Inner and outer pressure forming of nickel based super-alloy thin-walled part with variable diameter sections

A novel forming method of nickel based super-alloy thin-walled part with variable diameter sections was proposed by using inner and outer pressure with the visco-elasto-plastic pressure-carrying medium at room temperature,and the principle of the method was provided.Experiments and FE simulations were carried out to analyze the deformation characteristics for the part with larger variable diameter ratio(35%).The results show that visco-elasto-plastic pressure-carrying medium can meet the requirements of the room-temperature deformation condition for nickel based super-alloy sheet.The inner and outer pressure forming with the visco-elasto-plastic pressure-carrying medium can meet the requirements of dimensional accuracy for the thin-walled part with variable diameter sections.The thinning of wall-thickness is less than 4%.This method provides a new approach for near-net shape forming of nickel based super-alloy thin-walled parts with variable diameter sections.

Buckling Optimization of Curved Grid Stiffeners through the Level Set Based Density Method

Stiffened structures have great potential for improvingmechanical performance,and the study of their stability is of great interest.In this paper,the optimization of the critical buckling load factor for curved grid stiffeners is solved by using the level set based density method,where the shape and cross section(including thickness and width)of the stiffeners can be optimized simultaneously.The grid stiffeners are a combination ofmany single stiffenerswhich are projected by the corresponding level set functions.The thickness and width of each stiffener are designed to be independent variables in the projection applied to each level set function.Besides,the path of each single stiffener is described by the zero iso-contour of the level set function.All the single stiffeners are combined together by using the p-norm method to obtain the stiffener grid.The proposed method is validated by several numerical examples to optimize the critical buckling load factor.

Investigation on the Dielectric Properties of CO2 and CO2-Based Gases Based on the Boltzmann Equation Analysis

In this paper, the dielectric properties of CO2, CO2/air, CO2/O2, CO2/N2, CO2/CF4, CO2/CH4, CO2/He, C02/H2, CO2/NH3 and CO2/CO were investigated based on the Boltzmann equation analysis, in which the reduced critical electric field strength （E/N）cr of the gases was derived from the calculated electron energy distribution function （EEDF） by solv- ing the Boltzmann transport equation. In this work, it should be noted that the fundamental data were carefully selected by the published experimental results and calculations to ensure the validity of the calculation. The results indicate that if He, H2, N2 and CH4, in which there axe high ionization coefficients or a lack of attachment reactions, are added into CO2, the dielectric properties will decrease. On the other hand, air, O2, NH3 and CFa （ranked in terms of （E/N）cr value in increasing order） have the potential to improve the dielectric property of CO2 at room temperature.

A 330-500 GHz Zero-Biased Broadband Tripler Based on Terahertz Monolithic Integrated Circuits

A 330-500 GHz zero-biased broadband monolithic integrated tripler is reported. The measured results show that the maximum efficiency and the maximum output power are 2% and 194μW at 348 GHz. The saturation characteristic test shows that the output i dB compression point is about -8.5 dBm at 334 GHz and the maximum efficiency is obtained at the point, which is slightly below the 1 dB compression point. Compared with the conventional hybrid integrated circuit, a major advantage of the monolithic integrated circuit is the significant improvement of reliability and consistency. In this work, a terahertz monolithic frequency multiplier at this band is designed and fabricated.

SELECTING CLUSTER MODEL IN Sn - BASED SOLDER ALLOY DESIGN WITH DV - X_α CALCULATION METHOD

Applying calculation method in alloy design should be an important tendency due to its characters of inexpensive cost, high efficiency and prediction. DOS calculations of AuSn, AsSn and SbSn Sn- based alloys have been investigated by employing DV - Xa method, in which different cluster models were adopted to calculate electron structure.It is proved that some regulations must be taken into ac- count in order to carry out alloy design calculation successfully,which are described in this paper in detail.

Preparation and the Pore Structure of Viscose-based Activated Carbon Fibers Treated with Pretreatment Reagents

The viscose rayon was pretreated with four different pre-treatment reagents respectively, and the preparation ofactivated carbon fibers (ACF) was performed undersame carbonizing and activating conditions. The poresize distribution, the specific surface area, and the porestructure parameter of these viscose - based ACF werestudied by using quartz spring balance BET- weightmethod. The experiment result indicates that the poresize distribution and the pore structure parameter ofACF is varied by using different pretreatment reagents.

GRAPHICAL COMPUTING METHOD ON FOUR-BAR LINKAGE(1)——Inflexion Circle,Focal Axis,Ball's Point,Centering-point Curve and Circling-point Curve For Four ISPs,Coupler Curves Based on Ball's Points——

By means of programs GTMPAC based- on generalized triangle method,analysis and synthesis of mechanism design in accordance with absolutely graphicalmethod( absolutely germetrical method) are developed.In this paper,we make aspecial study about centering- point curve and circling- point curve and couplercurves based on Ball’s points.

面间煤柱与顺槽“掘-充-留”一体化科学问题与技术

我国将煤炭作为兜底保障能源的局面短期内无法改变,仍将长时间面临煤炭资源保护与煤基固废利用率低的难题。通过创新采掘方法,同时实现提高煤炭资源回采率、规模化处置煤基固废,为煤炭行业绿色可持续发展提供了新途径。在深入调研煤炭资源开采技术发展现状的基础上,提出了煤矿“掘-充-留”掘进新工法。从大断面巷道快速掘进、连续高效充填和巷道安全留设3个方面,通过理论分析、数值模拟等手段,系统论述了“掘-充-留”工法的科学问题和关键技术,研究结果表明:①针对大断面巷道快速掘进、掘进工作面围岩稳定性控制等工程难题,凝练了煤岩特性与掘进机截割参数匹配机制、覆岩载荷空间传递机制与围岩变形机理、锚杆/索-顶板相互作用关系及支护机制3个科学难题,构建了以掘进区地质环境超前实时感知、落-装-运煤多工序智能协同作业、钻锚支架随掘随支围岩时效控制和大断面巷道防漏风及通风优化为核心的技术体系;②从大断面巷道承载体系及时构建及其承载性能调控两个方面凝练了连续高效充填的科学问题,包括充填体-煤层-锚杆/索协同承载机制、多元固废基充填材料水化固结机制,明晰充填体物理力学特性时空演化规律,建立了充填空间安全高效搭建、充填材料工作性能调控、充填材料流动-固结感知为核心的连续高效充填关键技术体系,相关理论与技术的突破可以为充填材料的原材料优选及配比设计、添加剂开发/选型及工作性能调控、掘进速率及充填步距优化设计、充填体固结监测等提供基础理论依据;③基于巷道安全留设及全生命周期内围岩易断裂、易片帮和易损伤等关键难题,阐述了巷道围岩应力场时空分布特征、巷道变形与损伤演化机制、巷道围岩工程质量监测与稳定性调控理论3个科学问题,形成了以巷道围岩稳定性智能预警、巷道围岩变形控制为核心的关键技术体系。开展煤矿“掘-充-留”工法的科学研究与工程示范,实现固废规模化处置-面间煤柱高效回收-顺槽快速掘进的协同,可以推动煤炭行业绿色低碳转型发展。

NEW SOLID BASE DERIVED FROM AIPO4-5 SUPPORTED KF

Dispersion of KF on AlPO4-5 molecular sieve created basic sites and caused 1654 cm- band of bidentate carbonate in CO2 adsorption.After pre-treated above 823K. 5%KF/AlPO4-5exhibited basic catalytic activity in the isomerization of butenes at 273K. and the activity increasedwith the pre-treatment temperature up to 923K.

Biological Evaluation of New Schiff Bases: Synthesized from 4-Amino-3,5-dimethyl-1,2,4-triazole, Phenathroline and Bipyridine Dicarboxaldehydes

Four new Schiff bases with promising anticancer activity have been synthesized from 4-amino-3,5-dimethyl-1,2,4-triazole and di-pyridyl-aldehydes. Structures have been established by various spectroscopic methods. The compounds were tested in vitro to study their cytotoxicity and anti-oxidative activity in human lung carcinoma (A549), breast carcinoma (BT549), prostate adenocarcinoma (PC3) and mouse preadipocytes (3T3-L1) cells. Compound 1 was found to increase Glutathione (GSH) level slightly in all four cell lines. Compound 4 showed better selectivity and cytotoxicity against both BT549 and A549 cells compared to the anticancer drug tamoxifen. With the exception of compound 4 which reduced GSH levels in A549 and BT549, all other compounds maintained GSH levels in comparison to their respective controls.

Neuroanatomical Basis of Postoperative Pain and Assessment of Its Management in a Series of Patients Undergoing Caesarean Sections

Introduction: In recent decades, the cost of postoperative pain has been the subject of many studies based on protocols developed by scientific societies for its assessment and optimization. At the Regional Hospital of Saint-Louis (Senegal), several protocols have been developed for pain management, but no study has focused on the assessment of postoperative pain management specifically. We therefore initiated this work, the objectives of which were to remind the neuroanatomical and neurophysiological bases of postoperative pain, and to analyze the assessment and management of this pain in patients who have undergone a caesarean section. Materials and methods: This was a prospective and descriptive study, which took place in the gynecology-obstetrics department, over a period from January 2019 to July 2020. All patients who gave birth by cesarean section were included. The data was collected from a survey sheet written for this purpose. For each of the patients, the information was taken every day throughout the duration of postoperative hospitalization. Results: It appears from our work that after a cesarean section, the pain felt evolves on the first postoperative days with a peak during the second day. As in the data reported in the literature, there does not seem to be a difference in terms of pain intensity and analgesia dosage between scheduled and emergency caesarean sections. However, young age and female gender—for other types of surgeries—are risk factors associated with high postoperative pain scores. This trend is probably related to the low pain experience of tested patients. Our initial hypothesis was that acute post-operative pain after caesarean sections could be linked to defects in the perception and processing of pain by caregivers. Indeed, we have shown that awareness-raising, information, and training actions have made it possible to significantly improve the management of pain after a cesarean section. Conclusion: After a cesarean section the pain is intense, especially when the effects of the morphine wear off. However, in our context where morphine and its derivatives are only slightly used, the post-operative pain is maximal rapidly. This pain therefore needs to be researched and treated appropriately. After a campaign to raise awareness among healthcare personnel, it is possible to significantly improve the systematic administration of analgesics.

Ultrafast Laser Energy Density and Retinal Absorption Cross-Section Determination by Saturable Absorption Measurements

Laser pulse nonlinear transmission measurements through saturable absorbers of known absorption parameters allow the measurement of their energy density. On the other hand, nonlinear transmission measurements of laser pulses of known energy density through absorbing media allow their absorption parameter determination. The peak energy density w0P of second harmonic pulses of a mode-locked titanium sapphire laser at wavelength λP = 400 nm is determined by nonlinear energy transmission measurement TE through the dye ADS084BE (1,4-bis(9-ethyl-3-car-bazovinylene)-2-methoxy-5-(2’-ethyl-hexyloxy)-benzene) in tetrahydrofuran. TE(w0P) calibration curves are calculated for laser pulse peak energy density reading w0P from measured pulse energy transmissions TE. The ground-state absorption cross-section σP and the excited-state absorption cross-section σex at λP, and the number density N0 of the retinal Schiff base isoform RetA in pH 7.4 buffer of the blue-light adapted recombinant rhodopsin fragment of the histidine kinase rhodopsin HKR1 from Chlamydomonas reinhardtii were determined by picosecond titanium sapphire second harmonic laser pulse energy transmission measurement TE through RetA as a function of laser input peak energy density w0P. The complete absorption cross-section spectrum

超长水平段油基钻井液技术在威204H47-10井的应用

位于川中威远区块的威204H47-10井是一口水平段长达3210 m的页岩气开发井,在超长水平段的钻进过程中会钻遇泥页岩层及裂缝带,易出现泥页岩水平段垮塌、裂缝性漏失和井眼清洁难度大等问题。针对这一系列问题,本文通过优选出油基钻井液处理剂形成了一套具有强封堵性的油基钻井液体系,同时针对龙马溪组页岩易脆性地层及裂缝带制定了相应的防塌、防漏技术措施,具体配方为:白油+20%~25%盐水(CaCl2质量体积为20%~30%)+5%HYOZ+1%~2%HYOL+1%~2%TYODF-101+2%~3%HFLO+1%~2%FHXS+5%CaO+重晶石。威204H47-10井的顺利完钻表明,优选的油基钻井液体系和采取针对性防塌、防漏技术措施能在保障超长水平段安全钻进的同时提质增效,可为威远区块、甚至川渝片区超长水平段的钻进提供参考。

含香豆素骨架水杨醛Schiff base荧光材料的制备及光谱性能研究

以间苯二酚和乙酰乙酸乙酯为原料,草酸做催化剂,在无溶剂的条件下,经Pechmann反应催化合成了7-羟基-4-甲基香豆素,再经硝化、还原得到3-氨基7-羟基-4-甲基香豆素。利用3-氨基7-羟基-4-甲基香豆素与水杨醛缩合反应,制备了新型的含香豆素骨架水杨醛Schiff base衍生物,其结构由IR、1HNMR和元素分析确证。通过研究化合物紫外吸收光谱及荧光光谱发现该化合物具有优异光学活性。

刚性基础下现浇X形桩复合地基桩-土应力比分析

桩土应力比是反映复合地基承载特性的重要参数之一,可反映复合地基的荷载传递和变形机制。做为一种新型桩,目前尚未得出统一的计算X形桩复合地基桩土应力比的公式。沉淀池、滤池等构筑物是典型的具有混凝土底板(刚性基础)的结构,刚性基础下桩复合地基的承载性能有别于柔性基础。故结合南京桥北污水处理厂地基处理工程做现场静载荷试验,应用有限元软件ABAQUS建立刚性荷载板下现浇X形混凝土桩复合地基的模型,模拟不同桩身弹性模量、桩周土压缩模量、桩长、褥垫层厚度和压缩模量等参数下现浇X形混凝土桩复合地基的桩土应力比,结果表明,桩身或褥垫层模量增大、桩周土体模量减小、褥垫层厚度减小、桩长等增加都能使桩土应力比增大;现浇X形桩复合地基桩土应力比理想值为20～25,此时桩身模量取10～20 GPa,碎石褥垫层的厚度为20～40 cm,模量为30～45 MPa。

新型胺基抑制剂FYZ-1在长岭油田的应用

吉林油田松辽盆地南部长岭断陷登娄库组和营城组地层富含泥岩,易吸水膨胀,造成井眼垮塌等复杂情况发生,在现场聚磺钾盐钻井液的基础上,使用研制的胺基抑制剂FYZ-1进一步提高钻井液的抑制性能,有效抑制膨润土分散,岩心一次回收率由77.6%提高至95.1%。在长深登平26井和长深平14井等6口井进行了现场应用,结果表明,胺基抑制剂FYZ-1可有效解决坍塌、掉块等复杂情况,保证了长水平段安全、顺利钻进。

掺铒Bi_2O_3-GeO_2-Ga_2O_3-Na_2O玻璃中激发态吸收的抑制

对应用于1.55μm波段宽带放大的掺Er^(3+):Bi_2O_3-GeO_2-Ga_2O_3-Na_2O玻璃中激发态吸收的抑制进行了研究.为此,在该玻璃中分别引入了Ce^(3+)离子和B_2O_3组分.研究表明,随着玻璃中Ce_2O_3的掺杂或B_2O_3组分的引入,Er^(3+):~4I_(11/2)能级与Ce^(3+):~2F_(5/2)能级间的能量传递或Er^(3+):~4I_(11/2)→~4I_(13/2)能级间多声子弛豫速率相应提高,Er^(3+)离子~4I_(11/2)能级荧光寿命显著减小,激发态吸收得到有效抑制.同时,实验发现,Ce_2O_3的掺杂进一步提高了Er^(3+)离子~4I_(13/2)→~4I_(15/2)能级间总量子效率,增强了1.55μm波段荧光发射强度,而荧光发射谱宽基本保持不变.B_2O_3组分的引入虽在一定程度上削弱了1.55μm波段荧光发射强度,但进一步拓展了其荧光发射谱,且增益截面峰值波长移向长波段.

框架-偏置筒体——成都国金中心四号塔楼结构设计

成都国金中心四号酒店及住宅大楼地上51层,总高198 m,建筑的高宽比8.83,筒体高宽比18.7,采用了框架-偏置筒体结构体系。筒体外侧剪力墙内,通过布置型钢暗柱,满足了筒体加强区罕遇地震不屈服的性能化要求,并增强了筒体的延性;通过合理布置框架柱,有效满足了建筑对室内净高和结构对侧向刚度的综合要求;框架柱中设置型钢,减小了截面尺寸及自重。对结构的刚度、强度、整体稳定等指标进行了多遇地震下的反应谱和时程分析;同时补充了大震下弹塑性静力及动力时程分析,发现结构薄弱部位并针对性加强。

苯胺α-呋喃甲醛双齿单希夫碱过渡金属配合物的合成和表征

本文合成了单希夫碱配体-苯胺缩α-呋喃甲醛,使用过渡金属化合物FeCl3.6H2O、MnCl2.4H2O、CoCl2·6H2O、NiCl·26H2O与之配合生成了四种配合物,并用1HNMR、IR及元素分析等测试技术予以表征。