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B_(4)C陶瓷电火花工艺温度场仿真及试验研究
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作者 孙衍涛 郑雷 《盐城工学院学报(自然科学版)》 CAS 2024年第1期67-74,共8页
B_(4)C陶瓷具有硬度高、密度低等特性,在军工装甲等领域应用前景广阔,但由于硬度高、脆性大,传统加工方法难以胜任孔、槽等加工。考虑半导电特性,拟采用电火花方法对其进行孔加工技术研究。利用ANSYS软件对电火花放电过程中的单脉冲温... B_(4)C陶瓷具有硬度高、密度低等特性,在军工装甲等领域应用前景广阔,但由于硬度高、脆性大,传统加工方法难以胜任孔、槽等加工。考虑半导电特性,拟采用电火花方法对其进行孔加工技术研究。利用ANSYS软件对电火花放电过程中的单脉冲温度场进行仿真建模,输出凹坑半径、深度及温度场数值,并引入锥角物理量进行仿真和试验比对。结果表明:凹坑半径、深度随峰值电流、脉冲宽度增加而增加,温度场特点满足高斯热源正态分布;随着峰值电流、脉冲宽度的增加,仿真锥角和试验锥角数值更贴合。 展开更多
关键词 B_(4)C陶瓷 电火花方法 孔加工 单脉冲温度场 锥角
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HY-4型节流器在苏里格气田的应用 被引量:12
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作者 谷成义 冯朋鑫 +1 位作者 王晓荣 宋汉华 《石油钻采工艺》 CAS CSCD 北大核心 2010年第4期120-122,共3页
针对普通节流器在苏里格气田使用中存在打捞困难、寿命短、投放一段时间再开井生产失效率高等问题,研制了HY-4型节流器。在HY-4型节流器结构设计中,采用活塞提供坐封力,坐封力更大,克服了投放一段时间再开井失效率高的问题;解封结构采... 针对普通节流器在苏里格气田使用中存在打捞困难、寿命短、投放一段时间再开井生产失效率高等问题,研制了HY-4型节流器。在HY-4型节流器结构设计中,采用活塞提供坐封力,坐封力更大,克服了投放一段时间再开井失效率高的问题;解封结构采用卡瓦解封后,卡瓦上移给密封胶筒提供回缩空间,胶筒回缩后,大大减少了在打捞时与井管内壁的摩擦力,解决了节流器打捞难的问题;在气嘴材料选择上采用人工陶瓷耐磨材料,使气嘴使用寿命更长;胶筒材料采用氟橡胶,耐天然气腐蚀,使用寿命更长。在苏里格气田开展了34口井的现场试验,一次性投放施工成功率100%,开井生产正常。 展开更多
关键词 新型节流器 卡瓦 胶筒 气嘴
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4-(4,′4′-二苯基-1,′3′-丁二烯基)-N,N-二(4″-甲基苯基)苯胺的合成及性能 被引量:4
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作者 李祥高 吴安树 +1 位作者 何莉莉 王世荣 《精细化工》 EI CAS CSCD 北大核心 2005年第8期572-574,共3页
该文通过V ilsm e ier反应,用4,4′-二甲基三苯胺制得了4-[N,N-二(4′-甲基苯基)]氨基苯甲醛(Ⅰ),收率85.4%;Ⅰ与1,1-二苯基-3-氯丙烯经W ittig反应合成了三苯胺衍生物4-(4,′4′-二苯基-1,′3′-丁二烯基)-N,N-二(4″-甲基苯基)苯胺(... 该文通过V ilsm e ier反应,用4,4′-二甲基三苯胺制得了4-[N,N-二(4′-甲基苯基)]氨基苯甲醛(Ⅰ),收率85.4%;Ⅰ与1,1-二苯基-3-氯丙烯经W ittig反应合成了三苯胺衍生物4-(4,′4′-二苯基-1,′3′-丁二烯基)-N,N-二(4″-甲基苯基)苯胺(Ⅱ),收率43.0%,HPLC面积归一法测定目的产物为99.64%。通过紫外光谱、红外光谱、质谱和元素分析对产物的组成和结构进行了鉴定。用Ⅱ作空穴传输材料制成功能分离型有机光导体,测得其静电特性数据为V0=-580 V,VR=-20 V,E1/2=0.50 lx.s,表明Ⅱ具有优良的空穴传输特性。 展开更多
关键词 4-(4 4′-二苯基-1′ 3′-丁二烯基)-N N-二(4″-甲基苯基)苯胺 空穴传输材料 WITTIG反应
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窿4井超长裸眼油层套管固井实践与认识 被引量:1
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作者 顾军 向阳 +1 位作者 刘新云 寇明富 《钻采工艺》 CAS 2002年第4期4-5,8,共3页
窿 4井是玉门青西地区 1口重点探井 ,设计井深 470 0m ,主要目的层K1Z。介绍了该井固井关键技术 ,包括套管串设计、扶正器安放位置、水泥浆体系优选和施工压力校核。经测试该井获高产油流 ,证实层间封隔良好。并讨论了固井质量上下好中... 窿 4井是玉门青西地区 1口重点探井 ,设计井深 470 0m ,主要目的层K1Z。介绍了该井固井关键技术 ,包括套管串设计、扶正器安放位置、水泥浆体系优选和施工压力校核。经测试该井获高产油流 ,证实层间封隔良好。并讨论了固井质量上下好中间差的问题和浮箍密封良好却留塞 80 .6 3m的问题。 展开更多
关键词 窿4 超长裸眼 油层套管 固井 油气井
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4-溴-N,N-二(4-叔丁基苯基)-苯胺的合成及其光谱性能的研究 被引量:4
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作者 邢孔强 刘煜 +2 位作者 朱美香 苏国钧 朱卫国 《湘潭大学自然科学学报》 CAS CSCD 北大核心 2006年第3期64-67,共4页
以对溴苯胺和对叔丁基苯甲酸为原料,经Hofmann降解、Sandmeyer和Ullmann反应等反应,合成得到了一种具有空穴传输性能的环金属配合物电致磷光中间:4-溴-N,N-二(4-叔丁基苯基)-苯胺,反应产率为43.5%,产物结构经核磁氢谱、质谱得到了表征.... 以对溴苯胺和对叔丁基苯甲酸为原料,经Hofmann降解、Sandmeyer和Ullmann反应等反应,合成得到了一种具有空穴传输性能的环金属配合物电致磷光中间:4-溴-N,N-二(4-叔丁基苯基)-苯胺,反应产率为43.5%,产物结构经核磁氢谱、质谱得到了表征.紫外吸收光谱和荧光光谱研究表明:该化合物具有强烈的紫外-可见吸收和荧光发射性能,其氯仿溶液的最大紫外吸收波长为306 nm,最大荧光发射波长是543 nm.但薄膜的最大荧光发射波长蓝移至458 nm. 展开更多
关键词 4-溴-N、N-二(4-叔丁基苯基)-苯胺 合成 空穴传输材料 电致磷光
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水稻新品种新粳4号特征特性及机械精量旱穴直播高产栽培技术
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作者 文孝荣 张燕红 +4 位作者 唐福森 康民泰 托合提·艾买提 阿丽娅·吾不力卡斯木 王奉斌 《北方水稻》 CAS 2022年第1期54-56,共3页
新粳4号是新疆农业科学院选育的常规优质粳稻新品种,全生育期160 d左右,株型紧凑,分蘖力较强,茎秆粗壮、抗倒性强,适宜机械精量旱穴直播种植,2018年通过新疆维吾尔自治区审定。介绍了新粳4号的主要特征特性,从地块准备、播种、水肥管理... 新粳4号是新疆农业科学院选育的常规优质粳稻新品种,全生育期160 d左右,株型紧凑,分蘖力较强,茎秆粗壮、抗倒性强,适宜机械精量旱穴直播种植,2018年通过新疆维吾尔自治区审定。介绍了新粳4号的主要特征特性,从地块准备、播种、水肥管理、病虫草害防治等方面阐述了其机械精量旱穴直播高产栽培技术措施。 展开更多
关键词 水稻 新粳4 特征特性 精量旱穴直播 栽培技术
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1,1-二(对-二乙氨基苯基)-4-(α-萘基)-4-苯基-1,3-丁二烯的合成及其光电性能研究
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作者 李祥高 韩国栋 +1 位作者 吴安树 王世荣 《功能材料》 EI CAS CSCD 北大核心 2007年第10期1583-1586,共4页
以α-溴代萘和苯乙酮为主要原料合成了1-(α-萘基)-1-苯基-3-氯丙烯,该化合物与4,4’-双(二乙氨基)二苯甲酮经Grignard反应,脱水后得到目标产物1,1-二(对-二乙氨基苯基)-4-(α-萘基)-4-苯基-1,3-丁二烯(CT),产品纯度98.86%,收率36.4%。... 以α-溴代萘和苯乙酮为主要原料合成了1-(α-萘基)-1-苯基-3-氯丙烯,该化合物与4,4’-双(二乙氨基)二苯甲酮经Grignard反应,脱水后得到目标产物1,1-二(对-二乙氨基苯基)-4-(α-萘基)-4-苯基-1,3-丁二烯(CT),产品纯度98.86%,收率36.4%。通过质谱与核磁共振对产物的结构进行了表征,并对其进行X-射线单晶衍射分析,确定了分子构型。以Y-TiOPc为电荷产生材料,CT为空穴传输材料制备的功能分离型光导体光导性能参数为:V0=-850V,VR=-20V,Rd=17.5V,E1/2=0.60lx.s,表明CT具有优良的空穴传输特性。 展开更多
关键词 1 1-二(对-二乙氨基苯基)-4-(α-萘基)-4-苯基-1 3-丁二烯 空穴传输材料 光电性能
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4孔浸入式水口结晶器钢水流场的仿真分析及其在连铸生产中的应用 被引量:2
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作者 吴国文 李明晓 《特殊钢》 北大核心 2009年第3期46-47,共2页
为减少轴承钢300 mm×300 mm连铸坯的碳偏析,通过CFX-4.4软件仿真分析了连铸结晶器内钢水流动和传热凝固过程,探讨了有关工艺参数和浸入式水口结构的关系。实践表明,通过4孔水口替代直孔水口,铸坯的碳偏析级别由1.0~2.0级降至1.0~... 为减少轴承钢300 mm×300 mm连铸坯的碳偏析,通过CFX-4.4软件仿真分析了连铸结晶器内钢水流动和传热凝固过程,探讨了有关工艺参数和浸入式水口结构的关系。实践表明,通过4孔水口替代直孔水口,铸坯的碳偏析级别由1.0~2.0级降至1.0~1.5级,采用4孔水口中心碳偏析≤1.0级占79%,直孔水口仅为50%。 展开更多
关键词 轴承钢 连铸方坯 4孔浸入式水口 中心碳偏析
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TiHAP@g-C_(3)N_(4)异质结的制备及光催化降解甲基橙 被引量:1
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作者 伍林 胡明蕾 +2 位作者 王丽萍 黄少萌 周湘远 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2023年第5期503-510,I0001,I0002,共10页
通过水热法合成了钛羟基磷灰石(TiHAP)与g-C_(3)N_(4)复合光催化剂(TiHAP@g-C_(3)N_(4)),并对其结构和光学特性进行表征,通过甲基橙(MO)降解实验评价其光催化活性。结果表明:样品中短棒状TiHAP生长在g-C_(3)N_(4)表面,均保持原有晶型和... 通过水热法合成了钛羟基磷灰石(TiHAP)与g-C_(3)N_(4)复合光催化剂(TiHAP@g-C_(3)N_(4)),并对其结构和光学特性进行表征,通过甲基橙(MO)降解实验评价其光催化活性。结果表明:样品中短棒状TiHAP生长在g-C_(3)N_(4)表面,均保持原有晶型和化学结构;制备的TiHAP@g-C_(3)N_(4)纯度高,比表面积达107.92 m^(2)/g,较TiHAP、g-C_(3)N_(4)分别增大约135%、44%;在TiHAP@g-C_(3)N_(4)添加量为1.0 g/L、pH 7条件下,120 min内MO降解率达96.35%;3次循环实验降解率保持在80.02%以上,TiHAP@g-C_(3)N_(4)光催化性能良好且结构稳定。空穴(h^(+))在MO降解过程中作用最大,·O_(2)^(–)与·OH的作用递减。TiHAP@g-C_(3)N_(4)异质结的构建,增强了对光的吸收,提高了光生电子-h^(+)的分离效率,保留了氧化还原性更强的TiHAP价带h^(+)和g-C_(3)N_(4)导带电子,从而提升了光催化性能。 展开更多
关键词 紫外光催化 TiHAP@g-C_(3)N_(4) 甲基橙 异质结 光生电子-空穴
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加减桃红四物汤配合耳穴埋籽治疗慢性荨麻疹45例 被引量:2
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作者 倪永华 周艳 《浙江中医药大学学报》 CAS 2010年第2期208-209,共2页
[目的]观察桃红四物汤配合耳穴埋籽治疗慢性荨麻疹的临床疗效。[方法]:对45例慢性荨麻疹患者以桃红四物汤加减配合耳穴埋籽治疗。[结果]实验组有效38例,无效7例;对照组有效26例,无效19例。[结论]桃红四物汤加减配合耳穴埋籽治疗慢性荨... [目的]观察桃红四物汤配合耳穴埋籽治疗慢性荨麻疹的临床疗效。[方法]:对45例慢性荨麻疹患者以桃红四物汤加减配合耳穴埋籽治疗。[结果]实验组有效38例,无效7例;对照组有效26例,无效19例。[结论]桃红四物汤加减配合耳穴埋籽治疗慢性荨麻疹治疗有效。 展开更多
关键词 荨麻疹 桃红四物汤 耳穴埋籽
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单洞4车道隧道内轮廓关键指标统计分析与启迪 被引量:7
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作者 丁浩 《公路交通技术》 2012年第6期89-91,共3页
现行公路隧道设计规范对单洞4车道隧道的构造和设计尚无明确规定。基于其内轮廓设计角度,并参考相关研究成果,提出应将扁平率作为其关键指标。同时,结合对已建成类似隧道工程内轮廓扁平率的统计分析结果,指出对于分离式双洞8车道或单洞... 现行公路隧道设计规范对单洞4车道隧道的构造和设计尚无明确规定。基于其内轮廓设计角度,并参考相关研究成果,提出应将扁平率作为其关键指标。同时,结合对已建成类似隧道工程内轮廓扁平率的统计分析结果,指出对于分离式双洞8车道或单洞4车道隧道,其内轮廓设计时,扁平率(不含仰拱)取0.485,扁平率(含仰拱)取0.605,矢跨比取0.406,具有较好的技术经济性,可为4车道公路隧道设计提供借鉴。 展开更多
关键词 单洞4车道隧道 大跨扁平隧道 内轮廓 扁平率 设计
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Modeling the Interior of Black Holes Utilizing a 4-D Spatial Blackbody Radiation Model with an Exponential Distribution
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作者 Christopher Pilot 《Journal of High Energy Physics, Gravitation and Cosmology》 2019年第3期953-983,共31页
This is a second follow up paper on a model, which treats the black hole as a 4-D spatial ball filled with blackbody radiation. For the interior radiative mass distribution, we employ a new type of truncated probabili... This is a second follow up paper on a model, which treats the black hole as a 4-D spatial ball filled with blackbody radiation. For the interior radiative mass distribution, we employ a new type of truncated probability distribution function, the exponential distribution. We find that this distribution comes closest to reproducing a singularity at the center, and yet it is finite at 4-D radius, . This distribution will give a constant gravitational acceleration for a test particle throughout the black hole, irrespective of radius. The 4-D gravitational acceleration is given by the expression, , where R is the radius of the black hole, MR is its mass, and is the exponential shape parameter, which depends only on the mass, or radius, of the black hole. We calculate the gravitational force, and the entropy within the black hole interior, as well as on its surface, identified as the event horizon, which separates 3-D from 4-D space. Similar to a truncated Gaussian distribution, the gravitational force increases discontinuously, and dramatically, upon entry into the 4-D black hole from the 3-D side. It is also radius dependent within the 4-D black hole. Moreover, the total entropy is shown to be much less than the Bekenstein result, similar to the truncated Gaussian. For the gravitational force, we obtain, , where Mr is the radiative mass enclosed within a 4-D volume of radius r. This unusual force law indicates that the gravitational force acting upon a layer of blackbody photons at radius r is strictly proportional to the enclosed radiative energy, MrC2, contained within that radius, with 0.1λ being the constant of proportionality. For the entropy at radius, r, and on the surface, we obtain an expression which is order of magnitude comparable to the truncated Normal distribution. Tables are presented for three black holes, one having a mass equal to that of the sun. The other two have masses, which are ten times that of the sun, and 106 solar masses. The corresponding parameters are found to equal, , respectively. We compare these results to the truncated Gaussian distribution, which were worked out in another paper. 展开更多
关键词 Black HOLES 4-D SPATIAL BLACKBODY Radiation Model EXPONENTIAL Distribution
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YRY-4型钻孔应变观测抽水影响分析 被引量:2
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作者 王强 孟建国 +1 位作者 卢双苓 苗丽华 《地震地磁观测与研究》 2012年第3期137-140,共4页
分析泰安基准地震台YRY-4型钻孔应变仪仪器受不同位置抽水的影响,就地下岩石含水变化所产生的地形变干扰,简要分析地下水与地下岩石间的相互作用。这对地震前兆的研究有重要实用意义。
关键词 YRY-4型钻孔应变仪 钻孔抽水 干扰 形变
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On the Internal Structure of a Black Hole Utilizing a 4-D Spatial Blackbody Radiation Model
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作者 Christopher Pilot 《Journal of High Energy Physics, Gravitation and Cosmology》 2019年第3期719-772,共54页
A black hole is treated as a self-contained, steady state, spherically symmetric, 4-dimensional spatial ball filled with blackbody radiation, which is embedded in 3-D space. To model the interior distribution of radia... A black hole is treated as a self-contained, steady state, spherically symmetric, 4-dimensional spatial ball filled with blackbody radiation, which is embedded in 3-D space. To model the interior distribution of radiation, we invoke two stellar-like equations, generalized to 4-D space, and a probability distribution function (pdf) for the actual radiative mass distribution within its interior. For our purposes, we choose a truncated Gaussian distribution, although other pdf’s with support, r ∈[0, R], are possible. The variable, r = r(4), refers to the 4-D radius within the black hole. To fix the coefficients, (μ,σ), associated with this distribution, we choose the mode to equal zero, which will give maximum energy density at the center of the black hole. This fixes the parameter, μ = 0. Our black hole does not have a singularity at the center, and, moreover, it is well-behaved within its volume. The rip or tear in the space-time continuum occurs at the event horizon, as shown in a previous work, because it is there that we transition from 3-D space to 4-D space. For the shape parameter, σ , we make use of the temperature just inside the event horizon, which is determined by the mass, or radius, of the black hole. The amount of radiative heat inflow depends on mass, or radius, and temperature, T2 ≥ 2.275K , where, T2, is the temperature just outside the event horizon. Among the interesting consequences of this model is that the entropy, S(4), can be calculated as an extrinsic, versus intrinsic, variable, albeit in 4-D space. It is found that S(4) is much less than the comparable Bekenstein result. It also scales not as, R2 , where R is the radius of the black hole. Rather, it is given by an expression involving the lower incomplete gamma function, γ(s,x), and interestingly, scales with a more complicated function of radius. Thus, within our framework, the black hole is a highly-ordered state, in sharp contrast to current consensus. Moreover, the model-dependent gravitational “constant” in 4-D space, Gr(4), can be determined, and this will depend on radius. For the specific pdf chosen, Gr(4)Mr = 0.1c2(r4/σ2), where Mr is the enclosed radiative mass of the black hole, up to, and including, radius r. At the event horizon, where, r = R, this reduces to GR(4) = 0.2GR3/σ2, due to the Schwarzschild relation between mass and radius. The quantity, G, is Newton’s constant. There is a sharp discontinuity in gravitational strength at the 3-D/4-D interface, identified as the event horizon, which we show. The 3-D and 4-D gravitational potentials, however, can be made to match at the interface. This lines up with previous work done by the author where a discontinuity between 3-D and 4-D quantities is required in order to properly define a positive-definite radiative surface tension at the event horizon. We generalize Gauss’ law in 4-D space as this will enable us to find the strength of gravity at any radius within the spherically symmetric, 4-D black hole. For the pdf chosen, gr(4) = Gr(4)Mr/r3 = 0.1c2r/σ2, a remarkably simple and elegant result. Finally, we show that the work required to assemble the black hole against radiative pressure, which pushes out, is equal to, 0.1MRc2. This factor of 0.1 is specific to 4-D space. 展开更多
关键词 BLACK HOLE 4-D SPATIAL BLACKBODY Radiation Model Internal Structure RADIATIVE Pressure
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Are Black Holes 4-D Spatial Balls Filled with Black Body Radiation? Generalization of the Stefan-Boltzmann Law and Young-Laplace Relation for Spatial Radiative Transfers
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作者 Christopher Pilot 《Journal of High Energy Physics, Gravitation and Cosmology》 2019年第3期638-682,共45页
This is the first paper in a two part series on black holes. In this work, we concern ourselves with the event horizon. A second follow-up paper will deal with its internal structure. We hypothesize that black holes a... This is the first paper in a two part series on black holes. In this work, we concern ourselves with the event horizon. A second follow-up paper will deal with its internal structure. We hypothesize that black holes are 4-dimensional spatial, steady state, self-contained spheres filled with black-body radiation. As such, the event horizon marks the boundary between two adjacent spaces, 4-D and 3-D, and there, we consider the radiative transfers involving black- body photons. We generalize the Stefan-Boltzmann law assuming that photons can transition between different dimensional spaces, and we can show how for a 3-D/4-D interface, one can only have zero, or net positive, transfer of radiative energy into the black hole. We find that we can predict the temperature just inside the event horizon, on the 4-D side, given the mass, or radius, of the black hole. For an isolated black hole with no radiative heat inflow, we will assume that the temperature, on the outside, is the CMB temperature, T2 = 2.725 K. We take into account the full complement of radiative energy, which for a black body will consist of internal energy density, radiative pressure, and entropy density. It is specifically the entropy density which is responsible for the heat flowing in. We also generalize the Young- Laplace equation for a 4-D/3-D interface. We derive an expression for the surface tension, and prove that it is necessarily positive, and finite, for a 4-D/3-D membrane. This is important as it will lead to an inherently positively curved object, which a black hole is. With this surface tension, we can determine the work needed to expand the black hole. We give two formulations, one involving the surface tension directly, and the other involving the coefficient of surface tension. Because two surfaces are expanding, the 4-D and the 3-D surfaces, there are two radiative contributions to the work done, one positive, which assists expansion. The other is negative, which will resist an increase in volume. The 4-D side promotes expansion whereas the 3-D side hinders it. At the surface itself, we also have gravity, which is the major contribution to the finite surface tension in almost all situations, which we calculate in the second paper. The surface tension depends not only on the size, or mass, of the black hole, but also on the outside surface temperature, quantities which are accessible observationally. Outside surface temperature will also determine inflow. Finally, we develop a “waterfall model” for a black hole, based on what happens at the event horizon. There we find a sharp discontinuity in temperature upon entering the event horizon, from the 3-D side. This is due to the increased surface area in 4-D space, AR(4) = 2π2R3, versus the 3-D surface area, AR(3) = 4πR2. This leads to much reduced radiative pressures, internal energy densities, and total energy densities just inside the event horizon. All quantities are explicitly calculated in terms of the outside surface temperature, and size of a black hole. Any net radiative heat inflow into the black hole, if it is non-zero, is restricted by the condition that, 0cdQ/dt FR(3), where, FR(3), is the 3-D radiative force applied to the event horizon, pushing it in. We argue throughout this paper that a 3-D/3-D interface would not have the same desirable characteristics as a 4-D/3-D interface. This includes allowing for only zero or net positive heat inflow into the black hole, an inherently positive finite radiative surface tension, much reduced temperatures just inside the event horizon, and limits on inflow. 展开更多
关键词 BLACK Holes 4-D SPATIAL BALLS BLACK Body Radiation Stefan-Boltzmann LAW Young-Laplace RELATION
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Mxene/g-C_(3)N_(4)二维光催化材料的制备及其处理水中Cr(Ⅵ)的性能研究
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作者 罗大芳 叶元顺 +2 位作者 车晓艳 赵志欣 余联凤 《化学工程师》 CAS 2023年第1期4-9,共6页
在合成单层Mxene和石墨相C_(3)N_(4)的基础上,采用一步静电自组装法制备了不同Mxene含量的Mxene/g-C_(3)N_(4)复合光催化剂,采用XRD、TEM、XPS等方法对样品的结构和形貌进行了表征。考察了可见光激发下Mxene/g-C_(3)N_(4)复合光催化剂... 在合成单层Mxene和石墨相C_(3)N_(4)的基础上,采用一步静电自组装法制备了不同Mxene含量的Mxene/g-C_(3)N_(4)复合光催化剂,采用XRD、TEM、XPS等方法对样品的结构和形貌进行了表征。考察了可见光激发下Mxene/g-C_(3)N_(4)复合光催化剂光催化还原六价铬Cr(Ⅵ)的性能,分析了Mxene的负载量、溶液的pH值和不同的空穴牺牲剂对Mxene/g-C_(3)N_(4)光催化还原Cr(Ⅵ)性能的影响。结果表明,Mxene的负载不仅可以为光催化反应提供更多的表面活性位,还可以显著提高光生载流子的分离几率。当Mxene的负载量为10%、溶液pH值为2.0时,可见光还原Cr(Ⅵ)的效率比单一石墨相C_(3)N_(4)光催化剂提高了8.1倍。同时,酒石酸空穴牺牲剂的引入可以进一步提高光催化还原Cr(Ⅵ)效率。 展开更多
关键词 光催化还原六价铬Cr(Ⅵ) Mxene 石墨相C_(3)N_(4) 一步静电自组装法 空穴牺牲剂
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基于1/4波长短路枝节的双通带微带带通滤波器设计
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作者 沈捷 刘传洋 +1 位作者 卫明 汪寅 《通信对抗》 2021年第2期18-21,共4页
提出了一种基于1/4波长短路枝节阶梯阻抗谐振器(SESIR)的双通带微带带通滤波器的设计方法。首先,利用1/4波长SESIR产生两个通带,然后,利用J/K变换器把谐振腔合并在一起设计成微波滤波器,这里两个相邻的1/4波长SESIR通过一个带过孔枝节... 提出了一种基于1/4波长短路枝节阶梯阻抗谐振器(SESIR)的双通带微带带通滤波器的设计方法。首先,利用1/4波长SESIR产生两个通带,然后,利用J/K变换器把谐振腔合并在一起设计成微波滤波器,这里两个相邻的1/4波长SESIR通过一个带过孔枝节来连接耦合,此带过孔枝节不仅能使阶梯阻抗谐振器短路接地,而且可以作为一个K变换器。然后,用此方法设计了一种新型的二阶双通带切比雪夫带通滤波器,其中心频率点分别为2.45GHz和5.25GHz,相对带宽分别为11.67%和7%。实测结果与仿真结果吻合较好。 展开更多
关键词 双通带滤波器 1/4波长短路枝节阶梯阻抗谐振器 J/K变换器 过孔枝节
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Systematic analysis of low/hard state RXTE spectra of GX 339–4 to constrain the geometry of the system
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作者 Kalyani Bagri Ranjeev Misra +2 位作者 Anjali Rao Jagdish Singh Yadav Shiv Kumar Pandey 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第5期37-46,共10页
One of the popular models for the low/hard state of black hole binaries is that the standard accretion disk is truncated and the hot inner region produces, via Comptonization, hard X-ray flux.This is supported by the ... One of the popular models for the low/hard state of black hole binaries is that the standard accretion disk is truncated and the hot inner region produces, via Comptonization, hard X-ray flux.This is supported by the value of the high energy photon index, which is often found to be small,~ 1.7(〈 2), implying that the hot medium is starved of seed photons. On the other hand, the suggestive presence of a broad relativistic Fe line during the hard state would suggest that the accretion disk is not truncated but extends all the way to the innermost stable circular orbit. In such a case, it is a puzzle why the hot medium would remain photon starved. The broad Fe line should be accompanied by a broad smeared reflection hump at ~ 30 ke V and it may be that this additional component makes the spectrum hard and the intrinsic photon index is larger, i.e. 〉2. This would mean that the medium is not photon deficient, reconciling the presence of a broad Fe line in the observed hard state. To test this hypothesis,we have analyzed the RXTE observations of GX 339–4 from the four outbursts during 2002–2011 and identify observations when the system was in the hard state and showed a broad Fe line. We have then attempted to fit these observations with models, which include smeared reflection, to understand whether the intrinsic photon index can indeed be large. We find that, while for some observations the inclusion of reflection does increase the photon index, there are hard state observations with a broad Fe line that have photon indices less than 2. 展开更多
关键词 ACCRETION accretion disks - stars black holes - X-rays binaries - X-rays individual(GX 339-4
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巯基吡啶异构体对电镀铜填盲孔的影响研究
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作者 陈洁 宗高亮 +2 位作者 代禹涵 赵晓楠 肖宁 《电镀与精饰》 CAS 北大核心 2024年第9期1-9,共9页
本文以同分异构体2-巯基吡啶(2-MP)和4-巯基吡啶(4-MP)为研究对象,在对比其作为整平剂填充盲孔性能差异的基础上,阐述其分子构效关系。首先,通过哈林槽镀铜实验研究了2-MP与4-MP的填盲孔性能,结果表明,2-MP的填孔性能更佳,其填孔率可达... 本文以同分异构体2-巯基吡啶(2-MP)和4-巯基吡啶(4-MP)为研究对象,在对比其作为整平剂填充盲孔性能差异的基础上,阐述其分子构效关系。首先,通过哈林槽镀铜实验研究了2-MP与4-MP的填盲孔性能,结果表明,2-MP的填孔性能更佳,其填孔率可达82%。之后,通过量子化学计算,发现2-MP分子中S原子电子云密度低于4-MP,这说明2-MP更易吸附在铜表面。计时电位法测试结果表明:Cl^(-)可促进2-MP在铜表面的吸附,此外,2-MP与PEG之间的相互作用显著强于4-MP。最后,通过X射线光电子能谱(XPS)检测到了Cu-S键的存在,证明两种整平剂分子在铜表面均发生了化学吸附。然而,由于2-MP分子中的巯基S原子与N原子处于邻位,可以形成S-Cu^(2+)-N配合物,进而与Cl^(-)、PEG形成复杂且致密的抑制层,强烈抑制表面铜沉积,从而提高了其盲孔填孔率。 展开更多
关键词 电镀铜 填充盲孔 整平剂 2-巯基吡啶 4-巯基吡啶
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二乙二醇复配硫酸锂对水泥材料早强性能研究
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作者 赵永 《河南化工》 CAS 2024年第10期15-18,共4页
为改善水泥基封孔材料在煤矿工作环境中存在的早期强度低、自收缩、流失率高等缺陷,以水泥为基础,添加硫酸锂和二乙二醇进行复配。通过抗压强度、流动度、凝结时间、XRD、电镜扫描(SEM)等表征,研究了复合早强剂对水泥早强效果的影响。... 为改善水泥基封孔材料在煤矿工作环境中存在的早期强度低、自收缩、流失率高等缺陷,以水泥为基础,添加硫酸锂和二乙二醇进行复配。通过抗压强度、流动度、凝结时间、XRD、电镜扫描(SEM)等表征,研究了复合早强剂对水泥早强效果的影响。结果表明,添加质量比为0.4%的硫酸锂和质量比为0.04%二乙二醇到水泥材料中,效果最好,相较于同龄期空白组抗压强度分别提升96.59%、26.87%、25.32%、27.21%,且初终凝时间明显缩短。通过微观分析可知,硫酸锂和二乙二醇复配,加快了C_(3)S、C_(2)S的反应进程,缩短水泥凝结时间,CH和C—S—H会形成水化膜覆盖在水泥颗粒表面,使内部结构更为紧密,改善了水泥内部构造,显著提高了水泥基材料的早强性能。 展开更多
关键词 水泥基封孔材料 Li 2SO 4 二乙二醇 抗压强度
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