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The down-faulted basin zone and high disaster risk zone in Shanxi Province, China 被引量:8
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作者 刘惠敏 苏桂武 +1 位作者 邓砚 高庆华 《地震学报》 CSCD 北大核心 2004年第4期440-447,共8页
Shanxi Province is a region with frequent occurrence of earthquakes, floods and waterlogging, meteorological and geologic hazards, and agrobiohazards in China. The study shows that the formation and development of the... Shanxi Province is a region with frequent occurrence of earthquakes, floods and waterlogging, meteorological and geologic hazards, and agrobiohazards in China. The study shows that the formation and development of the down-faulted basin zone in Shanxi Province provides an available condition for preparation and occurrence of these hazards, so that the basin zone becomes an area with frequent occurrence of the hazards, such as earthquakes, floods and waterlogging, meteorological and geologic hazards and agrobiohazards in Shanxi and with their most serious interaction and mutual intensification. Moreover, the basin zone is an area with dense population and most concentrated industrial and agricultural productions and social-economic property in Shanxi. The comprehensive effect of the two factors caused the zone to be a high natural disaster risk area in Shanxi. For reduction of natural disasters and ensuring the sustainable social-economic development in Shanxi, it is necessary to regard the basin zone as an important area for disaster reduction in Shanxi and to carry out integrated disaster reduction. 展开更多
关键词 山西 断陷盆地 自然灾害 灾害风险 综合减灾
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Bisoprolol reverses down-regulation of potassium channel proteins in ventricular tissues of rabbits with heart failure 被引量:6
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作者 Xi Li Tingzhong Wang +3 位作者 Ke Han Xiaozhen Zhuo Qun Lu Aiqun Ma 《The Journal of Biomedical Research》 CAS 2011年第4期274-279,共6页
Remodeling of ion channels is an important mechanism of arrhythmia induced by heart failure (HF). We investigated the expression of potassium channel encoding genes in the ventricles of rabbit established by volumeo... Remodeling of ion channels is an important mechanism of arrhythmia induced by heart failure (HF). We investigated the expression of potassium channel encoding genes in the ventricles of rabbit established by volumeoverload operation followed with pressure-overload. The reversible effect of these changes with bisoprolol was also evaluated. The HF group exhibited left ventricular enlargement, systolic dysfunction, prolongation of corrected QT interval (QTc), and increased plasma brain natriuretic peptide levels in the HF rabbits. Several potassium channel subunit encoding genes were consistently down-regulated in the HF rabbits. After bisoprolol treatment, heart function was improved significantly and QTc was shortened. Additionally, the mRNA expression of potassium channel subunit genes could be partially reversed. The down-regulated expression of potassium channel subunits Kv4.3, Kv1.4, KvLQT1, minK and Kir 2.1 may contribute to the prolongation of action potential duration in the heart of rabbits induced by volume combined with pressure overload HF. Bisoprolol could partially reverse these down-regulations and improve heart function. 展开更多
关键词 heart failure potassium channel down-REGULATION animal models
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Down-staging depth score to predict outcomes in locally advanced rectal cancer achieving ypl stage after neoadjuvant chemo-radiotherapy versus de novo stage pl cohort:A propensity score-matched analysis 被引量:4
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作者 Ning Li Jing Jin +10 位作者 Jing Yu Shuai Li Yuan Tang Hua Ren Wenyang Liu Shulian Wang Yueping Liu Yongwen Song Hui Fang Zihao Yu Yexiong Li 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2018年第3期373-381,共9页
Objective:Prognosis of patients with locally advanced rectal cancer(LARC)but achieving yp T1–2N0 stage after neoadjuvant concurrent chemo-radiotherapy(CRT)has been shown to be favorable.This study aims to determ... Objective:Prognosis of patients with locally advanced rectal cancer(LARC)but achieving yp T1–2N0 stage after neoadjuvant concurrent chemo-radiotherapy(CRT)has been shown to be favorable.This study aims to determine whether the long-term outcome of yp T1–2N0 cases can be comparable to that of p T1–2N0 cohort that received definitive surgery for early disease.Method:From January 2008 to December 2013,449 consecutive patients with rectal cancer were treated and their outcome maintained in a database.Patients with LARC underwent total mesorectal excision(TME)surgery at4–8 weeks after completion of CRT,and those achieving stage yp I were identified as a group.As a comparison,stage p I group pertains to patients whose initially limited disease was not upstaged after TME surgery alone.After propensity score matching(PSM),comparisons of local regional control(LC),distant metastasis-free survival(DMFS),disease-free survival(DFS)and overall survival(OS)were performed using Kaplan-Meier analysis and log-rank test between yp I and p I groups.Down-staging depth score(DDS),a novel method of evaluating CRT response,was used for subset analysis.Results:Of the 449 patients,168 matched cases were generated for analysis.Five-year LC,DMFS,DFS and OS for stage p I vs.yp I groups were 96.7%vs.96.4%(P=0.796),92.7%vs.73.6%(P=0.025),91.2%vs.73.6%(P=0.080)and 93.1%vs.72.3%(P=0.040),respectively.In the DDS-favorable subset of the yp I group,LC,DMFS,DFS and OS resulted in no significant differences in comparison with the p I group(P=0.384,0.368,0.277 and0.458,respectively).Conclusions:LC was comparable in both groups;however,distant metastasis developed more frequently in down-staged LARC than de novo early stage cases,reflecting the need to improve the efficacy of systemic treatment despite excellent pathologic response.DDS can be an indicator to identify a subset of the yp I group whose longterm oncologic outcomes are as good as those of stage p I cohort. 展开更多
关键词 Rectal neoplasms neoadjuvant chemo-radiotherapy down-staging propensity score-matched analysis
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Outcomes of loco-regional therapy for down-staging of hepatocellular carcinoma prior to liver transplantation 被引量:3
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作者 Xian-Jie Shi, Xin Jin, Mao-Qiang Wang, Li-Xin Wei, Hui-Yi Ye, Yu-Rong Liang, Ying Luo and Jia-Hong DongDepartment of Hepatobiliary Surgery Department of Intervention Radiology Department of Pathology and Department of Radiology General Hospital of PLA, Beijing 100853, China 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2011年第2期143-150,共8页
BACKGROUND: The number of loco-regional therapies (LRTs) for hepatocellular carcinoma (HCC) has increased dramatically during the past decade. Many patients with HCC who were beyond the Milan criteria were allowed to ... BACKGROUND: The number of loco-regional therapies (LRTs) for hepatocellular carcinoma (HCC) has increased dramatically during the past decade. Many patients with HCC who were beyond the Milan criteria were allowed to receive a liver transplantation (LT) once the HCC was successfully down-staged. This retrospective study aimed to analyze the outcomes of LRTs prior to LT in patients with HCC beyond the Milan criteria. METHODS: We analyzed 56 patients treated from June 2006 to March 2010: 22 met the Milan criteria (T1+T2, 39.3%), 16 had T3 tumors (28.6%), and 11 had T4a tumors (19.6%), while 7 were suspected of tumor vascular invasion (T4b, 12.5%). All patients underwent preoperative LRTs, including transcatheter arterial chemoembolization, radiofrequency ablation, percutaneous ethanol injection, liver resection, and/or microwave coagulation therapy. The number of the patients who were successfully down-staged before LT, the types of LRTs used before LT, and their outcomes after LT were recorded. RESULTS: Eleven patients had necrotic tumors (pT0, 19.6%); 6 had pT1 tumors (10.7%), 22 had pT2 tumors (39.3%), 6 had pT3 tumors (10.7%), 5 had pT4a tumors (8.9%), and 6 had pT4b tumors (10.7%). The histopathologic tumors of 39 patients (69.6%) were down-staged and met the established Milan criteria (pT0-2). Imaging-proven under-staging was present in 5 HCC patients (8.9%) who had tumors involving the intrahepatic venous system. Twenty-three patients (41.1%) had stable HCC and 10 (17.9%) died. The 1-, 3- and 4-year survival rates were 96%, 73% and 61%, respectively, with a mean survival time of 22.29±1.63 months. Six patients died of tumorrecurrence. The 1-, 3- and 4-year recurrence-free survival (RFS) rates were 88%, 75% and 66%, respectively. The 3-year RFS of patients with pT0-2 tumors was 82%, which was markedly greater than that of patients with pT3 tumors (63%, P=0.018) or pT4 tumors (17%, P=0.000). Although the 3-year RFS of patients with pT3 tumors was greater than that of patients with pT4 tumors, the difference was not significant. CONCLUSIONS: Successful down-staging of HCCs can be achieved in the majority of carefully selected patients by LRTs. Importantly, patients who are successfully down-staged and undergo LT may have a higher RFS rate. 展开更多
关键词 hepatocellular carcinoma tumor down-staging loco-regional therapy liver transplantation
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Expression and Biological Function of N-myc Down-regulated Gene 1 in Human Cervical Cancer 被引量:3
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作者 王静 蔡晶 +4 位作者 李智敏 胡沙 于利利 肖兰 王泽华 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2010年第6期771-776,共6页
The expression of N-myc down-regulated gene 1 (NDRG1) has previously been reported to be involved in the proliferation,differentiation,invasion and metastasis of cancer cells,but its role in cervical cancer is still u... The expression of N-myc down-regulated gene 1 (NDRG1) has previously been reported to be involved in the proliferation,differentiation,invasion and metastasis of cancer cells,but its role in cervical cancer is still unclear.This study aimed to investigate the expression of NDRG1gene in human cervical cancer and its effect on aggressive tumor behaviors.The NDRG1 expression in cervical tissues and cells was detected by RT-PCR.Specific expression plasmid pEGFP-N1-NDRG1-GFP was used to enhance the expression of NDRG1 in human cervical cancer cell lines.The mRNA and protein level of NDRG1 was assessed by RT-PCR and Western blotting,respectively.Its effects on cell proliferation,migration,invasion,cell cycle and apoptosis were detected by MTT,transwell migration assay and flow cytometry (FCM),respectively.The results showed that the expression of NDRG1 in cervical cancer tissues and cells was significantly lower than in normal cervical tissues (P【0.001).After transfection with pEGFP-N1-NDRG1-GFP,the mRNA and protein expression of NDRG1 was up-regulated in Siha cells,which suppressed cell proliferation (P【0.001),induced cell cycle arrest (P【0.05),reduced invasion and migration of Siha cells (P【0.05),but caused no cell apoptosis.Moreover,vascular endothelial growth factor (VEGF),a tumor-induced angiogenesis factor,was markedly reduced and E-cadherin,a cell adhesion molecule,was increased in the cells transfected with pEGFP-N1-NDRG1-GFP.It was concluded that up-regulated NDRG1 may play a role in the suppression of malignant cell growth,invasion and metastasis of human cervical cancer. 展开更多
关键词 N-myc down-regulated gene 1 cervical cancer TRANSFECTION cell proliferation invasion
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Down-scaled regional ocean modeling system (ROMS) for high-resolution coastal hydrodynamics in Korea 被引量:4
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作者 LIM Hak-Soo KIM Chang S +2 位作者 PARK Kwang-Soon SHIM Jae Seol CHUN Insik 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第9期50-61,共12页
A down-scaled operational oceanographic system is developed for the coastal waters of Korea using a re- gional ocean modeling system (ROMS). The operational oceanographic modeling system consists of at- mospheric an... A down-scaled operational oceanographic system is developed for the coastal waters of Korea using a re- gional ocean modeling system (ROMS). The operational oceanographic modeling system consists of at- mospheric and hydrodynamic models. The hydrodynamic model, ROMS, is coupled with wave, sediment transport, and water quality modules. The system forecasts the predicted results twice a day on a 72 h basis, including sea surface elevation, currents, temperature, salinity, storm surge height, and wave information for the coastal waters of Korea. The predicted results are exported to the web-GIS-based coastal informa- tion system for real-time dissemination to the public and validation with real-time monitoring data using visualization technologies. The ROMS is two-way coupled with a simulating waves nearshore model, SWAN, for the hydrodynamics and waves, nested with the meteorological model, WRE for the atmospheric surface forcing, and externally nested with the eutrophication model, CE-QUAL-ICM, for the water quality. The op- erational model, ROMS, was calibrated with the tidal surface observed with a tide-gage and verified with current data observed by bottom-mounted ADCP or AWAC near the coastal waters of Korea. To validate the predicted results, we used real-time monitoring data derived from remote buoy system, HF-radar, and geostationary ocean color imager (GOCI). This down-scaled operational coastal forecasting system will be used as a part of the Korea operational oceanographic system (KOOS) with other operational oceanographic systems. 展开更多
关键词 down-scaled operational oceanographic system regional ocean modeling system wave coupledmodel real-time monitoring system
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A review of down-hole tubular string buckling in well engineering 被引量:14
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作者 De-Li Gao Wen-Jun Huang 《Petroleum Science》 SCIE CAS CSCD 2015年第3期443-457,共15页
Down-hole tubular string buckling is the most classic and complex part of tubular string mechanics in well engineering. Studies of down-hole tubular string buckling not only have theoretical significance in revealing ... Down-hole tubular string buckling is the most classic and complex part of tubular string mechanics in well engineering. Studies of down-hole tubular string buckling not only have theoretical significance in revealing the buckling mechanism but also have prominent practical value in design and control of tubular strings. In this review, the basic principles and applicable scope of three classic research methods (the beam-column model, buck- ling differential equation, and energy method) are intro- duced. The critical buckling loads and the post-buckling behavior under different buckling modes in vertical, inclined, horizontal, and curved wellbores from different researchers are presented and compared. The current understanding of the effects of torque, boundary condi- tions, friction force, and connectors on down-hole tubular string buckling is illustrated. Meanwhile, some unsolved problems and controversial conclusions are discussed. Future research should be focused on sophisticated description of buckling behavior and the coupling effect of multiple factors. In addition, active control of down-hole tubular string buckling behavior needs some attention urgently. 展开更多
关键词 down-hole tubular mechanics Tubular stringbuckling Wellbore configuration Boundary condition Friction force
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Quantum frequency down-conversion of single photons at 1552 nm from single InAs quantum dot 被引量:2
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作者 Ben Ma Si-Hang Wei +3 位作者 Ze-Sheng Chen Xiang-Jun Shang Hai-Qiao Ni Zhi-Chuan Niu 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第9期595-599,共5页
Near-infrared single photon sources in telecommunication bands, especially at 1550 nm, are required for long-distance quantum communication. Here a down-conversion quantum interface is implemented, where the single ph... Near-infrared single photon sources in telecommunication bands, especially at 1550 nm, are required for long-distance quantum communication. Here a down-conversion quantum interface is implemented, where the single photons emitted from single In As quantum dot at 864 nm is down converted to 1552 nm by using a fiber-coupled periodically poled lithium niobate(PPLN) waveguide and a 1.95 μmm pump laser, and the frequency conversion efficiency is ~40%. The singlephoton purity of quantum dot emission is preserved during the down-conversion process, i.e., g^((2))(0), only 0.22 at 1552 nm.This present technique advances the Ⅲ-Ⅴ semiconductor quantum dots as a promising platform for long-distance quantum communication. 展开更多
关键词 quantum frequency down-conversion quantum dot telecommunication band single photon
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Processing and analysis of transient pressure measurements from permanent down-hole gauges 被引量:2
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作者 Wang Fei 《Petroleum Science》 SCIE CAS CSCD 2012年第3期330-335,共6页
With permanent down-hole gauges (PDGs) widely installed in oilfields around the world in recent years, a continuous stream of transient pressure data in real time is now available, which motivates a new round of res... With permanent down-hole gauges (PDGs) widely installed in oilfields around the world in recent years, a continuous stream of transient pressure data in real time is now available, which motivates a new round of research interests in further developing pressure transient processing and analysis techniques. Transient pressure measurements from PDG are characterized by long term and high volume data. These data are recorded under unconstrained circumstances, so effects due to noise, rate fluctuation and interference from other wells cannot be avoided. These effects make the measured pressure trends decline or rise and then obscure or distort the actual flow behavior, which makes subsequent analysis difficult. In this paper, the problems encountered in analysis of PDG transient pressure are investigated. A newly developed workflow for processing and analyzing PDG transient pressure data is proposed. Numerical well testing synthetic studies are performed to demonstrate these procedures. The results prove that this new technique works well and the potential for practical application looks very promising. 展开更多
关键词 Permanent down-hole gauge transient pressure data processing deconvolution technique numerical well testing
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“Top-Down-Approach”降水相态分析法在双流机场一次降雪过程中的应用 被引量:1
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作者 褚芸欣 吴妮晏 赵清越 《高原山地气象研究》 2023年第4期146-150,共5页
选取ERA5再分析资料和常规气象资料等多源数据,运用“Top-Down-Approach”降水相态分析法,分析了2023年1月16日双流机场降雪过程,重点探究了降水相态的预报着眼点。结果表明:(1)湿度超过85%的-12~-16℃温度层有利于枝状雪花的形成,高浓... 选取ERA5再分析资料和常规气象资料等多源数据,运用“Top-Down-Approach”降水相态分析法,分析了2023年1月16日双流机场降雪过程,重点探究了降水相态的预报着眼点。结果表明:(1)湿度超过85%的-12~-16℃温度层有利于枝状雪花的形成,高浓度云中冰相粒子与水相粒子重叠区有利于低融化比雪花的形成,在预报时需重点关注。(2)当湿球0℃温度层偏低时,可降低降雪预报中对地面温度的限制。(3)结合温度廓线分析,微波辐射计液态水廓线产品可以指示冰云层主要分布高度,还能反映出液态水含量在降雪过程开始前显著增强且在降雪趋于结束时提前降低的变化特征,对降雪过程有一定的指示意义。 展开更多
关键词 降水相态 Top-down-Approach 物理机制 湿球温度
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认知视角下反义类词缀“up-”和“down-”的空间隐喻
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作者 何清玉 毛智慧 《海外英语》 2023年第4期77-79,共3页
文章以认知隐喻为理论框架,立足于充分语料,聚焦考察反义类词缀“up-”和“down-”的空间隐喻。研究发现,类词缀“up-”和“down-”通过意象图式的映射,可以由表示空间概念的具体始源域拓展到表示数量、地位、状态、时间等抽象概念的目... 文章以认知隐喻为理论框架,立足于充分语料,聚焦考察反义类词缀“up-”和“down-”的空间隐喻。研究发现,类词缀“up-”和“down-”通过意象图式的映射,可以由表示空间概念的具体始源域拓展到表示数量、地位、状态、时间等抽象概念的目标域。另外,类词缀“up-”和“down-”作为一对反义类词缀,其意象图式在数量域、地位域、状态域和时间域都呈现出正负极性的特征。 展开更多
关键词 空间隐喻 意象图式 反义类词缀 up- down-
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The down-faulted basin zone and high disaster risk zone in Shanxi Province, China
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作者 刘惠敏 苏桂武 +1 位作者 邓砚 高庆华 《Acta Seismologica Sinica(English Edition)》 CSCD 2004年第4期490-499,共10页
Shanxi Province is a region with frequent occurrence of earthquakes, floods and waterlogging, meteorological and geologic hazards, and agrobiohazards in China. The study shows that the formation and development of the... Shanxi Province is a region with frequent occurrence of earthquakes, floods and waterlogging, meteorological and geologic hazards, and agrobiohazards in China. The study shows that the formation and development of the down-faulted basin zone in Shanxi Province provides an available condition for preparation and occurrence of these hazards, so that the basin zone becomes an area with frequent occurrence of the hazards, such as earthquakes, floods and waterlogging, meteorological and geologic hazards and agrobiohazards in Shanxi and with their most serious interaction and mutual intensification. Moreover, the basin zone is an area with dense population and most concentrated industrial and agricultural productions and social-economic property in Shanxi. The comprehensive effect of the two factors caused the zone to be a high natural disaster risk area in Shanxi. For reduction of natural disasters and ensuring the sustainable social-economic development in Shanxi, it is necessary to regard the basin zone as an important area for disaster reduction in Shanxi and to carry out integrated disaster reduction. 展开更多
关键词 SHANXI down-faulted basin natural disasters disaster risk integrated disaster reduction
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Down-regulation of glucocorticoid receptor mRNA by glucocorticoids in rats
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作者 宋亮年 徐仁宝 《Journal of Medical Colleges of PLA(China)》 CAS 1991年第1期32-38,共7页
The effect of glucocorticoids on the down-regulation of glucocorticoidreceptor (GR) mRNA was studied in intact rats.GR mRNA was characterized byNorthern blot hybridization and quantitated by dot blot hybridization usi... The effect of glucocorticoids on the down-regulation of glucocorticoidreceptor (GR) mRNA was studied in intact rats.GR mRNA was characterized byNorthern blot hybridization and quantitated by dot blot hybridization using a hu-man GR cDNA fragment as a probe.Administration of hydrocortisone (F) inpolyvinyl alcohol (PVA) resulted in a rapid increase in plasma glucocorticoidswhich maintained at stress levels (20 to 40μg/dl) for about 3 d.HepaticGR mRNA decreased significantly to 73.5±6.3% of control values 6h followingF treatment,after which the decline of GR mRNA was gradual,reaching a mini-mum of 44.0±5.0% of control levels 3d after the treatment.The effect of F onthe down-regulation of hepatic GR mRNA lasted up to 11 d.In contrast,F treat-ment had no effect on GR mRNA in rat brain.These results are consistent withthe changes in GR in rats as reported previously,except that even though thehepatic cytosol GR decreased markedly,no significant changes in hepatic GRmRNA were found 1h after F treatment,strongly suggesting that thedown-regulation of GR by its ligands in vivo occurs at both transcriptional andposttranscriptional levels and is of tissue-specific fashion. 展开更多
关键词 GLUCOCORTICOID receptor hydrocortisone down-REGULATION cDNA MRNA Northern BLOT dot BLOT RATS
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Parametric down-conversion with local operation and two-way classical communication
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作者 刘强 谭勇刚 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第4期44-47,共4页
The decoy-state quantum key distribution protocol suggested by Adachi et al. (Phys. Rev. Lett 99 180503 (2007)) is proven to be secure and feasible with current techniques. It owns two attractive merits, i.e., its... The decoy-state quantum key distribution protocol suggested by Adachi et al. (Phys. Rev. Lett 99 180503 (2007)) is proven to be secure and feasible with current techniques. It owns two attractive merits, i.e., its longer secure transmission distance and more convenient operation design. In this paper, we first improve the protocol with the aid of local operation and two-way classical communication (2-LOCC). After our modifications, the secure transmission distance is increased by about 20 km, which will make the protocol more practicable. 展开更多
关键词 parametric down-conversion local operation and two-way classical communication B step
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Mechanical Analysis of the Down-Hole String in a Deep Well
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作者 何玉发 刘清友 朱筱岚 《Journal of Southwest Jiaotong University(English Edition)》 2010年第4期314-319,共6页
In a deep well,under high pressure and temperature,the force,deformation,and movement of the downhole string are very complicated. In this paper,based on the analysis of the working environment and load properties of ... In a deep well,under high pressure and temperature,the force,deformation,and movement of the downhole string are very complicated. In this paper,based on the analysis of the working environment and load properties of the down-hole string in deep wells,the factors of high temperature,high pressure,and the complex structure of wells have been taken into consideration. The loads of the down-hole string,stability,back buckle configuration,dynamic characteristics,mechanical strength,and deformation have been systematically studied. On this basis,mechanical models of a down-hole string under different conditions have been established and software for aiding analysis has been developed. By using this software,deep well strings under different construction parameters can be simulated and analyzed,providing a theoretical basis and method for down-hole string assembly,as well as string down-hole construction and operation. 展开更多
关键词 down-hole string Mechanical behavior Optimization design Software development
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Design of Software-Defined Down-Conversion and Up-Conversion: An Overview
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作者 Yue Zhang Li-Ke Huang +1 位作者 Carsten Maple Qing Xuan 《ZTE Communications》 2011年第4期10-14,共5页
In recent years, much attention has been paid to software-defined radio (SDR) technologies for multimode wireless systems SDR can be defined as a radio communication system that uses software to modulate and demodul... In recent years, much attention has been paid to software-defined radio (SDR) technologies for multimode wireless systems SDR can be defined as a radio communication system that uses software to modulate and demodulate radio signals. This article describes concepts, theory, and design principles for SDR down-conversion and up-conversion. Design issues in SDR down-conversion are discussed, and two different architectures, super-heterodyne and direct-conversion, are proposed. Design issues in SDR up-conversion are also discussed, and trade-offs in the design of filters, mixers, NCO, DAC, and signal processing are highlighted. 展开更多
关键词 SDR down-conversion UP-CONVERSION DIRECT-CONVERSION super-heterodyne conversion
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Simple and practical method of characterizing the parametric down-conversion source
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作者 王东 伍娟 +5 位作者 赵良圆 安雪碧 银振强 陈巍 韩正甫 王琴 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第11期83-88,共6页
Parametric down-conversion(PDC) sources play an important role in quantum information processing, therefore characterizing their properties is necessary. Here we present a statistical model to assess the properties ... Parametric down-conversion(PDC) sources play an important role in quantum information processing, therefore characterizing their properties is necessary. Here we present a statistical model to assess the properties of the PDC source with certain distribution, such as the brightness and photon channel transmissions, we only need to measure the singles and coincidences counts in a few seconds. Furthermore, we validate the model by applying it to a PDC source generating highly non-degenerate photon pairs. The results of the experiment indicate that our method is more simple, efficient, and less time consuming. 展开更多
关键词 parametric down-conversion brightness photon channel transmission
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A FREQUENCY DOMAIN QUANTITATIVE MEASUREMENT METHOD FOR BLOOD FLOW VELOCITY WITH BIDIRECTIONAL DOPPLERULTRASOUND AVOIDING DOWN-BAND CHANNEL
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作者 Wang Weiqi,Shao Qianming,Yu Jianguo(Department of Electronic Engineering,Fudan University, Shanghai, 200433, China) 《Chinese Journal of Biomedical Engineering(English Edition)》 1996年第4期147-154,共8页
The up-band signal of the second ultrasonic beam contained reversecomPOnent or blooll now. Using double ultrasonic beam,bidirectional Doppler ultrasound can avoid the use or two kinds or band filters and be simplified... The up-band signal of the second ultrasonic beam contained reversecomPOnent or blooll now. Using double ultrasonic beam,bidirectional Doppler ultrasound can avoid the use or two kinds or band filters and be simplified into a singlekind or band filter. In order to make the output more accurate,the inrluence of angle effect can be overcome by the table-out method and another special methodcalled cose recorrection.The experiment result is that when the deviation angle varies from-- 18' to +20' the relative error or output is less than 5%. 展开更多
关键词 Ultrasound BLOOD FLOW VELOCITY FREQUENCY separation down-bandchannel
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RNA pull-down联合质谱分析lncRNA HSFAS在增生性瘢痕中的作用及机制
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作者 夏童童 马芳 +8 位作者 孙浩原 刘虹麟 张正皓 杨佳琪 张慧萍 吴凯 沈江涌 姜怡邓 李桂忠 《中国组织工程研究》 CAS 北大核心 2025年第12期2492-2499,共8页
背景:课题组前期研究发现,增生性瘢痕特异性长链非编码RNA HSFAS是一种可用于增生性瘢痕诊断的新型生物标志物,但其如何在增生性瘢痕中发挥作用尚不清楚。目的:探讨长链非编码RNA HSFAS在增生性瘢痕中的作用及机制。方法:临床收集3例行... 背景:课题组前期研究发现,增生性瘢痕特异性长链非编码RNA HSFAS是一种可用于增生性瘢痕诊断的新型生物标志物,但其如何在增生性瘢痕中发挥作用尚不清楚。目的:探讨长链非编码RNA HSFAS在增生性瘢痕中的作用及机制。方法:临床收集3例行增生性瘢痕组织切除手术患者的新鲜增生性瘢痕皮肤组织和增生性瘢痕旁正常皮肤组织标本,应用免疫荧光技术检测两种皮肤组织冰冻切片中长链非编码RNA HSFAS的表达。应用酶消化法体外分离增生性瘢痕皮肤组织与正常皮肤组织原代成纤维细胞,采用qRT-PCR检测细胞中长链非编码RNA HSFAS mRNA表达,通过RNA pull-down联合质谱技术检测与长链非编码RNA HSFAS相互结合的蛋白,利用GO和KEGG分析长链非编码RNA HSFAS参与增生性瘢痕进展的主要功能和通路,通过catRAPID和RPISeq网站分析确定长链非编码RNA HSFAS与蛋白的靶向结合。结果与结论:①与正常皮肤组织相比,增生性瘢痕组织中的长链非编码RNA HSFAS表达升高(P<0.05);与正常皮肤组织来源成纤维细胞相比,增生性瘢痕组织来源成纤维细胞中长链非编码RNA HSFAS mRNA表达升高(P<0.05);②RNA pull-down联合质谱技术明确与长链非编码RNA HSFAS相互结合的蛋白有510个;GO和KEGG分析结果显示:这些蛋白主要涉及RNA剪接和加工、染色体合成和分离、细胞周期等过程,其中涉及RNA剪接和加工的蛋白有支架附着因子B2和DICER1,并且与长链非编码RNA HSFAS的结合分数较高;生物信息学技术分析验证结果显示,长链非编码RNA HSFAS与支架附着因子B2和DICER1蛋白存在相互结合;③结果显示,长链非编码RNA HSFAS可能通过与支架附着因子B2和DICER1蛋白相互结合调控RNA剪接和加工修饰影响基因表达,从而促进增生性瘢痕的发生发展。 展开更多
关键词 增生性瘢痕 lncRNA HSFAS 成纤维细胞 RNA pull-down 质谱分析
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East-west crustal structure and “down-bowing” Moho under the northern Tibet revealed by wide-angle seismic profile 被引量:19
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作者 张中杰 李英康 +5 位作者 王光杰 滕吉文 S.Klemperer 李敬卫 范进义 陈赟 《Science China Earth Sciences》 SCIE EI CAS 2002年第6期550-558,共9页
We recognized 6 sets of reflecting P- and S-wave events from Moho and other interfaces within the crust, respectively, with the wide-angle seismic data acquired from 510 km-long Selincuo-Ya'anduo profile in the no... We recognized 6 sets of reflecting P- and S-wave events from Moho and other interfaces within the crust, respectively, with the wide-angle seismic data acquired from 510 km-long Selincuo-Ya'anduo profile in the northern Tibet, fitted the observed events with forward modeling, and interpreted crustal structure of P- and S-wave velocities and Poisson's ratio under the profile. The results demonstrate that the crustal structure between Yarlungzangbo and Bangong-Nujiang sutures changes abruptly, and the crust is the thickest at the middle part of the profile with thickness of 80 km or more. The 'down-bowing' Moho is the striking feature for the crustal variation along the west-east direction. The Moho uplifts with steps, and the uplifting rate westward is greater than that eastward. The heterogeneity of P- and S-wave velocities exists both vertically and horizontally, and one lower velocity layer (LVL) exists with the depth range of 27-34 km and the thickness range of 5-7 km. For the upper crust, Poisson's ratio is the lowest at the middle part of the profile; for the lower crust, the Poisson's ratio at the east segment is lower than that at west segment, which means that the crustal rigidity for the upper crust is different from the lower crust, and the lower crust under the east segment of the profile is more ductile. We infer that the substance in the lower crust endured eastward flow along with the collision between Eurasian and Indian plates, and the 'down-bowing' Moho is attributable to the multi-phase E-W tectonic processes. 展开更多
关键词 northern Tibet WIDE-ANGLE seismic profile P- and S-WAVE velocity Poisson's ratio 'down-bowing' Moho eastward flow of materials.
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