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基于作物Cd富集系数的土壤有效态Cd化学浸提方法筛选
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作者 俞磊 孙晓艺 +3 位作者 秦璐瑶 王静 王萌 陈世宝 《地学前缘》 EI CAS CSCD 北大核心 2024年第2期111-120,共10页
土壤中镉(Cd)被作物吸收的程度及其生态风险取决于土壤中Cd的赋存形态,基于Cd有效形态的污染土壤风险评价及在此基础上制订污染土壤修复安全阈值是Cd污染农田土壤风险评价和治理亟待解决的问题。目前针对土壤中重金属有效态的化学浸提... 土壤中镉(Cd)被作物吸收的程度及其生态风险取决于土壤中Cd的赋存形态,基于Cd有效形态的污染土壤风险评价及在此基础上制订污染土壤修复安全阈值是Cd污染农田土壤风险评价和治理亟待解决的问题。目前针对土壤中重金属有效态的化学浸提方法较多,但缺乏针对不同性质土壤中有效态Cd的普适性浸提方法已成为Cd污染土壤风险评价技术瓶颈。本研究采集了全国9个不同性质农田土壤,以水稻、小白菜和玉米为测试作物,通过外源添加方法制备Cd污染土壤,结合土壤培养和盆栽实验,测定了5种常用化学浸提方法,包括中性无机盐浸提方法(CaCl_(2)浸提法)、弱酸浸提法(HCl浸提法)、络合螯合剂浸提方法(DTPA和ETPA浸提法)和组合浸提方法(Mehlich-3(M3)浸提法)对不同性质土壤中有效态Cd浸提效果及其与作物Cd吸收的量化关系,筛选适用于不同性质土壤中有效态Cd的通用浸提方法。结果表明,不同化学浸提法提取的土壤有效态Cd含量间具有显著差异,不同浸提方法对土壤中Cd的浸提率(%)为DTPA≈EDTA≈HCl>M3≈CaCl_(2)。不同化学浸提态Cd与作物Cd吸收的相关系数间具有显著差异,基于综合相关系数方法,得出5种不同浸提态Cd与作物Cd吸收的综合相关系数为I M3=0.765,I EDTA=0.641,I DTPA=0.627,I HCl=0.606,I CaCl_(2)=0.711,M3浸提态Cd含量与不同性质土壤中水稻、小白菜和玉米植株地上部Cd相关性最高,可作为不同性质土壤中有效态Cd通用浸提方法。相关研究结果可为农田土壤中Cd有效态评价及Cd污染农田的修复提供理论依据。 展开更多
关键词 污染土壤 富集系数 化学浸提方法 筛选
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钛网上CdS纳米微球的制备及可见光下产氢性能研究
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作者 陈志强 崔磊 +2 位作者 董晶 李海霞 夏炜炜 《硅酸盐通报》 CAS 北大核心 2024年第2期727-733,共7页
为了提高催化剂的光催化产氢能力,本文采用简单的水热法,在处理后的钛网表面生长了CdS纳米微球。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线光电子能谱(XPS)等测试手段对样品的成分、结构、形貌进行了表征... 为了提高催化剂的光催化产氢能力,本文采用简单的水热法,在处理后的钛网表面生长了CdS纳米微球。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线光电子能谱(XPS)等测试手段对样品的成分、结构、形貌进行了表征,并研究了其光电化学性能及可见光下光催化性能。结果表明,钛网上生长的CdS微球由纳米棒组装而成,通过缺陷调控,Cd/S物质的量之比为1∶1(CdS-1)的样品具有良好的光电响应,在零偏压下最大光电流约为140μA,可见光下的产氢率可达212.6μmol·h^(-1)·cm^(-2),并且方便回收,是一种理想的光催化产氢材料。 展开更多
关键词 水热法 缺陷调控 钛网 cdS纳米微球 光电化学性能 光催化产氢
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Application of the “Six-Step Teaching Method” in the Nursing Teaching of Obstetric Interns
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作者 Rui Liu Kun Yuan Yuanyuan Li 《Open Journal of Nursing》 2023年第9期615-623,共9页
Objective: The “six-step teaching method” is a teaching method, which is summarized based on practical experience. This study aimed to explore the effect of “six-step teaching method” in clinical teaching of ... Objective: The “six-step teaching method” is a teaching method, which is summarized based on practical experience. This study aimed to explore the effect of “six-step teaching method” in clinical teaching of obstetrics. Methods: A quasi-experimental study design was used, 30 nursing students who entered obstetrics practice from March 2022 to July 2022 were selected as the control group according to the order of time, and traditional teaching methods were adopted. From August to December 2022, 30 interns were selected as the experimental group, and the “six-step teaching method” was adopted. After 8 weeks of clinical practice, the assessment results and teaching effect satisfaction of the two groups were compared. Results: The scores of obstetrical specialty in the experimental group were higher than those in the control group, and the difference was statistically significant (P < 0.05);The evaluation of teaching methods, teaching quality, classroom atmosphere and individual observation ability, clinical thinking ability and nurse-patient communication ability of the experimental group were higher than those of the control group, and the differences were statistically significant (P Conclusion: “six-step teaching method” can effectively master the professional knowledge of obstetrics, stimulate the clinical thinking ability of interns, and improve the teaching effect and satisfaction. . 展开更多
关键词 six-step Teaching method Obstetrics Intern Nursing Education
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Exact Traveling Wave Solutions to Phi-4 Equation and Joseph-Egri (TRLW) Equation and Calogro-Degasperis (CD) Equation by Modified (G'/G2)-Expansion Method
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作者 Maha Al-Harbi Waleed Al-Hamdan Luwai Wazzan 《Journal of Applied Mathematics and Physics》 2023年第7期2103-2120,共18页
In this study, we will introduce the modified (G'/G<sup>2</sup>)-expansion method to explore some of the exact traveling wave solutions of some nonlinear partial differential equations namely, Phi-4 eq... In this study, we will introduce the modified (G'/G<sup>2</sup>)-expansion method to explore some of the exact traveling wave solutions of some nonlinear partial differential equations namely, Phi-4 equation, Joseph-Egri (TRLW) equation, and Calogro-Degasperis (CD) equation. As a result, we have obtained solutions for the equations expressed in terms of trigonometric, hyperbolic and rational functions. Moreover, some selected solutions are plotted using some specific values for the parameters. 展开更多
关键词 Exact Solutions Modified (G'/G2)-Expansion method Phi-4 Equation Joseph-Egri (TRLW) Equation Calogro-Degasperis (cd) Equation
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建筑物密集区浅埋分岔隧道优化CD法施工力学效应研究
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作者 陈扬勇 王江华 +2 位作者 李强 冉东傲 靳晓光 《公路交通技术》 2024年第4期148-157,共10页
为揭示建筑物密集区浅埋分岔隧道施工力学效应,依托与白帝城长江大桥隧道锚近接的宝塔坪分岔隧道工程,开展优化CD法施工过程三维有限元数值模拟研究。不同循环进尺、先后行洞施工顺序和二次衬砌施作时机等工况下浅埋分岔隧道施工力学数... 为揭示建筑物密集区浅埋分岔隧道施工力学效应,依托与白帝城长江大桥隧道锚近接的宝塔坪分岔隧道工程,开展优化CD法施工过程三维有限元数值模拟研究。不同循环进尺、先后行洞施工顺序和二次衬砌施作时机等工况下浅埋分岔隧道施工力学数值模拟结果表明:1)隧道开挖进尺与围岩变形和建筑物沉降成正相关关系,对围岩应力影响不明显,隧道选择1.0 m~2.0 m的循环进尺较为合理;2)分岔隧道左、右洞的开挖顺序以及两隧道掌子面距离对围岩变形影响较大,但对建筑物沉降和围岩应力影响很小,施工时应至少将先行洞开挖40 m后再进行后行隧道的开挖;3)隧道二次衬砌施作时机对围岩变形及建筑物沉降有一定影响,对隧道围岩应力几乎没有影响,隧道开挖进尺60 m后施作二次衬砌可行。 展开更多
关键词 浅埋分岔隧道 施工力学效应 优化cd 建筑物密集区 数值模拟
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山岭公路隧道CD法开挖过程安全稳定性分析
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作者 惠冰 王琳 +2 位作者 张文俊 陈朋 赵忠孝 《浙江工业大学学报》 北大核心 2024年第1期86-92,共7页
不良地质条件下大断面隧道的开挖常采用CD法,在开挖过程中,完成最后一部台阶开挖后隧道全断面成型,这时需要及时对断面进行支护,以防止诱发隧道局部大变形甚至坍塌。为了预防隧道局部大变形或坍塌的发生,笔者以济潍高速某山岭隧道CD法... 不良地质条件下大断面隧道的开挖常采用CD法,在开挖过程中,完成最后一部台阶开挖后隧道全断面成型,这时需要及时对断面进行支护,以防止诱发隧道局部大变形甚至坍塌。为了预防隧道局部大变形或坍塌的发生,笔者以济潍高速某山岭隧道CD法开挖为研究对象进行全过程动态监测,采用有限元软件MIDAS 2020对台阶法开挖最后一部进行全过程的高仿真度模拟。研究结果表明:隧道沉降、收敛监测所得到的实测拟合曲线与有限元软件计算所得的模拟曲线基本吻合,通过选择合适的开挖步长,CD法开挖能够有效减小拱顶沉降和洞壁的收敛。短台阶法开挖和适时支护是控制隧道围岩变形,保证其安全稳定的关键,可以有效地保证浅埋大断面隧道的安全与长期的稳定。 展开更多
关键词 cd 山岭隧道 数值模拟 监测
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Cd污染中低风险农田水稻Cd含量控制方法分析
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作者 鲍茂林 丁家鑫 +2 位作者 朱旭娟 何国发 王立军 《安徽农学通报》 2024年第10期59-62,共4页
为了探究土壤Cd轻度污染稻田Cd含量的降低方法,进一步保障水稻质量,本试验在土壤Cd污染中低风险地块种植不同水稻品种,分别采用施石灰、硅肥和硒肥等不同处理方式,探究不同品种水稻重金属Cd积累的影响因素,为土壤Cd污染中低风险地块水... 为了探究土壤Cd轻度污染稻田Cd含量的降低方法,进一步保障水稻质量,本试验在土壤Cd污染中低风险地块种植不同水稻品种,分别采用施石灰、硅肥和硒肥等不同处理方式,探究不同品种水稻重金属Cd积累的影响因素,为土壤Cd污染中低风险地块水稻Cd达标提供参考。结果表明,不同品种水稻Cd含量的积累差异有统计学意义(P=0.000401),通过选择适宜品种来保障水稻中Cd含量不超标是可行的,且选择适宜品种的效果优先于通过土壤改良和增施其他营养元素的方式,以降低水稻中Cd含量;在偏酸性土壤中施用石灰可能通过钝化土壤中的Cd从而降低水稻Cd含量;可通过控制淹水程度影响水稻Cd含量。 展开更多
关键词 cd 水稻 施肥 中低风险农田 控制方法
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CdS催化剂的制备技术与应用现状
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作者 时彦卫 王东 文静 《矿冶》 CAS 2023年第1期71-77,共7页
CdS在可见光区域表现出优异的光化学性质和量子效率,目前被逐步应用在光催化制氢、降低碳排放、光催化降解污染物等催化领域。为给CdS催化剂的科学研究和产业发展提供智力支持,从专利分析的角度,依据CdS催化剂相关专利申请发展趋势、申... CdS在可见光区域表现出优异的光化学性质和量子效率,目前被逐步应用在光催化制氢、降低碳排放、光催化降解污染物等催化领域。为给CdS催化剂的科学研究和产业发展提供智力支持,从专利分析的角度,依据CdS催化剂相关专利申请发展趋势、申请人类型、技术构成及专利维持时间等数据,分析CdS催化剂的发展趋势及潜在价值,并结合CdS催化剂制备方法及具体应用场景等相关专利技术对CdS制备技术和应用现状进行概述分析。结果表明:近年来,有关CdS领域的专利申请量在大幅度增加,中国、美国和日本是该领域专利申请的主要目标国,我国的大专院校是CdS催化剂领域的研发主力,我国在CdS催化剂领域的科研成果的工业转化还有待加强。 展开更多
关键词 cdS 催化剂 专利分析 cdS制备方法 cdS产业发展
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CdS Thin Films Deposited by CBD Method on Glass 被引量:1
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作者 何星伟 刘伟丰 +1 位作者 朱长飞 江国顺 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第4期471-476,I0004,共7页
CdS thin films were prepared by chemical-bath-deposited method and the effect of temperature and time on the properties of CdS thin films was studied. Independent of the deposited temperature, the growth was mainly co... CdS thin films were prepared by chemical-bath-deposited method and the effect of temperature and time on the properties of CdS thin films was studied. Independent of the deposited temperature, the growth was mainly controlled by the ion-by-ion growth mechanism at the beginning of the film deposition, then the cluster-by-cluster mechanism came to be dominant. The growth rate increased faster with the increasing of temperature until the thickness reached the limitation, then thickness instead become thinner. The scanning electron micro- scope results revealed that the morphology of the CdS film changed from pinholes to rough, inhomogeneous surface with increasing deposition time and deposition temperature. The X- ray diffraction results showed the film structure was a mixture of two phases: hexagonal and cubic, and it was very important to controll deposition time to the film's crystal phase. All films in depth of approxilnate 100 nm existed above 65% transmittance, the absorption edge became "red-shift" with temperature rising. At 60 and 70℃, with 20 min deposited-time, the energy band gap was more than 2.42 eV and decreased with time, while at 80 and 90℃ the energy band gap was less than 2.42 eV and increased little when the time changed from 10min to 15 nfin at 80℃. 展开更多
关键词 cdS thin film Chemical-bath-deposited method CIGS solar cell Direct energy band gap
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Preparation and properties of CdS thin films grown by ILGAR method 被引量:1
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作者 QIUJijun JINZhengguo WUWeibing LIUXiaoxin CHENGZhijie 《Rare Metals》 SCIE EI CAS CSCD 2004年第4期311-316,共6页
CdS thin films were deposited by the ion layer gas reaction (TLGAR) method.Structural, chemical, topographical development as well as optical and electrical properties ofas-deposited and annealed thin films were inves... CdS thin films were deposited by the ion layer gas reaction (TLGAR) method.Structural, chemical, topographical development as well as optical and electrical properties ofas-deposited and annealed thin films were investigated by XRD, SEM, XPS, AFM and UV-VIS. The resultsshowed that the thin films are uniform, compact and good in adhesion to the substrates, and thegrowth of the films is 2.8 nm/cycle. The evolution of structure undergoes from the cubic structureto the hexagonal one with a preferred orientation along the (002) plane after annealing at 673 K. Anamount of C, O and Cl impurities can be reduced by increasing the drying temperature or byannealing in N2 atmosphere. It was found that the band gap of the CdS films shifts to higherwavelength after annealing or increasing film thickness. The electrical resistivity decreases withincreasing annealing temperature and film thickness. 展开更多
关键词 cdS thin film preparation and properties ILGAR method ANNEALING
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Cd(Ⅱ)吸附剂巯基丙酰化玉米秸秆的制备与表征 被引量:1
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作者 田龙 王刚 +1 位作者 徐敏 孙永鹏 《化学研究与应用》 CAS 北大核心 2023年第10期2283-2292,共10页
以玉米秸秆(CS)、左旋-半胱氨酸(L-CySH)、氢氧化钠(NaOH)、碳二亚胺盐酸盐(EDC·HCl)、N-羟基琥珀酰亚胺(NHS)为原料,通过化学反应将巯基(-SH)引入到CS中,制备出Cd(Ⅱ)吸附剂巯基丙酰化玉米秸秆(MPCS);以MPCS对水样中Cd(Ⅱ)的吸附... 以玉米秸秆(CS)、左旋-半胱氨酸(L-CySH)、氢氧化钠(NaOH)、碳二亚胺盐酸盐(EDC·HCl)、N-羟基琥珀酰亚胺(NHS)为原料,通过化学反应将巯基(-SH)引入到CS中,制备出Cd(Ⅱ)吸附剂巯基丙酰化玉米秸秆(MPCS);以MPCS对水样中Cd(Ⅱ)的吸附去除率为考察对象,利用单因素实验法研究MPCS制备的影响因素,并确定MPCS的最优制备条件。结果表明,当CS粒径为40目(0.45 mm)、活化剂选取0.5 mol·L^(-1)NaOH溶液、n(EDC·HCl):n(CySH)为0.025:1、m(NHS):m(EDC·HCl)为0.75:1、反应物比例m(CS):m(CySH)为1:5、反应介质pH值为10.0、反应温度为55℃、反应时间为3 h时,制备出的MPCS对水样中Cd(Ⅱ)吸附效果最好,Cd(Ⅱ)的最高去除率可达98.96%。红外分析(FTIR)、扫描电镜(SEM)、能谱分析(EDS)表明,MPCS的制备中CS纤维素分子链中成功引入了巯基,吸附后的MPCS表面附着大量Cd(Ⅱ)。 展开更多
关键词 玉米秸秆 吸附 单因素实验法 含镉废水
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SIMULATION OF TYPHOON'SANOMALOUS TRACK(Ⅱ)──CD METHOD
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作者 林缅 李家春 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1999年第1期43-50,共8页
Contour dynamics (CD) method for the motions of typhoon is presented in this paper. The effect of asymmetric inner structure on the typhoon'sanomalous track has been discussed in different environmental steering. ... Contour dynamics (CD) method for the motions of typhoon is presented in this paper. The effect of asymmetric inner structure on the typhoon'sanomalous track has been discussed in different environmental steering. Todemonstrate the feasibility of the method, the track of Typhoon Yancy(9012) isconcerned with. The numerical results show that the method can describe the tendency of looping qualitatively. 展开更多
关键词 TYPHOON anomalous track contour dynamics (cd) method
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Exciton emissions of CdS nanowire array fabricated on Cd foil by the solvothermal method
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作者 Yong Li Peng-Fei Ji +3 位作者 Ya-Juan Hao Yue-Li Song Feng-Qun Zhou Shu-Qing Yuan 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第1期369-373,共5页
Nanowires have recently attracted more attention because of their low-dimensional structure, tunable optical and electrical properties for next-generation nanoscale optoelectronic devices. Cd S nanowire array, which i... Nanowires have recently attracted more attention because of their low-dimensional structure, tunable optical and electrical properties for next-generation nanoscale optoelectronic devices. Cd S nanowire array, which is(002)-orientation growth and approximately perpendicular to Cd foil substrate, has been fabricated by the solvothermal method. In the temperature-dependent photoluminescence, from short wavelength to long wavelength, four peaks can be ascribed to the emissions from the bandgap, the transition from the holes being bound to the donors or the electrons being bound to the acceptors, the transition from Cd interstitials to Cd vacancies, and the transition from S vacancies to the valence band,respectively. In the photoluminescence of 10 K, the emission originated from the bandgap appears in the form of multiple peaks. Two stronger peaks and five weaker peaks can be observed. The energy differences of the adjacent peaks are close to 38 me V, which is ascribed to the LO phonon energy of Cd S. For the multiple peaks of bandgap emission, from low energy to high energy, the first, second, and third peaks are contributed to the third-order, second-order, and first-order phonon replica of the free exciton A, respectively;the fourth peak is originated from the free exciton A;the fifth peak is contributed to the first-order phonon replica of the excitons bound to neutral donors;the sixth and seventh peaks are originated from the excitons bound to neutral donors and the light polarization parallel to the c axis of hexagonal Cd S, respectively. 展开更多
关键词 cdS nanowires array solvothermal method PHOTOLUMINESCENCE exciton emissions
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三维乒乓菊状CdS/BiOBr催化剂的制备及其光催化降解罗丹明B
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作者 李红颖 徐毅 +4 位作者 杨帆 任瑞鹏 周全 吴丽杰 吕永康 《纺织学报》 EI CAS CSCD 北大核心 2023年第9期124-133,共10页
为提升BiOBr的光催化性能,通过两步法合成了三维乒乓菊状CdS/BiOBr催化剂。首先利用溶剂热法制备了BiOBr纳米片,接着采用水热法直接在层状BiOBr表面生长CdS粒子制备了CdS/BiOBr催化剂,并通过调整CdS与BiOBr的量比来调控催化剂的形貌。... 为提升BiOBr的光催化性能,通过两步法合成了三维乒乓菊状CdS/BiOBr催化剂。首先利用溶剂热法制备了BiOBr纳米片,接着采用水热法直接在层状BiOBr表面生长CdS粒子制备了CdS/BiOBr催化剂,并通过调整CdS与BiOBr的量比来调控催化剂的形貌。对制备的CdS/BiOBr催化剂的结构、形貌、光学性能等进行了表征分析,考察了其在可见光下对罗丹明B(RhB)的降解效果和稳定性,通过活性物种捕获实验和电子自旋共振测试分析确定了降解过程中的主要活性物质。结果表明:当CdS与BiOBr的量比为1∶3时,二者发生规则组合,形成独特的三维乒乓菊状层级结构;该催化剂有优异的光催化性能和稳定性,在可见光照射下120 min降解了99.5%的RhB,一级动力学常数为0.044 min^(-1),是纯BiOBr的3.67倍,经过7次光催化循环后仍保留了90.1%的催化活性;·O_(2)^(-)和h^(+)在RhB降解过程中发挥了主要作用,结合CdS和BiOBr的带隙结构提出了一种可能的光催化降解途径。 展开更多
关键词 光催化 印染废水处理 罗丹明B 水热法 降解机制 BiOBr cdS
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Growth and Physical Properties of CdS/TiO_2 Bilayer by Plasma-Based Method
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作者 T.Hoseinzadeh M.Ghoranneviss +1 位作者 E.Akbarnejad Z.Ghorannevis 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第3期39-42,共4页
The titanium oxide (TiO2) nanotubes have attracted attention for their use in dye-sensitized solar cells as photoanode. In this study semiconducting cadmium sulfide (CdS) nanoparticles arc grown on top opened TiO2... The titanium oxide (TiO2) nanotubes have attracted attention for their use in dye-sensitized solar cells as photoanode. In this study semiconducting cadmium sulfide (CdS) nanoparticles arc grown on top opened TiO2 nanotubes arrays by radio-frequency magnetron sputtering. X-ray diffraction, scanning electron mieroscopy, transmission electron microscopy and diffuse reflection spectra are used to study structural, morphological and optical properties of the CdS/TiO2 bilayer. 展开更多
关键词 cdS TIO Growth and Physical Properties of cdS/TiO2 Bilayer by Plasma-Based method
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基于称名反应模型的CD-CAT选题方法比较研究
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作者 张杰 罗照盛 +1 位作者 喻晓锋 秦春影 《心理科学》 CSCD 北大核心 2023年第6期1495-1503,共9页
当前大多数CD-CAT有关的研究都是基于0-1计分的数据资料展开的,而在实际的教育与心理测验中,还包含大量称名反应数据。本文基于称名反应认知诊断模型(NR-cRUM)开发了适用于称名反应数据的CD-CAT(以下简称NCDCAT),并将7种0-1计分CD-CAT... 当前大多数CD-CAT有关的研究都是基于0-1计分的数据资料展开的,而在实际的教育与心理测验中,还包含大量称名反应数据。本文基于称名反应认知诊断模型(NR-cRUM)开发了适用于称名反应数据的CD-CAT(以下简称NCDCAT),并将7种0-1计分CD-CAT的选题方法引入NCD-CAT中。比较不同条件下,不同选题方法对被试判准率和测验效率的影响。结果表明NR_PWCDI、NR_MPWKL等PWKL系新方法和NR_SHE/MI方法能较好地适用于NCD-CAT,且在大多数条件下优于基线方法 NR_PWKL。研究拓展了称名多级计分CD-CAT的选题方法。 展开更多
关键词 cd-CAT 称名反应 NR-cRUM 选题方法 多项选择题
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特大断面隧道部分直CD导坑法施工技术探讨 被引量:1
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作者 李建军 石建勋 王兵 《红水河》 2023年第5期127-132,共6页
当隧道区域地质条件受限时多采用双侧壁导坑法施工,但在实际施工中由于各开挖分块之间施工干扰大,严重影响施工进度。笔者以兰州白塔山隧道工程为依托,通过对掌子面围岩深入分析,结合现场工法的改进,首次提出将双侧壁导坑工法变更为部分... 当隧道区域地质条件受限时多采用双侧壁导坑法施工,但在实际施工中由于各开挖分块之间施工干扰大,严重影响施工进度。笔者以兰州白塔山隧道工程为依托,通过对掌子面围岩深入分析,结合现场工法的改进,首次提出将双侧壁导坑工法变更为部分直CD导坑法。监控量测数据分析结果表明:部分直CD导坑法在超大断面隧道施工过程中也可以较好地控制隧道围岩变形及地表沉降;并且由于单个导坑断面增大,大型机械设备操作空间充足,月进度增加了4倍,施工效率明显提高;同时,每延米进尺造价节约13499.03元。部分直CD导坑法的应用实践,为隧道设计提供可借鉴的经验,也为类似工程施工提供参考。 展开更多
关键词 隧道 部分直cd导坑法 工法转换 施工技术
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红辉沸石两步水热制备高品质X型分子筛及其高效吸附Cd^(2+)、Ni^(2+)性能研究
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作者 裴胤昌 莫胜鹏 +1 位作者 解庆林 陈南春 《材料导报》 CSCD 北大核心 2023年第24期86-94,共9页
本研究以红辉沸石为原料,经两步水热法制备高品质的X型分子筛,探究了n(H_(2)O/SiO_(2))、n(Na_(2)O/SiO_(2))、n(Al_(2)O_(3)/SiO_(2))、陈化时间、晶化温度、晶化时间等因素对红辉沸石转化为X型分子筛的影响,以及考察了X型分子筛对Cd^(... 本研究以红辉沸石为原料,经两步水热法制备高品质的X型分子筛,探究了n(H_(2)O/SiO_(2))、n(Na_(2)O/SiO_(2))、n(Al_(2)O_(3)/SiO_(2))、陈化时间、晶化温度、晶化时间等因素对红辉沸石转化为X型分子筛的影响,以及考察了X型分子筛对Cd^(2+)、Ni^(2+)的吸附性能。研究表明,X型分子筛的最优转化条件为:n(H_(2)O/SiO_(2))=55、n(Na_(2)O/SiO_(2))=1.1、n(Al_(2)O_(3)/SiO_(2))=0.33、陈化时间48 h、晶化温度82℃、晶化时间4 h。红辉沸石溶解后解聚为低聚态Si物种且在体系中保留参与分子筛的生长,使得所合成的X型分子筛相对结晶度达100%、n(Si/Al)值为1.14,并缩短了晶化时间和降低了晶化温度,其中所合成的X型分子筛对Cd^(2+)和Ni^(2+)的吸附容量分别达到173.553 mg/g和75.897 mg/g。因此,本研究将为天然矿物快速转化为高品质的X型分子筛设计与制备提供理论基础和技术支持。 展开更多
关键词 红辉沸石 X型分子筛 两步水热法 吸附性能 镉离子 镍离子
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The effect of the different labeling and red cell removed methods on measuring the CD34^+cells of the cord blood
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《中国输血杂志》 CAS CSCD 2001年第S1期415-,共1页
关键词 cells of the cord blood cd The effect of the different labeling and red cell removed methods on measuring the cd34
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Elastic and Optoelectronic Properties of KCdF3:ab initio Calculations through LDA/GGA/TB-mBJ within FP-LAPW Method
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作者 K. Ephraim Babu N. Murali +2 位作者 K. Vijaya Babu B. Kishore Babu V. Veeraiah 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第1期108-112,共5页
Ab initio calculations are performed on the electronic, structural, elastic and optical properties of the cubic per- ovskite KCdF3. Tile Kohn Sham equations are solved by applying the full potential linearized augment... Ab initio calculations are performed on the electronic, structural, elastic and optical properties of the cubic per- ovskite KCdF3. Tile Kohn Sham equations are solved by applying the full potential linearized augmented plane wave (FP-LAPW) method. The exchange correlation effects are included through the local density approximation (LDA ), generalized gradient approximation (GGA) and modified Becke-Johnson (mBJ) exchange potential The calculated lattice constant is in good agreement with the experimental result. The elastic properties such as elastic constants, anisotropy factor, shear modulus, Young's modulus and Poisson's ratio are calculated. KCdF3 is ductile and elastically anisotropic. The calculations of the electronic band structure, density of states (DOS) and charge density show that this compound has an indirect energy band gap (M-F) with a mixed ionic and covalent bonding. The contribution of the different bands is analyzed from the total and partial density of states curves. Optical response of the dielectric functions, optical reflectivity, absorption coefficient, real part of optical conductivity, refractive index, extinction coefficient and electron energy loss, are presented for the energy range of O-40eV. The compound KCdF3 can be used for high-frequency optical and optoelectronic devices. 展开更多
关键词 GGA cd Elastic and Optoelectronic Properties of KcdF3:ab initio Calculations through LDA/GGA/TB-mBJ within FP-LAPW method LDA FP
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