全文获取类型
收费全文 | 5876篇 |
免费 | 196篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 88篇 |
综合类 | 3篇 |
化学工业 | 729篇 |
金属工艺 | 363篇 |
机械仪表 | 98篇 |
建筑科学 | 180篇 |
矿业工程 | 88篇 |
能源动力 | 146篇 |
轻工业 | 539篇 |
水利工程 | 35篇 |
石油天然气 | 12篇 |
无线电 | 565篇 |
一般工业技术 | 940篇 |
冶金工业 | 1584篇 |
原子能技术 | 57篇 |
自动化技术 | 649篇 |
出版年
2023年 | 44篇 |
2022年 | 35篇 |
2021年 | 123篇 |
2020年 | 80篇 |
2019年 | 98篇 |
2018年 | 95篇 |
2017年 | 75篇 |
2016年 | 130篇 |
2015年 | 100篇 |
2014年 | 131篇 |
2013年 | 310篇 |
2012年 | 234篇 |
2011年 | 308篇 |
2010年 | 244篇 |
2009年 | 228篇 |
2008年 | 245篇 |
2007年 | 267篇 |
2006年 | 220篇 |
2005年 | 145篇 |
2004年 | 136篇 |
2003年 | 116篇 |
2002年 | 99篇 |
2001年 | 92篇 |
2000年 | 99篇 |
1999年 | 84篇 |
1998年 | 375篇 |
1997年 | 227篇 |
1996年 | 174篇 |
1995年 | 119篇 |
1994年 | 102篇 |
1993年 | 129篇 |
1992年 | 64篇 |
1991年 | 64篇 |
1990年 | 43篇 |
1989年 | 59篇 |
1988年 | 52篇 |
1987年 | 48篇 |
1986年 | 59篇 |
1985年 | 59篇 |
1984年 | 47篇 |
1983年 | 43篇 |
1982年 | 48篇 |
1981年 | 54篇 |
1980年 | 46篇 |
1979年 | 36篇 |
1978年 | 39篇 |
1977年 | 77篇 |
1976年 | 98篇 |
1974年 | 42篇 |
1973年 | 35篇 |
排序方式: 共有6076条查询结果,搜索用时 31 毫秒
61.
Some indication of the use of Phenidone in PQ developer systems in large scale motion picture laboratory practice is given. Various characteristics, which were examined on a plant scale before MQ systems were abandoned in favour of PQ systems, are discussed; the stabilities and economics of the two systems are compared. 相似文献
62.
M. Manca Zeichen corresponding author I. S. Robinson 《International journal of remote sensing》2013,34(9):1797-1798
Abstract The study presented here is a part of an attempt to improve the operational algorithm used at the Centre de Météorologie Spatiale (CMS) to calculate Sea Surface Temperature (SST) from Advanced Very High Resolution Radiometer (AVHRR) data. The errors produced by SST retrieval algorithms are analysed through two experiments: an examination of the errors calculated on a validation file and an analysis of the temperatures of oceanic cloud-free areas seen under two distinct satellite zenith angles (θ) for consecutive night-time orbits. This Letter presents the part of the study dedicated to the effect of large viewing angles on the retrieval of SST. Correction terms are proposed and compared, on the same set of data, to split window algorithms using θ dependent coefficients 相似文献
63.
Timothy Zurrer Kenneth Wong Jonathan Horlyck Emma C. Lovell Joshua Wright Nicholas M. Bedford Zhaojun Han Kang Liang Jason Scott Rose Amal 《Advanced functional materials》2021,31(9):2007624
The vast chemical and structural tunability of metal–organic frameworks (MOFs) are beginning to be harnessed as functional supports for catalytic nanoparticles spanning a range of applications. However, a lack of straightforward methods for producing nanoparticle-encapsulated MOFs as efficient heterogeneous catalysts limits their usage. Herein, a mixed-metal MOF, NiMg-MOF-74, is utilized as a template to disperse small Ni nanoclusters throughout the parent MOF. By exploiting the difference in Ni O and Mg O coordination bond strength, Ni2+ is selectively reduced to form highly dispersed Ni nanoclusters constrained by the parent MOF pore diameter, while Mg2+ remains coordinated in the framework. By varying the ratio of Ni to Mg in the parent MOF, accessible surface area and crystallinity can be tuned upon thermal treatment, influencing CO2 adsorption capacity and hydrogenation selectivity. The resulting Ni nanoclusters prove to be an active catalyst for CO2 methanation and are examined using extended X-ray absorption fine structure and X-ray photoelectron spectroscopy. By preserving a segment of the Mg2+-containing MOF framework, the composite system retains a portion of its CO2 adsorption capacity while continuing to deliver catalytic activity. The approach is thus critical for designing materials that can bridge the gap between carbon capture and CO2 utilization. 相似文献
64.
65.
Liam Betsworth Huw Bowen Simon Robinson Matt Jones 《Personal and Ubiquitous Computing》2014,18(7):1631-1650
Heritage sites are an important part of understanding our role in history. They have the potential to teach us important lessons, such as where we came from and subsequently, the people it has made us today. As members of a large, heritage-led, regeneration project, we are working with the Hafod–Morfa Copperworks, a heritage site in the Lower Swansea Valley where there is not much to see or hear. The few ruins at the site make it difficult to imagine what the site would have been like back in its heyday. Our goal at the site is to draw people together, not to view a finished piece of curated heritage, but rather, to start conversations about their memories and the significance of the site to them and to discover what they would like to see at the site in the future. The technology we are producing is about engaging with the local community and stakeholders as groups to provoke discussion. This contrasts with previous uses of mobile guides which only attempt to be tourist aids. In this article, we report on two prototype technologies we have developed to help accomplish this task. Throughout the article, we discuss how and why designing performative technologies could help encourage people to visit, socialise and communicate within the area. Our early results suggest that expressive performative technologies are good at gaining spectators’ attention and encouraging an active engagement between performer and spectator. 相似文献
66.
Kaidi Nie Felix von Drigalski Joshua C. Triyonoputro Chisato Nakashima Yoshiya Shibata Yoshinori Konishi 《Advanced Robotics》2020,34(7-8):477-498
ABSTRACTIn this paper, we describe the approach of Team O2AS to complete the task-board task of the World Robot Challenge 2018, held in Tokyo. We use a custom gripper and graspable tools with in-built compliance to work with various kinds of parts, increase robustness against uncertainties, and to avoid complicated control strategies. The robots are able to finish all the sub-tasks without the need to exchange grippers. The main idea is to use mechanical compliance and self-centering mechanisms to deal with uncertainty. This is achieved by aligning the objects using either the gripper and tools, or by the design of the robot motions. 相似文献
67.
Pooja Kaur Dr. Alice Johnson Joshua Northcote-Smith Dr. Chunxin Lu Dr. Kogularamanan Suntharalingam 《Chembiochem : a European journal of chemical biology》2020,21(24):3618-3624
Immunogenic cell death (ICD) offers a method of stimulating the immune system to attack and remove cancer cells. We report a copper(II) complex containing a Schiff base ligand and a polypyridyl ligand, 4 , capable of inducing ICD in breast cancer stem cells (CSCs). Complex 4 kills both bulk breast cancer cells and breast CSCs at sub-micromolar concentrations. Notably, 4 exhibits greater potency (one order of magnitude) towards breast CSCs than salinomycin (an established breast CSC-potent agent) and cisplatin (a clinically approved anticancer drug). Epithelial spheroid studies show that 4 is able to selectively inhibit breast CSC-enriched HMLER-shEcad spheroid formation and viability over non-tumorigenic breast MCF10 A spheroids. Mechanistic studies show that 4 operates as a Type II ICD inducer. Specifically, 4 readily enters the endoplasmic reticulum (ER) of breast CSCs, elevates intracellular reactive oxygen species (ROS) levels, induces ER stress, evokes damage-associated molecular patterns (DAMPs), and promotes breast CSC phagocytosis by macrophages. As far as we are aware, 4 is the first metal complex to induce ICD in breast CSCs and promote their engulfment by immune cells. 相似文献
68.
Bram H. Frohock Jessica M. Gilbertie Dr. Jennifer C. Daiker Dr. Lauren V. Schnabel Dr. Joshua G. Pierce 《Chembiochem : a European journal of chemical biology》2020,21(7):933-937
The failure of frontline antibiotics in the clinic is one of the most serious threats to human health and requires a multitude of novel therapeutics and innovative approaches to treatment so as to curtail the growing crisis. In addition to traditional resistance mechanisms resulting in the lack of efficacy of many antibiotics, most chronic and recurring infections are further made tolerant to antibiotic action by the presence of biofilms. Herein, we report an expanded set of 5-benzylidene-4-oxazolidinones that are able to inhibit the formation of Staphylococcus aureus biofilms, disperse preformed biofilms, and, in combination with common antibiotics, are able to significantly reduce the bacterial load in a robust collagen-matrix model of biofilm infection. 相似文献
69.
Russell C. Rockne Andrew D. Trister Joshua Jacobs Andrea J. Hawkins-Daarud Maxwell L. Neal Kristi Hendrickson Maciej M. Mrugala Jason K. Rockhill Paul Kinahan Kenneth A. Krohn Kristin R. Swanson 《Journal of the Royal Society Interface》2015,12(103)
Glioblastoma multiforme (GBM) is a highly invasive primary brain tumour that has poor prognosis despite aggressive treatment. A hallmark of these tumours is diffuse invasion into the surrounding brain, necessitating a multi-modal treatment approach, including surgery, radiation and chemotherapy. We have previously demonstrated the ability of our model to predict radiographic response immediately following radiation therapy in individual GBM patients using a simplified geometry of the brain and theoretical radiation dose. Using only two pre-treatment magnetic resonance imaging scans, we calculate net rates of proliferation and invasion as well as radiation sensitivity for a patient''s disease. Here, we present the application of our clinically targeted modelling approach to a single glioblastoma patient as a demonstration of our method. We apply our model in the full three-dimensional architecture of the brain to quantify the effects of regional resistance to radiation owing to hypoxia in vivo determined by [18F]-fluoromisonidazole positron emission tomography (FMISO-PET) and the patient-specific three-dimensional radiation treatment plan. Incorporation of hypoxia into our model with FMISO-PET increases the model–data agreement by an order of magnitude. This improvement was robust to our definition of hypoxia or the degree of radiation resistance quantified with the FMISO-PET image and our computational model, respectively. This work demonstrates a useful application of patient-specific modelling in personalized medicine and how mathematical modelling has the potential to unify multi-modality imaging and radiation treatment planning. 相似文献
70.
Alaster Yoxall Victor Gonzalez Joshua Best Elena M. Rodriguez‐Falcon Jennifer Rowson 《Packaging Technology and Science》2019,32(10):496-507
Accessible packaging is continually receiving greater attention as an ageing population becomes a primary driver behind inclusive design. As we age, our strength dexterity and some cognitive functions decline. For this reason, the ease of interaction with simple tasks in daily living becomes an ever increasing concern. ISO 17480 “Packaging Guidelines” consider capability issues relating to packaging and ageing to broadly come under three areas, namely, strength, dexterity, and cognition. Significant previous work has been undertaken looking at the issue of strength on packaging accessibility, with fewer studies looking at the relationship between the physical demands of dexterity and the understanding of how to open the pack. In this previous work, there has been little attempt to quantify the effect of the affordances, perceptual information and symbology, and the physical demands of the pack and how this relates to accessibility. Hence, this exploratory study seeks to use motion capture and a dexterity test, along with a cognitive demand test to study this relationship and any changes with age. This research indicates that the dexterous demands of a task are linked to the cognitive demands; and thus in reaching a level of comprehension of the pack and how to access the product a subject may interact with a pack effectively. 相似文献