全文获取类型
收费全文 | 521篇 |
免费 | 25篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 4篇 |
综合类 | 1篇 |
化学工业 | 118篇 |
金属工艺 | 4篇 |
机械仪表 | 12篇 |
建筑科学 | 14篇 |
能源动力 | 12篇 |
轻工业 | 96篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 27篇 |
一般工业技术 | 83篇 |
冶金工业 | 16篇 |
原子能技术 | 13篇 |
自动化技术 | 143篇 |
出版年
2023年 | 10篇 |
2022年 | 13篇 |
2021年 | 21篇 |
2020年 | 9篇 |
2019年 | 16篇 |
2018年 | 19篇 |
2017年 | 13篇 |
2016年 | 24篇 |
2015年 | 13篇 |
2014年 | 22篇 |
2013年 | 47篇 |
2012年 | 26篇 |
2011年 | 46篇 |
2010年 | 27篇 |
2009年 | 23篇 |
2008年 | 30篇 |
2007年 | 29篇 |
2006年 | 24篇 |
2005年 | 17篇 |
2004年 | 17篇 |
2003年 | 11篇 |
2002年 | 16篇 |
2001年 | 13篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 11篇 |
1997年 | 9篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 7篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有547条查询结果,搜索用时 15 毫秒
101.
102.
Effect of the use of anti‐hail nets on codling moth (Cydia pomonella) and organoleptic quality of apple (cv. Braeburn) grown in Alto Adige Region (northern Italy)
下载免费PDF全文
![点击此处可从《Journal of the science of food and agriculture》网站下载免费的PDF全文](/ch/ext_images/free.gif)
103.
104.
Direct experimental identification and quantification of the pressure contribution to a pressure-assisted sterilization process efficacy is difficult. However, dynamic kinetic models of thermal inactivation can be used to assess the lethality of a purely thermal process having the same temperature profile. Thus, a pressure-assisted process' temperature record can be used to generate a corresponding purely thermal survival curve with parameters determined in conventional heating experiments. Comparison of the actual final survival ratio with that calculated for the purely thermal process would reveal whether the hydrostatic pressure had synergistic or antagonistic effect on bacterial spores survival. The effect would be manifested in the number of log cycles subtracted or added to the survival ratio, and in the length of time at the holding temperature needed to produce the final survival ratio of the combined process. A set of combined treatments would reveal how the temperature and pressure profiles affect the pressure's influence on the process' lethality to either vegetative cells or spores. The need to withdraw samples during the thermal and combined processes would be avoided if the thermal survival parameters could be calculated by the "three endpoints method," which does not require the entire survival curve determination. Currently however, this method is limited to thermal inactivation patterns characterized by up to 3 survival parameters, the Weibull-Log logistic (WeLL) model, for example. 相似文献
105.
This paper presents an image-based dynamic visual servoing to make a mobile robot able to track a moving object on the workspace by using a calibrated on board vision system. The stability of the proposed system is proved based on its passivity properties. A robustness analysis and an L2-gain performance analysis are also presented. Experimental results are shown to illustrate the system performance. 相似文献
106.
The Arrhenius equation revisited 总被引:2,自引:0,他引:2
The Arrhenius equation has been widely used as a model of the temperature effect on the rate of chemical reactions and biological processes in foods. Since the model requires that the rate increase monotonically with temperature, its applicability to enzymatic reactions and microbial growth, which have optimal temperature, is obviously limited. This is also true for microbial inactivation and chemical reactions that only start at an elevated temperature, and for complex processes and reactions that do not follow fixed order kinetics, that is, where the isothermal rate constant, however defined, is a function of both temperature and time. The linearity of the Arrhenius plot, that is, Ln[k(T)] vs. 1/T where T is in °K has been traditionally considered evidence of the model's validity. Consequently, the slope of the plot has been used to calculate the reaction or processes' "energy of activation," usually without independent verification. Many experimental and simulated rate constant vs. temperature relationships that yield linear Arrhenius plots can also be described by the simpler exponential model Ln[k(T)/k(T(reference))] = c(T-T(reference)). The use of the exponential model or similar empirical alternative would eliminate the confusing temperature axis inversion, the unnecessary compression of the temperature scale, and the need for kinetic assumptions that are hard to affirm in food systems. It would also eliminate the reference to the Universal gas constant in systems where a "mole" cannot be clearly identified. Unless proven otherwise by independent experiments, one cannot dismiss the notion that the apparent linearity of the Arrhenius plot in many food systems is due to a mathematical property of the model's equation rather than to the existence of a temperature independent "energy of activation." If T+273.16°C in the Arrhenius model's equation is replaced by T+b, where the numerical value of the arbitrary constant b is substantially larger than T and T(reference), the plot of Ln k(T) vs. 1/(T+b) will always appear almost perfectly linear. Both the modified Arrhenius model version having the arbitrary constant b, Ln[k(T)/k(T(reference)) = a[1/ (T(reference)+b)-1/ (T+b)], and the exponential model can faithfully describe temperature dependencies traditionally described by the Arrhenius equation without the assumption of a temperature independent "energy of activation." This is demonstrated mathematically and with computer simulations, and with reprocessed classical kinetic data and published food results. 相似文献
107.
Luiz Guilherme Meira de Souza Flavio Anselmo Silva de Lima Luiz Guilherme Vieira Meira de Souza Natanaeyfle Randemberg Gomes dos Santos Jailton Weber Gomes 《机械工程与自动化:英文版》2014,(9):716-720
The science space in a state school in Natal city was built using a composite consisting of gypsum, EPS (expanded polystyrene), shredded tire, cement and water. Mechanical and thermal resistances were evaluated. Inside the blocks, three types of fillings (EPS plates, aluminum cans and 500 mL bottles of mineral water) were placed in order to obtain a walls with higher thermal resistance, but also to give it an ecologically correct order, considering that both the tire and the EPS occupy a large space in landfills and require years to be degraded when released into the environment. Compression tests were conducted according to the rules. The experiments demonstrated that the temperature difference between the internal and external surfaces on the walls reached levels above 12.0 ℃. It was also demonstrated that the proposed composite has adequate mechanical strength to be used for sealing walls. The proposed use of the composite can contribute to reduce the significant housing deficit of Brazil, producing popular houses at low cost and with little time to work. 相似文献
108.
Niederer SA Kerfoot E Benson AP Bernabeu MO Bernus O Bradley C Cherry EM Clayton R Fenton FH Garny A Heidenreich E Land S Maleckar M Pathmanathan P Plank G Rodríguez JF Roy I Sachse FB Seemann G Skavhaug O Smith NP 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2011,369(1954):4331-4351
Ongoing developments in cardiac modelling have resulted, in particular, in the development of advanced and increasingly complex computational frameworks for simulating cardiac tissue electrophysiology. The goal of these simulations is often to represent the detailed physiology and pathologies of the heart using codes that exploit the computational potential of high-performance computing architectures. These developments have rapidly progressed the simulation capacity of cardiac virtual physiological human style models; however, they have also made it increasingly challenging to verify that a given code provides a faithful representation of the purported governing equations and corresponding solution techniques. This study provides the first cardiac tissue electrophysiology simulation benchmark to allow these codes to be verified. The benchmark was successfully evaluated on 11 simulation platforms to generate a consensus gold-standard converged solution. The benchmark definition in combination with the gold-standard solution can now be used to verify new simulation codes and numerical methods in the future. 相似文献
109.
Physicochemical characterization and stability of inulin gels 总被引:1,自引:0,他引:1
Emma Chiavaro Elena Vittadini Claudio Corradini 《European Food Research and Technology》2007,225(1):85-94
The ability of three commercial inulins (Raftilose ®P95, Frutafit IQ®, and Frutafit TEX®) with different chemical composition (oligo-polysaccharides profile) to form gels (at 25 and 50 °C) was evaluated. Raftilose®P95 (rich in mono-disaccharides) did not form gels, Frutafit IQ® (mainly oligosaccharides) gelatinized in the 30–60% w/w concentration range and Frutafit TEX® (mainly long-chain saccharides) in the 20–40% w/w range. Textural and thermal properties of the gels were studied and their stability was evaluated during storage at 4 °C. Frutafit TEX® gels (both fresh and during storage) were harder, more adhesive, and less cohesive than Frutafit IQ® gels (40% w/w). At 40% w/w, Frutafit TEX® gels had a significantly higher amount of freezable water than Frutafit IQ®, and the DSC thermogram line shapes indicated that ice melting was more uniform and occurred at higher temperatures in Frutafit TEX® than in the Frutafit IQ® gels. Ice melting profile was not significantly affected by both gelification temperature and storage time. Frutafit IQ® gels were more stable than Frutafit TEX® gels during storage. 相似文献
110.
Andrea Germini Elena Scaravelli Francesca Lesignoli Stefano Sforza Roberto Corradini Rosangela Marchelli 《European Food Research and Technology》2005,220(5-6):619-624
A new DNA extraction method suitable for a wide variety of complex food matrices has been devised and applied in combination with a new polymerase chain reaction (PCR) method for the sensitive detection of a specific DNA sequence univocally identifying the presence of potentially allergenic hazelnut (Corylus avellana). A 156 base pair amplicon corresponding to an internal region of the complementary DNA of the major hazelnut allergen (Cor a 1) was designed, and was found to be highly specific; the method was tested on both pure and complex food matrices and was found to be able to confirm the presence of hazelnut down to 5 pg of its DNA. The sequence of the amplicon was further confirmed by high-performance liquid chromatography (HPLC) analysis with a specific peptide nucleic acid (PNA) probe. A 15-mer PNA probe was expressly designed and synthesized to hybridize an internal sequence of the previously described amplicon. Given its reported sequence specificity and high hybridization efficiency, the PNA probe was used to develop an anion-exchange HPLC method allowing for a fast and reliable confirmation of the identity of the amplified products. The PCR–HPLC method was successfully tested on commercial samples, allowing for the detection of the presence of potentially hidden allergens even in products where the presence of hazelnut as an ingredient or possible contaminant was not reported. 相似文献