective effect. This study aimed to examine the mechanism of action of thioperamide during brain edema in a rat model of neonatal hypoxic ischemic encephalopathy. Our results showed that thioperamide significantly decreased brain water content and malondialdehyde levels, while significantly increased histamine levels and superoxide dismutase activity in the hippocampus. This evidence demonstrates that thioperamide could pre vent oxidative damage and attenuate brain edema following neonatal hypoxicischemic encepha Iopathy. We further observed that changes in the above indexes occurred after combined treatment of thioperamide with the H1 receptor antagonist, pyrilamine, and the H2 receptor antagonist, ci metidine. Experimental findings indicated that pyrilamine reversed the effects of thioperamide; however, cimetidine had no significant influence on the effects of thioperamide. Our present findings suggest that thioperamide can increase brain histamine content and attenuate brain edema and oxidative damage by acting in combination with postsynaptic H1 receptors in a rat model of neo natal hypoxicischemic encephalopathy.

Research on data assimilation strategy of turbulent separated flow over airfoil

In order to increase the accuracy of turbulence field reconstruction,this paper combines experimental observation and numerical simulation to develop and establish a data assimilation framework,and apply it to the study of S809 low-speed and high-angle airfoil flow.The method is based on the ensemble transform Kalman filter(ETKF)algorithm,which improves the disturbance strategy of the ensemble members and enhances the richness of the initial members by screening high flow field sensitivity constants,increasing the constant disturbance dimensions and designing a fine disturbance interval.The results show that the pressure distribution on the airfoil surface after assimilation is closer to the experimental value than that of the standard Spalart-Allmaras(S-A)model.The separated vortex estimated by filtering is fuller,and the eddy viscosity field information is more abundant,which is physically consistent with the observation information.Therefore,the data assimilation method based on the improved ensemble strategy can more accurately and effectively describe complex turbulence phenomena.

旋转倒立摆虚拟仿真模型构建与验证

为了解决旋转倒立摆在理论建模与工程应用之间存在偏差的问题,提出一种基于Matlab虚拟仿真与试验数据相结合的建模方法,并使用实物验证模型建立的有效性。通过Solidworks与Matlab连接得到倒立摆刚体模型,在SimMechan-ics内添加机电部分,线性化得到系统在不稳定平衡点的理想模型。在实物试验基础上辨识系统参数,得到仿真模型。在模型基础上研究了倒立摆的起摆与稳摆算法。试验结果表明,虚拟仿真模型可以直观显示与记录系统变量变化情况,与实物结构对比,整体响应与实际倒立摆差距很小。

Anthropogenic Effects on Biogenic Secondary Organic Aerosol Formation

Anthropogenic emissions alter biogenic secondary organic aerosol(SOA)formation from naturally emitted volatileorganic compounds(BVOCs).We review the major laboratory and field findings with regard to effects of anthropogenicpollutants(NO_(x),anthropogenic aerosols,SO_(2),NH_(3))on biogenic SOA formation.NO_(x) participate in BVOC oxidationthrough changing the radical chemistry and oxidation capacity,leading to a complex SOA composition and yield sensitivitytowards NO_(x) level for different or even specific hydrocarbon precursors.Anthropogenic aerosols act as an importantintermedium for gas-particle partitioning and particle-phase reactions,processes of which are influenced by the particlephase state,acidity,water content and thus associated with biogenic SOA mass accumulation.SO_(2)modifies biogenic SOAformation mainly through sulfuric acid formation and accompanies new particle formation and acid-catalyzedheterogeneous reactions.Some new SO_(2)-involved mechanisms for organosulfate formation have also been proposed.NH_(3)/amines,as the most prevalent base species in the atmosphere,influence biogenic SOA composition and modify theoptical properties of SOA.The response of SOA formation behavior to these anthropogenic pollutants varies amongdifferent BVOCs precursors.Investigations on anthropogenic-biogenic interactions in some areas of China that aresimultaneously influenced by anthropogenic and biogenic emissions are summarized.Based on this review,somerecommendations are made for a more accurate assessment of controllable biogenic SOA formation and its contribution tothe total SOA budget.This study also highlights the importance of controlling anthropogenic pollutant emissions witheffective pollutant mitigation policies to reduce regional and global biogenic SOA formation.

Cerebrolysin improves sciatic nerve dysfunction in a mouse model of diabetic peripheral neuropathy

To examine the effects of Cerebrolysin on the treatment of diabetic peripheral neuropathy, we first established a mouse model of type 2 diabetes mellitus by administering a high-glucose, high-fat diet and a single intraperitoneal injection of streptozotocin. Mice defined as diabetic in this model were then treated with 1.80, 5.39 or 8.98 m L/kg of Cerebrolysin via intraperitoneal injections for 10 consecutive days. Our results demonstrated that the number, diameter and area of myelinated nerve fibers increased in the sciatic nerves of these mice after administration of Cerebrolysin. The results of several behavioral tests showed that Cerebrolysin dose-dependently increased the slope angle in the inclined plane test（indicating an improved ability to maintain body position）, prolonged tail-flick latency and foot-licking time（indicating enhanced sensitivity to thermal and chemical pain, respectively, and reduced pain thresholds）, and increased an index of sciatic nerve function in diabetic mice compared with those behavioral results in untreated diabetic mice. Taken together, the anatomical and functional results suggest that Cerebrolysin ameliorated peripheral neuropathy in a mouse model of type 2 diabetes mellitus.

Study on mass transfer of ethyl acetate in polymer adsorbent by experimental and theoretical breakthrough curves

A new polymeric adsorbent with highly hypercrosslinked structure was developed for the removal of VOCs from polluted air. The purpose of this work is to obtain the intraparticle mass transfer coefficient of the adsorbent particles. Adsorption experiments for obtaining breakthrough curves were carried out with a fixed bed system. A dynamic mathematical model for the fixed bed adsorption system was developed.By model fitting, the overall mass transfer coefficient was determined when the deviation error was minimum. Then, the intraparticle mass transfer coefficient of the adsorbent was determined when the external mass transfer resistance was eliminated at higher velocities. Furthermore, a linear relationship of the intraparticle mass transfer coefficient and equilibrium coefficient at lower inlet gas concentrations range was correlated. Moreover, an equation for predicting external mass transfer coefficient at low Reynolds number range at room temperature was obtained.

Desorption of VOC from polymer adsorbent in multistage fluidized bed

The desorption process of volatile organic compounds(VOC)from a polymer adsorbent in counter-current multistage fluidized bed was studied.And a mathematical model considering the mass transfer dynamics was developed,which was validated from experiment data.The gaseous ethyl acetate mass transfer was discussed,and the limiting step is the intraparticle mass transfer of the desorption process.The value of intraparticle mass transfer coefficient is between 1.85×10-6 and 1.38×10-5 m·s-1 under temperature of 100–160°C.Experiments under different operating conditions were carried out.The effects of operating conditions such as gas–solid flow ratio,gas inlet temperature and total stage number of multistage fluidized bed on outlet VOCs concentration and desorption efficiency were discussed.The maximum outlet VOCs concentration and corresponding desorption efficiency of the multistage fluidized bed desorber was calculated under different gas inlet temperatures and total stage numbers.

Theoretical and Applied Mechanics Letters

The placement of pressure taps on the surface of the wind tunnel test model is an important means toobtain the surface pressure distribution.However,limited by space location and experimental cost,it isdifficult to arrange enough pressure measuring taps on the surface of complex models to obtain completepressure distribution information,thus it is impossible to obtain accurate lift and moment characteristicsthrough integration.The paper proposes a refined reconstruction method of airfoil surface pressure basedon compressed sensing,which can reconstruct the pressure distribution with high precision with lesspressure measurement data.Tests on typical airfoil subsonic flow around flow show that the accuracyof lift and moment after the pressure integration reconstructed by 4-8 measuring points can meet therequirements of the national military standard.The algorithm is robust to noise,and provides a new ideafor obtaining accurate force data from sparse surface pressure tests in engineering.

基于NAO机器人各类编程方式分析

机器人是目前新兴研究的热点之一,而类人型机器人又是服务机器人中重要的组成部分,其重要性不言而喻。NAO机器人作为类人型机器人中较为成熟的一款产品,是一个非常优秀的类人型机器人的开发平台。针对在开发的过程中,NAO机器人出现的编译环境多样,对于初学者不宜选择等问题,本文以人脸识别为例,设计实验,通过分析对比官方开发的较为直观的可视化编译环境,以及发挥空间更大的Python语言编译这两者之间的区别,对初学者和后续开发的需求和使用体验做出了分析。