全文获取类型
收费全文 | 425篇 |
免费 | 20篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 100篇 |
金属工艺 | 9篇 |
建筑科学 | 14篇 |
能源动力 | 1篇 |
轻工业 | 86篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 32篇 |
一般工业技术 | 69篇 |
冶金工业 | 61篇 |
原子能技术 | 3篇 |
自动化技术 | 65篇 |
出版年
2023年 | 6篇 |
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 10篇 |
2019年 | 15篇 |
2018年 | 8篇 |
2017年 | 12篇 |
2016年 | 11篇 |
2015年 | 8篇 |
2014年 | 15篇 |
2013年 | 25篇 |
2012年 | 33篇 |
2011年 | 38篇 |
2010年 | 30篇 |
2009年 | 26篇 |
2008年 | 18篇 |
2007年 | 24篇 |
2006年 | 23篇 |
2005年 | 13篇 |
2004年 | 13篇 |
2003年 | 11篇 |
2002年 | 14篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 5篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1972年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有445条查询结果,搜索用时 31 毫秒
71.
Ming Tian Taylor Ticer Qikun Wang Sierra Walker Anthony Pham Annie Suh Sara Busatto Irina Davidovich Rawan Al‐Kharboosh Laura Lewis‐Tuffin Baoan Ji Alfredo Quinones‐Hinojosa Yeshayahu Talmon Shane Shapiro Felix Rückert Joy Wolfram 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(10)
Extracellular vesicles secreted from adipose‐derived mesenchymal stem cells (ADSCs) have therapeutic effects in inflammatory diseases. However, production of extracellular vesicles (EVs) from ADSCs is costly, inefficient, and time consuming. The anti‐inflammatory properties of adipose tissue‐derived EVs and other biogenic nanoparticles have not been explored. In this study, biogenic nanoparticles are obtained directly from lipoaspirate, an easily accessible and abundant source of biological material. Compared to ADSC‐EVs, lipoaspirate nanoparticles (Lipo‐NPs) take less time to process (hours compared to months) and cost less to produce (clinical‐grade cell culture facilities are not required). The physicochemical characteristics and anti‐inflammatory properties of Lipo‐NPs are evaluated and compared to those of patient‐matched ADSC‐EVs. Moreover, guanabenz loading in Lipo‐NPs is evaluated for enhanced anti‐inflammatory effects. Apolipoprotein E and glycerolipids are enriched in Lipo‐NPs compared to ADSC‐EVs. Additionally, the uptake of Lipo‐NPs in hepatocytes and macrophages is higher. Lipo‐NPs and ADSC‐EVs have comparable protective and anti‐inflammatory effects. Specifically, Lipo‐NPs reduce toll‐like receptor 4‐induced secretion of inflammatory cytokines in macrophages. Guanabenz‐loaded Lipo‐NPs further suppress inflammatory pathways, suggesting that this combination therapy can have promising applications for inflammatory diseases. 相似文献
72.
Elisabetta DE MARIA Abdorrahim BAHRAMI Thibaud L’YVONNET Amy FELTY Daniel GAFFÉ Annie RESSOUCHE Franck GRAMMONT 《Frontiers of Computer Science》2022,16(3):163404-115
Having a formal model of neural networks can greatly help in understanding and verifying their properties, behavior, and response to external factors such as disease and medicine. In this paper, we adopt a formal model to represent neurons, some neuronal graphs, and their composition. Some specific neuronal graphs are known for having biologically relevant structures and behaviors and we call them archetypes. These archetypes are supposed to be the basis of typical instances of neuronal information processing. In this paper we study six fundamental archetypes (simple series, series with multiple outputs, parallel composition, negative loop, inhibition of a behavior, and contralateral inhibition), and we consider two ways to couple two archetypes: (i) connecting the output(s) of the first archetype to the input(s) of the second archetype and (ii) nesting the first archetype within the second one. We report and compare two key approaches to the formal modeling and verification of the proposed neuronal archetypes and some selected couplings. The first approach exploits the synchronous programming language Lustre to encode archetypes and their couplings, and to express properties concerning their dynamic behavior. These properties are verified thanks to the use of model checkers. The second approach relies on a theorem prover, the Coq Proof Assistant, to prove dynamic properties of neurons and archetypes. 相似文献
73.
Stability effects associated with the introduction of a partial and a complete Ca2+-binding site into human lysozyme 总被引:2,自引:0,他引:2
Haezebrouck Petra; Baetselier Annie De; Joniau Marcel; Dael Herman Van; Rosenberg Steve; Hanssens Ignace 《Protein engineering, design & selection : PEDS》1993,6(6):643-649
Two mutants of human lysozyme were synthesized. Mutant A92D,in which Ala92 was substituted by Asp, contains a partial Ca2+-bindingsite and mutant M4, in which Ala83, Gm86, Asn88 and Ala92 werereplaced by Lys, Asp, Asp and Asp respectively, contains thecomplete Ca -binding site of bovine a-lactalbumin. The Ca2+-bindingconstants of wild type human lysozyme and of mutants A92D andM4, measured at 25C and pH 7.5, were 2(1) x 102 M"1, 8(2)x l^M"1 and 9(0.5) x 10* M"1 respectively. Information gatheredfrom mkrocalorimetrk and CD spectro-scopic measurements indicatesthat the conformational changes of the M4 mutant lysozyme, inducedby Ca2+ binding, are smaller than those observed for bovinea-lactalbumin and for the Ca2+-binding equine lysozyme. At pH4.5, the thermostability of both the apo and Ca2+ forms of theA92D human was decreased in comparison with that of native humanlysozyme. In particular, within the apo form of this mutantan a-helix-containing sequence was destabilized. In contrast,at the same pH the thermostability of the apo and Ca2+ formsof the M4 mutant lysozyme was increased. The e-ammonium groupof the Lys83 side chain is assumed to be responsible for thestabilization of the apo form of this mutant. 相似文献
74.
Any node in a wireless sensor network is a resource constrained device in terms of memory, bandwidth, and energy, which leads to a large number of packet drops, low throughput, and significant waste of energy due to retransmission. This paper presents a new approach for predicting congestion using a probabilistic method and controlling congestion using new rate control methods. The probabilistic approach used for prediction of the occurrence of congestion in a node is developed using data traffic and buffer occupancy. The rate control method uses a back-off selection scheme and also rate allocation schemes, namely rate regulation (RRG) and split protocol (SP), to improve throughput and reduce packet drop. A back-off interval selection scheme is introduced in combination with rate reduction (RR) and RRG. The back-off interval selection scheme considers channel state and collision-flee transmission to prevent congestion. Simulations were conducted and the results were compared with those of decentralized predictive congestion control (DPCC) and adaptive duty-cycle based congestion control (ADCC). The results showed that the proposed method reduces congestion and improves performance. 相似文献
75.
Andrew J. Chappell Daniel M. Allwood Rebecca Johns Samantha Brown Kiran Sultana Annie Anand Trevor Simper 《Journal of the International Society of Sports Nutrition》2018,15(1):42
Background
Use of supplements to aid performance is common practice amongst recreationally active individuals, including those without a sufficient evidence base. This investigation sought to assess whether acute supplementation with 8 g of citrulline malate (CM) (1.11: 1 ratio) would improve anaerobic performance.Methods
A randomised double blind placebo control trial was employed, using a counterbalanced design. We recruited recreationally active men and women to take part in an isokinetic chair protocol, based on German Volume Training (GVT) whereby participants attempted to perform 10 sets of 10 repetitions against a force representing 70% of their peak concentric force.Results
The number of repetitions achieved over the course of the GVT was 94.0?±?7.9 and 90.9?±?13.9 for placebo and CM respectively. There was no significant difference between the placebo and CM treatment for number of repetitions (P?=?0.33), isometric (P?=?0.60), concentric (P?=?0.38), or eccentric (P?=?0.65) peak force following the GVT. Total muscle soreness was significantly higher in the CM compared to the placebo treatment following the GVT protocol over 72 h (P?=?0.01); although this was not accompanied by a greater workload/number of repetitions in the CM group.Conclusions
We conclude that an acute dose of CM does not significantly affect anaerobic performance using an isokinetic chair in recreational active participants. Practical implications include precaution in recommending CM supplementation. Coaches and athletes should be aware of the disparity between the chemical analyses of the products reviewed in the present investigation versus the manufacturers’ claims.76.
77.
78.
The major whey proteins IgG, serum albumin and alpha-lactalbumin were purified from camel milk using gel permeation and ion-exchange chromatography. Specific antisera against each of them were raised and used to quantify their heat denaturation in early or mature milk over a range of 60-90 degrees C for 10-60 min using the single radial immunodiffusion technique. The heat denaturation midpoints for the mature milk heated 30 min were 67.2, 73.0 and 77.5 degrees C for IgG, albumin and alpha-lactalbumin respectively. The early milk was more sensitive to heat treatment with coagulation at low temperature and heat denaturation midpoints of 64.8, 71.6 and 72.6 degrees C respectively. This difference was related to the high IgG content of the early milk (12.6 mg/ml v. 0.5 mg/ml for the mature milk) and stresses the importance of monitoring the IgG level of milk to assess the absence of colostrum. 相似文献
79.
Sherely Annie Paul Kuruvilla Joseph Gem Mathew Laly A. Pothen Sabu Thomas 《Polymer Composites》2010,31(5):816-824
Short natural fiber thermoplastic composites are usually fabricated by melt mixing or solution mixing followed by conventional methods like injection molding or compression molding. In melt mixing, the fibers are subjected to high shear and this damage the natural fiber. In solution mixing, the use of the organic solvent is essential and its use is hazardous. Development of a novel method commingling to prepare polypropylene (PP)/short natural fiber composite is the main objective of this study. The influence of fiber loading on the mechanical properties of the composites prepared by the above method has been evaluated. The applications and limitations of several equations to predict physical properties such as tensile strength and modulus of the composites have been described. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers 相似文献
80.
Annie 《石油石化物资采购》2010,(11)
有人这样形象地总结了阿尔迪成功的秘诀:只放一只羊!因为,无数个想放一群羊的人,到最后,却一只羊也没剩下,原因就是他们被无尽的贪欲挤垮,而最后失掉了一群羊。 相似文献