EFFECT OF CATHODIC PROTECTION ON FRACTURE BEHAVIOUR OF LOWALLOY STEELS IN SEAWATER

Fracture behaviour of low-alloy steels AIST4340,HY100,Welten60,AISIA537 and A131 in artificial seawater under static,cyclic loading and at cathodic protection potential has been investigated by using the techniques of fracture mechanics, electrochemistry and electronfractography.The results reveal that at hydrogen evolution potentials(cathodic pro- tection potential)the critical yield strength required for the occurrance of SCC decreases from 985 at corrosion potential(E_c)to 872 MPa.The effect of cathodic protection on crack propagation of corrosion fatigue(CF)is not simple,it is closely related to the yield strength of steels and their SCC behaviour.For the steels with high yield strength,cathodic protection promotes(da/dN)_Ⅱ evidently,and reduces △K_(th) value.The(da/dN)-△K curves dis- play a plateau at the third stage of CF for steels with medium or low yield strength.It is men- tioned that the cathodic protection potential for oceaneering constructures should be control- led at top level of the protective range.It seems reasonable that the strength of steel for oceaneeing use might be increased by 200 or 300 MPa.

Water protection in the western semiarid coal mining regions of China: A case study

The coal industry in China has been moving from the semiarid eastern to the drier western regions since the beginning of this century.Water protection is of the utmost concern for coal mining in these regions.Lu'an,as one of the state coal mining bases in China,has been seeing increasingly heavier pressure for the protection of water resources.This article considers Lu'an as an example and describes the ways these concerns may be alleviated.High mine-water utilization rates have effectively reduced wasting of water and,consequently,have reduced water demand.Using the top layers of the Ordavician as aquifuge barriers can prevent floor karst water inrush into the longwall face and can protect the regional Ordovician karst water resources at the same time.The strength of the overlying Quaternary clay can protect against roof collapse and has successfully preserved the Quaternary porous water resource.

Correlation between Hemagglutination Inhibition Titer and Protection against Infectious Bronchitis Virus Challenge in SPF Layers

[ Objective] To study the correlation between HI titer and protection against IBV challenge in SPF layers. [ Method ] SPF layers were randomly divided into four groups, namely group A1, A2, B1 and B2. The group A1 was immunized with H120 live vaccine. The group A2 was first immunized with H120 live vaccine and later boosted with ND-IB-EDS trivalent inactivated vaccine. The group B1 was used as unimmunized chal- lenge control. The group B2 was kept as unimmunized unchallenged control. The blood samples were taken prior and post-vaccination at intervals and HI tests were conducted. At the laying peak, the group A1, A2 and B1 were challenged with IBV M4t virulent strain. The clinical features and egg production of layers were monitored and recorded. [Result] After 30 d post vaccination with H120 live vaccine, the HI titer reached 4.45 log2; after 30 days boosting with ND-IB-EDS trivalent inactivated vaccine, the HI titer reached to 7.35 log2. Before challenge, HI antibody titer in group A1, A2, B1 and B2 were respectively 4.24 log2, 7.40 Iog2, 2.10 log2 and 2.10 log2. After challenge, chickens in unimmunized challenge control group B1 showed respiratory symptoms, egg production dropped by 30.9%, and they produced more soft-shelled, no-shelled or abnormal eggs. In the group A1, some chickens had light respiratory symptoms and egg production dropped by 11.7%. In the group A2, the egg production of all chickens was as normal as the group B2. [ Conclusion] When the HI titer was over 6 log2, challenge by virulent virus had no impact on egg produc- tion; when the HI titer was 5 log2, 4 log2 and less 3 log2, egg production dropped by 6.0%, 11.3% and 29.6%, respectively. Thus, the HI anti- body level in chickens has close correlation with protection against IBV challenge.

Sample investigation and evaluation of the water quality in aquaculture ponds around the basic farmland protection areas in Foshan city

To investigate the water quality of sampling in aquaculture ponds around the basic farmland protection areas in the five districts of Foshan city, and use the environmental pollution index to evaluate the condition of water quality. The results indicated that water temperature and pH of aquaculture ponds cound meet the requirements of fish normal growth,and dissolved oxygen was rich, but the water quality was over fertilized generally. In 20 investigation spots of the five districts, the content of CODCr, NH4^＋-N and TP exceeded 90%, 30% and 85% respectively. The pollution degrees of the water quality from high to low in aquaculture ponds were Chancheng district,Nanhai district, Sanshui district, Shunde district, Gaoming district. The comprehensive quality index of aquaculture ponds was 1.44 in Foshan city, the water quality was polluted severly as a whole. The share rate of pollution load of TP was the highest, the second were CODCr and NH4^＋-N. On the whole, the pollution of organic matter was very prominent in the water quality of aquaculture ponds around the basic farmland protection areas in Foshan city that had been eutrophicated.

Bioflavonoids as Important Component of Biological Protection from Ionizing Radiation

New advances in the area of deciphering the mechanism for a possible modification of the biological effects of radiation exposure at the genetic level make it possible to distinguish the group of radiation protective agents having their own specific features in the implementation of their beneficial effects. The mechanism of the radioprotective action of bioflavonoids is worthy of a detailed analysis in view of their great biological importance. Radiobiological studies show that antioxidants can reduce the radiation damage to membranes and favor more adequate energy dependent adaptive and reparative processes after the exposure to radiation. Bioflavonoids are significant component of “biological protection” for a enhance of resistance of the body to environmental factors that are adverse for human health, including ionizing radiation, with reducing the risk of carcinogenic effects and decreasing the biological age. The best practical value of bioflavonoids, can be considered as the agents for prophylaxis against the development of oxidative stress. These are the reasons why the administration of natural antioxidants have a pathogenetic justification for exposures to chronic (months, years) low-rate-dose ionizing radiation. These agents were previously and are currently being developed for use during long-term, low-ratedose exposures to radiation, under conditions of long space missions. Acting as low-dose stressors through a hormetic mechanism and a “substrate” support of adaptive shifts radiomodulators results in an increase in the antioxidant defense of the body and the rearrangement of its functioning in the new environment with the modulation of gene expression of antioxidant response elements by activation of Nrd2/KeapI and Sirtuin/FoxO pathways and a decrease in the transcription factor NF-κB.

Turbo-Coded Modulation of EVRC Speech Encoder with Unequal Error Protection for Fading Channels

The Enhanced Variable Rate Codec (EVRC) is a standard for the Speech Service Option 3 for Wideband Spread Spectrum Digital System, which has been employed in both IS-95 cellular systems and ANSI J-STC-008 PCS (Personal Communications Systems). This paper investigated the combination of turbo codes with Unequal Error Protection (UEP) and 16-QAM modulation for EVRC codec of Rate 1 to get power and bandwidth efficient coding scheme. The results show that the UEP system outperforms the Equal Error Protection (EEP) one by 1.45 dB at BER of 10 -5.

将腐蚀与防护实验和国家重大工程衔接的课程思政案例设计

将胶州湾跨海大桥材料的腐蚀防护研究作为实际应用案例引入物理化学实验教学。通过结合工程实际改进实验,增加了相关材料在不同腐蚀介质中的腐蚀行为研究等内容,对相关材料及几类防护措施的防护效果进行了比较研究。实验将原物理化学实验中涉及的线性扫描伏安(极化曲线测量)和电化学阻抗方法进行了组合,对Q235和Q275两种合金钢、锌合金和镁合金两种牺牲阳极材料、无涂层和有环氧涂层的钢铁在模拟海水和真实海水两种电解质溶液环境中的腐蚀性能和防护效果进行了研究。改进后的实验可以增强学生学以致用的意识,增强他们对工程问题的综合性和复杂性的认识,还可以培养团队意识和合作能力,通过培养腐蚀防护意识和绿色环保意识强化学生的学科素养和社会责任感。

测井仪被动式热管理系统室温冷却研究

被动式热管理系统能使测井仪内部电子器件的温度在工作时间内不超过耐温指标,然而热管理系统优异的隔热性能导致测井仪需要较长时间冷却,才能投入下一次工作。为此,提出了一种针对测井仪的室温冷却方案。通过将电路骨架从保温瓶内抽出置于空气中实现快速冷却,同时设置芯片保护壳避免内部电子器件与空气直接接触,能够避免较高温差所产生的热应力及水蒸气液化对内部电子器件的损坏,实现快速冷却。模拟和试验验证了该方案的可行性,同时模拟探究了不同因素对冷却方案效果的影响,确定了最佳的冷却方案。研究结果表明,所提出的室温冷却方案可以解决测井仪被动式热管理系统冷却散热的问题,提高测井工作的效率。

电力信息物理系统中信息系统物理化的建模及分析方法

该文基于信息系统物理化的设想提出电力信息物理系统(cyber-physical power system,CPPS)中的信息流建模和计算分析方法。采用连续时间函数来刻画信息流的特征,并定义信息网络运行参数为流量累积函数、信息流速和时延。首先,基于遍历法搜索出信息流路径,建立信息流速矩阵的范式;然后利用改进的网络演算(network calculus,NC)特性赋值流速矩阵的元素;进一步采用流量累积函数表征信源数据发送规律,从而显式求解时延上界。最后将提出的信息流建模方法应用于智能变电站自动化系统的时延计算,通过与OPNET的仿真结果相比较,验证所提出模型的有效性,而且该方法可以提供定量分析指标以优化变电站组网方案设计中的信息流分布。

未来30年中国耕地和高标准农田分布的省级预测

科学预测中国未来耕地和高标准农田分布对于保障我国粮食安全和提高耕地质量具有重要意义。该研究假设未来各省份耕地和高标准农田占全国总面积比例不变,根据各省份耕地和高标准农田实际面积、未来全国耕地及各省份高标准农田规划面积等数据,基于最小二乘法的二次多项式拟合预测未来30 a全国及各省份耕地面积和高标准农田面积,进而预测未来各省份耕地面积保有率和高标准农田占耕地比例。结果表明:(1)到2050年,我国耕地面积稳定在1.20×10^(8)hm^(2),耕地面积保有率稳定在100%,高标准农田面积达到1.03×10^(8)hm^(2),高标准农田占耕地比例从2020年的43.59%增长到2050年的85.89%,增长近一倍。(2)七大区域中,黄淮海区、长江中下游区、东南区的高标准农田占耕地比例较高,在2020年均已达到70%以上,东北区、西北区、青藏区、西南区高标准农田占耕地比例则处于40%~60%之间。到2050年,受耕地比例稳定中略有下降的趋势影响,黄淮海区、长江中下游区、东南区、青藏区高标准农田占耕地比例均达90%以上,东北区、西北区、西南区则处于70%~90%之间。(3)从各省份来看,江西省、浙江省、福建省、广东省等南方省份的高标准农田建设比例较高,而内蒙古自治区、黑龙江省、辽宁省、吉林省、山东省等北方省份的耕地面积保有率较高。研究得到的耕地面积及其保有率、高标准农田面积及其占耕地比例等指标的分省份预测值可以为未来相关部门制定国土空间规划等提供科学依据,也可以为未来耕地布局和农田利用等研究提供分省份的总量参考。

基于迭代算法分析的无线通信信号识别研究

为进一步提升我国植保无人机通信系统的作业效率,基于迭代计算思维,针对其无线通信信号的识别与处理模块展开分析。以通信路径原理为基础,以通信信道资源识别、功率改进为切入点,搭建准确的通信迭代计算模型,进行特性分析与关联匹配设置,并展开整机通信作业参数试验效果验证。结果表明:基于迭代算法分析的无线通信信号识别与处理各模块功能运行稳定,信号时延率与信道误码率均相对降低,通信的识别准确率相对提升8.94%,整体通信综合效率提升至96.93%。此迭代算法分析准确,设计效果明显,对于类似智慧型农机装备的通信质量与通信效率提升有较好的参考价值。

某三级甲等医院专利状况分析及对策研究

目的了解郑州大学第一附属医院2013—2022年专利申请和授权情况,发现专利管理工作中存在的问题,并探讨对策。方法统计医院2013—2022年专利数据,对专利申请和授权情况、授权专利类型分布、专利技术领域、有效率和转化情况进行分析。结果2013—2022年医院共申请专利5145件,获授权专利3385件。2013—2016年申请量和授权量持续上升,2016—2019年迅猛增长,并在2020年达到顶峰,随后申请量和授权量均下降;发明授权权利占比较低,实用新型授权专利占比较高;无效专利占授权专利总数的31.99%,且专利转化率低。结论医院专利申请量较大,但高质量专利申请占比较低,整体趋势并不乐观。建议建立完善的专利管理体系,加大经费扶持力度,完善专利奖励制度,加强专利管理人才队伍建设,建立高价值专利培育体系,健全专利转化平台建设。

抗日本乙型脑炎病毒的线粒体靶向小分子化合物的筛选及鉴定

[目的]线粒体作为重要的能量代谢细胞器,不仅可以调控宿主先天免疫通路影响病毒复制,而且其生物学功能的改变与病毒生命周期密不可分。本文旨在确定抑制日本乙型脑炎病毒(JEV)的线粒体靶向化合物。[方法]通过体外CCK-8、间接免疫荧光、蛋白免疫印迹、RT-qPCR以及细胞因子检测等试验,对382种线粒体靶向化合物抗JEV的效果进行评价,筛选到的敏感药物在小鼠体内进行抗病毒效果验证。[结果]通过药物初筛,从382种药物中筛选出9种疑似抗JEV药物,进一步的体外分子试验筛选确定了其中3种药物对JEV复制有明显的抑制作用,分别为丙酮酸钠(sodium 2-oxopropanoate)、布喹那(brequinar)及松果菊苷(echinacoside)。动物试验结果表明,3种药物有效抑制了JEV在小鼠体内的增殖,给药组小鼠体重增加明显高于对照组,血液中的病毒含量更低,死亡率更低,细胞因子水平出现显著变化,其中以布喹那给药组最为明显。[结论]成功筛选出3种抗JEV的线粒体靶向化合物,为探究线粒体在病毒复制中发挥的作用提供了借鉴,也为抗JEV的临床药物研发提供了新思路。

2023年邹城市春花生植保贡献率的测算评估

为了客观反映植保工作在花生生产中对病虫草害的控制效果,评价植保工作在花生生产中的作用,2023年选取全国花生绿色防控示范县邹城为测试点,开展花生重大病虫害植保贡献率的评价。试验设严格综防区、农户自防区和空白对照区,通过试验示范区的防控效果、花生产量、投入成本三个指标进行综合评估。结果表明:2023年邹城市试验区花生病虫草害的防控植保贡献率为33.1%,严格综防区较农户自防区增收11642.85元/hm^(2),表明农户自防区还有很大的增收空间。本项工作通过科学防控可实现增产增效目的,为其他地区春花生植保贡献率的评估提供了技术参考。

柔性直流输电系统的高频谐波保护方法与工程实践

柔性直流输电系统受电力电子设备本身特性以及控制系统影响,在多种运行工况下易出现不同频率的振荡问题。作为实现设备安全和电网稳定运行的决定因素,保护系统应实现对系统谐波的准确监测以及可靠动作。根据高频振荡时的电流能量累积作用,给出了基于反时限动作的电流类谐波保护算法。基于高频谐波电压特性,分别给出了过零点监测保护算法、谐波畸变率保护算法以及宽谐波保护算法,各保护算法相互配合,实现对不同电压振荡类型的全面保护。最后,给出了国内柔性直流工程实践中配置的高频谐波保护,结合保护原理对系统发生高频振荡后的动作特性进行分析,验证了高频谐波保护的有效性和准确性。

基于深度学习的植保无人机识别系统应用研究

针对人工识别病虫害种类并定位的方法精度低、速度慢且人工成本巨大的问题,基于深度学习对植保无人机的识别系统应用进行研究。该识别系统主要包括3层,分别是感知层、传输层和应用层。为使植保无人机能够准确地识别病虫害种类并定位,采用深度学习算法进行人工智能识别,并对卷积神经网络和识别的评价指标进行了设计。为验证该识别系统的性能,进行了训练和测试试验及系统在其他数据集的测试试验。试验结果表明:系统的病害识别率较高,且具有良好的可移植性。

多纹钱蝶鱼源海豚链球菌的分离鉴定及灭活疫苗的免疫效果

为探究养殖的多纹钱蝶鱼(Selenotoca multifasciata)病害频发的原因,建立有效的病害防控方法,对暴发于海南养殖场的多纹钱蝶鱼病害开展调查并进行灭活疫苗的研制及免疫保护效果评估。分离到2株病原菌LSSM和DFSM,经形态学和16S rDNA序列分析,将病原鉴定为海豚链球菌(Streptococcus iniae)。将这2株菌与实验室收集保藏的2株鱼源海豚链球菌(菌株GXTO和GXAS)进行了血清型鉴定和耐药性、致病性分析,制备了灭活疫苗并评价了疫苗的免疫保护效果。研究表明:4株海豚链球菌鉴定为血清Ⅰ型。所有菌株均对青霉素类、头孢类、四环素等23种抗生素高度敏感、对丁胺卡那耐药,其中海南株LSSM、DFSM对庆大霉素和卡那霉素抗生素耐药,广西株GXTO和GXAS对庆大霉素和卡那霉素敏感。DFSM、GXTO和LSSM对多纹钱蝶鱼的半数致死量(LD_(50))分别为7.20×10^(2)、2.72×10^(3)和3.40×10^(6) CFU/尾,GXAS未显示毒力。分别制备3株毒株(DFSM、GXTO和LSSM)的灭活疫苗,通过腹腔注射途径免疫多纹钱蝶鱼,各组免疫鱼在同源菌株攻毒后,获得的免疫保护率分别为84.6%~85.7%、69.2%~71.4%和33.3%~40.0%;此外,DFSM免疫鱼在异源毒株LSSM和GXTO攻毒后,获得的交叉免疫保护率分别为86.7%和100%。本研究确定了海豚链球菌是海南养殖的多纹钱蝶鱼病害频发的病原,使用DFSM株制备的海豚链球菌灭活疫苗对多纹钱蝶鱼有良好的免疫保护效果。

长江大保护试点城市某污水处理厂尾水湿地净化效果研究

为探寻污水处理厂配套尾水湿地净化效果,以长江大保护试点城市某污水处理厂尾水湿地为例,通过现场调查与采样,分析湿地出水水质特征,探讨影响湿地污染物去除效率因素。结果表明:尾水湿地出水COD、NH_(3)-N及TP浓度满足设计目标,潜流湿地对COD去除率较高,表流湿地对氨氮及磷的去除率较高,优于涵养塘;湿地实际运行水力负荷、水力停留时间和污染物负荷与设计值不符,影响污染物去除效果;据此提出湿地运行优化建议,促进湿地深度脱氮除磷,提升尾水湿地效能;运行优化可提高潜流湿地污染物去除率,同时污水处理厂减少碳排放94.74 gCO_(2)m^(3)。研究结果可为该尾水湿地运行管理及长江大保护试点城市系列污水处理厂配套尾水湿地设计与运维提供参考。

红曲霉菌孢子冻干保护剂的研究

以红曲霉菌为真空冷冻干燥菌种,通过单因素试验研究不同保护剂对红曲霉菌孢子存活率的影响,在此基础上,采用正交试验优化筛选出最优保护剂组合为蔗糖添加量14%、乳糖添加量3%、海藻糖添加量7%。验证试验得出,以该配方配制的保护剂冻干后红曲霉菌的存活率达到78.47%。

不同瘤胃保护性胆碱对围产后期奶牛酮病发病率和血液代谢指标的影响

本试验通过尼龙袋降解试验和饲喂试验,比较两种过瘤胃胆碱的干物质降解率和胆碱保护率及其对围产期奶牛酮病发病率和血液代谢指标的影响。研究分为两个部分:试验一使用尼龙袋法在瘤胃瘘管奶牛上对两种过瘤胃胆碱(A为对照组,B为试验组)的干物质降解率和胆碱保护率进行测定。试验二选取广西某规模化奶牛场的围产牛,采用分阶段对比试验设计,于产前21d开始至分娩分别饲喂含过瘤胃氯化胆碱A和过瘤胃氯化胆碱B的日粮;试验期间全混合日粮(TMR)配方保持不变。试验结果表明:与对照组相比,试验组胆碱的瘤胃干物质降解率较低,过瘤胃保护率较高。试验组奶牛酮病发病率较低;在产后14d和21d,试验组奶牛血液葡萄糖浓度显著增加。综上,根据瘤胃保护率、奶牛酮病发病率和血液代谢试验结果可知,试验组过瘤胃胆碱优于对照组。