A novel three-step implicit iteration process for threeΦ-hemicontractive mapping in the intermediate sense

In this paper,we introduce a three-step composite implicit iteration process for approximating the common fixed point of three uniformly continuous and asymptotically generalizedΦ-hemicontractive mappings in the intermediate sense.We prove that our proposed iteration process converges to the common fixed point of three finite family of asymptotically generalizedΦ-hemicontractive mappings in the intermediate sense.Our results extends,improves and complements several known results in literature.

Preparation and Characterization of Component Materials for Intermediate Temperature Solid Oxide Fuel Cell by Glycine-Nitrate Process

La1-xSrxGa1-y MgyO3-δ(LSGM) electrolyte, La1-xSrxCr1-y MnyO3-δ( LSCM ) anode and La1-xSrxFe1-y MnyO3-aaaaaaa(LSFM) cathode materials were all synthesized by glycine-nitrate process (GNP). The microstructure and characteristics of LSGM, LSCM and LSFM were tested via X-ray diffraction(XRD), scanning electron microcopy (SEM), A C impedance and four-probe direct current techniques. XRD shows that pure perovskite phase LSGM electrolyte and electrode (LSCM anode and LSFM cathode) materials were prepared after being sintered at 1400℃for 20 h and at 1000℃for 5 h, respectively. The max conductivities of LSGM (ionic conductivity), LSCM (total conductivity) and LSFM (total conductivity) materials are 0.02, 10, 16 S·cm-1 in the air below 850℃, respectively. The conductivity of LSCM becomes smaller when the atmosphere changes from air to pure hydrogen at the same temperature and it decreases with the temperature like metal. The porous and LSGM-based LSCM anode and LSFM cathode films were prepared by screen printing method, and the sintering temperatures for them were 1300 and 1250℃, respectively. LSGM and electrode (LSCM and LSFM) materials have good thermal and chemical compatibility.

FREE RADICAL INTERMEDIATES THEIR POLARIZATION DURING REDOX PROCESSES OF BILE PIGMENTS

The investigation of bile pigments (bilirubin (BR), biliverdin (BV), purpurin (Pu), choletelin (Ch) etc.) by cyclic voltammetry, in-situ rapid scanning thin layer spectroelectrochemistry and ESR spectroscopy indicates that many free radical intermediates and polymers are produced during oxidation and reduction processes.

Techno-Economic Analysis and Life Cycle Assessment for the Typical Intermediate Crude Refining Scheme in China

The integration of refinery and petrochemical units(IRPUs)has become an inevitable choice for the sustainable development of petrochemical industry.The utilization efficiency of petroleum resources could be improved obviously through IRPUs.However,integrating economic and environmental impacts into the model of IRPUs is still a grand challenge.Herein,a model called TEA-GHG-OPWM(Techno-Economic Analysis and GreenHouse Gases Oriented Plant-Wide Model)has been established on Aspen HYSYSTM platform to calculate the energy consumption,the technoeconomic performance,and the GHG emissions for two different kinds of schemes,viz,:VRHCU(Vacuum Residue Hydrocracking Unit)and VRDS-RFCC(Vacuum Residue Desulfurization and Residue Fluid Catalytic Cracking).Furthermore,a novel processing pathway named VGOHDT-HTMP-DC(Vacuum Gas Oil Hydrotreating,Hydrogenation and TMP coupling process and Delayed Coking)has also been developed to find methods to improve the economic performance based on a ten-million-CNY output value(TMYOV)and a reduced GHG emissions.Our results demonstrate that VRHCRU could consume more energy and emit more GHG(877.11 t of CO2 eq·TMYOV^-1·h^-1)than VRDS-RFCC(817.03 t of CO2 eq·TMYOV^-1·h^-1)and VGOHDT-HTMP-DC(721.96 t of CO2 eq·TMYOV^-1·h^-1),while obtaining a higher mass yield of petrochemicals.The VGOHDT-HTMP-DC process exhibits the lowest feedstock consumption,hydrogen consumption,energy consumption,and GHG emissions,indicating that VGOHDT-HTMP-DC has both well economic and environmentally friendly performance.

Resolving Mixed Intermediate Phases in Methylammonium-Free Sn-Pb Alloyed Perovskites for High-Performance Solar Cells

The complete elimination of methylammonium(MA)cations in Sn-Pb composites can extend their light and thermal stabilities.Unfortunately,MA-free Sn-Pb alloyed perovskite thin films suffer from wrinkled surfaces and poor crystallization,due to the coexistence of mixed intermediate phases.Here,we report an additive strategy for finely regulating the impurities in the intermediate phase of Cs_(0.25)FA_(0.75)Pb_(0.6)Sn_(0.4)I_(3)and,thereby,obtaining high-performance solar cells.We introduced d-homoserine lactone hydrochloride(D-HLH)to form hydrogen bonds and strong Pb-O/Sn-O bonds with perovskite precursors,thereby weakening the incomplete complexation effect between polar aprotic solvents(e.g.,DMSO)and organic(FAI)or inorganic(CsI,PbI_(2),and SnI_(2))components,and balancing their nucleation processes.This treatment completely transformed mixed intermediate phases into pure preformed perovskite nuclei prior to thermal anneal-ing.Besides,this D-HLH substantially inhibited the oxidation of Sn^(2+) species.This strategy generated a record efficiency of 21.61%,with a Voc of 0.88 V for an MA-free Sn-Pb device,and an efficiency of 23.82%for its tandem device.The unencapsulated devices displayed impressive thermal stability at 85℃ for 300 h and much improved continuous operation stability at MPP for 120 h.

Performance of La_(1-x)Sr_xCr_(1-y)Mn_yO_(3-δ) anode materials for intermediate temperature solid oxide fuel cell

La1-xSrxCr1-yMnyO3-δ(LSCM) anode materials were synthesized by glycine nitrate process(GNP). Thermo-gravimetric analysis(TGA) and differential scanning calorimetric(DSC) methods were adopted to investigate the reaction process of LSCM anode materials. The oxides prepared were characterized via X-ray diffraction(XRD),scanning electron microscope and energy dispersive spectroscopy(SEM-EDS),direct current four-electrode and temperature process reduction(TPR) techniques. XRD patterns indicate that perovskite phase created after the precursor was sintered at 1 000 ℃ for 5 h,and single perovskite-type oxides formed after the precursor were sintered at 1 200 ℃ for 5 h. The powders are micrometer size after sintering at 1 000 ℃ and 1 200 ℃,respectively. The conductivities of LSCM samples increase linearly with increasing the temperature from 250 ℃ to 850 ℃ in air and the maximum value is 32 S/cm for La0.7Sr0.3Cr0.5Mn0.5O3-δ. But it is lower about two orders of magnitude in pure hydrogen or methane than that of the same sample in the air. TPR result indicates that LSCM offers excellently catalytic performance.

Developing an Efficient Technology for Key Intermediates Production Used in Enzymatic Synthesis of Cladribine and Nelarabine

The pilot-scale process for preparing 2-amino-6-chloro-9-（2＇,3＇,5＇-tri-O-acetyl-Dq3-ribofuranosyl）-purine and 2-chloroadenosine has been developed with a total yield of the desired compounds 73% and 44.5%, respectively. These compounds are useful intermediates for enzymatic synthesis of active pharmaceutical ingredients Nelarabine and Cladribine. The starting material--commercially avaliable guanosine--was acetylated with acetic anhydride, yielding 2,3,5-tri-O-acetylguanosine, which was further deoxyhalogenated with phosphorous oxychloride in presence of tetraethylammonia chloride. Diazotization of the resulting intermediate with tert-butylnitrite leads to the corresponding ribofuranosyl-substituted 2,6-dichloropurine, which was converted to 6-chloroadenosine by reaction with methanolic ammonia.

Techniques and Technological Aspects of Palm Oil (Elaeis guineensis) Processing in Cameroon

Crude palm Oil (CPO) processing is very popular in African Countries. In Cameroon, various actors are involved ranging from agro-industrial complexes to traditional processing by smallholders who use very inefficient equipment and thus have low oil extraction rates. Small-scale processing by smallholders dates back to the early 1980s and has witnessed a lot of changes as a result of new actors in the sector, changing technologies and to an extent, government policies. This paper attempts a review of the origins and evolution of small-scale palm oil processing using intermediate technology, highlighting its importance to both the farmer and the national economy. An attempt is made to look into the future of this activity, with proposals for its consolidation.

Reaction pathway led by silicate structure transformation on decomposition of CaSiO_3 in alkali fusion process using NaOH

The mechanism of decomposition of calcium inosilicate(CaSiO_3) synthesized through chemical deposition method using analytical reagent NaSiO_3·9H_2O and CaCl_2 during the alkali fusion process using NaOH was investigated by Raman spectroscopy in situ,X-ray diffraction and Fourier transform infrared spectrometer(FTIR).The results show that the tetrahedral silica chains within CaSiO_3 are gradually disrupted and transformed into nesosilicate with the isolated SiO_4 tetrahedra at the beginning of the alkali fusion process.The three intermediates including Ca_2SiO_4,Na_2CaSiO_4 and Na_2SiO_3 appear simultaneously in the decomposition of CaSiO_3,while the final products are Ca(OH)_2 and Na_4SiO_4.It can be concluded that there exist two reaction pathways in the alkali fusion process of CaSiO_3:one is ion exchange,the other is in the main form of the framework structure change of silicate.The reaction pathway is led by silicate structure transformation in the alkali fusion process.

基于字词融合的低词汇信息损失中文命名实体识别方法

中文命名实体识别(CNER)任务是一种自然语言处理技术,旨在识别文本中具有特定类别的实体,如人名、地名、组织机构名等,它是问答系统、机器翻译、信息抽取等自然语言应用的基础底层任务。由于中文不具备类似英文这样的天然分词结构,基于词的NER模型在中文命名实体识别上的效果会因分词错误而显著降低,基于字符的NER模型又忽略了词汇信息的作用,因此,近年来许多研究开始尝试将词汇信息融入字符模型中。WC-LSTM通过在词汇的开始字符和结束字符中注入词汇信息,使模型性能获得了显著的提升。然而,该模型依然没有充分利用词汇信息,因此在其基础上提出了基于字词融合的低词汇信息损失NER模型LLL-WCM,对词汇的所有中间字符融入词汇信息,避免了词汇信息损失。同时,引入了两种编码策略平均(avg)和自注意力机制(self-attention)以提取所有词汇信息。在4个中文数据集上进行实验,结果表明,与WC-LSTM相比,该方法的F1值分别提升了1.89%,0.29%,1.10%和1.54%。

前列腺素D_(2)受体拮抗剂关键中间体的工艺改进

前列腺素D2受体拮抗剂是治疗哮喘和过敏性疾病的潜在药物,其关键中间体合成方法尚不成熟。以N-乙酸叔丁酯吲哚和环状苯并磺酰醛亚胺为底物,自制的新型螺环噁唑啉为配体,路易斯酸为催化剂,通过催化的傅克烷基化反应制备了前列腺素D2受体拮抗剂的关键中间体。配体筛选结果表明:不同的配体对反应的收率起到关键作用,其中螺环喹啉噁唑啉配体和三氟甲磺酸锌复合物催化的反应收率最高,且未产生开环结构的双吲哚副产物。通过对反应溶剂、底物物质的量之比和反应温度等反应条件的研究,确定了最佳的反应条件:以二氯甲烷为反应溶剂,N-乙酸叔丁酯吲哚和环状苯并磺酰醛亚胺物质的量之比为1∶1, 0℃反应时,收率最高可达97%。该工艺反应条件温和,使用了廉价且环境友好的催化剂,避免使用传统工艺中腐蚀性和易制爆物料。

生物可降解聚酯酰胺的合成、结构性能及其纺织材料在医疗卫生领域的应用

从单体原料出发系统介绍了聚酯酰胺(PEAs)的结构和性能,综述了其主要聚合方法,梳理并剖析其纺织材料在医疗卫生领域的应用进展,指出PEAs要在环境保护领域及医疗卫生领域占据重要位置,仍需要在原料选择、制备工艺与性能等多个方面展开探索。

甲磺酸非诺多泮合成工艺研究进展

甲磺酸非诺多泮(Fenodopam Mesylate)由于性质稳定、疗效可靠,安全性高、不良反应甚微等优势是目前用于重症高血压治疗效果较好的药物。本文综述了甲磺酸非诺多泮的合成路线,并对其优缺点进行分析,为后续合成工艺优化提供支持,以便得到操作简单、经济高效、绿色环保的工业化生产路线。

电缆中间接头缺陷仿真与局部放电实验研究

由于电缆接头制作工艺的影响,中低压电缆的中间接头故障率较高。以10 kV XLPE电缆为对象,研究缺陷类型对电缆局部电场分布与局部放电特性的影响。通过构建电场分析的仿真模型,搭建局部放电实验平台,研究不同的电缆接头制作缺陷对电缆接头局部电场畸变的影响,对实验试样进行局部放电实验。结果表明,电缆接头制作过程中不同类型的缺陷及缺陷大小对电缆接头部位电场分布、电场的畸变程度、放电初始电压与放电量均有不同程度的影响。研究结果为构建电缆线路工作状态在线监测系统以及电缆运行状态评估与故障诊断提供了依据。

TA4/Q235层状复合材料激光穿透焊研究

为解决钛/钢层状金属在熔焊过程中易产生脆性金属间化合物而导致接头出现裂纹、难以实现可靠连接的难题,对TA4和Q235层状复合材料的激光穿透焊接进行工艺探索,并添加T2紫铜作为中间层进行工艺优化。结果显示,在合适的工艺参数下,TA4/Q235激光穿透焊接接头呈酒杯状,焊缝上下部分出现明显的元素交换,引发裂纹缺陷;引入Cu作为中间层后,得到的Ti-Cu-Fe焊接接头成形良好。能谱分析结果表明,添加Cu可有效阻隔Ti、Fe的直接接触,避免了脆性金属间化合物的产生,焊缝晶粒在一定程度上得以细化且开裂现象明显减少,从而改善了TA4/Q235的焊接性;激光穿透焊接的最佳参数为激光功率3 000 W,线速度2.0 m/min。研究结果对Ti/Fe复合板在航空航天、石油化工等领域的应用有积极的探索作用,具有重要的工程应用前景。

金属活性中间体在亚硫酸盐活化技术中的产生和作用研究进展

近年来,金属活性中间体在亚硫酸盐(S(IV))活化技术中的产生和作用受到广泛关注,但是,金属活性中间体的产生使得S(IV)活化技术中的机制更为复杂。目前文献关于S(IV)活化技术的研究主要集中在新体系的开发,鲜有研究对金属活性中间体在S(IV)活化技术中的产生和作用进行较为详细的分类与总结。基于此,从不同金属活性中间体的类型出发,总结了金属活性中间体在S(IV)活化技术中的产生及其鉴定方法;从污染物的性质、S(IV)的浓度、pH和溶解氧四个方面阐述金属活性中间体在S(IV)活化技术中的作用。针对目前S(IV)活化技术的研究现状和需求进行展望,以期为S(IV)活化技术在水污染控制领域的应用提供参考。

药物和药物中间体合成工艺分析

目的:基于当前我国药物和药物中间体行业发展规模,探讨合成工艺,旨在为药企优化生产技术,提高经济效益提供借鉴。方法:通过举例法分析了几种常见的药物中间体合成工艺分析,并结合具体实践应用,给出了详细的合成工艺应用方法。结果:药企在药物和药物中间体合成过程中,选择定向硝化合成技术、缩合合成技术、吉非替尼中间体合成工艺、膜分离法、帕博西尼母核中间体合成工艺等,将提高药物中间体合成效率。结论:药企通过加强中间体合成工艺研究,能够进一步满足生产需求,促进药企发展壮大。

基于MATLAB建模的电磁兼容测试中接收机数字化设计

随着虚拟仪器的快速发展,对如何将虚拟仪器的可定制性、易扩展、价格低廉等优势应用于电磁兼容测试的接收机进行了研究。通过让数字化虚拟仪器部分取代乃至完全取代传统仪器,已成为日后电磁兼容技术革新的关注焦点。基于MATLAB软件搭建了接收机的模型,实现了接收机的数字化设计。其中中频滤波器的滤波窗函数采用高斯函数,带宽通过修正系数拟合;检波器经过傅里叶变换,实现信号的频谱计算以及包络线绘制。模型通过频选信号的变化,能够实现峰值和平均值两种检波效果。实际测试结果与模型仿真结果误差小于10%,符合企业测试要求。该模型具有较强的扩展性与兼容性,能对整车与高低压零部件的电磁兼容问题进行一定的监测,设计经验对后续电磁兼容测试过程整体数字化发展有着重要意义。

改良西门子法高纯晶硅精馏工艺的节能改进

改良西门子法的发展因高纯晶硅产能饱和、能耗高而受到限制。为了降低能耗,将工业上常用的精馏节能手段应用于改良西门子法高纯晶硅精馏工艺,采用中间再沸器与热泵精馏两种措施对精馏工艺进行改进,并使用Aspen Plus软件对改进工艺与原工艺进行模拟分析。结果表明,以10万t/a精馏单元为例,该改进工艺可使年运行费用降低759万元,经济效益显著。

达罗他胺中间体2-氯-4(1 H-吡唑-3-基)苯甲腈的合成工艺

2-氯-4(1H-吡唑-3-基)苯甲腈是抗前列腺癌新药达罗他胺的重要中间体片段。本文以4-溴-2-氯苯甲腈和1-(2-四氢吡喃基)-1 H-吡唑-5-硼酸频哪酯为原料,经Suzuki偶联和水解脱保护两步反应,在50 g反应规模时,以大于95%的总收率和大于99%的纯度得到2-氯-4(1H-吡唑-3-基)苯甲腈。该反应原料安全易得,产物分离简单,反应收率和产物纯度高,特别是第一步Suzuki偶联反应母液可循环套用,节约了Pd催化剂和生产成本,适合工业化生产。