首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   72篇
  免费   4篇
电工技术   1篇
化学工业   19篇
金属工艺   1篇
机械仪表   5篇
建筑科学   8篇
轻工业   3篇
石油天然气   2篇
无线电   9篇
一般工业技术   12篇
冶金工业   2篇
自动化技术   14篇
  2024年   1篇
  2023年   2篇
  2022年   5篇
  2021年   1篇
  2020年   9篇
  2019年   8篇
  2018年   3篇
  2017年   7篇
  2016年   5篇
  2015年   4篇
  2014年   5篇
  2013年   6篇
  2012年   6篇
  2011年   3篇
  2010年   1篇
  2009年   1篇
  2008年   1篇
  2007年   3篇
  2005年   1篇
  2004年   1篇
  1997年   1篇
  1995年   1篇
  1982年   1篇
排序方式: 共有76条查询结果,搜索用时 15 毫秒
11.
12.
13.
Racial disparities in incidence and survival exist for many human cancers. Racial disparities are undoubtedly multifactorial and due in part to differences in socioeconomic factors, access to care, and comorbidities. Within the U.S., fundamental causes of health inequalities, including socio-economic factors, insurance status, access to healthcare and screening and treatment biases, are issues that contribute to cancer disparities. Yet even these epidemiologic differences do not fully account for survival disparities, as for nearly every stage, grade and histologic subtype, survival among Black women is significantly lower than their White counterparts. To address this, we sought to investigate the proteomic profiling molecular features of endometrial cancer in order to detect modifiable and targetable elements of endometrial cancer in different racial groups, which could be essential for treatment planning. The majority of proteins identified to be significantly altered among the racial groups and that can be regulated by existing drugs or investigational agents are enzymes that regulate metabolism and protein synthesis. These drugs have the potential to improve the worse outcomes of endometrial cancer patients based on race.  相似文献   
14.
Epigenetic modifications are known to regulate cell phenotype during cancer progression, including breast cancer. Unlike genetic alterations, changes in the epigenome are reversible, thus potentially reversed by epi-drugs. Breast cancer, the most common cause of cancer death worldwide in women, encompasses multiple histopathological and molecular subtypes. Several lines of evidence demonstrated distortion of the epigenetic landscape in breast cancer. Interestingly, mammary cells isolated from breast cancer patients and cultured ex vivo maintained the tumorigenic phenotype and exhibited aberrant epigenetic modifications. Recent studies indicated that the therapeutic efficiency for breast cancer regimens has increased over time, resulting in reduced mortality. Future medical treatment for breast cancer patients, however, will likely depend upon a better understanding of epigenetic modifications. The present review aims to outline different epigenetic mechanisms including DNA methylation, histone modifications, and ncRNAs with their impact on breast cancer, as well as to discuss studies highlighting the central role of epigenetic mechanisms in breast cancer pathogenesis. We propose new research areas that may facilitate locus-specific epigenome editing as breast cancer therapeutics.  相似文献   
15.
Energy harvesting is about deriving energy from environment and converting into electricity. In this paper, optimal design of a cantilever piezoelectric energy harvester is presented with the aim to capture electrical power from a vibratory feeder in mining industry. Rayleigh–Ritz method is utilized for the modeling of the cantilever piezoelectric, taking into account possible variation in the width, nonequivalent layer lengths and thickness for unimorph and bimorph configurations. Innovatively, intelligent artificial immune system is utilized for multi-objective optimization of the shape parameters of the system. To verify the presented analytical shape optimization method, finite element analysis of the designed system is also presented, to investigate the output voltage and stress distribution along the piezoelectric layer. Moreover, the experimental setup is generated and verification tests are performed to derive frequency response diagram of the system. The obtained results are encouraging, indicating good agreement between experiments, FE analysis and theoretical results.  相似文献   
16.
The effect of silica fume on deterioration resistance to sulfate attack in seawater within tidal zone and simulated wetting-drying condition has been studied in Portland cement concretes and pastes containing silica fume (SF) with/without ground granulated blast furnace slag (GGBS). Changes in the compressive strength and capillary water absorption of specimens as a function of SF content have been investigated combined with phases determination by means of scanning electron microscopy and X-ray energy dispersion analysis. The strength change factors (SCFs) of specimens with SF (the more SF content, the higher strength loss) were greater than that of the mixes without SF or cured under tap water. Mg2+ ion originated attack found to be the dominating deterioration mechanism as confirmed by X-ray and chemical analyses.Further, the incorporation of GGBS with SF mixes in different exposure conditions led to the worst performance in all of the test environments. Lower cement content and hydration rate accompanied with particular chemical composition of GGBS made concrete and paste specimens to be more susceptible to deleterious seawater environment.  相似文献   
17.
In this paper, a new criterion for passivity of haptic devices is obtained. This criterion creates a relationship between Coulomb friction coefficient, viscous friction coefficient, sampling rate, and the maximum simulated stiffness. The process of derivation of the passivity criterion is described in detail. This criterion is improved compared with other existing criteria and predicts passivity in haptic rendering more accurately. In particular, for speeds of less than 5?cm/s, the new passivity criterion should replace the previous criteria to avoid unwanted vibrations of stiff virtual walls. Analytical and numerical investigations are presented to validate the new criterion. A specific trajectory is designed and the movement of the haptic robot is investigated on this trajectory to validate and compare this passivity criterion with the previous criteria.  相似文献   
18.
Reliable packet transmission over error-prone wireless networks has received a lot of attention from the research community. In this paper, instead of using simple packet retransmissions to provide reliability, we consider a novel retransmission approach, which is based on the importance of bits (symbols). We study the problem of maximizing the total gain in the case of partial data delivery in error-prone wireless networks, in which each set of bits (called symbols) has a different weight. We first address the case of one-hop single packet transmission, and prove that the optimal solution that maximizes the total gain has a round-robin symbol transmission pattern. Then, we extend our solution to the case of multiple packets. We also enhance the expected gain using random linear network coding. Our simulation results show that our proposed multiple packets transmission mechanism can increase the gain up to 60%, compared to that of a simple retransmission. Moreover, our network coding scheme enhances the expected total gain up to 15%, compared to our non-coding mechanism.  相似文献   
19.
According to the concept of an intrinsic hybrid composite, adhesive bonding is designed for generating the connection between the applied fiber reinforced polymer and a metallic insert. To induce adhesive bonding, a metallic insert, made of aluminum, is coated. This contribution focusses on the development of a suitable coating system. To this end, the coating system must meet certain requirements. On one hand, demands on the coating like ductility can be deduced from analyzing the manufacturing process. On the other hand, requirements like corrosion protection as well as high static and dynamic strength arise from specific applications under considerations. The utilized coating system is based on organically modified silicate layers (Ormosil) applied using a sol–gel process. To prove that this coating system fulfils the requirements, the corrosion protection is analysed by impedance spectroscopy. Furthermore, different mechanical experimental investigations are performed to verify the ductility of the coating as well as the strength of the resulting interface. Hence, it is shown that the considered coating system can be applied for the analysed intrinsic hybrid composite manufactured in series.  相似文献   
20.
The aim of this numerical investigation is to evaluate the laminar forced convection of biologically synthesized water-silver nanofluid through a heat sink (HS) filled with porous foam (PHS) using first and second laws of thermodynamics. The impacts of inlet velocity (V = 0.5–3 m·s−1) and volume fraction of nanofluid (φ = 0–1%) on the performance metrics of HS are assessed and the outcomes are compared with those of the non-porous HS (NHS). The outcomes revealed that for both the PHS and NHS, the increase of V causes an intensification in convection coefficient, pumping power, and entropy generation due to fluid friction, while the maximum CPU temperature, thermal resistance, and entropy generation due to the heat transfer reduces by boosting V. Also, it was found that the augmentation of V results in intensification in convection coefficient, pumping power, overall hydrothermal performance, and frictional entropy generation, while the opposite is true for maximum CPU temperature, thermal resistance, and thermal entropy generation. Furthermore, it was reported that, except for φ = 0.5%, the overall hydrothermal performance of NHS is better than that of PHS, while PHS has better second-law performance than NHS in all the studied cases. Also, it can be concluded that the best hydrothermal performance for PHS belongs to φ = 1% and V = 0.5 m·s−1, while for NHS, these values are 1% and 2 m·s−1.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号