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海底门声学计算及水下多孔介质材料降噪

舰船科学技术 2024年第2期46卷 128-133页

作者：漆琼芳华如南余昊成郑建国武汉第二船舶设计研究所湖北武汉430064 华中科技大学航空航天学院湖北武汉430074

分别建立船舶海底门的声场模型和声-固耦合模型,对海底门的声传递损失、结构湿模态进行计算,获取海底门降噪设计需避开的共振频率。建立海底门的流体模型,采用URANS和FW-H对流场及水动力噪声进行数值计算,云图显示格栅背面出现了显著的... 详细信息

分别建立船舶海底门的声场模型和声-固耦合模型,对海底门的声传递损失、结构湿模态进行计算,获取海底门降噪设计需避开的共振频率。建立海底门的流体模型,采用URANS和FW-H对流场及水动力噪声进行数值计算,云图显示格栅背面出现了显著的流动分离及压力脉动,且压力峰值条带沿着格栅对角线方向分布,频谱曲线显示海底门水动力噪声以低频为主。数值计算表明,当仅将海底门钢制格栅替换成水下多孔介质材料时降噪3.4 dB。共振频率计算及水下多孔介质材料应用为海底门声学设计提供了思路。

关键词：海底门声-固耦合模型湿模态声传递损失水下多孔介质材料

Synthesis and ion exchange properties for Cs^+ of ammonium-type mordenite

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Rare Metals 2015年第10期34卷 752-756页

作者： Dian-Quan Dong jian-guo zheng Xian-Lian Han College of Chemical Engineering School of Qingdao University of Science and Technology

Cesium content in the seawater is 3.0 9 10-4 mg·L-1, and ammonium-type mordenite was used to exchange cesium from cesium source. K-type mordenite was obtained by hydrothermal synthesis method. After ammonium-modified, ion exchange properties such as saturated ion exchange capacities and selectivity coefficients for alkali metal ions were determined. At the same time, ion exchange isothermal curves of ammonium-type mordenite for Cs+ and NH4+ were determined at 25°*** electrolyte solution theory was used to work out activity coefficients of the system, and the Kielland diagram of the ion exchange system was obtained. The calculated equilibrium constant(Ka) and ion free enthalpy(DG0) of mordenite for Cs+ and NH4+ are 1.455 and -930.3J·mol-1, respectively, indicating that ion exchange process of ammonium-type mordenite for cesium is a spontaneous process.

关键词： Ion exchange Thermodynamics Mordenite Cesium

气相色谱-质谱法测定食品接触材料及制品中4种癸二酸酯类化合物迁移量

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质谱学报 2024年第4期45卷 558-566,I0005页

作者：陈湘颖曾铭阿文伟范莹颖曾莹陈燕芬李丹钟怀宁郑建国广州海关技术中心广东广州510623

本研究建立了气相色谱-质谱(GC-MS)法同时测定食品接触材料及制品中癸二酸二正丁酯、癸二酸二(2-乙基己基)酯、癸二酸二异辛酯和癸二酸二(2,2,6,6-四甲基-4-哌啶)酯等4种癸二酸酯类化合物在食品模拟物及化学替代溶剂中的迁移量。对于化... 详细信息

本研究建立了气相色谱-质谱(GC-MS)法同时测定食品接触材料及制品中癸二酸二正丁酯、癸二酸二(2-乙基己基)酯、癸二酸二异辛酯和癸二酸二(2,2,6,6-四甲基-4-哌啶)酯等4种癸二酸酯类化合物在食品模拟物及化学替代溶剂中的迁移量。对于化学替代溶剂95%乙醇和异辛烷,采用直接液体进样法;对于橄榄油食品模拟物,用乙腈萃取后采用基质分散萃取净化后上机测试;对于其他食品模拟物(水、4%乙酸、10%乙醇、20%乙醇和50%乙醇),采用正己烷萃取后上机测试。在优化的实验条件下,4种化合物的分离效果良好,在0.30~5.0 mg/kg和0.50~5.0 mg/kg浓度范围内分别呈良好的线性关系,相关系数(r2)大于0.995;4种癸二酸酯类化合物迁移量的检出限和定量限分别为0.1~0.2、0.3~0.5 mg/kg。对塑料样品水、4%乙酸、10%乙醇、20%乙醇、50%乙醇、95%乙醇和异辛烷浸泡液进行0.30、2.0、4.0 mg/kg 3个浓度水平的添加实验,对橄榄油浸泡液进行0.50、2.0、4.0 mg/kg 3个浓度水平的添加实验,测得加标回收率在92.5%~108%之间,相对标准偏差(RSD)在2.4%~8.8%之间。本方法灵敏度高、精密度和准确度好,能够满足食品接触材料及制品中4种癸二酸酯类化合物迁移量的检测需求。

关键词：气相色谱-质谱(GC-MS) 食品接触材料及制品癸二酸酯迁移

Preparation of Nano-crystalline Tungsten Carbide Thin Film by Magnetron Sputtering and Their Electrocatalytic Property for PNP Reduction

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Chinese Chemical Letters 2005年第11期16卷 1539-1542页

作者： Hua Jun zheng jian guo HUANG Chun An MA Department of Applied Chemistry Research Center of Nano Science ＆ Technology Zhejiang University of Technology Hangzhou 310032

Nano-crystalline tungsten carbide thin films were deposited on Ni substrates by magnetron sputtering using WC as target material. The crystal structure and morphology of the thin films were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM） Electrochemical investigations showed that the electrode of the thin film exhibited higher electrocatalytic activity in the reaction of p-nitrophenol （PNP） reduction. FT-IR analysis indicated that p-aminophenol （PAP） was synthesized after two step reduction of PNP on nano-crystalline tungsten carbide thin film electrode.

关键词： Tungsten carbide nano-crystalline electrocatalyst p-nitrophenol.

Science Letters:Binary tree of posterior probability support vector machines

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第2期12卷 83-87页

作者： Dong-li WANG jian-guo zheng Yan ZHOU Glorious Sun School of Business and Management Donghua University Shanghai 200051 China College of lnformation Engineering Xiangtan University Xiangtan 411105 China

Posterior probability support vector machines (PPSVMs) prove robust against noises and outliers and need fewer storage support vectors (SVs). Gonen et al. (2008) extended PPSVMs to a multiclass case by both single-machine and multimachine approaches. However, these extensions suffer from low classification efficiency, high computational burden, and more importantly, unclassifiable regions. To achieve higher classification efficiency and accuracy with fewer SVs, a binary tree of PPSVMs for the multiclass classification problem is proposed in this letter. Moreover, a Fisher ratio separability measure is adopted to determine the tree structure. Several experiments on handwritten recognition datasets are included to illustrate the proposed approach. Specifically, the Fisher ratio separability accelerated binary tree of PPSVMs obtains overall test accuracy, if not higher than, at least comparable to those of other multiclass algorithms, while using significantly fewer SVs and much less test time.

关键词： Binary tree Support vector machine Handwritten recognition Classification

Single Crystal Castability and Undercoolability of PWA1483 Superalloy

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Acta Metallurgica Sinica(English Letters) 2019年第11期32卷 1415-1420页

作者： De-Xin Ma Fu Wang jian-zheng guo Wen-Liang Xu Wedge Central South Research Institute Shenzhen 518045China State Key Laboratory for Powder Metallurgy Central South UniversityChangsha 410083China State Key Laboratory for Manufacturing System Engineering School of Mechanical EngineeringXi'an Jiaotong UniversityXi'an 710049China

Both of the single crystal(SX) castability and undercoolability of PWA1383 superalloy were investigated during the directional solidifi cation and isothermal cooling. In all the six SX parts of a casting cluster, no stray grains were found, revealing a defect-free SX structure. This excellent SX castability of the superalloy was attributed to its good undercoolability. The melting point(T_L) and the critical nucleation temperature( T_N) of the alloy were measured to be 1327 °C and 1306 °C, respectively. The statistic average of the critical nucleation undercooling Δ T_N = T_L-T_N of the alloy was determined to be about 21 K, exhibiting a relatively great capacity to be deeply cooled to a temperature below the melting point without the onset of solidifi cation.

关键词： Superalloys Crystal growth Phase transitions

Anti-sense oligonucleotide labeled with technetium-99m using hydrazinonictinamide derivative and N-hydroxysuccinimidyl S-acetylmercaptoacetyltriglycline: A comparison of radiochemical behaviors and biological properties

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World Journal of Gastroenterology 2008年第14期14卷 2235-2240页

作者： Yun-Chun Li Tian-Zhi Tan jian-guo zheng Chun Zhang Department of Nuclear Medicine West China Hospital Sichuan University 37 Guoxue Alley Chengdu 610041 Sichuan Province China

AIM:To explore and compare the radiochemical behavior and biological property of anti-sense oligonuc-leotide (ASON) labeled with technetium-99m using N-hydroxysuccinimidyl S-acetylmercaptoacetyltriglycl ine (NHS-MAG3) and hydrazinonictinamide derivative (HYNIC). METHODS:After HYNIC and NHS-MAG3 were synthesized, ASON was labeled with technetium-99m using HYNIC and NHS-MAG3 as a bifunctional chelator. The in vivo and in vitro stability, binding rates of labeled compounds to serum albumen, biodistribution of 99mTc-MAG3-ASON and 99mTc-HYNIC-ASON in BALB/C mouse and its HT29 tumor cellular uptake were compared. RESULTS:The labeling efficiency and stability of 99mTc-MAG3-ASON were significantly higher than those of 99mTc-HYNIC-ASON (P = 0.02, and P = 0.03, respectively). 99mTc-MAG3-ASON had a significantly lower rate of binding to serum albumen than 99mTc-HYNIC-ASON (P 0.05) and significantly higher in lung and kidney (P < 0.05). The HT29 tumor cellular uptake rate of 99mTc-MAG3-ASON was significantly higher than that of 99mTc-HYNIC-ASON (P < 0.05). CONCLUSION:99mTc-MAG3-ASON shows superior radiochemical behaviors and biological properties than 99mTc-HYNIC-ASON. 99mTc-MAG3-ASON is a potential radiopharmaceutical agent for in vivo application.

关键词： Anti-sense oligonucleotide Radiolabeling Technetium-99m N-hydroxysuccinimidyl S-acetylmercapt oacetyltriglycline Hydrazinonictionamide derivative

Enhanced photocataly tic activity of TiO_2 by surface fluorination in degradation of organic cationic compound

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Journal of Environmental Sciences 2007年第1期19卷 86-89页

作者： YANG Shi-ying CHEN You-yuan zheng jian-guo CUI Ying-jie Key Lab of Maline Environmental Science and Ecology Ministry of Education Ocean University of China Qingdao 266100 China College of Environmental Science and Engineering Ocean University of China Qingdao 266100 China

Experiments were carried out to investigate the influence of TiO2 surface fluorination on the photodegradation of a representative organic cationic compound, Methylene Blue （MB）. The eleetropositive MB shows poor adsorption on TiO2 surface; its degradation performs a HO. radical-mediated mechanism. In the F-modified system, the kinetic reaction rate enlarged more than 2.5 fold that was attributed mainly to the accumulating adsorption of MB and the increased photogenerated hole available on the F-modified TiO2 surface.

关键词： photocatalysis mechanism adsorption surface fluorination photogenerated hole Methylene Blue(MB)

Role of the reduction site in the fluorinated or sulfated TiO_2 photocatalytic process

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Journal of Environmental Sciences 2007年第10期19卷 1239-1244页

作者： YANG Shi-ying HU Hong CHEN You-yuan zheng jian-guo CUI Ying-jie Key Lab of Marine Environmental Science and Ecology Ministry of Education Ocean University of China Qingdao 266100 China College of Environmental Science and Engineering Ocean University of China Qingdao 266100 China

In this article, the effects of ZiO2 surface fluorination and sulfation, on the active oxygen species formed at the reduction site in the photocatalytic process, namely O2^＊- and H2O2, were investigated from a new perspective. The superoxide radical, （O2^＊-）, was determined by colorimetry of nitroblue tetrazolium, a prominent O2^＊- scavenger. Hydrogen peroxide （H2O2） was estimated by using the iodide-starch method. In the naked TiO2 photocatalysis, O2^＊-, though less reactive, was a very important intermediate. When the TiO2 surface was fluorinated, more O2^＊- and H2O2 were produced, which indicated that the surface modification could greatly reduce the recombination of photogenerated electrons and holes, thus enhancing the photocatalytic rate. In the sulfated system, photocatalysis proceeded with a more complicated mechanism. These results added support to the view of fluoride-induced enhancement and sulfide＇s nonappreciable inhibition effect.

关键词： TiO2 photocatalysis superoxide radicals surface modification initial mechanism