资源类型

期刊论文 45

年份

2023 2

2022 2

2021 4

2020 2

2019 3

2018 1

2017 2

2016 2

2015 2

2014 1

2012 1

2011 1

2010 3

2009 1

2008 10

2007 4

2004 2

2003 2

展开 ︾

关键词

力常数 2

狭义相对论 2

键能 2

键长 2

4D打印 1

光速不变公设 1

光量子 1

凸极同步电机 变速恒频 交流励磁 双馈 1

制造业 1

刺激响应材料 1

力矩反馈器 1

原子光谱 1

双馈型 1

变流器 1

变速恒频 1

并网逆变器；模型预测控制；直接功率控制；三矢量；恒定开关频率；功率误差 1

微机电系统 1

恒流/恒压转换；并联稳压器；无级功率重构；水下观测网 1

时间常数 1

展开 ︾

检索范围：

排序： 展示方式：

The energy consumption in a batch stripper and a batch rectifier

Xianbao CUI, Tianyang FENG, Ying ZHANG, Zhicai YANG,

《化学科学与工程前沿（英文）》 2009年 第3卷 第4期   页码 443-452 doi: 10.1007/s11705-009-0266-6

摘要： The energy consumption in a batch rectifier and a batch stripper was investigated with a shortcut mathematical model. The minimum energy consumption of a batch stripper was compared to that of a batch rectifier under “general constant reflux” and “general constant distillate composition” with the ratio of minimum energy consumption /. When the feed contains a large amount of light component, the product purity specification is low and the relative volatility is small, the minimum energy consumption of a batch stripper is less than that of a batch rectifier under “general constant reflux” and “general constant distillate composition”. When the feed contains a small amount of light component, the product purity specification is very high and the relative volatility is low, a batch stripper can also consume less energy only in the “general constant distillate composition” operation mode. In other cases, a batch rectifier can consume less energy.

关键词： constant reflux     feed     energy consumption     general constant     product purity    

HTML PDF 收藏

Improved control of hypertension following laparoscopic fundoplication for gastroesophageal reflux disease

null

《医学前沿（英文）》 2017年 第11卷 第1期   页码 68-73 doi: 10.1007/s11684-016-0490-7

摘要：

This study aims to determine whether successful laparoscopic fundoplication for gastroesophageal reflux disease (GERD) can improve the control of hypertension. We conducted an observational study of GERD patients with hypertension. The esophageal and gastroesophageal symptoms of these patients were successfully treated with laparoscopic fundoplication, as measured by the reduced GERD symptoms and proton pump inhibitor consumption. A hypertension control scale was used to classify the use of antihypertensive medications and the quality of blood pressure control before and after anti-reflux surgery. Wilcoxon signed-ranks test was used for the statistical analyses. Seventy GERD patients were included in the analysis and followed up for a mean period of 3.5±1.4 years. Prior to surgery, all participating patients were taking at least one class of antihypertensive medication, and 56 patients (80%) had intermittently high blood pressure. After surgery, the mean number of antihypertensive medication classes per patient was significantly reduced from 1.61±0.77 pre-procedure to 1.27±0.88 post-procedure (P?<?0.001). The blood pressure of 48 of the 56 cases (86%) with preoperative intermittent high blood pressure returned to normal post procedure. A total of 50 patients (71%) recorded improvements on the hypertension control scale, with the overall mean score decreasing from 3.1±1.0 pre-procedure to 1.4±1.0 post-procedure (P?<?0.001). Therefore, successful laparoscopic fundoplication may result in better blood pressure control in some hypertensive GERD patients. This result suggests a possible connection between gastroesophageal reflux and hypertension.

关键词： gastroesophageal reflux disease     hypertension     blood pressure     laparoscopic fundoplication    

HTML PDF 收藏

A belated revelation: from gastroesophageal reflux derived asthma to laryngotracheal irritation even

WANG Zhonggao

《医学前沿（英文）》 2008年 第2卷 第2期   页码 127-129 doi: 10.1007/s11684-008-0023-0

摘要： The author has been inspired by the Global Evidence-Based Consensus for gastroesophageal reflux (GER), which put forward four extra-esophageal syndromes: reflux cough syndrome, reflux laryngitis syndrome, reflux dental erosion syndrome and the reflux asthma syndrome. The author himself happened to receive five emergency rescue treatments following apparent “bronchial asthma”, which was to be diagnosed as GER at his own insistence. PPI resulted in some relief. After being rescued again from suffocation, he had a fundaplication, which was performed at the Englewood Hospital & Medical Center, Englewood, USA in March 2006. The procedure immediately cleared up his “asthma”. A month later he brought forth a Center for GER in an army hospital in Beijing, China. Up to now, 601 patients with mainly respiratory distress (84%) were treated by Stretta Radiofrequency, 58 by surgery and more by PPI. The GER Center is now complete with a ward. GER patients with respiratory distresses turned out to fare better than those with acid regurgitation. A nozzle-shaped pharynx was found in patients with the reflux. Animal study revealed that the refluxate entered into trachea and even lungs. Gradually a hypothesis of a gastro-oesophago-laryngo-tracheal reflux took shape.Our modest effort to treat GER-derived respiratory distresses has got off to an encouraging start amid relative shortage of experience and facilities. We would like to share two thoughts with scholars and experts at home and abroad:1. The GER-derived asthma is not asthma, but GER pure and simple;2. The pathogenesis of “asthma” is not asthma, but laryngotracheal irritation/spasm and its sequence.

关键词： laryngotracheal irritation/spasm     gastro-oesophago-laryngo-tracheal     sequence     fundaplication     encouraging    

HTML PDF 收藏

Insult of gastroesophageal reflux on airway: clinical significance of pharyngeal nozzle

null

《医学前沿（英文）》 2015年 第9卷 第1期   页码 117-122 doi: 10.1007/s11684-014-0343-1

摘要：

At the very time of global paying the highest attention to the worst insults of smoking as well as haze on the airway, everybody knows both are exogenous and noticeable. However, people mostly, including many medical personnel, do not know how badly the gastroesophageal reflux (GER) insults on our own airway. Symptoms of GER are commonly seen as heartburn and regurgitation, which can be mostly tolerated. However, when the up going gastric content reversely passes the esophagus and then the distal pharynx, where it appears a beak like stricture, serving as a nozzle, so as to produce numerous micro-particles and reach the oro-nasal cavity and also the airway causing allergic rhinitis and asthmatic attacks, even pulmonary parenchyma lesions. It will reduce life quality or even jeopardize life. The point that the endogenous insult appears in the respiratory system, but originates from the digestive tract is not well known and often undiagnosed and not correctly treated. The GER induced airway challenge is a treatable and preventive entity, as soon as a diagnosis is made, a good relief could be expected by means of life style adjustment, medicine, or fixation of the patulous cardia through radiofrequency or fundoplication. The author Dr. Zhonggao Wang had suffered it for long and symptoms disappeared for 8 years after anti-reflux surgery. Here is a presentation of Dr. Zhonggao Wang and his team’s work and would call attention to the public so as to recognize this relatively unknown entity — a treatable condition occurring from human itself, but not from outside surroundings as smoking or haze does.

关键词： gastroesophageal reflux     airway     pharyngeal nozzle     micro-aspiration     asthma    

HTML PDF 收藏

Research progress on low dielectric constant modification of cellulose insulating paper for power transformers

《化学科学与工程前沿（英文）》 2023年 第17卷 第8期   页码 991-1009 doi: 10.1007/s11705-022-2259-7

摘要： Because of the increase in the transmission voltage levels, the demand for insulation reliability of power transformers has increasingly become critical. Cellulose insulating paper is the main insulating component of power transformers. To improve the insulation level of ultrahigh voltage transformers and reduce their weight and size, reducing the dielectric constant of oil-immersed cellulose insulating paper is highly desired. Cellulose is used to produce power-transformer insulating papers owing to its excellent electrical properties, renewability, biodegradability and abundance. The dielectric constant of a cellulose insulating paper can be effectively reduced by chemical or physical modification. This study presents an overview of the foreign and domestic research status of the use of modification technology to reduce the dielectric constant of cellulose insulating papers. All the mentioned methods are analyzed in this study. Finally, some recommendations for future modified cellulose insulating paper research and applications are proposed. This paper can provide a reference for further research on low dielectric constant cellulose insulating paper in the future.

关键词： low dielectric constant     chemical and physical modification     cellulose insulating paper     transformer     nanomaterials.    

HTML PDF 收藏

Analysis and characterization of wind-solar-constant torque spring hybridized model

Shantanu ACHARYA,Subhadeep BHATTACHARJEE

《能源前沿（英文）》 2014年 第8卷 第3期   页码 279-289 doi: 10.1007/s11708-014-0312-z

摘要： Solar and wind are the most promising renewable energy resources. But their unpredictable and varying nature prevents them from being used as the sole resource for power generation. This paper presents a model of wind and solar thermal hybrid power plant with a spring storage system which is expected to play an efficient role in combating with the drawbacks related to renewable power generation. In the proposed scheme, wind energy is harnessed by a hybrid vertical axis wind turbine, solar energy is utilized by a Stirling engine, and the surplus energy is stored in a winding spring. The paper discusses the working methodologies and analyses the performance of such 2.6 kW hybrid power plant model. It has been observed that the plant is capable of consistently generating 50% of its rated capacity irrespective of limitations in solar and wind resources.

关键词： hybrid vertical axis wind turbine     Stirling engine     solar-thermal energy     wind energy     constant torque spring    

HTML PDF 收藏

Development of a fan-stirred constant volume combustion chamber and turbulence measurement with PIV

《能源前沿（英文）》 2022年 第16卷 第6期   页码 973-987 doi: 10.1007/s11708-021-0762-z

摘要： A fan-stirred combustion chamber is deve-loped for spherically expanding flames, with P and T up to 10 bar and 473 K, respectively. Turbulence characteristics are estimated using particle image velocimetry (PIV) at different initial pressures (P = 0.5–5 bar), fan frequencies (ω = 0–2000 r/min), and impeller diameters (D = 100 and 114 mm). The flame propagation of methanol/air is investigated at different turbulence intensities (u′=0–1.77 m/s) and equivalence ratios (φ = 0.7–1.5). The results show that u′ is independent of P and proportional to ω, which can be up to 3.5 m/s at 2000 r/min. LT is independent of P and performs a power regression with ω approximately. The turbulent field is homogeneous and isotropic in the central region of the chamber while the inertial subrange of spatial energy spectrum is more collapsed to –5/3 law at a high ReT. Compared to laminar expanding flames, the morpho-logy of turbulent expanding flames is wrinkled and the wrinkles will be finer with the growth of turbulence intensity, consistent with the decline of the Taylor scale and the Kolmogorov scale. The determined SL in the present study is in good agreement with that of previous literature. The SL and ST of methanol/air have a non-monotonic trend with φ while peak ST is shifted to the richer side compared to SL. This indicates that the newly built turbulent combustion chamber is reliable for further experimental study.

关键词： fan-stirred combustion chamber     turbulence characteristics     particle image velocimetry (PIV)     methanol     turbulent expanding flames    

HTML PDF 收藏

Effect of laparoscopic fundoplication treatment on gastroesophageal reflux disease-related respiratory

Zhong-Gao WANG MD, FACS, Feng JI MD, PhD, Yun-Gang LAI MD, PhD, Xiang GAO MD, PhD, Cheng-Chao ZHANG MD, PhD, Ji-Min WU MD, PhD, Xiu CHEN MD, PhD, Ibrahim M. IBRAHIM MD, FACS,

《医学前沿（英文）》 2010年 第4卷 第2期   页码 254-258 doi: 10.1007/s11684-010-0029-2

摘要： Gastroesophageal reflux disease (GERD) was diagnosed and fundoplication was performed, which relieved the symptoms. This paper explores the effect of fundoplication on GERD-related respiratory symptoms. From January 2007 to October 2008, 64 patients with respiratory symptoms related to GERD were consecutively enrolled for laparoscopic fundoplication. Of these, 60 patients had respiratory symptoms mainly combined with gastroesophageal reflux, while four had respiratory symptoms only. All patients had GERD confirmed, and medical treatment provided before surgery resulted in an insufficiently favorable effect or even producing further complications. All the patients were requested to fill a questionnaire form regarding the severity of symptoms and their medication so as to make an evaluation score for the follow-up. The outcome of respiratory symptoms after surgery was as follows: excellent in 23 cases (35.9%); good in 28 (43.8%); fair in 5 (7.8%); poor in 8 (12.5%). The mean respiratory symptom score decreased from 6.3±2.65 to 2.33±2.37. Laparoscopic fundoplication can be an effective treatment for the majority of patients with GERD-related respiratory symptoms.

关键词： gastroesophageal reflux disease     pH monitoring     laparoscopic fundoplication     respiratory symptom    

HTML PDF 收藏

Solar photovoltaic fed dual input LED lighting system with constant illumination control

Kinattingal SUNDARESWARAN,Kevin Ark KUMAR,Payyalore Raman VENKATESWARAN,Sankaran PALANI

《能源前沿（英文）》 2016年 第10卷 第4期   页码 473-478 doi: 10.1007/s11708-016-0420-z

摘要： A dual input LED lighting scheme with constant illumination is proposed in this paper. The scheme employs a photovoltaic array as the first input and a battery as the second one. A microcontroller is programmed to operate a changeover switch as well as a DC-DC converter for uninterrupted and constant illumination in work place. The scheme is suitable for conference halls, laboratories, clean rooms, marriage halls, theaters, etc. The complete modeling, design and experimentation of the proposed scheme are explained and the economic viability of the scheme is justified.

关键词： photovoltaic     LED light     dual input     P&O algorithm    

HTML PDF 收藏

Outcome of Stretta radiofrequency and fundoplication for GERD-related severe asthmatic symptoms

null

《医学前沿（英文）》 2015年 第9卷 第4期   页码 437-443 doi: 10.1007/s11684-015-0422-y

摘要：

This study aimed to investigate the outcome of treatment with Stretta radiofrequency (SRF) or laparoscopic Nissen fundoplication (LNF). A total of 137 gastroesophageal reflux disease (GERD) patients with severe asthmatic symptoms who responded inadequately to medical treatment for asthma were investigated. The patients were followed up 1 year and 5 years after SRF (n = 82) or LNF (n = 55) treatment. A questionnaire covering 29 related symptoms and medication use was employed. Digestive, respiratory, and ear-nose-throat (ENT) symptom scores significantly decreased after antireflux treatment. Symptom scores respectively changed from 17.2±10.1, 31.9±6.6, and 21.1±11.8 to 5.0±6.2, 11.5±10.2, and 6.3±6.8 at 1 year and to 5.6±6.5, 13.1±10.1, and 7.8±7.2 at 5 years (P <0.001). The outcome of LNF was significantly better than that of SRF in terms of digestive (P <0.001, P = 0.001), respiratory (P = 0.006, P = 0.001), and ENT symptoms (P = 0.006, P = 0.003) at both 1 year and 5 years. SRF and LNF were both effective against the digestive symptoms of GERD as well as GERD-related severe asthmatic and ENT symptoms, with better outcomes exhibited by the LNF group. Severe asthmatic symptoms and GERD were closely associated, and this finding warrants further study.

关键词： asthma     gastroesophageal reflux     Stretta radiofrequency     laparoscopic Nissen fundoplication    

HTML PDF 收藏

用经典力学计算氢分子的键长键能及力常数

陈景

《中国工程科学》 2003年 第5卷 第6期   页码 39-43

摘要：

氢原子中1 s电子的电子云呈球形，电子的最大几率密度分布出现在玻尔半径a0的球壳内，认为几率密度分布及电子云属统计规律，意味着已经使用了宏观时标，这样就使氢分子体系中能量和时间的作用量远大于普郎克常数；根据电子云的交叠，用经典力学计算了基态氢分子的结构常数，获得键长、键能及力常数的表达式分别为Re = 〓a0，De = ze/4〓a0,k = ze/2〓，采用原子单位（a.u.）时z、e及a0均为1，获得Re=1.414 a.u.，De=0.177 a.u.，k=0.354 a.u.，这些数值与实验值的相对误差分别<1%，<2%和<4%；成键模型直观，物理意义明确，计算中不含任何人为性参数。

关键词： 氢分子     键长     键能     力常数    

HTML PDF 收藏

新型双馈变速凸极同步电机

宁玉泉

《中国工程科学》 2004年 第6卷 第12期   页码 27-31

摘要：

提出一种新型双馈变速凸极同步电机，阐述了它的基本原理和结构，电机的转子采用分裂磁极和正交绕组, 结构简单、可靠。转子绕组由低频交流变频电源供电，使电机具有变速恒频的特性。通过原型样机的试验，验证了该项发明的正确性和实用性，它将在大型水电、风电中得到广泛应用。

关键词： 凸极同步电机 变速恒频 交流励磁 双馈    

HTML PDF 收藏

Constant temperature control of tundish induction heating power supply for metallurgical manufacturing

Yufei YUE, Qianming XU, Peng GUO, An LUO

《能源前沿（英文）》 2019年 第13卷 第1期   页码 16-26 doi: 10.1007/s11708-018-0572-0

摘要： The tundish induction heating power supply (TIHPS) is one of the most important equipment in the continuous casting process for metallurgical manufacturing. Specially, the constant temperature control is greatly significant for metallurgical manufacturing. In terms of the relationship between TIH load temperature and output power of TIHPS, the constant temperature control can be realized by power control. In this paper, a TIHPS structure with three-phase PWM rectifiers and full-bridge cascaded inverter is proposed. Besides, an input harmonic current blocking strategy and a load voltage feedforward control are also proposed to realize constant temperature control. To meet the requirement of the system, controller parameters are designed properly. Experiments are conducted to validate the feasibility and effectiveness of the proposed TIHPS topology and the control methods.

关键词： tundish induction heating power supply (TIHPS)     constant temperature control     input harmonic current blocking     load voltage feedforward    

HTML PDF 收藏

Seismic response of precast reinforced concrete wall subjected to cyclic in-plane and constant out-of-plane

《结构与土木工程前沿（英文）》 2021年 第15卷 第5期   页码 1128-1143 doi: 10.1007/s11709-021-0753-5

摘要： This paper provides insight into the seismic behavior of a full-scale precast reinforced concrete wall under in-plane cyclic loading combined with out-of-plane loading replicated by sand backfill to simulate the actual condition of basement walls. The tested wall exhibited flexural cracks, owing to the high aspect ratio and considerable out-of-plane movement due to lateral pressure from the backfill. The wall performed satisfactorily by exhibiting competent seismic parameters and deformation characteristics governed by its ductile response in the nonlinear phase during the test with smaller residual drift. Numerical analysis was conducted to validate experimental findings, which complied with each other. The numerical model was used to conduct parametric studies to study the effect of backfill density and aspect ratio on seismic response of the proposed precast wall system. The in-plane capacity of walls reduced, while deformation characteristics were unaffected by the increase in backfill density. An increase in aspect ratio leads to a reduction in in-plane capacity and an increase in drift. Curves between the ratio of in-plane yield capacity and design shear load of walls are proposed for the backfill density, which may be adopted to determine the in-plane yield capacity of the basement walls based on their design shear.

关键词： precast wall     basement wall     out-of-plane response     quasi-static test     sand backfill     seismic parameters    

HTML PDF 收藏

Convective heat transfer in helical coils for constant-property and variable-property flows with high

Yufei MAO, Liejin GUO, Bofeng BAI, Ximin ZHANG

《能源前沿（英文）》 2010年 第4卷 第4期   页码 546-552 doi: 10.1007/s11708-010-0116-8

摘要： Forced convection heat transfer of single-phase water in helical coils was experimentally studied. The testing section was constructed from a stainless steel round tube with an inner diameter of 10 mm, coil diameter of 300 mm, and pitch of 50 mm. The experiments were conducted over a wide Reynolds number range of 40000 to 500000. Both constant-property flows at normal pressure and variable-property flows at supercritical pressure were investigated. The contribution of secondary flow in the helical coil to heat transfer was gradually suppressed with increasing Reynolds number. Hence, heat transfer coefficients of the helical tube were close to those of the straight tube under the same flow conditions when the Reynolds number is large enough. Based on the experimental data, heat transfer correlations for both incompressible flows and supercritical fluid flows through helical coils were proposed.

关键词： convective heat transfer     helical coils     high Reynolds number     supercritical pressure     variable property    

HTML PDF 收藏

标题 作者 时间 类型 操作

The energy consumption in a batch stripper and a batch rectifier

Xianbao CUI, Tianyang FENG, Ying ZHANG, Zhicai YANG,

期刊论文

Improved control of hypertension following laparoscopic fundoplication for gastroesophageal reflux disease

null

期刊论文

A belated revelation: from gastroesophageal reflux derived asthma to laryngotracheal irritation even

WANG Zhonggao

期刊论文

Insult of gastroesophageal reflux on airway: clinical significance of pharyngeal nozzle

null

期刊论文

Research progress on low dielectric constant modification of cellulose insulating paper for power transformers

期刊论文

Analysis and characterization of wind-solar-constant torque spring hybridized model

Shantanu ACHARYA,Subhadeep BHATTACHARJEE

期刊论文

Development of a fan-stirred constant volume combustion chamber and turbulence measurement with PIV

期刊论文

Effect of laparoscopic fundoplication treatment on gastroesophageal reflux disease-related respiratory

Zhong-Gao WANG MD, FACS, Feng JI MD, PhD, Yun-Gang LAI MD, PhD, Xiang GAO MD, PhD, Cheng-Chao ZHANG MD, PhD, Ji-Min WU MD, PhD, Xiu CHEN MD, PhD, Ibrahim M. IBRAHIM MD, FACS,

期刊论文

Solar photovoltaic fed dual input LED lighting system with constant illumination control

Kinattingal SUNDARESWARAN,Kevin Ark KUMAR,Payyalore Raman VENKATESWARAN,Sankaran PALANI

期刊论文

Outcome of Stretta radiofrequency and fundoplication for GERD-related severe asthmatic symptoms

null

期刊论文

用经典力学计算氢分子的键长键能及力常数

陈景

期刊论文

新型双馈变速凸极同步电机

宁玉泉

期刊论文

Constant temperature control of tundish induction heating power supply for metallurgical manufacturing

Yufei YUE, Qianming XU, Peng GUO, An LUO

期刊论文

Seismic response of precast reinforced concrete wall subjected to cyclic in-plane and constant out-of-plane

期刊论文

Convective heat transfer in helical coils for constant-property and variable-property flows with high

Yufei MAO, Liejin GUO, Bofeng BAI, Ximin ZHANG

期刊论文