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Spectra-assisted laser focusing in quantitative analysis of laser-induced breakdown spectroscopy for copper alloys
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作者 李守杰 郑荣儿 +5 位作者 出口祥啓 叶旺全 田野 郭金家 李颖 卢渊 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第4期204-209,共6页
Laser-induced breakdown spectroscopy(LIBS)is a capable technique for elementary analysis,while LIBS quantitation is still under development.In quantitation,precise laser focusing plays an important role because it ens... Laser-induced breakdown spectroscopy(LIBS)is a capable technique for elementary analysis,while LIBS quantitation is still under development.In quantitation,precise laser focusing plays an important role because it ensures the distance between the laser and samples.In the present work,we employed spectral intensity as a direct way to assist laser focusing in LIBS quantitation for copper alloys.It is found that both the air emission and the copper line could be used to determine the position of the sample surface by referencing the intensity maximum.Nevertheless,the fine quantitation was only realized at the position where the air emission(e.g.O(I)777.4 nm)reached intensity maximum,and also in this way,a repeatable quantitation was successfully achieved even after 120 days.The results suggested that the LIBS quantitation was highly dependent on the focusing position of the laser,and spectra-assisted focusing could be a simple way to find the identical condition for different samples’detection.In the future,this method might be applicable in field measurements for LIBS analysis of solids. 展开更多
关键词 LIBS laser focusing spectra assistance quantitative analysis copper alloys
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CAUCHY TYPE INTEGRALS AND A BOUNDARY VALUE PROBLEM IN A COMPLEX CLIFFORD ANALYSIS
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作者 曹南斌 李尊凤 +1 位作者 杨贺菊 乔玉英 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期369-385,共17页
Clifford analysis is an important branch of modern analysis;it has a very important theoretical significance and application value,and its conclusions can be applied to the Maxwell equation,Yang-Mill field theory,quan... Clifford analysis is an important branch of modern analysis;it has a very important theoretical significance and application value,and its conclusions can be applied to the Maxwell equation,Yang-Mill field theory,quantum mechanics and value problems.In this paper,we first give the definition of a quasi-Cauchy type integral in complex Clifford analysis,and get the Plemelj formula for it.Second,we discuss the H?lder continuity for the Cauchy-type integral operators with values in a complex Clifford algebra.Finally,we prove the existence of solutions for a class of linear boundary value problems and give the integral representation for the solution. 展开更多
关键词 Clifford analysis Cauchy type integral Plemelj formula Holder continuous boundary value problems
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Uncertainty and sensitivity analysis of in-vessel phenomena under severe accident mitigation strategy based on ISAA-SAUP program
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作者 Hao Yang Ji-Shen Li +2 位作者 Zhi-Ran Zhang Bin Zhang Jian-Qiang Shan 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第1期108-123,共16页
The phenomenology involved in severe accidents in nuclear reactors is highly complex.Currently,integrated analysis programs used for severe accident analysis heavily rely on custom empirical parameters,which introduce... The phenomenology involved in severe accidents in nuclear reactors is highly complex.Currently,integrated analysis programs used for severe accident analysis heavily rely on custom empirical parameters,which introduce considerable uncertainty.Therefore,in recent years,the field of severe accidents has shifted its focus toward applying uncertainty analysis methods to quantify uncertainty in safety assessment programs,known as“best estimate plus uncertainty(BEPU).”This approach aids in enhancing our comprehension of these programs and their further development and improvement.This study concentrates on a third-generation pressurized water reactor equipped with advanced active and passive mitigation strategies.Through an Integrated Severe Accident Analysis Program(ISAA),numerical modeling and uncertainty analysis were conducted on severe accidents resulting from large break loss of coolant accidents.Seventeen uncertainty parameters of the ISAA program were meticulously screened.Using Wilks'formula,the developed uncertainty program code,SAUP,was employed to carry out Latin hypercube sampling,while ISAA was employed to execute batch calculations.Statistical analysis was then conducted on two figures of merit,namely hydrogen generation and the release of fission products within the pressure vessel.Uncertainty calculations revealed that hydrogen production and the fraction of fission product released exhibited a normal distribution,ranging from 182.784 to 330.664 kg and from 15.6 to 84.3%,respectively.The ratio of hydrogen production to reactor thermal power fell within the range of 0.0578–0.105.A sensitivity analysis was performed for uncertain input parameters,revealing significant correlations between the failure temperature of the cladding oxide layer,maximum melt flow rate,size of the particulate debris,and porosity of the debris with both hydrogen generation and the release of fission products. 展开更多
关键词 Gen-III PWR Severe accident mitigation Wilks’formula HYDROGEN Fission products Uncertainty and sensitivity analysis
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Analysis of Adverse Reactions in the Treatment of COVID-19 with Three Chinese Patent Medicines and Three Herbal Formulas
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作者 Li Qiao Wang Aili +1 位作者 Wu Di Chen Yuwen 《Asian Journal of Social Pharmacy》 2023年第1期8-16,共9页
Objective To explore the rules and characteristics of the adverse drug reactions(ADRs)of three Chinese patent medicines and three herbal formulas for the treatment of COVID-19,and to provide a reference for clinical s... Objective To explore the rules and characteristics of the adverse drug reactions(ADRs)of three Chinese patent medicines and three herbal formulas for the treatment of COVID-19,and to provide a reference for clinical safe medication.Methods The cases and ADR reports of the three Chinese patent medicines and three herbal formulas in PubMed,Web of Science,Springer Link,CNKI,Wanfang and VIP database were retrieved from December 2019 to May 2021.Then we extracted and analyzed the effective information included in the literature.Results and Conclusion According to the pre-developed retrieval plan,a total of 136 documents were obtained,and a total of 6 documents met the inclusion criteria finally.553 patients used three Chinese patent medicines and three herbal formulas,and there were 133 cases of adverse reactions.The adverse reactions of patients taking the three Chinese patent medicines and three herbal formulas can all be explained under the theory of traditional Chinese medicine,and the adverse reactions can be eliminated by adding or subtracting the flavor of the medicine or stopping the medicine. 展开更多
关键词 three Chinese patent medicines and three herbal formulas adverse drug reaction document analysis
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A Computer-Assisted Corpus Analysis (CACA) of Professional Discourse
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作者 K. Manvender H-Z Yasmin Sarimah Shamsudin 《Sino-US English Teaching》 2012年第6期1236-1245,共10页
关键词 语料库 电脑辅助 话语 语言能力 计算机辅助 马来西亚 石油工业 语言知识
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Analysis of high-frequency local coupling instability induced by multi- transmitting formula - P-SV wave simulation in a 2D waveguide 被引量:6
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作者 Xie Zhinan Zhang Xubin 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2017年第1期1-10,共10页
Local coupling instability will occur when the numerical scheme of absorbing boundary condition and that of the field wave equation allow energies to spontaneously enter into the computational domain. That is, the two... Local coupling instability will occur when the numerical scheme of absorbing boundary condition and that of the field wave equation allow energies to spontaneously enter into the computational domain. That is, the two schemes support common wave solutions with group velocity pointed into the computation domain. The key to eliminate local coupling instability is to avoid such wave solutions. For lumped-mass finite element simulation of P-SV wave motion in a 2D waveguide, an approach for stable implementation of high order multi-transmitting formula is provided. With a uniform rectangular mesh, it is proven and validated that high-freqaency local coupling instability can be eliminated by setting the ratio of the element size equal to or greater than x/2 times the ratio of the P wave velocity to the S wave velocity. These results can be valuable for dealing instability problems induced by other absorbing boundary conditions. 展开更多
关键词 absorbing boundary condition local coupling instability dispersion analysis group velocity multi-transmitting formula
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Plemelj Formula for Cauchy Type Integral on Certain Distinguished Boundary in Universal Clifford Analysis 被引量:3
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作者 XU Na DU Jinyuan 《Wuhan University Journal of Natural Sciences》 CAS 2007年第3期385-390,共6页
Under the foundation of Cauchy integral formula on certain distinguished boundary for functions with values in universal Clifford algebra, we define the Cauchy type integral with values in a universal Clifford algebra... Under the foundation of Cauchy integral formula on certain distinguished boundary for functions with values in universal Clifford algebra, we define the Cauchy type integral with values in a universal Clifford algebra, obtain its Cauchy principal value and Plemelj formula on certain distinguished boundary. 展开更多
关键词 universal Clifford analysis Cauchy type integral Plemelj formula
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Civil Aircraft Assisted Space-Air-Ground Integrated Networks: Architecture Design and Coverage Analysis 被引量:2
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作者 Shuxun Li Qian Chen +2 位作者 Zhe Li Weixiao Meng Cheng Li 《China Communications》 SCIE CSCD 2022年第1期29-39,共11页
In this paper, we propose a novel AIenabled space-air-ground integrated networks(SAGIN). This new integrated networks architecture consists of LEO satellites and civil aircrafts carrying aerial base stations, called &... In this paper, we propose a novel AIenabled space-air-ground integrated networks(SAGIN). This new integrated networks architecture consists of LEO satellites and civil aircrafts carrying aerial base stations, called "civil aircraft assisted SAGIN(CAA-SAGIN)". The assistance of civil aircrafts can reduce the stress of satellite networks, improve the performance of SAGIN, decrease the construction cost and save space resources. Taking the Chinese mainland as an example, this paper has analyzed the distribution of civil aircrafts, and obtained the coverage characteristics of civil aircraft assisted networks(CAAN). Taking Starlink as the benchmark, this paper has calculated the service gap of CAAN, and designed the joint coverage constellation. The simulation results prove that the number of satellites in CAASAGIN can be greatly reduced with the assistance of civil aircrafts at the same data rate. 展开更多
关键词 AI-enabled space-air-ground integrated networks civil aircraft assisted networks satellite constellation design joint coverage analysis
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Efficacy of totally laparoscopic compared with laparoscopic-assisted total gastrectomy for gastric cancer: A meta-analysis 被引量:14
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作者 Song Wang Mei-Lan Su +4 位作者 Yang Liu Zhi-Ping Huang Ning Guo Tian-Jin Chen Zhong-Hui Zou 《World Journal of Clinical Cases》 SCIE 2020年第5期900-911,共12页
BACKGROUND Laparoscopic radical gastrectomy is currently the most common surgical approach for gastric cancer.The main difference between totally laparoscopic total gastrectomy(TLTG)and laparoscopic-assisted total gas... BACKGROUND Laparoscopic radical gastrectomy is currently the most common surgical approach for gastric cancer.The main difference between totally laparoscopic total gastrectomy(TLTG)and laparoscopic-assisted total gastrectomy(LATG)is the route of digestive tract reconstruction.However,TLTG is currently not widespread as the safety and feasibility of intracorporeal esophagojejunostomy is uncertain.AIM To compare the short-term efficacy of TLTG and LATG for radical gastrectomy of gastric cancer,and to determine the safety and feasibility of intracorporeal esophagojejunostomy.METHODS PubMed,EMBASE,and Web of Science databases were searched for all relevant articles regarding TLTG vs LATG for gastric cancer published up to October 1,2019.Inclusion and exclusion criteria were established.All the basic conditions of patients and important clinical data related to surgery were extracted,and a meta-analysis was performed with RevMan 5.3 software.RESULTS Eight studies involving a total of 1883 cases(869 cases in the TLTG group and 1014 cases in the LATG group)were included.Compared with the LATG group,reduced intraoperative blood loss(weighted mean difference=-35.37,95%CI:-61.69--9.06,P=0.008)and a larger number of retrieved lymph nodes(weighted mean difference=3.11,95%CI:-2.60-12.00,P=0.01)were found in the TLTG group.There were no significant differences in operating time,anastomotic time,tumor size,proximal resection margin length,postoperative pain score,time to first flatus,time to first oral intake,postoperative hospital stay,postoperative anastomosis-related complication rate and overall complication rate between the two groups(P>0.05).CONCLUSION Intracorporeal esophagojejunostomy is safe and feasible.TLTG has the advantages of being minimally invasive,reduced intraoperative blood loss and easier access to lymph nodes compared with LATG.Totally laparoscopic gastrectomy is likely to be the surgical trend for gastric cancer in the future. 展开更多
关键词 Gastric cancer Total gastrectomy ESOPHAGOJEJUNOSTOMY Totally laparoscopic LAPAROSCOPIC-assisted META-analysis
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Dry eye and corneal sensitivity after small incision lenticule extraction and femtosecond laser-assisted in situ keratomileusis:a Meta-analysis 被引量:10
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作者 Wen-Ting Cai Qing-Yu Liu +6 位作者 Cheng-Da Ren Qing-Quan Wei Jun-Ling Liu Qian-Yi Wang Ya-Ru Du Meng-Mei He Jing Yu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2017年第4期632-638,共7页
AIM:To assess the corneal sensitivity and the incidences of dry eye after small incision lenticule extraction(SMILE) and femtosecond laser-assisted in situ keratomileusis(FSLASIK).METHODS:The Meta-analysis was p... AIM:To assess the corneal sensitivity and the incidences of dry eye after small incision lenticule extraction(SMILE) and femtosecond laser-assisted in situ keratomileusis(FSLASIK).METHODS:The Meta-analysis was performed using Rev Man 5.3.We searched on Pub Med from inception to March 2016.Summary weighted mean difference(WMD) and 95% confidence intervals(CIs) were used to analyze the datum.Random-effects or fixed-effects models were chosen up to between-study heterogeneity.The main outcomes were composed of the Ocular Surface Disease Index(OSDI) scores,tear film break-up time(TBUT),Schirmer Test and corneal sensitivity.RESULTS:Eight eligible studies including 772 eyes(386 in SMILE group and 386 in FS-LASIK group) were identified.The parameters have no significiant difference heterogeneity between SMILE and FS-LASIK group preoperatively.There were significant differences between the two groups in OSDI scores at one and three months postoperatively,in TBUT at one and three months postoperatively,in corneal sensitivity at one week,about one month and three months postoperatively.However,there was no significant difference observed in Schirmer Test at the follow-up periods.CONCLUSION:Compare to FS-LASIK,dry eye and the corneal sensitivity recover better in the SMILE group,in first three months after the surgery. 展开更多
关键词 dry eye corneal sensation small incision lenticule extraction femtosecond laser-assisted in situ keratomileusis META-analysis
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Numerical modeling and deformation analysis for electromagnetically assisted deep drawing of AA5052 sheet 被引量:4
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作者 刘大海 李春峰 于海平 《中国有色金属学会会刊:英文版》 EI CSCD 2009年第5期1294-1302,共9页
Electromagnetic forming(EMF)is a high-velocity manufacturing technique which uses electromagnetic(Lorentz)body forces to shape sheet metal parts.One of the several advantages of EMF is the considerable ductility incre... Electromagnetic forming(EMF)is a high-velocity manufacturing technique which uses electromagnetic(Lorentz)body forces to shape sheet metal parts.One of the several advantages of EMF is the considerable ductility increase observed in several metals,with aluminum featuring prominently among them.Electromagnetically assisted sheet metal stamping(EMAS)is an innovative hybrid sheet metal processing technique that combines EMF into traditional stamping.To evaluate the efficiency of this technique,an experimental scheme of EMAS was established according to the conventional stamping of cylindrical parts from aluminum and the formability encountered was discussed.Furthermore,a "multi-step,loose coupling" numerical scheme was proposed to investigate the deformation behaviors based on the ANSYS Multiphysics/LS-DYNA platform through establishing user-defined subroutines.The results show that electromagnetically assisted deep drawing can remarkably improve the formability of aluminum cylindrical parts.The proposed numerical scheme can successfully simulate the related Stamping-EMF process,and the deformation characteristics of sheet metal reflect experimental results.The predicted results are also validated with the profiles of the deformed sheets in experiments. 展开更多
关键词 电磁成形 变形分析 数值模拟 深冲板 钣金冲压 加工技术 金属板材 生态管理
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Systematic review and Meta-analysis of treating open angle glaucoma with gonioscopy-assisted transluminal trabeculotomy 被引量:2
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作者 Chun-Yan Guo Xiao-Hui Qi Jian-Ming Qi 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2020年第2期317-324,共8页
●AIM:To systematically review and Meta-analyze studies of managing open angle glaucoma(OAG)with gonioscopyassisted transluminal trabeculotomy(GATT)and to evaluate its effectiveness and safety.●METHODS:Eligible studi... ●AIM:To systematically review and Meta-analyze studies of managing open angle glaucoma(OAG)with gonioscopyassisted transluminal trabeculotomy(GATT)and to evaluate its effectiveness and safety.●METHODS:Eligible studies were retrieved and screened from five main electronic databases.Mean difference(MD)was hired to show the pooled effectiveness of intraocular pressure(IOP)and medication decrease achieved by GATT.In addition,combined surgical success and reoperation rates were calculated,and complications were also summarized.●RESULTS:Ten studies were included for systematic review,but one study was not pooled for Meta-analysis due to the repeated data.The combined IOP decrease after GATT was 9.81 mm Hg(95%CI:7.98-11.63 mm Hg)which showed significant reduction from the baselines(Z=10.52,P<0.0001).Similarly,the number of medications after GATT also decreased distinctly compared with that of medication before the surgery(Z=9.09,P<0.0001),and the pooled medication decrease was 1.68(95%CI:1.31-2.04).In addition,the combined surgical success rate was 85%,while the pooled reoperation rate was 20%.Sightthreatening complications occurred scarcely,whereas the pooled occurrence rate of hyphemia was as high as 36.0%.●CONCLUSION:GATT could effectively lower IOP and decrease medications for patients with OAG.Moreover,the procedure appears to be a safe and promising treatment for OAG due to its minimally-invasive and conjunctiva-sparing nature. 展开更多
关键词 gonioscopy-assisted TRANSLUMINAL TRABECULOTOMY open angle glaucoma INTRAOCULAR pressure complication META-analysis
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Derivation and Analysis of A New Reconstruction Formula from Cone-beam Projections
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作者 You Jiangsheng and Bao Shanglian 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1996年第4期399-408,共10页
A new method to compute the first derivative of 3-DRadon transform is given for cone-beam data taken from any orbit.Smith and Grangeat even derived cone-beam inversion formulaswhich are the basic work in fully 3-D ... A new method to compute the first derivative of 3-DRadon transform is given for cone-beam data taken from any orbit.Smith and Grangeat even derived cone-beam inversion formulaswhich are the basic work in fully 3-D image reconstruction algorithm andare used extensively now. In thispaper we will give a new inversion formula and a simple necessaryand sufficient condition which guarantees the complete reconstructionalgorithm. 展开更多
关键词 CONE formula beam RECONSTRUCTION analysis
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Association analysis datamining the compatibility regulations of Li Dong Yuan's formula of spleen and stomach 被引量:1
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作者 ChenBo JiangYongguang HuBo LiuJuan 《中医药学刊》 2004年第4期613-615,共3页
Analyzing systemically more than 550 Li Dong Y uan’s formula of spleen and stomach by using the association rule to mine the in formation relativity between formula, herbal medicine and syndrome.From this we can stud... Analyzing systemically more than 550 Li Dong Y uan’s formula of spleen and stomach by using the association rule to mine the in formation relativity between formula, herbal medicine and syndrome.From this we can study better the compatibility regulations of the 展开更多
关键词 脾胃系病证 中医药疗法 相关规则 LI Dong YUAN 药-效关系
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Reliability Verification and Practical Effectiveness Evaluation of the Nursing Administration Analysis Formulae Based on PSYCHOMS^(■)
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作者 Misao Miyagawa Kaori Katou +5 位作者 Yuko Yasuhara Kazuyuki Matsumoto Motoyuki Suzuki Takako Takebayashi Tetsuya Tanioka Rozzano Locsin 《Health》 2014年第21期3013-3021,共9页
In psychiatric hospitals, the ratios between patients versus physician and patients versus nurse are low as compared to those in general hospitals. Furthermore, usages of electronic medical records are also low so tha... In psychiatric hospitals, the ratios between patients versus physician and patients versus nurse are low as compared to those in general hospitals. Furthermore, usages of electronic medical records are also low so that nurse administrators are limited in their ability to compile, analyze, and generate patient care staffing information for their administrative use. Psychiatric nurse administrators anticipate the development of a nursing administration analysis system that could perform personnel data simulation, manage information on nursing staff, and manage ward/ practice operations. Responding to this situation, the authors developed a nursing administration analysis system utilizing formulae from the Psychiatric Outcome Management System, PSYCHOMS&reg;to aid nurse administrators. Such formulae are awaiting patent approval. The purpose of this study was to examine the validity of the formulae and the Structured Query Language (SQL) statement, and its practical effectiveness of analyzing data. The study findings showed that two kinds of computation expressions—a classification and extraction were able to display required information desired by nurse administrators. Moreover, significant information critical to assigning staff was validated to ensure high quality of nursing care according to the function and characteristic of the hospital ward. 展开更多
关键词 analysis formulae Nursing Administration analysis Psychiatric Hospital PSYCHOMS^(■)
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General formula for phonon-assisted n-photon absorption in solids
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作者 邓洪祥 蒋晓东 +5 位作者 向霞 孙凯 袁晓东 郑万国 高飞 祖小涛 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第10期573-583,共11页
A general formula for phonon-assisted n-photon absorption in solids is obtained by (n + 1)-th order perturbation technique. The complicated calculation process for transition element of n-photon absorption is simpl... A general formula for phonon-assisted n-photon absorption in solids is obtained by (n + 1)-th order perturbation technique. The complicated calculation process for transition element of n-photon absorption is simply demonstrated by a diagram approach that is proposed in this work. We find that the transition element for the n-photon absorption has a simple form, i.e., it is just the first term of the n-th order fist kind Bessel function. 展开更多
关键词 general formula phonon-assisted photons absorption n order perturbation technique diagram approach intense laser
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ON LINE COMPUTATION OF EMPIRICAL FORMULA BY MEANS OF ELEMENTAL ANALYSIS AND ITS PROGRAM DESIGN
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作者 钱朴 胡培荣 金正成 《苏州大学学报(自然科学版)》 CAS 1995年第2期90-94,共5页
On line determination of empirical formula for organic compounds with an automatic elemental analyzer and its program design method were investigated. The computational results shews that the reliability of computatio... On line determination of empirical formula for organic compounds with an automatic elemental analyzer and its program design method were investigated. The computational results shews that the reliability of computational results depends on the accuracy of the analytical data and the organic compound itself. 展开更多
关键词 在线估算 经验公式 元素分析 程序设计 有机化合物 分子量 分子式 原子比率
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Microwave-Assisted Transition Metal Nanostructure Synthesis: Power-Law Signature Verification
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作者 Victor J. Law Denis P. Dowling 《American Journal of Analytical Chemistry》 2023年第8期326-349,共24页
A power-law (y = cx<sup>n</sup>) signature between process energy budget (kJ) and process energy density (kJ·ml<sup>-1</sup>) of microwave-assisted synthesis of silver and gold nanostructu... A power-law (y = cx<sup>n</sup>) signature between process energy budget (kJ) and process energy density (kJ·ml<sup>-1</sup>) of microwave-assisted synthesis of silver and gold nanostructures has been recently described [Law and Denis. AJAC, 14(4), 149-174, (2023)]. This study explores this relation further for palladium, platinum, and zinc oxide nanostructures. Parametric cluster analysis and statistical analysis is used to test the power-law signature of over four orders of magnitude as a function of six microwave applicator-types metal precursor, non-Green Chemistry synthesis and claimed Green Chemistry. It is found that for the claimed Green Chemistry, process energy budget ranges from 0.291 to 900 kJ, with a residual error ranging between −33 to +25.9 kJ·ml<sup>-1</sup>. The non-Green Chemistry synthesis has a higher process energy budget range from 3.2 kJ to 3.3 MJ, with a residual error of −33.3 to +245.3 kJ·ml<sup>-1</sup>. It is also found that the energy profile over time produced by software controlled digestion applicators is poorly reported which leads to residual error problematic outliers that produce possible phase-transition in the power-law signature. The original Au and Ag database and new Pd, Pt and ZnO database (with and without problematic outliers) yield a global microwave-assisted synthesis power-law signature constants of c = 0.7172 ± 0.3214 kJ·ml<sup>-1</sup> at x-axes = 0.001 kJ, and the exponent, n = 0.791 ± 0.055. The information in this study is aimed to understand variations in historical microwave-assisted synthesis processes, and develop new scale-out synthesis through process intensification. 展开更多
关键词 Microwave-assisted Synthesis PD Ag Pt AU ZnO POWER-LAW Residual Error Statistical analysis Parametric Cluster analysis
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水中硝酸盐氮稳定同位素比值测定前处理方法的优化
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作者 袁红朝 贺珍 +6 位作者 张丽萍 耿梅梅 许丽卫 陈闻 彭灿 唐思宇 王久荣 《中国无机分析化学》 CAS 北大核心 2024年第7期889-895,共7页
水体中过量的硝酸盐会导致严重的水生生态恶化和环境污染问题。氮稳定同位素技术为水体污染来源的判断及水生系统氮素转化机理研究提供了强有力的工具。在前人基础上,通过开发Cu^(2+)-Cd复合催化结合超声波辅助加速反应,优化硝酸盐氮同... 水体中过量的硝酸盐会导致严重的水生生态恶化和环境污染问题。氮稳定同位素技术为水体污染来源的判断及水生系统氮素转化机理研究提供了强有力的工具。在前人基础上,通过开发Cu^(2+)-Cd复合催化结合超声波辅助加速反应,优化硝酸盐氮同位素比值测定前处理方法。考察了Cu^(2+)添加量、超声功率以及反应时间变化对NO_(3)^(-)-N转化生成N_(2)O气体及其氮同位素比值的影响,在单因素实验基础上采用正交实验优化得到了最佳反应条件,并采用不同^(15)N同位素比值的KNO_(3)标准溶液结合气体预浓缩装置与稳定同位素质谱仪联用系统对新方法进行了验证。新方法单次反应体系中氮最低量为1.0μg,其中自然丰度和高丰度样品δ^(15)N分析精度小于1‰,富集样品的^(15)N分析精度可达0.1 atom%以内(CV<1%);且所有标准样品的^(15)N测定值与参考值基本一致。将优化后的方法应用于不同来源水样中硝酸盐氮稳定同位素比值测定,均可获得较好的精度,较原方法提高了前处理效率,且精度更优。建立的方法准确可靠,操作简单,耗时短,适用于水中硝酸盐氮稳定同位素比值测定的批量、快速前处理。 展开更多
关键词 水体 硝酸盐 氮同位素测定 前处理 超声波辅助
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三种固废改性生土材料配方设计及力学性能研究
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作者 张坤 付智勇 +3 位作者 张凌寒 杨文豪 兰官奇 朱熹育 《硅酸盐通报》 CAS 北大核心 2024年第2期603-616,636,共15页
为改善生土材料的力学性能,本研究以铁尾矿、煤矸石、电石渣、油泥与水泥等材料作为掺和料对生土进行改性。基于单形格子法设计配方,对3种配方、180个改性生土试件进行抗压强度试验,研究不同因素对试件破坏形态、抗压强度和试验数据离... 为改善生土材料的力学性能,本研究以铁尾矿、煤矸石、电石渣、油泥与水泥等材料作为掺和料对生土进行改性。基于单形格子法设计配方,对3种配方、180个改性生土试件进行抗压强度试验,研究不同因素对试件破坏形态、抗压强度和试验数据离散性的影响;利用频数分析法,研究了固废改性生土材料的最优配方;通过CT扫描,从细观层面分析受荷后材料内部的分形和孔隙。结果表明:改性生土试件抗压破坏形态基本相同,极限位移受掺料影响显著。以煤矸石与电石渣、铁尾矿与水泥、油泥与水泥作为掺和料均可大幅提高改性生土试件的力学性能,掺和料种类、掺量对改性生土试件强度及数据离散性影响显著。经过频数寻优,3种配方的理想强度掺和料配比分别为1)铁尾矿12.1%~19.5%(质量分数,下同)、水泥13.9%~19.1%、生土65.5%~69.9%;2)电石渣6.7%~14.1%、煤矸石8.9%~11.8%、生土76.7%~81.8%;3)油泥11.4%~14.4%、水泥17.4%~19.4%、生土67.1%~70.5%。材料内部的分形和孔隙特征稳定,表现出较小的波动性和良好的密实性。 展开更多
关键词 改性生土 固废利用 抗压强度 配方设计 频数分析法
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