期刊文献+
共找到2,120篇文章
< 1 2 106 >
每页显示 20 50 100
Gestational diabetes mellitus combined with fulminant type 1 diabetes mellitus, four cases of double diabetes: A case report
1
作者 Hui Li Yun Chai +6 位作者 Wei-Hong Guo Yu-Meng Huang Xiao-Na Zhang Wen-Li Feng Qing He Jin Cui Ming Liu 《World Journal of Clinical Cases》 SCIE 2024年第4期787-794,共8页
BACKGROUND Fulminant type 1 diabetes mellitus(FT1DM)that occurs during pregnancy or the perinatal period is known as pregnancy-related FT1DM(PF),always without history of abnormal glucose metabolism.Here,we present fo... BACKGROUND Fulminant type 1 diabetes mellitus(FT1DM)that occurs during pregnancy or the perinatal period is known as pregnancy-related FT1DM(PF),always without history of abnormal glucose metabolism.Here,we present four patients who developed FT1DM during treatment but were first diagnosed with gestational diabetes mellitus(GDM).CASE SUMMARY The clinical data of four patients with GDM combined with FT1DM admitted to our hospital between July 2018 and April 2021 were collected,and the patients and their infants were followed up.All patients were diagnosed with GDM during the second trimester and were treated.The blood glucose level elevated suddenly during the third trimester and then were diagnosed with FT1DM.Two patients had an insulin allergy,and two had symptoms of upper respiratory tract infection before onset.One patient developed ketoacidosis,and three developed ketosis.Two patients had cesarean section deliveries,and two had vaginal deliveries.The growth and development of the infants were normal.C-peptide levels were lower than those at onset,suggesting progressive impairment of islet function.The frequencies of the DRB109:01,DQB103:03,DQA103:02,DPA101:03,DPA102:02,DPB105:01,DRB401:03,G 01:01,and G 01:04 human leukocyte antigen(HLA)-G alleles were high in the present study.CONCLUSION In comparison with pregnancy-associated FT1DM(PF),patients with GDM combined with FT1DM had an older age of onset,higher body mass index,slower onset,fewer prodromal symptoms,and less acidosis.The pathogenesis may be due to various factors affecting the already fragileβ-cells of GDM patients with genetically susceptible class II HLA genotypes.We speculate that GDM combined with FT1DM during pregnancy,referred to as“double diabetes,”is a subtype of PF with its own unique characteristics that should be investigated further. 展开更多
关键词 Fulminant type 1 diabetes mellitus Gestational diabetes mellitus Pregnancy-related fulminant type 1 diabetes mellitus double diabetes Case report
下载PDF
Treatment of Complex Proximal Tibial Fractures (Types V &VI of Schautzker Classification) by Double Plate Fixation with Single Anterior Incision 被引量:3
2
作者 Ebrahim Ghayem Hassankhani Farzad Omidi Kashani Golnaz Ghayem Hassankhani 《Open Journal of Orthopedics》 2013年第4期208-212,共5页
Background: complex proximal tibial fractures (Types V & VI of Schautzker classification) are the major problems in orthopedic surgery and associated with high complication rates. There are many alternatives in tr... Background: complex proximal tibial fractures (Types V & VI of Schautzker classification) are the major problems in orthopedic surgery and associated with high complication rates. There are many alternatives in treatment of these fractures. Aim: to evaluate the results of double plating with single anterior incision in complex proximal tibial fractures (Types V& VI of Schautzker classification).Methods and Materials: 22 patients (16 males and 6 females) with Types V and VI of Schautzker classification of proximal tibial fractures (14 cases were Type V and 8 cases were Type VI) were treated by double plating with single anterior incision method between May 2006 and May 2011. The bony and functional outcome was evaluated according to Knee Society Score. Results: According to Knee Society Score, the results were as follows: excellent in 19 patients (86.4%), good in 2 patients (9.1%), fair in 1 patient (4/5%), and poor in no patient (0%).Conclusion: the double plate fixation with single anterior incision is the best, effective and simple procedure in treatment of complex proximal tibial fractures (Types V and VI of Schautzker classification). 展开更多
关键词 Proximal Tibial Fractures typeS V & VI of Schautzker CLASSIFICATION double Plate Fixation SINGLE ANTERIOR INCISION
下载PDF
Double filtration plasmapheresis for pregnancy with hyperlipidemia in glycogen storage disease type Ia:A case report 被引量:1
3
作者 Jie Wang Yi Zhao +2 位作者 Pan Chang Bin Liu Rong Yao 《World Journal of Clinical Cases》 SCIE 2022年第28期10273-10278,共6页
BACKGROUND Glycogen storage disease type Ia(GSDIa) is an autosomal recessive inborn error of carbohydrate metabolism that is caused by deficiency of the enzyme glucose-6-phosphatase(G6Pase),leading to disturbed glycog... BACKGROUND Glycogen storage disease type Ia(GSDIa) is an autosomal recessive inborn error of carbohydrate metabolism that is caused by deficiency of the enzyme glucose-6-phosphatase(G6Pase),leading to disturbed glycogenolysis and gluconeogenesis.Patients with GSDIa show severe fasting hypoglycemia,hyperlipidemia,hyperlactacidemia,and hyperuricemia,which are associated with fatal outcomes in pregnant women and fetuses.CASE SUMMARY Herein,we report the case of a 24-year-old female who on her first visit to the hospital,presented with pregnancy combined with extremely high hyperlipidemia and hyperlactic acidosis with anemia,and frequent hypoglycemia occurred during the treatment.Genetic tests revealed a mutation in the G6Pase gene(G6PC) at 17q21,the patient was finally diagnosed with glycogen storage disease type Ia for the first time after 22 years of inaccurate treatment.She has been treated with a continuous double filtration plasmapheresis(DFPP) strategy to remove blood lipids,and a cornstarch diet therapy.The patient did not develop pancreatitis during the course of the disease and a healthy baby girl weighing 3 kg was delivered.CONCLUSION Patients with GSDIa may be misdiagnosed as epilepsy.DFPP can be used to control hyperlipidemia in GSDIa patients during pregnancy. 展开更多
关键词 Glycogen storage disease type Ia PREGNANCY HYPERLIPIDEMIA double filtration plasmapheresis Case report
下载PDF
Double-directional control bolt support technology and engineering application at large span Y-type intersections in deep coal mines 被引量:13
4
作者 GUO, Zhibiao SHI, Jianjun +2 位作者 WANG, Jiong CAI, Feng WANG, Fuqiang 《Mining Science and Technology》 EI CAS 2010年第2期254-259,共6页
Under deep and complex geological conditions,severe deformation occurs at intersection points of Y-type roadways with large cross sections during engineering projects in coal mines,especially at junction arches.Based ... Under deep and complex geological conditions,severe deformation occurs at intersection points of Y-type roadways with large cross sections during engineering projects in coal mines,especially at junction arches.Based on in-situ investigations and theoretical studies,we have summarized typical forms of destruction and identified high stress and unrestricted support at both sides of junction arch as its main causes.In this study,we also presented double-directional control bolt support technology for a large Y-type span intersection,applied to deep intersection engineering in the Jiahe Coal Mine,which has proved effective. 展开更多
关键词 Y-type intersection double-directional control bolt support deep coal mines
下载PDF
EFFICIENCY ANALYSIS OF DOUBLE CRANK RING-PLATE-TYPE PIN-CYCLOIDAL GEAR PLANETARY DRIVE 被引量:5
5
作者 LiXin HeWeidong +1 位作者 LindaSchmidt LiLixing 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2003年第3期252-255,共4页
From the general formula for calculating the efficiency of planetary geartrains, the efficiency of the double crank ring-plate-type pin-cycloidal gear planetary drive isderived. To prove the theory, an experimental st... From the general formula for calculating the efficiency of planetary geartrains, the efficiency of the double crank ring-plate-type pin-cycloidal gear planetary drive isderived. To prove the theory, an experimental study has been conducted. The tested value of theefficiency of a sample set of the new-type drive in the experiment agrees with the calculated one.It shows that the new-type drive is of not merely high bearing capacity, but also quite highefficiency. 展开更多
关键词 double crank ring-plate-type Pin-cycloidal gear planetary drive Meshefficiency
下载PDF
Mathematical Model and Geometrical Model of Double Pitch ZN-type Worm Gear Set Based on Generation Mechanism 被引量:2
6
作者 SHU Linsen CAO Huajun +2 位作者 LI Xianchong ZHANG Chenglong LI Yuxia 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第3期549-555,共7页
The current researches on the tooth surface mathematical equations and the theory of gearing mainly pay attention to the ordinary type worm gear set(e.g., ZN, ZA, or ZK). The research of forming mechanism and three-... The current researches on the tooth surface mathematical equations and the theory of gearing mainly pay attention to the ordinary type worm gear set(e.g., ZN, ZA, or ZK). The research of forming mechanism and three-dimensional modeling method for the double pitch worm gear set is not enough. So there are some difficulties in mathematical model deducing and geometry modeling of double pitch ZN-type worm gear set based on generation mechanism. In order to establish the mathematical model and the precise geometric model of double pitch ZN-type worm gear set, the structural characteristics and generation mechanism of the double pitch ZN-type worm gear set are investigated. Mathematical model of the ZN-type worm gear set is derived based on its generation mechanism and the theory of gearing. According to the mathematical model of the worm gear set which has been developed, a geometry modeling method of the double pitch ZN-type worm and worm gear is presented. Furthermore, a geometrical precision calculate method is proposed to evaluate the geometrical quality of the double pitch worm gear set. As a result, the maximum error is less than 6′10–4 mm in magnitude, thus the model of the double pitch ZN-type worm gear set is available to meet the requirements of finite element analysis and engineering application. The derived mathematical model and the proposed geometrical modeling method are helpful to guiding the design, manufacture and contact analysis of the worm gear set. 展开更多
关键词 double pitch ZN-type worm gear set generation mechanism mathematical model geometrical model
下载PDF
On Fatou Type Convergence of Convolution Type Double Singular Integral Operators
7
作者 Harun Karsli 《Analysis in Theory and Applications》 CSCD 2015年第3期307-320,共14页
In this paper, some approximation formulae for a class of convolution type double singular integral operators depending on three parameters of the type(T_λf)(x, y) = ∫_a^b ∫_a^b f(t, s)K_λ(t-x,s-y)dsdt, x,y ∈(a,... In this paper, some approximation formulae for a class of convolution type double singular integral operators depending on three parameters of the type(T_λf)(x, y) = ∫_a^b ∫_a^b f(t, s)K_λ(t-x,s-y)dsdt, x,y ∈(a,b), λ ∈ Λ [0,∞),(0.1)are given. Here f belongs to the function space L_1( <a,b >~2), where <a,b> is an arbitrary interval in R. In this paper three theorems are proved, one for existence of the operator(T_λf)(x, y) and the others for its Fatou-type pointwise convergence to f(x_0, y_0), as(x,y,λ) tends to(x_0, y_0, λ_0). In contrast to previous works, the kernel functions K_λ(u,v)don't have to be 2π-periodic, positive, even and radial. Our results improve and extend some of the previous results of [1, 6, 8, 10, 11, 13] in three dimensional frame and especially the very recent paper [15]. 展开更多
关键词 Fatou-type convergence convolution type double singular integral operators μgeneralized Lebesgue point
下载PDF
New Pyrometer with Double Y-type Optical Fibers
8
作者 SHI Weidong, LI Zhiquan, TANG Xuhui, JIANG Wanlu(Yanshan University, Qinhuangdao 066004, CHN) 《Semiconductor Photonics and Technology》 CAS 1997年第1期40-43,49,共5页
Abstract: A new pyrometer, which can solve the affection of emissivity change in temperature measuring, has been developed by double Y - type optical fibers. The mathematical model of the new pyrometer is presented an... Abstract: A new pyrometer, which can solve the affection of emissivity change in temperature measuring, has been developed by double Y - type optical fibers. The mathematical model of the new pyrometer is presented and the errors of the new pyrometer are analyzed. 展开更多
关键词 EMISSIVITY double Y - type Optical Fibers PYROMETER
下载PDF
New Double Integrals Weighted Cebysev Type Inequalities
9
作者 A. Guezane-Lakoud F. Aissaoui 《Journal of Mathematics and System Science》 2012年第5期286-291,共6页
In the last years, the theory of integral inequalities are playing a very significant role in all fields of mathematics, many monographs have been devoted to this subject and present a very active and attractive field... In the last years, the theory of integral inequalities are playing a very significant role in all fields of mathematics, many monographs have been devoted to this subject and present a very active and attractive field of research, the applications of integral inequalities have known a great development in many branches of mathematics in statistics, differential equations and numerical integration, The aim of this paper is to establish new extension of the weighted montgomery identity for double integrals then used it to establish new t^eby^evtype inequalities. 展开更多
关键词 Cebysev type inequalities montgomery identity weighted peanokemel double integrals Cebysevinequalities weightedtCebysev inequalities ostrowski inequality.
下载PDF
A New Type of Double-Lumen Catheter to Replace Current One in RCA 被引量:1
10
作者 Yingfeng Xue Zhenguo Yu 《International Journal of Clinical Medicine》 2016年第9期620-627,共8页
Objective: To replace the peripheral venous puncture for blood sampling with taking blood samples extracorporally from arterial line before predilution during RCA-CRRT performed. Methods: A new type of double-lumen fe... Objective: To replace the peripheral venous puncture for blood sampling with taking blood samples extracorporally from arterial line before predilution during RCA-CRRT performed. Methods: A new type of double-lumen femoral catheter was used instead of the current tubes. The new type of double-lumen tube had a greater distance from the inner venous ports to the inner arterial ports than current tubes. The minimum distance from the venous port to the arterial port was greatly lengthened. Replacement solution contained citrate, zero Ca<sup>2+</sup>, zero bicarbonate, low Na<sup>+</sup>. Blood samples were synchronously collected from the arterial line before the infusion of citrate replacement fluid and from the peripheral vein. The iCa concentration data of two groups were analyzed to observe the difference between iCa concentration levels in the arterial line and in peripheral vein;the anticoagulant effect of RCA and possible complications were observed, such as bleeding, clottings and hypocalcaemia. Results: 28 times of RCA-CRRT were performed on17 AKI and CRF patients with active bleeding or at the high risk of bleeding;336 blood samples were collected. Statistics showed that the difference of iCa concentration between arterial line group and the peripheral vein group was not significant (P = 0.9), there is a high degree of similarity between the iCa concentration of arterial line blood and the peripheral venous blood. None of the patients developed citrate toxicity or metabolic alkalosis. None induced bleeding, or bleeding aggravated. No obvious clotting occurred. Systemic calcium concentration was achieved in the ideal range. Conclusion: In clinical practice, the data of iCa concentration from arterial line can be used to replace that from peripheral vein when the new type of double-lumen femoral catheter is placed in femoral vein. RCA-CRRT therapy is safe and effective. 展开更多
关键词 RCA-CRRT Ionized Calcium Arterial Line Peripheral Vein New type of double-Lumen Femoral Catheter
下载PDF
Interlayer distance effects on absorption coefficient and refraction index change in p-type double-δ-doped GaAs quantum wells
11
作者 H Noverola-Gamas L M Gaggero-Sager O Oubram 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第12期186-190,共5页
In the framework of the Thomas–Fermi(TF) approach, a model for the p-type double-δ-doped(DDD) system in Ga As is presented. This model, unlike other works in the literature, takes into account that the Poisson equat... In the framework of the Thomas–Fermi(TF) approach, a model for the p-type double-δ-doped(DDD) system in Ga As is presented. This model, unlike other works in the literature, takes into account that the Poisson equation associated with the system is nonlinear. The electronic structure is calculated for heavy and light holes. The changes in the electronic structure result of the distance d between the doped layers are studied. In particular, the relative absorption coefficient as well as the relative refractive index change is calculated as a function of the incident photon energy for heavy holes. The effect of the interlayer distance exhibits, in the absorption coefficient, a red shift of the peak position and a decrease in amplitude when the distance increases. In addition, the relative refractive index change node has a red shift as well as the interlayer distance increases. The calculations show that the effect of the separation between layers has a greater influence on the linear terms. These results are very important for theoretical calculations and engineering of optical and electronic devices based in δ-doped Ga As. 展开更多
关键词 double delta-doping p-type GaAs layers electronic structure Thomas–Fermi approach nonlinear optical properties
下载PDF
Research and Exploration on the Construction of Double Qualified Teachers in Software Engineering 被引量:1
12
作者 Yili Li Guobin Zhu +1 位作者 Man Fang Jimin Shi 《计算机教育》 2021年第12期121-125,共5页
In order to solve the problem of insufficient integration of school-enterprise supervisors in the current school-enterprise cooperation model,this article introduces the ideas and results of the construction of a team... In order to solve the problem of insufficient integration of school-enterprise supervisors in the current school-enterprise cooperation model,this article introduces the ideas and results of the construction of a team with double-qualified instructors majored in software engineering.Specifically,the integration of production and education are carried out in three stages,i.e.,enterprise cooperation courses,enterprise internship,and graduation design(internship),by taking the software engineering major of the School of Information and Software Engineering of the University of Electronic Science and Technology of China as a case study. 展开更多
关键词 software engineering double qualification type faculty development
下载PDF
On the structure and representations of non-balanced quantum doubles
13
作者 CHEN Li-li LI Fang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2012年第4期475-488,共14页
For a field k and two finite groups G and X, when G acts on X from the right by group automorphisms, there is a Hopf algebra structure on k-space (kX°P)* kG (see Theorem 2.1), called a non-balanced quantum ... For a field k and two finite groups G and X, when G acts on X from the right by group automorphisms, there is a Hopf algebra structure on k-space (kX°P)* kG (see Theorem 2.1), called a non-balanced quantum double and denoted by Dx(G). In this paper, some Hopf algebra properties of Dx (G) are given, the representation types of Dx (G) viewed as a k-algebra are discussed, the algebra structure and module category over Dx(G) are studied. Since the Hopf algebra structure of non-balanced quantum double DX (G) generMizes the usual quantum double D(G) for a finite group G, all results about Dx(G) in this paper can also be used to describe D(G) as a special case and the universal R-matrix of Dx (G) provides more solutions of Yang-Baxter equation. 展开更多
关键词 non-balanced quantum double Hopf Mgebra representation type quasi-triangularity quiver.
下载PDF
On Turán type inequality with doubling weights and A weights
14
作者 虞旦盛 韦宝荣 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第7期764-768,共5页
Let Hn be the set of real algebraic polynomials of degree n, whose zeros all lie in the interval [-1,1]. The well known Turán type inequalities tell us that forf(x)∈Hn, it holds ‖f'‖≥C√n‖f‖. This note d... Let Hn be the set of real algebraic polynomials of degree n, whose zeros all lie in the interval [-1,1]. The well known Turán type inequalities tell us that forf(x)∈Hn, it holds ‖f'‖≥C√n‖f‖. This note deals with the weighted Turán type inequalities with the weights having inner singularities under L^p norm for 0〈p≤∞. Our results essentially extend the result of Wang and Zhou (2002), and the method used in this paper is simpler and more direct than that of Wang and Zhou (2002). The results and methods have their own values in approximation theory and computation. 展开更多
关键词 Turán type inequality doubling weights A weights
下载PDF
Supporting Research for "Double Teachers" Team Construction of School-enterprise Cooperation Take Professional Tourism Management School-enterprise Cooperation "Double" Teachers Construction as An Example
15
作者 Yuxia Chen 《International Journal of Technology Management》 2015年第8期57-59,共3页
This paper mainly studies cooperative education problems of tourism management professional school-enterprise cooperation. Since the 1990s, many universities have begun to explore the issue of school-enterprise cooper... This paper mainly studies cooperative education problems of tourism management professional school-enterprise cooperation. Since the 1990s, many universities have begun to explore the issue of school-enterprise cooperation in running schools, and tourism management major is one of the popular professional cooperative education, there has been various forms of cooperative education, both success and failure cases. Many scholars take in-depth research of the issues and come up with many innovative ideas. Currently, much tourism management major of higher colleges gradually embarked on the road of school-enterprise cooperation. This study is under the background of the booming Chinese tourism higher education, school-enterprises cooperation have continued deepen, from both theoretical and practical aspects have a deep thinking in tourism management professional school-enterprise cooperative education issues systems. 展开更多
关键词 school-enterprise cooperation double type CONSTRUCTION RESEARCH
下载PDF
液晶填充一维阶梯型Double-period结构局域模的调控特性
16
作者 黄志红 《南昌大学学报(理科版)》 CAS 北大核心 2016年第6期536-541,共6页
利用传输矩阵法研究了向列相液晶填充一维阶梯型Double-period第4代准周期结构局域模的电场方向、外界温度调控特性。通过改变电场方向和外界温度,研究该结构透射谱的调控特性。结果表明:温度一定时,液晶的有效折射率都随着夹角θ的增... 利用传输矩阵法研究了向列相液晶填充一维阶梯型Double-period第4代准周期结构局域模的电场方向、外界温度调控特性。通过改变电场方向和外界温度,研究该结构透射谱的调控特性。结果表明:温度一定时,液晶的有效折射率都随着夹角θ的增大而逐渐减小,局域模波长随夹角θ的增大而发生蓝移;当夹角θ接近54°时,向列相液晶的有效折射率与温度呈现近正比线性关系;夹角θ小于54°时,向列相液晶的有效折射率随温度升高而逐渐减小,局域模波长随外界温度(300~378.15K)的升高而发生蓝移;夹角θ大于54°时,随温度升高,向列相液晶的有效折射率先减小后增大,局域模波长先发生蓝移再发生红移。无论是外界温度升高还是电场方向夹角的增大,局域模的调控量始终是减小的,且局域模的调控量与液晶有效折射率差值成正比线性关系。 展开更多
关键词 阶梯型double-period结构 局域模 传输矩阵法 调控量 折射率差值
下载PDF
Control over hysteresis curves and thresholds of optical bistability in different semiconductor double quantum wells
17
作者 Hamedi H R Mehmannavaz M R Afshari Hadi 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第8期373-380,共8页
The effects of optical field on the phenomenon of optical bistability(OB) are investigated in a K-type semiconductor double quantum well(SDQW) under various parametric conditions. It is shown that the OB threshold can... The effects of optical field on the phenomenon of optical bistability(OB) are investigated in a K-type semiconductor double quantum well(SDQW) under various parametric conditions. It is shown that the OB threshold can be manipulated by increasing the intensity of coupling field. The dependence of the shift of OB hysteresis curve on probe wavelength detuning is then explored. In order to demonstrate controllability of the OB in this SDQW, we compare the OB features of three different configurations which could arise in this SDQW scheme, i.e., K-type, Y-type, and inverted Y-type systems. The controllability of this semiconductor nanostructure medium makes the presented OB scheme more valuable for applications in all-optical switches, information storage, and logic circuits of all optical information processing. 展开更多
关键词 optical bistability semiconductor double quantum wells K-type Y-type and inverted Y-type schemes OB threshold intensity
下载PDF
PsychoGrapho: A Double-Blind Cohort Study of Jungian Typology and Handwriting Analysis
18
作者 E. Marcus Barnes Jan Six Raymond C. Hawkins II 《Psychology Research》 2016年第1期50-56,共7页
关键词 心理学 心理学家 理论 研究方法
下载PDF
地浸砂岩型铀矿松散岩层单动双管取心钻具的研制与试验 被引量:1
19
作者 李博 刘晓阳 +2 位作者 王琳 邓氚军 杨爱军 《铀矿地质》 CSCD 2024年第1期181-188,共8页
为解决单管钻具取心工艺方法在深部目的层/矿层等松散岩层取心中存在的取心质量差、取心效率低和操作难度大的问题,开展了地浸砂岩型铀矿松散岩层单动双管钻具的研制和试验。通过设计和改进单动机构、断心结构、液力退心机构和快拆机构... 为解决单管钻具取心工艺方法在深部目的层/矿层等松散岩层取心中存在的取心质量差、取心效率低和操作难度大的问题,开展了地浸砂岩型铀矿松散岩层单动双管钻具的研制和试验。通过设计和改进单动机构、断心结构、液力退心机构和快拆机构,研制了两类分别具有可直接液力退心和快速拆卸功能的SD型单动双管钻具。试验结果表明:SD110型双管钻具可在免拆内管的情况下实现地表快速液力退心,提高双管钻具退心效率;SDKC110型钻具可快速拆装更换内管,实现退心和钻进平行作业。与单管钻具相比,SD系列单动双管钻具在松散岩层的平均回次长度提高28.62%,平均机械钻速提高11.61%;与常规单动双管钻具相比,退心操作时间降低了32.69%。SD系列单动双管钻具适用于在松散破碎地层进行取心钻进应用,可有效提高岩心采取效率和岩心质量。 展开更多
关键词 单动双管钻具 液力退心 快速拆卸 设计与试验
下载PDF
基于双螺旋式加热器的柔性MEMS流量传感器
20
作者 王琪 冯建国 +2 位作者 马渊明 陈兴 许高斌 《传感器与微系统》 CSCD 北大核心 2024年第2期41-44,共4页
针对传统流量传感器的量程限制,提出了一种基于双螺旋结构加热器的柔性基底微机电系统(MEMS)热式流量传感器。在基底上打出均匀通孔阵列以降低热传导损耗,两对测温电阻对称分布在加热器两侧,以获得较宽量程,在微小流量与大流量下均表现... 针对传统流量传感器的量程限制,提出了一种基于双螺旋结构加热器的柔性基底微机电系统(MEMS)热式流量传感器。在基底上打出均匀通孔阵列以降低热传导损耗,两对测温电阻对称分布在加热器两侧,以获得较宽量程,在微小流量与大流量下均表现出较高灵敏度。采用基于惠斯通电桥的检测电路实现输出电压的测量,同时保持加热器与环境温度恒定温差200 K,对电阻自热进行补偿。传感器工作温度-100~400℃,量程为0~60 m/s;低流速下灵敏度约为12.75 V/(m·s^(-1)),分辨率可达0.001 mm/s,高流速下灵敏度约为1.4 mV/(m·s^(-1)),功耗低至1.3 mW。 展开更多
关键词 微机电系统 热流量 双螺旋结构 热温差式 柔性
下载PDF
上一页 1 2 106 下一页 到第
使用帮助 返回顶部