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Alternating Current Zeeman and Stark Interference Effect in Ramsey Separated Oscillating Fields

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Chinese Physics Letters 2001年第2期18卷 202-204页

作者： CHEN Jing-Biao wang feng-zhi YANG Dong-Hai wang Yi-Qiu Department of Electronics and Key Laboratory for Quantum Information and Measurements of Education MinistryPeking UniversityBeijing 100871

Analytic expressions have been derived of the alternating current(ac)Zeeman and ac Stark effect in an atomic beam magnetic resonance method using Ramsey separated oscillating *** interesting feature which will affect the normal Ramsey pattern is that an interference fringe is superimposed on the dispersion lineshapes of the normal ac Zeeman or ac Stark *** point out that this new character of ac Zeeman(ac Stark)effect generally exists in all kinds of Ramsey method,for example,in the optical Ramsey atomic interferometer and atomic beam frequency *** important implication is that,particularly in an atomic beam frequency standard using Ramsey method,this effect has an influence on the evaluation of the second-order Doppler frequency shift.

关键词： effect Ramsey Zeeman

Identification of thermal effects involved in DSC experiment on Al-Cu-Mg-Ag alloys with high Cu:Mg ratio

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International Journal of Minerals,Metallurgy and Materials 2011年第6期18卷 671-675页

作者： Jian-bo Zhang Yong-an Zhang Bao-hong Zhu feng wang zhi-hui Li Xi-wu Li Bai-qing Xiong State Key Laboratory of Nonferrous Metals and Processes General Research Institute for Non-ferrous Metals Beijing 100088 China

Precipitation reactions in the differential scanning calorimetry （DSC） of an Al-Cu-Mg-Ag alloy were identified by analyzing the results from hardness test,electrical conductivity test,and transmission electron microscope （TEM） *** is discovered that thermal effects can be identified through selected area electron diffraction and bright-field *** reaction peaks around 171,231,and 276℃ can be attributed to a structural rearrangement of coherent zones,to the precipitation of Ω phases,and to the precipitation of Ω and θ＇ and possible combination with the transition of θ＇→θ,*** addition,the hardness and electrical conductivity of the alloy change proportionately with the progression of reactions during the heating *** phenomenon can be attributed to the evolution of the micro-structure.

关键词： aluminum alloys thermal effects identification differential scanning calorimetry microstructure

Molecular Structures and Catalytical Performance in Suzuki-coupling Reaction of Novel Dipalladium Clip-shaped Complexes with Bifunctional Pyrazolate Ligands

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Chinese Journal of Structural Chemistry 2021年第7期40卷 843-850,837页

作者： HU Xiao-Peng wang zhi-feng DENG Wei TONG Jin YU Shu-Yan Laboratory fdr Self-assembly Chemistry Center of Excellence for Environmental Safety and Biological EffectsBeijing Key Laboratory for Green Catalysis and SeparationDepartment of Environment and LifeBeijing University of TechnologyBeijing 100124China

A series of clip-shaped cationic molecular corners C1~C4(C1=[(bpy)_(2)Pd_(2)(L^(1))_(2)]^(2+),C2=[(dmbpy)_(2)Pd_(2)(L^(1))_(2)]^(2+),C3=(bpy)_(2)Pd_(2)(L^(2))_(2)]^(2+),C4=(dmbpy)_(2)Pd_(2)(L^(2))_(2)]^(2+),bpy=2,2-bipyridine,dmbpy=4,4΄-dimethyl-2,2-bipyridine)were synthesized through dipalladium complexes[(bpy)_(2)Pd_(2)(NO_(3))_(2)](NO_(3))_(2),[(dmbpy)_(2)Pd_(2)(NO_(3))_(2)](NO_(3))_(2)and bifunctional pyrazole ligands 4-(3,4-dimethoxyphenyl)-3,5-dimethyl-1H-pyrazol(HL^(1))and 4,4΄-(5-(^(1)H-pyrazol-4-yl)-1,3-phenylene)dipyridine(HL^(2)).Complexes C1~C4 were characterized by^(1)H and^(13)C NMR,electrospray ionization mass spectrometry(ESI-MS),elemental analysis,and IR *** X-ray diffraction analysis of C1∙2NO_(3)−revealed a Pd_(2)dimetallic clip-shaped structure which was synthesized by two bifunctional ligands doubly bridged by the[(bpy)Pd]_(2)dimetal ***,all of the complexes with NO_(3)−as counter anions exhibited high-efficiency catalytical performance in the Suzuki-coupling reaction attributed to the tunable impact and weak dinuclear Pd(Ⅱ)···Pd(Ⅱ)intramolecular bonding interaction.

关键词： dipalladium supra molecules bifunctional pyrazolate ligands catalysis Suzuki-coupling reaction

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Influence of different post core materials on the color of Empress 2 full ceramic crowns

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Chinese Medical Journal 2006年第20期119卷 1715-1720页

作者： GE Jing wang Xin-zhi feng Hai-lan Department of Prosthodontics School and Hospital of StomatologyPeking University Beijing 100081 China

Background For esthetic consideration, dentin color post core materials were normally used for all-ceramic crown restorations. However, in some cases, clinicians have to consider combining a full ceramic crown with a metal post core. Therefore, this experiment was conducted to test the esthetical possibility of applying cast metal post core in a full ceramic crown restoration.Methods The color of full ceramic crowns on gold and Nickel-Chrome post cores was compared with the color of the same crowns on tooth colored post cores. Different try-in pastes were used to imitate the influence of a composite cementation on the color of different restorative combinations. The majority of patients could not detect any color difference less than △E 1.8 between the two ceramic samples. So, △E 1.8 was taken as the objective evaluative criterion for the evaluation of color matching and patients＇ satisfaction. Results When the Empress 2 crown was combined with the gold alloy post core, the color of the resulting material was similar to that of a glass fiber reinforced resin post core （△E = 0.3）. The gold alloy post core and the try-in paste did not show a perceptible color change in the full ceramic crowns, which indicated that the color of the crowns might not be susceptible to change between lab and clinic as well as during the process of composite cementation. Without an opaque covering the Ni-Cr post core would cause an unacceptable color effect on the crown （△E = 2.0）, but with opaque covering, the color effect became more clinically satisfactory （△E = 1.8）. Conclusions It may be possible to apply a gold alloy post core in the Empress 2 full ceramic crown restoration when necessary. If a non-extractible Ni-Cr post core exists in the root canal, it might be possible to restore the tooth with an Empress 2 crown after covering the labial surface of the core with one layer of opaque resin cement.

关键词： color difference ceramic crown post core try-in paste

Preliminary experience using transthoracic echocardiography guiding percutaneous closure of ruptured right sinus of Valsalva aneurysm

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Chinese Medical Journal 2011年第10期124卷 1477-1482页

作者： LI Yue wang Guang-yi wang zhi-feng GUO Liang Department of Ultrasound Chinese People's Liberation Army General Hospital Beijing 100853 China Department of Cardiology Chinese People's Liberation Army General Hospital Beijing 100853 China

Background In the 21st century, minimally invasive treatment is one of the main developmental directions of medical sciences. It is well known that the echocardiography plays an important role during interventional treatments of some structural heart diseases. Because the ruptured right sinus of the Valsalva aneurysm （RRSVA） is a rare disease, there were few reports about percutaneous catheter closure of RRSVA. This study aimed to sum up our experience with transthoracic echocardiography （TTE） during percutaneous catheter closure of *** Five RRSVA cases were treated with percutaneous catheter closure. The whole procedure was guided and monitored by TTE and fluoroscopy. The maximum diameter of the RRSVA was measured by TTE before and after the catheter passed through the rupture site. A duct occluder 2 mm larger than the maximum diameter was chosen. The closure effects were evaluated with TTE and fluoroscopy immediately after the occluding device was deployed. All patients were followed up by TTE for 8 to 30 *** Before the catheter passed through the rupture site the maximum diameter of the RRSVA measured with TTE and aortography were （7.9 ±2.1） mm and （7.8 ± 1.8） mm. After the catheter passed through the rupture site the maximum diameter measured with TTE was （11.2 ± 3.2） mm, which was significantly larger than before the procedure （P 〈0.05）. The percutaneous catheter closure was successful in four cases and failed in one. Compared to the aortography the TTE was better at distinguishing residual shunts from aortic valve regurgitation immediately after the occluding device was deployed. There were no complications during 8 to 30 months of *** Transthoracic echocardiography can play an important role during percutaneous catheter closure of RRSVA,especially for estimating the size of the RRSVA after the catheter passes through the rupture site, and differentiating residual shunt from aortic valve regurgitation immediately after the

关键词： transthoracic echocardiography ruptured aneurysm of sinus percutaneous catheter closure

Supplementary inferior phrenic artery embolization in the interventional treatment of hemoptysis

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Chinese Medical Journal 2009年第5期122卷 514-520页

作者： LIU feng-yong wang Mao-qiang FAN Qing-sheng DUAN feng wang zhi-jun SONG Peng Department of Interventional Radiology Clinical Division of Medicine Chinese People's Liberation Army General Hospital Beijing 100853 China

Background Transcatheter bronchial artery embolization （BAE） is widely used for the treatment of hemoptysis and the immediate success rate is high, but there are still some hemorrhage recurrences. One of the common reasons for failure of BAE is collateral branches as blood supply. The inferior phrenic artery （IPA） is one of the most common collateral branches that is scarcely reported. Our purpose was to observe manifestations of IPA supplying to hemoptysis and evaluate the efficacy and safety of IPA embolization. Methods Angiography during interventional treatment of 178 hemoptysis patients in the past 7 years confirmed that IPA hemorrhage resulted in hemoptysis in 25 patients （26-67 years old） who had： lung cancer （11 patients）, bronchiectasis （11 patients）, chronic lung inflammation （2 patients）, and pulmonary tuberculosis （1 patient）. Among the 25 patients, 7 patients had twice interventional operations within one week and 6 patients still experienced intraoperative hemoptysis after conventional embolization of the bronchial artery, the internal thoracic artery, and the intercostal artery, then had the second interventional operation immediately. The total number of cases were 191. Selective embolization of the IPA was performed using polyvinyl alcohol microspheres, gelatin sponge particles, and microcoil. The safety and clinical significance of IPA embolization were evaluated. The Pearson X2 test and Fisher＇s exact probability test were used in this study. Results Selective IPA angiography showed increased diameter of the IPA, disorganization of the branches, and varying degrees of angiogenesis. In 11 cases, contrast material was seen in vessels supplying the tumor and in the tumor. In 9 cases, contrast material had leaked into the area supplied by the IPA; in 8 cases, non-specific flake-like deposits of contrast material were seen; and in 14 cases, abnormal communication or shunt was visualized. Lesions were closely related to the pleura in 25 patients. Fiftee

关键词： hemoptysis inferior phrenic arteries angiography embolization, therapeutic

Endovascular embolization of pulmonary arteriovenous malformations

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Chinese Medical Journal 2010年第1期123卷 23-28页

作者： LIU feng-yong wang Mao-qiang FAN Qing-sheng DUAN feng wang zhi-jun SONG Peng Department of Interventional Radiology Clinical Division ofInternal Medicine Chinese People's Liberation Army GeneralHospital Beijing 100853 China

Background The major consequence of pulmonary arteriovenous malformations （PAVMs） is the direct inflow of blood from the pulmonary artery to the pulmonary vein which induces hypoxemia. Severe complications include transient ischemic attacks, paradoxical embolization in the central nervous system, massive hemoptysis or hemothorax, etc. The conventional treatment is surgical intervention. However, this can be very traumatic and dangerous. Endovascular embolization has advantages over surgery such as a faithful therapeutic effect, a low complication rate, repeatability, etc. Methods Patients （n=-23） with symptomatic PAVMs underwent endovascular embolization; 11 were males and 12 were females, with ages ranging from 6 months to 58 years. During the embolization, microcoils were applied in 6 cases and standard steel coils were used in 17 cases. Results Multiple PAVMs lesions were found in 16 cases and single PAVMs lesion was found in 7 cases. Embolotherapy was carried out 28 times for 23 patients. The success rate was 100%. The results of pulmonary arteriography after treatment showed that single lesion disappeared completely while the main abnormal vessels in multiple lesions also disappeared. The mean blood oxygen saturation increased from （78.04＋8.22）% to （95.13＋3.67）% after the procedure. A correlated groups t test showed changes in blood oxygen saturation before and after embolization （t=9.101, P 〈0.001）. Symptoms of cardiac insufficiency disappeared in 5 cases and vascular murmur in the chest disappeared in 13 cases. After embolization, mild chest pain occurred in 11 cases, small amounts of pleural effusion occurred in 5 cases, and 1 patient died 2 months later because of a pyogenic infection secondary to the pulmonary infarction. Among the 22 remaining cases, with overall follow-up ranging from 18 months to 12 years, general conditions were fine, daily lives were normal and there were no neurologic symptoms or signs, except for 3 patients with diffused PAVMs who h

关键词： pulmonary arteriovenous malformations pulmonary artery endovascular embolization pulmonary arteriography

Microstructural evolution during tempering process and mechanical properties of Cr-Ni-Mo-V/Nb high strength steel

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Journal of Iron and Steel Research International 2025年第1期32卷 270-281页

作者： Zi-wei Lv Jing Fan Rui wang zhi-qiang Yu Yan Kang Yong Hu Lei-feng Tuo Jürgen Eckert zhi-jie Yan School of Materials Science and Engineering North University of ChinaTaiyuan 030051ShanxiChina Shanxi Key Laboratory of Advanced Metal Materials for Special Environments North University of ChinaTaiyuan 030051ShanxiChina School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024ShanxiChina Erich Schmid Institute of Materials Science Austrian Academy of SciencesLeoben 8700Austria Department of Materials Science Chair of Materials PhysicsMontanuniversitat LeobenLeoben 8700Austria

High strength steels exhibit superior mechanical properties due to the unique microstructure,which successfully solves the drawback of the inevitable strength-toughness trade-off that occurs in traditional *** we investigated the effect of matrix and precipitates on mechanical properties of Cr-Ni-Mo-V/Nb steel after water quenching and tempering(150-500℃).The results showed that the microstructure of the present steel is noticeably tuned by changing the tempering *** excellent combination of strength(a yield strength of 1308 MPa with a total elongation of 8.2%)and toughness(Charpy V-notch impact toughness of 40.5 J/cm^(2))is obtained upon tempering at 200℃.This is attributed to the lath martensite containing high dislocation density,the martensite-twin substructure,and the strengthening effects of the precipitated needle-likeε-carbides and spherical VC *** acicularε-carbides are replaced by the rod-shaped Fe_(3)C at the tempering temperature of 350℃,resulting in the remarkable deterioration in strength,hardness,and *** carbides formed at a tempering temperature of 500℃ are beneficial to the enhancement of the elongation and toughness,but the strength decreases due to the matrix softening caused by the recovery of dislocation.

关键词： High strength steel Tempering Microstructure Carbide Mechanical property

Dramatic Changes of Matrix Metalloproteinases-7 and Lysozyme in the Ulcerative Colitis of Mice Induced by Dextran Sulfate Sodium

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Journal of Integrative Agriculture 2014年第4期13卷 858-869页

作者： KANG Jing-jing ZHAO De-ming TENG Ke-dao JIAO Xi-lan wang Ping-li SUN Zhe NI Pei-pei wang zhi-feng ZHANG Rui YANG Yu-rong LIANG Hong-de Pathology Laboratory College of Animal Husbandry and Veterinary Science Henan Agricultural University College of Animal Medicine China Agricultural University

Ulcerative colitis （UC） is a lifelong illness with profound emotional and social impacts, and could cause serious damage to large intestine, especially in colon. However, the pathogenesis of UC remained unclear. The present study attempts to find out the role of matrix metalloproteinases-7 （MMP-7） and lysozyme in the pathogenesis of UC through a mice model induced by dextran sulfate sodium （DSS）. The UC model was evaluated both by disease activity index （DAI） and the intestinal histopathology. The results show that there is a high correlation between the DAI score and the pathological changes of colon. Interleukin-6 （IL-6） serum levels and large intestinal fluids levels in UC mice are always higher than that of the control groups, which might be associated with the degree of the inflammation damage in the colon. The change tendency of the MMP-7 mRNA and protein expressions are both up-regulated firstly and then down-regulated from 1 to 5 d in the colon, but only the MMP-7 protein is up-regulated at 7 d again. The up-regulated MMP-7 levels in the early stage of UC may play a protective role through the activated defensins, while the down-regulated levels in the mid-later stage of UC may be connected with the severe lesions in the colon. However, the up-regulated MMP-7 levels in the later stage of UC in the colon may also contribute to the tissue repair or be served as a marker to CRC （colorectal cancer）. The distribution of lysozyme protein indicates that there may be Paneth-like cells in the colon. Both the changes of MMP-7 and lysozyme in the small intestine may play a protective role for the safe environment of the whole gut, especially to the colon of UC.

关键词： matrix metalloproteinases-7 lysozyme interleukin-6 ulcerative colitis dextran sulfate sodium