废铁屑制备三草酸合铁酸钾虚实结合的综合化学实验设计

将无机化学中的两个制备实验(硫酸亚铁铵的制备、三草酸合铁酸钾的制备)和分析化学中的组成分析实验(铁离子、草酸根离子和结晶水含量测定)进行综合,设计了一个综合化学实验。在制备部分引入线上虚拟操作和线下自主设计环节,分析部分不仅使用了传统的化学分析法,同时引入红外光谱仪(IR)和X射线衍射仪(XRD)对产品进行表征分析。通过该实验的实施,可使学生进一步巩固减压过滤、重结晶、滴定等基本实验操作技能;掌握利用大型仪器对产品的组成和结构进行表征的方法;锻炼学生综合应用化学理论知识解决实践问题的能力。同时结合思政教育,有助于培养学生的安全环保意识和科学探索精神,提高学生的实验责任心和对化学学科的兴趣。

Characteristics of Xiao Chai Hu decoction based on randomized controlled trials: A bibliometric analysis

Objective:To explore the characteristics of Xiao Chai Hu(XCH)decoction in randomized controlled trials(RCTs)using a bibliometric method.Methods:Seven databases including PubMed,Web of Science,Embase,Cochrane library,China National Knowledge Infrastructure(CNKI),Chinese Scientific Journal Database(VIP)and Wanfang database were retrieved from inception to May 27,2022.In the study,XCH decoction(or modified)used alone or combined with conventional Western medicine as an intervention measure was included.The basic characteristics,funding support,relevant diseases,intervention methods,and adverse events(AEs)were analyzed.Data analysis was performed using SPSS 26.0 software.Results:A total of 813 RCTs were included,published from 1989 to 2022.There was only one Englishlanguage literature with the recent impact factor of 5.374.There were 147 studies were from Chineselanguage core journals,with the highest impact factor of 2.414.Only 6.15%of the literatures mentioned funding support.96.31%of the included literature reported the statistical significance of using XCH decoction.The diseases treated mainly included chronic hepatitis B(9.35%),cough variant asthma(5.66%),dizziness(5.54%),bile reflux gastritis(4.43%),and fever(4.18%).However,the overall research design of the included literature was poor,and large sample size,multicenter RCTs are needed.The incidence of AEs of XCH decoction alone was 8.86%,which was significantly lower than that of conventional Western medicine treatment.The combination of XCH decoction and conventional Western medicine treatment could reduce the incidence of AEs,and no serious adverse event was reported.Conclusion:Although the included studies show that XCH decoction is widely used,and has good efficacy and few AEs.Due to the low quality of the included RCTs,there may be some bias,and its rational use based on the specific conditions is recommended in clinical practice.

Tetra-alkylsulfonate functionalized poly(aryl ether) membranes with nanosized hydrophilic channels for efficient proton conduction

The microstructure of polymer electrolyte membranes plays a key role in ion conductivity and water transport.Herein,fluorinated poly(aryl ether)s with tetra-alkylsulfonate side chains(SFPAEs)have been successfully synthesized from the copolymerization of a newly developed tetra-allyl-containing bisphenol(TABP)monomer,followed by the thiol-ene addition with sodium 3-mercapto-1-propanesulfonate to attach the ionic groups at the end of the flexible chains.Being the first of its kind,the densely distributed and lengthy alkylsulfonate group possesses the benefit of ease to self-assemble into hydrophilic domains during membrane preparation via solution casting.Indeed,the TEM characterizations revealed that distinct hydrophilic channels of 1-2 nm width had been formed,much larger than those of a home-made control sample where only di-alkylsulfonate side chains were attached.The SFPAE-4-45 with an IECw of 2.0 mmol g^-1 exhibited an enhanced proton conductivity of 143.7 m S cm^-1 at room temperature,which was superior to that of Nafion 212(91.0 m S cm^-1).Furthermore,the oxidative stabilities of SFPAEs were significantly higher than those of non-fluorinated analogs in literature.This study offered a new route to engineering the pendent structure of ionomers for well-defined microscopic morphologies.

我国设立本科职业教育学位的思考

本科职业教育是为适应产业转型升级和区域经济社会发展以及提高职业教育办学水平而设立的新兴高等职业教育层次。在回顾国内高等职业教育发展和借鉴国外本科职业教育学位研究和实践的基础上,提出职业教育本科层次应设立应用学士学位,并明确该学位的定位原则。从教学培养体系、职业资格证书、衔接机制来探讨应用学士学位实施的关键要素,以及建立相应的保障制度保证本科职业院校人才培养方案的科学性和有效性。

Giant neurogenic tumors of mediastinum: report of two cases and literature review

Neurogenic tumors are commonly found in the mediastinum, especially in the posterior mediastinum or in the chest wall, neurogenic tumors may reach large size before becoming symptomatic. If the neurogenic tumor occupied more than half size of the chest wall accompanied by mediastinal shift, tracheal compression, or superior vena reflux disorder, it may be called giant intrathoracic neurogenic tumors. Giant intrathoracic neurogenic tumors are relatively rare. Most of intrathoracic neurogenic tumors were benign or low-grade malignant tumors in nature. Complete surgical excision should be the rule for these patients. We report two cases of giant neurogenic tumors, and study the clinical manifestations, diagnostic methods, surgical management, and prognosis in the light of the most important published data.

Research on the Optimal Dose of FSH for Superovulation of Mongolian Cattle

In this study, purebred Mongolian cattle were treated with a series of technical means including superovulation, artificial insemination, non-surgical embryo flushing, embryo grading and embryo cryopreservation, aiming at exploring a set of mature, stable production and breeding program for purebred Mongolian cattle embryos. The results showed that the optimal dose of FSH for superovulation of bred Mongolian cattle was 410 IU; the optimal dose of FSH for superovulation of muhiparous Mongolian cattle was 440 IU. Bred Mongolian cattle exhibited higher average number of available embryos and embryo utilization rate compared with muhiparous Mongolian cattle, but the latter exhibited higher average number of embryos recovered.

Research on Flashover Voltage Prediction of Catenary Insulator Based on CaSO_(4) Pollution with Different Mass Fraction

Pollution flashover accidents occur frequently in railway OCS in saline-alkali areas.To accurately predict the pollution flashover voltage of insulators,a pollution flashover warning should be made in advance.According to the operating environment of insulators along the Qinghai-Tibet railway,the pollution flashover experiments were designed for the cantilever composite insulator FQBG-25/12.Through the experiments,the flashover voltage under the influence of soluble contaminant density(SCD)of different pollution components,non-soluble deposit density(NSDD),temperature(T),and atmospheric pressure(P)was obtained.On this basis,the GA-BP neural network prediction model was established.P,SCD,NSDD,CaSO_(4) mass fraction(w(CaSO_(4))),and T were taken as input parameters,50%flashover voltage(U_(50%))of the insulator was taken as output parameters.The results showed that the prediction deviation was less than 10%,which meets the basic engineering requirements.The results could not only provide early warning for the anti-pollution flashover work of the railway power supply department,but also be used as an auxiliary contrast to verify the accuracy of the results of the experiments,and provide a theoretical basis for the classification of pollution levels in different regions.

4例具有挑战性且不寻常的视网膜病例临床精粹讨论

3位国际视网膜专家在中山眼科中心(Zhongshan Ophthalmic Center,ZOC)眼底病中心进行临床查房并讨论了4例具有挑战性且不寻常的视网膜病例:1)VHL病合并视网膜血管母细胞瘤的11年随访观察;2)半剂量光动力疗法(photodynamic therapy,PDT)或微脉冲激光光凝治疗中心性浆液性视网膜病变(central serous chorioretinopathy,CSC)的观察;3)视神经缺陷儿童的诊断与治疗;4)合并虹膜晶状体脉络膜缺损的视网膜脱离(retinal detachment,RD)的治疗选择。通过讨论有助于我们更好地了解这四例视网膜疾病的发病机制和治疗方法,及其与全身疾病的关系。

Case 02-2017-Discussion of clinical pearls derived from 4 challenging and unusual retinal cases

Four challenging and unusual retinal cases:(I)11-year follow-up for retinal hemangioblastoma with von Hippel-Lindau(VHL)disease;(II)treatment for central serous chorioretinopathy(CSC)-observation,half does photodynamic therapy(PDT)or micropulse laser photocoagulation;(III)diagnosis and treatment for a child with optic nerve defect;(IV)the optional treatment for retinal detachment(RD)with iridolenticular choroidal coloboma,were presented and discussed by three international retinal specialists at a retinal clinical round in Fundus Diseases Center of Zhongshan Ophthalmic Center(ZOC).The discussion helps us a better understanding of the pathogenesis and managements of these four retinal diseases and their association with systemic conditions.

Designing Tough,Printable,and Adaptable Eutectogels with Multinetworks via Synergy of Rapid Orthogonal Photopolymerizations and Solvent Effect in Seconds

Achieving a straightforward design of tough,printable,and adaptable polymeric eutectogels is still challenging in related fields due to the uncontrollable polymerization and solvent-exchanging processes,and inherent contrasting multiple networks.Here,we report a one-step synergistic strategy based on ruthenium chemistry-catalyzed photopolymerization and solvent effect for preparing high-performance eutectogels.This orthogonal ruthenium photochemistry helps multinetworks formation via phenol-coupling of gelatin and copolymerization of acrylamide(AAm)and[2-(methacryloyloxy)ethyl]trimethylammonium tetrafluoroborate(META)monomers in seconds.The obvious difference in the supramolecular interactions of free AAm monomers and polymerized units in P(AAm-co-META)with deep eutectic solvents(DESs)significantly promotes the microphase-separation behavior in eutectogels.Consequently,the in situ polymerization and microphase-separation behavior enable the as-prepared eutectogel materials to have excellent mechanical properties(stress of∼1.2 MPa),toughness(∼4.0 MJ m^(−3)),elasticity,adaptivity,and conductivity(∼0.5 S m^(−1)at room temperature).Also,the critical strength of the resultant eutectogels can be modulated by varying the DES constituents.This rapid and well-controlled synergistic approach is compatible with extrusion printing techniques to make flexible sensors with high sensitivities and response times to detect pressure in a range of 0–500 kPa.Such a general and simple strategy has application potential in biological,engineering,and material sciences.

Electromagnetic anisotropic homogeneous model for eddy-current field in single-phase wound core

The analysis of the eddy-current field in the wound core widely used in the field of transformer energy conservation is taken as the theme.Adopting the homogenisation idea to consider the unique geometry of the wound core and features of its equivalent multi-stage circular cross-section magnetic boundary,a homogeneous model consisting of a columnar material with continuous homogeneous electromagnetic anisotropy is established by deriving the Maxwell equations of the magnetic quasi-static field in the columnar coordinate system.Finally,a homogeneous fine element model for the eddycurrent field in the wound core is established and the accuracy of the model has been verified by the test platform.The result shows that the homogeneous model can be effectively used for the analysis of the eddy-current field in the wound core,and the error of calculating the eddy-current loss under different excitation conditions is less than 6%under the premise of extremely saving the engineering calculation cost,which will help improve the operational performance of the wound core and contribute to the energysaving goal of the high-voltage equipment.

Antibacterial evaporator based on reduced graphene oxide/polypyrrole aerogel for solar-driven desalination

Solar-driven water evaporation is a sustainable method to purify seawater.Nevertheless,traditional volumetric water-evaporation systems suffer from the poor sunlight absorption and inefficient light-to-thermal conversion.Also,their anti-bacterial and antifouling performances are crucial for the practical application.Herein,we introduce reduced graphene oxide(RGO)with broadband absorbance across the entire solar spectrum,and polypyrrole(PPy),an antibacterial polymer with efficient solar absorption and low thermal conductivity,to develop integrated RGO/PPy aerogel as both the solar absorber and evaporator for highly efficient solar-driven steam generation.As a result,the RGO/PPy aerogel shows strong absorption and good photothermal performance,leading to an evaporation rate of 1.44 kg·m^(−2)·h^(−1)and high salt rejection(up to 99.99%)for real seawater,with photothermal conversion efficiency>90%under one sun irradiation.The result is attributed to the localized heat at the air-water interface by the RGO/PPy and its porous nature with functional groups that facilitates the water evaporation.Moreover,the RGO/PPy demonstrates excellent durability and antibacterial efficiency close to 100%for 12 h,crucial characteristics for longterm application.Our well-designed RGO/PPy aerogel with efficient water desalination performance and antibacterial property provides a straightforward approach to improve the solar-driven evaporation performance by multifunctional materials integration,and offers a viable route towards practical seawater desalination.

Transient thermal network model for train-induced wind cooling dry-type on-board traction transformer in electric multiple units

Thermal characteristic is one of the key performances of dry-type on-board traction transformer(D-OBTT),which directly affects the operation safety of the new generation electric multiple units.However,due to the particularity of train-induced wind cooling mode of D-OBTT,the existing efficient thermal modelling methods cannot be used under fluctuating air velocity and load.A time-saving transient thermal model for D-OBTT is proposed.First,the framework of the transient thermal network model(TTNM)is proposed considering the coexistence of non-fully and fully developed state of the train-induced wind and the addition heat flow in the solid domain.Then,a novel formula for calculating the length of non-fully developed section considering the geometric dimensions and heat flux density is proposed based on computational fluid dynamics(CFD)parametric sweeps for the first time.The accuracy of TTNM is validated by a D-OBTT experimental setup,and the time consumption is significantly reduced compared with CFD.

Effect of damage zone around borehole on carbon dioxide injection promoted gas extraction in soft and low-permeability coal seam

Injecting external CO_(2) into soft and low-permeability coal seams can improve CH4 extacctinn efficiency, and also benefit in CO_(2) sequestration. However, the distribution law of damage zone around borehole in soft coal seam and its effect on the efficiency of CO_(2) injection promoted CH4 extraction are not clear. In this paper, a multi-physics coupling mathematical model considering damage effect is established for simulating the process of CO_(2) injection promoted CH4 extraction in soft and low-permeability coal seam. The distribution of damage zone and permeability around boreholes under different diameters and coal strengths are analyzed. The gas pressure and gas content in coal seam during CO_(2) injection promoted CH4 extraction when the model considered damage effect are compared with that of ignored. The results show that small borehole diameter corresponds to narrow damage zone around the borehole in coal seam. The damage zone expands with the increase of the borehole diameter. The damage zone increases exponentially with the borehole diameter, while decreases exponentially with the compressive strength of coal seam. The highest permeability in the damage zone has increased by nearly 300 times under the condition of simulated case. CH4 pressure around the extraction borehole reduces, and the reduction area expands with the increase of time. Compared with the result of considering the damage effect, the reduction area of ignoring it is smaller, and the reducing speed is slower. The integrated effect of CO_(2) injection and CH4 extraction leads to rapid decrease of CH4 content in coal seam near the boreholes. The CO_(2) pressure and content increase around the injection borehole, and the increasing area gradually extends to the whole coal seam. In soft coal seams, failure to consider the damage effect will underestimate the efficiency of CH4 extraction and CO_(2) sequestration, resulting conservative layout of boreholes.

Reasonable start time of carbon dioxide injection in enhanced coalbed methane recovery involving thermal-hydraulic-mechanical couplings

Injection of gas (CO_(2)) into coal seams is an effective method to benefit from both CO_(2) geological storage and coalbed methane recovery. Based on the dual pore structure of coal mass, and the Weibull distribution of fracture permeability, a menmal-hydraulic-mechanical (THM) coupling mathematical model is proposed involving the non-isothermal adsorption of binary gases, dynamic gas diffusion between matrix and fractures, multiphase seepage, coal deformation, heat conduction and heat convection. This mathematical model is applied to study the process of CO_(2)-enhanced coalbed methane recovery (CO_(2)-ECBM). Results show that the CH4 content of CO_(2)-ECBM in coal seam decreases significantly when compared with that of regular drainage, and decreases rapidly in the early stage but slowly in the later stage. Coal seam permeability evolution is triggered by changes in gas adsorption/desorption, temperature and effective stress. For regular drainage, the early permeability shows a decreasing trend dominated by the increase of effective stress, while the later permeability shows an increasing trend dominated by the CH4 desorption caused shrinkage of coal matrix. For CO_(2)-ECBM, the permeability in coal seam generally shows a downward trend due to both matrix swelling induced by gas adsorption and thermal expansion, particularly near injection well. There appears an increased and delayed peak production rate of CH4. The CH4 production rate of CO_(2)-ECBM is always higher than that of regular drainage. The CH4 cumulative production and CO_(2) cumulative storage linearly increase with time, and the CH4 cumulative production of CO_(2)-ECBM increased by 39.2% in the duration of 5000 d compared with regular drainage. Reasonable CO_(2) injection starting time can overcome the issue of early CO_(2) breakthrough and ineffective increase of CH4 production. In the studied case, the optimal injection starting time is 2500 d. Compared with the simultaneous CH4 extraction and CO_(2) injection, the CH4 cumulative production of optimal time has increased by 30.1%. The research provides a reference for determining the reasonable CO_(2) injection time under similar conditions.

Literature review of driving risk identification research based on bibliometric analysis

In order to understand the current research status and development direction of driving risk identification at home and abroad,relevant literatures in the field of driving risk identification from the China National Knowledge Infra-structure(CNKI)and Web of Science(WOS)in recent 12 years(2011-2022)were selected as research samples,and literature metrology tools VOSviewer and Citespace were used for visual analysis.The situation was analyzed from the aspects of chronological distribution,national cooperation network,distribution of domestic institutions,journal performance and keywords overview,literature coupling clustering and research hotspots.The results show that the number of published papers fluctuates year by year,and China,the United States and Germany have the largest number of published papers.The United States is at the center of international cooperation.The CNKI shows that universities in China such as Chang’an University and Chongqing Jiaotong University have published a large number of documents.According to the statistics of WOS,Accident Analysis&Prevention is the most widely published journal in the world.The average level of the journal is high and the quality of articles is better.Combining the research contents of CNKI and WOS,the main research directions can be clustered into five cluster themes by using the coupling function in VOSviewer,including driving risk assessment considering driver factors,the influence of driving environment on driving risk,driving risk assessment considering multi-source characteristic data,multiaspect research on driving risk and risk identification of non-traditional vehicles in specific scenarios.Human-machine co-driving,artificial intelligence,intelligent driving,risk identification and natural driving are the current research hotspots and the future research trends.

Degree of polymerisation estimation for insulation paper immersed in silicone oil using frequency domain dielectric spectroscopy

Frequency domain dielectric spectroscopy(FDS)is an effective method reflecting the changes of ageing status of silicone oil‐immersed insulation paper.For better evaluating the ageing status of silicone oil‐immersed insulation paper,an evaluation method was studied by analysing the ageing kinetic model and results of FDS.First,the method to separate the different polarization losses and conductivity loss from the results of FDS was studied.Then,based on the idea of ageing correction translation coefficient and timevarying pre exponential factor,the zero order ageing dynamic model was modified,which combines the ageing kinetic model with the results of FDS.Finally,the evaluation method for the degree of polymerisation(DP)of silicone oil‐immersed paper was proposed,and experiments were conducted to obtain the parameters in the modified model and then to verify the proposed method.The results show that the proposed method can be used to evaluate the DP effectively.

Genomic characterizations of H4 subtype avian influenza viruses from live poultry markets in Sichuan province of China, 2014–2015

Dear Editor,Avian influenza viruses (AIVs) have posed a serious threat to poultry production and public health. To date, more than fourteen AIV subtypes that are able to infect human beings have been documented. Also, it is suggested that new subtypes may be reported in the future, owing to the migration of wild birds and live poultry transportation (Gao, 2018).Poultry may act as a potential incubator for novel subtypes of avian influenza virus (Bi et al., 2016a; Bi et al., 2016b; Liu et al., 2014a; Su et al., 2017). Up to date, the H7N9 AIV emerged in February 2013 has caused 1,567 human cases,with a fatality rate of 39.2%(http://www.who.int/influenza/

Experimental study on ageing characteristics of electric locomotive ethylene propylene rubber cable under mechanical-thermal combined action

The train-mounted ethylene propylene rubber(EPR)cables of electric locomotive are partly restricted by the body structure and spatial layout and are in a combined envi-ronment of strong mechanical bending and thermal ageing.The degradation character-istics of the insulation layer have not yet received sufficient attention.In order to study the ageing characteristics of EPR cables of electric locomotive under the combined action of machine and thermal,this paper designs a bending-thermal combined ageing test platform for cables with a temperature of 135°C,bending diameter of 393.52 mm,590.28 mm and unbending cables,and tests after ageing.The product has been tested by infrared spectroscopy,scanning electron microscopy,elongation at break and broadband dielectric spectroscopy.The research results show that the bending outer part of the train-mounted EPR cable is a pain point.Under the combined action of bending and thermal,whether it is microstructure or macro performance,the degradation rate and degree of the bending of outer insulation layer are greater than the value under a single thermal ageing condition.Mechanical bending has an accelerating effect on the ageing of the EPR insulation layer.The research results can provide a reference for the ageing characteristics of the train-mounted EPR cable under the bending-thermal synergy and the evaluation of operating state of the train-mounted EPR cable under bending-thermal operating conditions.

Five Independent Cases of Human Infection with Avian Influenza H5N6—Sichuan Province,China,2021

Summary What is known about this topic?The emerging H5Ny lineages of the avian influenza virus(AIV)with genomic reassortments have posed a continuous threat to animals and human beings.Since the first case of avian influenza A(H5N6)virus infection in 2014,the World Health Organization has reported a total of 38 cases by August 6,2021.