全文获取类型
收费全文 | 122篇 |
免费 | 9篇 |
学科分类
工业技术 | 131篇 |
出版年
2024年 | 3篇 |
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 8篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 11篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 7篇 |
2012年 | 4篇 |
2011年 | 10篇 |
2010年 | 6篇 |
2009年 | 7篇 |
2008年 | 10篇 |
2007年 | 3篇 |
2006年 | 3篇 |
2004年 | 1篇 |
2002年 | 1篇 |
1999年 | 1篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有131条查询结果,搜索用时 281 毫秒
111.
A.C. Mofor A.S. Bakin B. Postels M. Suleiman A. Elshaer A. Waag 《Thin solid films》2008,516(7):1401-1404
We have deposited and characterised ZnO on flexible and transparent plastic polymer. We employed a specially designed vapour phase growth system with elemental sources for zinc and oxygen and deposited thin ZnO films at temperatures below 400 °C. Basic photoluminescence characterisation confirms ZnO. Ohmic contacts were fabricated on these layers and the layers exhibit significantly high electron concentration with carrier mobility μ of up to 10.78 cm2 V−1 s−1. Furthermore, we show how these layers can be processed with conventional device processing techniques. 相似文献
112.
David J. White Mark J. Thompson Muhannad T. Suleiman Vernon R. Schaefer 《Canadian Metallurgical Quarterly》2008,134(4):428-436
Soil movements associated with slope instability induce shear forces and bending moments in stabilizing piles that vary with the buildup of passive pile resistance. For such free-field lateral soil movements, stress development along the pile element is a function of the relative displacement between the soil and the pile. To investigate the effects of relative soil-pile displacement on pile response, large-scale load tests were performed on relatively slender, drilled, composite pile elements (cementitious grout with centered steel reinforcing bar). The piles were installed through a shear box into stable soil and then loaded by lateral translation of the shear box. The load tests included two pile diameters (nominal 115 and 178?mm) and three cohesive soil types (loess, glacial till, and weathered shale). Instrumentation indicated the relative soil-pile displacements and the pile response to the loads that developed along the piles. Using the experimental results, an analysis approach was evaluated using soil p-y curves derived from laboratory undrained shear strength tests. The test piles and analyses helped characterize behavioral stages of the composite pile elements at loads up to pile section failure and also provided a unique dataset to evaluate the lateral response analysis method for its applicability to slender piles. 相似文献
113.
Nafion®‐117 was exposed to supercritical fluid (SCF) CO2 and a cation solution using two different approaches: first was processed with SCF CO2, and then exchanged using six different cations: K+1, Ca+2, Ba+2, Cu+2, Fe+3, and Al+3. The second method performed the cation substitution first, followed by the SCF CO2 processing. The resulting composite membranes were characterized using several techniques: thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transforms infrared spectroscopy (FT‐IR), small angle X‐ray scattering (SAXS), and X‐ray diffraction (XRD). These techniques were used to identify the changes in the chemical and thermal properties of the membranes, as well as to evaluate changes in the resulting morphologies and crystallinities. Proton conductivity and methanol permeability were measured to understand how the different approaches promoted or inhibited the transport of certain substances through the membrane. Significant differences in their thermal, physical and transport properties were observed when Nafion® was processed with SCF CO2 and exchanged with cations. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
114.
This paper used annual time series data over the period 1973–2008 to estimate energy demand functions for South Korea and Indonesian aggregated whole economy and Residential sectors. Furthermore, the underlying energy demand trend (UEDT), which may be non-linear and reflects not only technical progress, which usually produces greater energy efficiency, but also other factors such as changes in consumer tastes and the economic structure that may be working in the opposite direction, is also examined in the paper. In estimating the price and income elasticities, the study applies Harvey’s structural time series approach where a stochastic trend is used as a proxy for UEDT. Empirical evidence from this study reveals that the estimated long-run income and price elasticities range from 0.58 to 1.15 and from −0.09 to −066, respectively. Furthermore the stochastic form for the UEDT is preferred for both countries and sectors, suggesting a wide variation in the exogenous effects of energy saving technical progress in addition to other pertinent exogenous factors such as economic structure, consumer preferences, and socio-economic influences. 相似文献
115.
MY Suleiman AN Passannante RL Onder WF Greene-Helms SG Perretta 《Canadian Metallurgical Quarterly》1997,84(5):1076-1080
The cardiovascular consequences of epidural anesthesia secondary to sympathetic blockade are well documented; however, their repercussions on renal hemodynamics in humans have not been reported. We investigated the effect of epidural anesthesia on renal blood flow (RBF) in 13 healthy volunteers 18-45 yr of age. RBF was measured using paraaminohippurate clearance before and after bilateral T6 epidural sensory block (to ensure adequate sympathetic renal nerve blockade). Epidural anesthesia was established using 22 +/- 3 mL of 2% plain lidocaine (without epinephrine) via L1-L2 epidural catheter; urine output was measured using a three-way Foley catheter. Mean arterial pressure remained > or = 70 mm Hg in all subjects without any pharmacologic intervention. Mean RBF before epidural anesthesia was 16.1 +/- 6.8 mL.kg-1.min-1 and 14.3 +/- 2.9 mL.kg-1.min-1 after bilateral T6 epidural blockade. We conclude that the institution of epidural anesthesia in healthy subjects does not result in a significant change in RBF (P > 0.25). 相似文献
116.
Rami K. Suleiman 《Journal of Adhesion Science and Technology》2020,34(12):1315-1330
AbstractA hybrid organic–inorganic sol–gel coating was successfully prepared and subsequently functionalized individually with five different metal oxide additives. The effect of the incorporated oxides on the corrosion protection performance and scratch-resistance properties of the hybrid base coating on mild steel substrates was investigated using electrochemical techniques, namely electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) as well as mechanical testing. The steel-coated specimens were immersed in 3.5?wt.% NaCl corrosive medium for two weeks and the results reveal an excellent corrosion protection performance by all coating formulations with a significant high corrosion-resistance property for the sample loaded with molybdenum oxide. Scanning electron microscopy (SEM) images proved the absence of corrosion signs, defects, micro cracks, or delamination on the surface of the coated samples. Compared with the pure hybrid coating, all the metal oxide-embedded coatings (except for the sample loaded with yttrium(III) oxide) show comparable aqueous contact angle values as well as enhanced hardness and adherence properties. No noticeable dependence was observed for the surface roughness parameters as a function of the type of incorporated metal oxide within the sol–gel matrix. Overall, the results of this study demonstrate that metal oxides can be advantageous to the desired properties of hybrid sol–gel coatings applied to steel surfaces. 相似文献
117.
Performance Evaluation and Resource Management of Hierarchical MACRO-/MICRO Cellular Networks using MOSEL-2 总被引:1,自引:1,他引:0
Aymen I. Zreikat Suleiman Yerima Khalid Al-Begain 《Wireless Personal Communications》2008,44(2):153-179
The paper presents a performance evaluation and resource management of hierarchical MACRO-/MICRO cellular networks using the
new Modeling and Evaluation Language (MOSEL-2). MOSEL-2 with new constructs has the ability to find the performance and reliability
modeling and evaluation of systems with exponential and non-exponential distributions. A MACRO/MICRO cell structure is solved
numerically and mathematically in this paper to handle the handoff calls. Additionally, a simulation program is written to
validate these results. In order to reduce the loss probability, a guard channels are introduced at the MICRO cell and channel
reservation at the MACRO cell. Additionally, the concept of queuing is introduced where there is a possibility for the handoff
calls from both MACRO and MICRO layers to be queued when all the resources are occupied. MOSEL-2 is used to find the numerical
solution for this problem with both exponential and general exponential (GE) distribution. The performance analysis show the
efficiency of the proposed scheme to manage the handoff calls and the ability of the suggested scheme to reduce the blocking
probability of handover calls and the loss probability as the main objective is to block the new connection rather than terminating
the ongoing connection as well as balancing the load all over the whole network. It is shown in this paper that there are
a set of important factors that affect the performance, such as: reservation policy, channel allocation, handover ratio, capacity
of the queue and the variation of the inter-arrival times. These factors are discussed via some important performance measures,
such as: new call blocking probability, blocking probability of handover calls, loss probability, utilization and the average
delay of the queue. 相似文献
118.
Sherif S. AbdelSalam Sri Sritharan Muhannad T. Suleiman 《Canadian Metallurgical Quarterly》2010,15(6):749-758
The Federal Highway Administration (FHWA) mandated the use of the load and resistance factor design (LRFD) approach in the U.S. for all new bridges initiated after September 2007. This paper presents the bridge deep foundation practices established through a nationwide survey of more than 30 DOTs in 2008. Highlighted by this study are the benefits of the LRFD as well as how the flexibility of its usage is being exploited in design practice. The study collected information on current foundation practice, pile analysis and design, pile drivability, pile design verification, and quality control. Since this is the first nationwide study conducted on the LRFD topic following the FHWA mandate, the status on the implementation of LRFD for bridge foundation design was also examined. The study found that: (1) more than 50% of the responded DOTs are using the LRFD for pile design, while 30% are still in transition to the LRFD; and (2) about 30% of the DOTs, who use the LRFD for pile foundations, are using regionally calibrated resistance factors to reduce the foundation costs. 相似文献
119.
Mohamed M. Mekkawy David J. White Charles T. Jahren Muhannad T. Suleiman 《Canadian Metallurgical Quarterly》2010,24(2):159-169
Shoulder rutting and pavement edge drop-offs are common performance problems associated with granular shoulders. Being hazardous to drivers and difficult to maintain, such problems require more attention. Shoulder rutting is primarily caused by bearing capacity failure of the subgrade, whereas edge drop-offs develop by surface runoff erosion, vehicle-induced wind erosion, or vehicle off-tracking. Evaluating the performance of several granular shoulders in Iowa revealed that 2/3 of the inspected sections had an edge drop-off greater than 38 mm, while 40% had a subgrade layer with a California bearing ratio less than 10. A high-speed camera was used to study vehicle tire-aggregate interaction upon off-tracking. Off-tracking was found to elevate and displace aggregate particles away from the pavement edge. Based on these findings, six test sections were stabilized and monitored. The granular layer of four sections was stabilized using polymer emulsion, foamed asphalt, Portland cement, and soybean oil. The soft subgrade layer of two sections was stabilized using Class C fly ash and biaxial geogrid. This paper discusses granular shoulder performance problems, the repair and monitoring of six stabilized test sections, and recommendations to improve the long-term performance of granular shoulders. 相似文献
120.
Behavior of Driven Ultrahigh-Performance Concrete H-Piles Subjected to Vertical and Lateral Loadings
Muhannad T. Suleiman Thomas Vande Voort Sri Sritharan 《Canadian Metallurgical Quarterly》2010,136(10):1403-1413
In the United States, an estimated $1 billion is spent annually on repair and replacement of deep foundations. In a recent study, the possibility of using ultrahigh-performance concrete (UHPC) for deep foundation applications was explored with the objectives of increasing the service life of deep foundations supporting bridges to 75 years and reducing maintenance costs. This paper focuses on field evaluation of two UHPC piles and references a steel H-pile. An UHPC pile with an H shape was designed to simplify the process of casting the pile and reduce the volume (i.e., cost) of the material needed to cast the pile. Two instrumented UHPC piles were driven in loess on top of a glacial till clay soil and load tested under vertical and lateral loads. This paper provides a complete set of results for the field investigation conducted on UHPC H-shaped piles. The results presented in this paper prove that the designed UHPC piles can be driven using the same equipment used to drive steel H-piles through hard soil layers without a pile cushion. The vertical load capacity of the UHPC pile was over 80% higher than that of the steel H-piles. 相似文献