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非均衡湍流边界层脉动压力测试研究

船舶力学 2016年第5期20卷 515-522页

作者：庞业珍俞孟萨中国船舶科学研究中心船舶振动噪声重点实验室江苏无锡214082

通过建立非均衡湍流边界层脉动压力测试技术及可提供较高测试信噪比的低噪声风洞试验装置,采用表面贴装式硅微传声器线列阵,测量获得了不同压力梯度模型的湍流边界层脉动压力特性,压力梯度模型表面湍流边界层脉动压力低频平台区幅值增加... 详细信息

通过建立非均衡湍流边界层脉动压力测试技术及可提供较高测试信噪比的低噪声风洞试验装置,采用表面贴装式硅微传声器线列阵,测量获得了不同压力梯度模型的湍流边界层脉动压力特性,压力梯度模型表面湍流边界层脉动压力低频平台区幅值增加3-5 dB;回归得到了非均衡湍流边界层流脉动压力频谱与Strauhal数及Re数和压力梯度相关的拟合模型,具有一定的适用性;压力梯度对湍流边界层脉动压力频率—波数谱的影响主要集中在300 Hz以下的低频段,传输波数附近峰脊区谱级增加3-5 dB。

关键词：非均衡湍流边界层脉动压力波数—频率谱

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舰船辐射声场及声源特性测量方法研究综述

船舶力学 2017年第1期21卷 107-126页

作者：俞孟萨庞业珍中国船舶科学研究中心江苏无锡214082

舰船辐射声场及声源特性测量是船舶声学研究的主要方向。文章梳理了舰船模型和实船声学测量的基本问题,重点综述了频响逆矩阵法、无限与有限空间波束形成、无界近场声全息、有界空间近场声全息和远场声全息、声强和声矢量及时反声聚焦... 详细信息

舰船辐射声场及声源特性测量是船舶声学研究的主要方向。文章梳理了舰船模型和实船声学测量的基本问题,重点综述了频响逆矩阵法、无限与有限空间波束形成、无界近场声全息、有界空间近场声全息和远场声全息、声强和声矢量及时反声聚焦等测量方法的发展脉络和取得的进展。

关键词：舰船声场声源近场声全息波束形成声强矢量

DIFFERENTIATION BETWEEN MALIGNANT AND BENIGN OVARIAN TUMORS BY MAGNETIC RESONANCE IMAGING

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Chinese Medical Sciences Journal 2006年第4期21卷 270-275页

作者： Min Chen Wen-chao Wang Cheng Zhou Ni-na Zhou Kui Cai zheng-han Yang Wei-feng Zhao sa-ying Li Guo-zhen Li Department of Radiology Beijing Hospital Beijing 100730

Objective To determine the magnetic resonance （MR） imaging findings of an ovarian mass which are most predictive of malignancy and assess the value of intravenous gadolinium administration in the characterization of an ovarian mass. Methods Totally 74 consecutive patients with a clinically or sonographicaUy indeterminate adnexal mass underwent MR imaging, of whom 59 had subsequent surgical resection of 70 adnexal masses. These 59 patients formed the study population. MR imaging studies were prospectively and independently reviewed by a senior and a junior radiologist. The senior radiologist also reevaluated the studies in a blind fashion after a minimum 6 months interval. The sensitivity, specificity, positive predictive value, and negative predictive value of contrast-enhanced and unenhanced MR im- aging were evaluated Results The most predictive MR imaging findings for malignancy were presence of vegetations in a cystic lesinn and presence of necrosis in a solid lesion. The odds ratio was even higher when the ancillary finding of peritoneal metastasis or ascites was present. Contrast media contributed significantly to lesinn characterization. Total 70 ovarian masses were detected by contrast-enhanced MR imaging including 37 malignant ovarian masses and 33 benign ovarian masses with 87% （61/70）accuracy, 86% （32/37）sensitivity, 88% （29/33）specificity, 89% （32/36）positive predictive value, and 85% （29/34） negative predictive value, whereas 70 ovarian masses were detected by unenhanced MR imaging with 74% （52/70） accuracy, 73 % （27/37） sensitivity, 76 % （ 25/33 ） specificity, 77% （27/35） positive predictive value, and 71% （ 25/35 ） negative predictive value. There were significant differences in accuracy （ P 〈 0. 01 ）, sensitivity （ P 〈0. 01 ）, specificity （ P 〈0. 01 ） between contrast-enhanced and unenhanced MR imaging. Conclusion Contrast-enhanced MR imaging is highly accurate in detection and characterization of complex adnexal masses.

关键词： ovarian tumor malignancy magnetic resonance imaging

Electro-generation of TGA by Ni-msa-mCS bipolar membrane

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Chinese Chemical Letters 2007年第11期18卷 1411-1415页

作者： zhen Xia Huang Xi zheng Ri Yao Chen Xiao Chen zhen Chen Experiment Center College of Chemistry and Materials Science Fujian Normal University Fuzhou 350007 China

Ni-msa-mCS bipolar membrane （BM） was prepared by sodium alginate （sa） and chitosan （CS）, which were modified by Ca^2＋ and glutaraldehyde as linking reagents, respectively, msa-mCS membrane was characterized by FTIR, SEM, TG and used as a separator in the electrolysis cell to produce thioglycolic acid （TGA）. The experiment results show that TGAwas prepared effectively by electro-reduction of dithiodiglycolic acid （DTDGA） with the mixture of TGA and DTDGA in the cathodic chamber. The current efficiency was up to 66.7% at the room temperature （25 ℃） during the current density of 10 mA/cm^2. Compared with the traditional metal reduction method, the electro-reduction technology saves the zinc powder and eliminates the pollution to environment.

关键词： Bipolar membrane Modified sodium alginate Modified chitosan Thioglycolic acid Dithiodiglycolic acid

Equivariant Lagrangian Minimal S^3 in CP^3

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Acta Mathematica Sinica,English Series 2006年第4期22卷 1215-1220页

作者： zhen Qi LI Yong Qian TAO Department of Mathematics Nanchang University Nanchang 330047 P. R. China

The equivariant Lagrangian minimal immersion of sa into *** is studied. The complete classification and analytic expression for such kinds of immersions are given.

关键词： complex projective space equivariant lagrangian minimal submanifold

Static Recrystallization Behavior of sa508-III Steel during Hot Deformation

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Journal of Iron and Steel Research International 2016年第5期23卷 466-474页

作者： Ding-qian DONG Fei CHEN zhen-shan CUI Institute of Forming Technology and Equipment Shanghai Jiao Tong University College of Manufacturing Science and Engineering Southwest University of Science and Technology

The static recrystallization behavior of sa508-III steel was investigated by isothermal double-hit hot compression tests at the deformation temperature of 950-1 250 ℃,the strain rate of 0. 01-1 s^（-1）,and the inter-pass time of 1-300 *** effects of deformation parameters,including forming temperature,strain rate,degree of deformation（ pre-strain） and initial austenite grain size,on the softening kinetics were analyzed. Experimental results show that static recrystallization kinetics is strongly dependent on deformation temperature and degree of deformation,while less affected by the strain rate and initial grain size. The kinetics and microstructural evolution equations of static recrystallization for sa508-III steel were developed to predict the softening behavior and the statically recrystallized grain size,respectively. Based on the comparison between the experimental and predicted results,it is found that the established equations can give a reasonable estimate of the static softening behavior for sa508-III steel.

关键词： softening fraction static recrystallization kinetic equation microstructure sa508-III steel

Evaluation of an ischemic model in ischemia prone and general Mongolian gerbils by neurological symptom, injury,and sex difference

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Animal Models and Experimental Medicine 2018年第1期1卷 62-67页

作者： Xiao-yan Du Chang-long Li Meng Guo Ying Wang Hong-gang Guo Fang-wei Dai Xiao-ying sa zhen-wen Chen School of Basic Medical Science Capital Medical University Department of Laboratory Animal Capital Medical University Zhejiang Center of Laboratory Animals Zhejiang Academy of Medical Science

Background: In the previous study, we established an ischemia-prone gerbil population(IG), which was selectively bred to increase the incidence of unilateral carotid arterial occlusion(UCO)-induced ischemia in Mongolian gerbils. However, if the characteristics of ischemia model in IG are the same as those in general gerbils(GG), and if the neurological symptoms are associated with the neurological insults in IG is still ***: In the present study, we evaluated the UCO model in IG by analyzing neurological symptoms, neurological injury in the hippocampal CA1 region and compared with ***: The data showed that the ratios of neurological symptom scores ≥ 2 in the IG and GG groups were 65.0% vs 30.0%, respectively, and were significantly different(P <.01).The neuronal damage following a UCO ischemic insult in the IG group was more severe compared to the GG group. There was a high correlation between the neurological insults' scale and the neurological symptom score in the IG and GG groups(r =.979 and.943 in the IG and GG groups, respectively). In animals with mild neurological symptom scores(2 and 3), the neuronal insults were significantly different between female and male gerbils in both IG and ***: Our findings suggest that IG population would likely be more advantageous to establish an ischemic model.

关键词： anterior communicating artery Circle of Willis gerbil ischemia-prone neurological injury,posterior communicating artery sex difference

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新疆鲜杏雾化熏蒸保鲜设备的改进和应用

现代食品科技 2024年第7期40卷 106-117页

作者：田全明曹振殷贝贝王成炜魏佳吴斌新疆农业大学园艺学院新疆乌鲁木齐830052 新疆大学化工学院新疆乌鲁木齐830046 新疆农业科学院农产品贮藏加工研究所新疆乌鲁木齐830091 新疆农业大学食品科学与药学学院新疆乌鲁木齐830052

该研究以工业雾化装置为基础,通过对雾化熏蒸设备硬件及软件方面的改制及工艺设计,提高了雾化熏蒸效率。结果表明:通过增加3组药箱和熏蒸剂箱,采用高压雾化主机和超微雾化喷头实现了雾化熏蒸选择的多样性和熏蒸剂的自动配比(配比范围1:1... 详细信息

该研究以工业雾化装置为基础,通过对雾化熏蒸设备硬件及软件方面的改制及工艺设计,提高了雾化熏蒸效率。结果表明:通过增加3组药箱和熏蒸剂箱,采用高压雾化主机和超微雾化喷头实现了雾化熏蒸选择的多样性和熏蒸剂的自动配比(配比范围1:1~1:200)。采用亚克力熏蒸箱,高压雾化主机的最佳压力是5.0 MPa,最佳工作方式为间歇雾化75 s;在550 m3保鲜库中,高压雾化主机的最佳设定压力是6.5 MPa,装置最佳工作方式为连续雾化7 min,再经熏蒸剂自然沉降3 min,雾化喷头安装方式为“1米一间隔”,雾化熏蒸试材摆放区域距离保鲜库四周墙壁50 cm,摆放高度距离雾化喷头安装位置垂直向下0.5~1.0 m。采用40 mmol/L sa雾化熏蒸处理能有效保持小白杏、赛买提杏贮藏品质。贮藏至第7天时,小白杏的硬度为8.72 N、可溶性固形物为15.9%、可滴定酸含量为0.49%、发病率为0,分别是对照组的1.66、1.10、1.58倍;赛买提杏的硬度为9.01 N、可溶性固形物为13.5%、可滴定酸含量为0.67%、发病率为0,分别是对照组的1.57、1.69、1.60倍。该研究旨在为雾化熏蒸技术在鲜杏贮藏保鲜中的应用提供技术支撑。

关键词：雾化熏蒸杏水杨酸保鲜

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多层声学覆盖层复合的有限长弹性圆柱壳声辐射特性研究

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船舶力学 2007年第5期11卷 788-797页

作者：白振国俞孟萨中国船舶科学研究中心江苏无锡214082

针对水下双层圆柱壳内外壳体各表面敷设隔声阻尼层的情况,建立了有限长多层复合加实肋板的双层圆柱壳水下声辐射计算模型。对模型采用模态展开法,系统考虑壳体与隔声层和实肋板耦合,外表面声学覆盖层作用和外部声场耦合,并以状态矢量对... 详细信息

针对水下双层圆柱壳内外壳体各表面敷设隔声阻尼层的情况,建立了有限长多层复合加实肋板的双层圆柱壳水下声辐射计算模型。对模型采用模态展开法,系统考虑壳体与隔声层和实肋板耦合,外表面声学覆盖层作用和外部声场耦合,并以状态矢量对应的矩阵形式导出复合壳体辐射声功率的计算表达式。数值计算了隔声阻尼层和外场声学覆盖层层参数,实肋板参数和壳体阻尼对模型辐射声功率的影响。研究结果表明:有实肋板时阻尼层的降噪量最高接近15dB,实肋板的声短路作用限制了隔声阻尼层的降噪效果;双层隔声阻尼层比单层隔声阻尼层降噪效果好3-4dB。外场声学覆盖层受实肋板影响较阻尼层小,其降噪量达10dB左右。

关键词：隔声阻尼层实肋板外场声学覆盖层辐射声功率