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81.
Maria Väisänen Françoise Martz Elina Kaarlejärvi Riitta Julkunen-Tiitto Sari Stark 《Journal of chemical ecology》2013,39(11-12):1390-1399
Mountain crowberry (Empetrum nigrum ssp. hermaphroditum) is a keystone species in northern ecosystems and exerts important ecosystem-level effects through high concentrations of phenolic metabolites. It has not been investigated how crowberry phenolics will respond to global climate change. In the tundra, grazing by reindeer (Rangifer tarandus) affects vegetation and soil nutrient availability, but almost nothing is known about the interactions between grazing and global climate change on plant phenolics. We performed a factorial warming and fertilization experiment in a tundra ecosystem under light grazing and heavy grazing and analyzed individual foliar phenolics and crowberry abundance. Crowberry was more abundant under light grazing than heavy grazing. Although phenolic concentrations did not differ between grazing intensities, responses of crowberry abundance and phenolic concentrations to warming varied significantly depending on grazing intensity. Under light grazing, warming increased crowberry abundance and the concentration of stilbenes, but decreased e.g., the concentrations of flavonols, condensed tannins, and batatasin-III, resulting in no change in total phenolics. Under heavy grazing, warming did not affect crowberry abundance, and induced a weak but consistent decrease among the different phenolic compound groups, resulting in a net decrease in total phenolics. Our results show that the different phenolic compound groups may show varying or even opposing responses to warming in the tundra at different levels of grazing intensity. Even when plant phenolic concentrations do not directly respond to grazing, grazers may have a key control over plant responses to changes in the abiotic environment, reflecting multiple adaptive purposes of plant phenolics and complex interactions between the biotic and the abiotic factors. 相似文献
82.
Elina B. Caramão L.M.F. Gomes M.D. Oliveira A. Bristoti Fernando M. Lanças 《Petroleum Science and Technology》2013,31(8):881-898
ABSTRACT Selective isolation of coal tar bases was performed by using two different separation methods: liquid-liquid extraction (LLE) and column liquid chromatography (CLC). Two cuts, A (boiling range 100°C – 230°C) and B (boiling range 230°C – 300°C), obtained by distillation of “Mina do Leao” coal tar oil, are compared after the isolation of bases by both methods through elemental analysis, infra-red spectroscopy and mass yield. In addition, cut A and its bases generated by both LLE and CLC were investigated by GC/MS. Pyridines, quinolines and anilines are the major classes found in the base fractions obtained by both methods. Although both showed to be equally selective for base isolation, the column liquid chromatography method demonstrated better recovery. 相似文献
83.
ABSTRACT A Brazilian high ash coal tar oil has been distilled into six distinct cuts (A to F) which are further fractionated by column liquid chromatography into eight discrete chemical classes (PLC1 to PLC 8). A proper sequence of eluents allows the separation of 5 classes containing hydrocarbons (saturated, olefinic, monoaromatic, diaromatic and polyaromatic), one of intermediate polarity (resins) and two polar fractions (asphaltenes and asphaltols). More than 50% of the oil is verified to distill above 300°C. Infra-red and nuclear magnetic res-sonance spectroscopy confirms the sucess of the group-type fractionation. Very small amounts of hydrocarbons were found, the resins being the major fraction in all cuts studied. 相似文献
84.
Marjaana Karhu Juha Lagerbom Soili Solismaa Mari Honkanen Arnold Ismailov Marja-Liisa Räisänen Elina Huttunen-Saarivirta Erkki Levänen Päivi Kivikytö-Reponen 《Ceramics International》2019,45(4):4840-4848
This paper presents studies on the utilization of aluminosilicate-based mining tailings as raw materials for mullite-based ceramics. Based on the 3:2 stoichiometric composition, mullite was synthesised by reactive sintering with a series of powder mixtures with alumina additions. X-ray diffractometry and scanning electron microscopy analyses revealed that, at the specific mineralogical composition, mullite structure formed surrounded by an amorphous glass phase in reaction-sintered powder mixtures. Results demonstrated that the chemical and mineralogical composition of mining tailings do have an effect on mullite formation possibilities and, only with the particular mineralogical composition, the mullite formation is possible regardless of the correct Al:Si ratio in tailings. Physical and mechanical properties of the formed ceramics were defined, showing comparable values to 3:2 mullite reference. Mullite structure formation enables a better thermal resistance up to above 1450?°C of the formed tailings-based ceramics compared to other aluminosilicates, reflecting their utilization potential for refractory ceramic applications. 相似文献
86.
Olga Elina 《Centaurus; international magazine of the history of science and medicine》2018,60(4):257-275
In this paper, private gardens are portrayed as spaces and implements of aristocratic passion for plant collecting, of competition within the gentry, as well as of scientific professionalisation for botanists. This paper traces the early history of botanical collections in the Russian Empire from the 18th to the early 19th century as part of an elite culture which encouraged amateur patrons to invest in expeditions, gardens, and, consequently, in professionals to manage such projects. Young graduates of European universities who began their careers working at private botanical institutions could later successfully apply for academic positions. The circulation of specimens had developed as a key element of botanical collection and an important basis for the networking of professionals and amateurs around the world. This paper argues that collecting plant specimens became an important means for engaging in “power games” and even “plant diplomacy.” These new responsibilities significantly increased botanists' status as experts. A diverse group of personalities, such as the Empress Catherine II, King George III of England, the industrialist Prokophy Demidov, aristocrat Alexei Razumovsky, Joseph Banks, President of the Royal Society, the academician Peter Simon Pallas—all shared a passion for botanical collecting and were engaged in power games at different levels, using botany as an instrument of influence. 相似文献
87.
Outi Elina Mäkinen Viivi Wanhalinna Emanuele Zannini 《Critical reviews in food science and nutrition》2016,56(3):339-349
A growing number of consumers opt for plant-based milk substitutes for medical reasons or as a lifestyle choice. Medical reasons include lactose intolerance, with a worldwide prevalence of 75%, and cow's milk allergy. Also, in countries where mammal milk is scarce and expensive, plant milk substitutes serve as a more affordable option. However, many of these products have sensory characteristics objectionable to the mainstream western palate. Technologically, plant milk substitutes are suspensions of dissolved and disintegrated plant material in water, resembling cow's milk in appearance. They are manufactured by extracting the plant material in water, separating the liquid, and formulating the final product. Homogenization and thermal treatments are necessary to improve the suspension and microbial stabilities of commercial products that can be consumed as such or be further processed into fermented dairy-type products. The nutritional properties depend on the plant source, processing, and fortification. As some products have extremely low protein and calcium contents, consumer awareness is important when plant milk substitutes are used to replace cow's milk in the diet, e.g. in the case of dairy intolerances. If formulated into palatable and nutritionally adequate products, plant-based substitutes can offer a sustainable alternative to dairy products. 相似文献
88.
Rajkovic A Uyttendaele M Ombregt SA Jaaskelainen E Salkinoja-Salonen M Debevere J 《Journal of food protection》2006,69(4):847-852
Potato puree and penne pasta were inoculated with cereulide producing B. cereus 5964a and B. cereus NS117. Static incubation at 28 degrees C proved these two foods to be a better substrate for higher cereulide production (4,080 ng/g in puree and 3,200 ng/g in penne were produced by B. cereus 5964a during 48 h of incubation) compared with boiled rice (2,000 ng/g). This difference occurred despite B. cereus counts of more than 10(8) CFU/g in all three products. Aeration of cultures had a negative effect on cereulide production, causing concentrations more than 10-fold lower than in some statically incubated samples. Cereulide production remained undetectable in shaken milk, whereas it reached 1,140 ng/ml in statically incubated milk. At 12 and 22 degrees C, presence of background flora was also a determinative factor. A total B. cereus count of more than 106 CFU/ml did not necessarily lead to uniform cereulide production and was also dependent on the B. cereus strain involved. In this study, we confirm that a number of factors play a crucial role in the determination of the extent to which, if at all, cereulide will be produced. Among those, type of the food, temperature, pH, and whether additional aeration (via incubation on an orbital shaker) is induced had an important role. An important effect was also induced by the cereulide-producing strain involved. 相似文献
89.
Jaisan Islam Elina KC Soochong Kim Hyong Kyu Kim Young Seok Park 《International journal of molecular sciences》2021,22(16)
The nucleus accumbens core (NAcc) is an important component of brain reward circuitry, but studies have revealed its involvement in pain circuitry also. However, its effect on trigeminal neuralgia (TN) and the mechanism underlying it are yet to be fully understood. Therefore, this study aimed to examine the outcomes of optogenetic stimulation of NAcc GABAergic neurons in an animal model of TN. Animals were allocated into TN, sham, and control groups. TN was generated by infraorbital nerve constriction and the optogenetic virus was injected into the NAcc. In vivo extracellular recordings were acquired from the ventral posteromedial nucleus of the thalamus. Alterations of behavioral responses during stimulation “ON” and “OFF” conditions were evaluated. In vivo microdialysis was performed in the NAcc of TN and sham animals. During optogenetic stimulation, electrophysiological recordings revealed a reduction of both tonic and burst firing activity in TN animals, and significantly improved behavioral responses were observed as well. Microdialysis coupled with liquid chromatography/tandem mass spectrometry analysis revealed significant alterations in extracellular concentration levels of GABA, glutamate, acetylcholine, dopamine, and citrulline in NAcc upon optic stimulation. In fine, our results suggested that NAcc stimulation could modulate the transmission of trigeminal pain signals in the TN animal model. 相似文献
90.
Aarnisalo K Vihavainen E Rantala L Maijala R Suihko ML Hielm S Tuominen P Ranta J Raaska L 《International journal of food microbiology》2008,121(3):275-284
Microbial risk assessment provides a means of estimating consumer risks associated with food products. The methods can also be applied at the plant level. In this study results of microbiological analyses were used to develop a robust single plant level risk assessment. Furthermore, the prevalence and numbers of Listeria monocytogenes in marinated broiler legs in Finland were estimated. These estimates were based on information on the prevalence, numbers and genotypes of L. monocytogenes in 186 marinated broiler legs from 41 retail stores. The products were from three main Finnish producers, which produce 90% of all marinated broiler legs sold in Finland. The prevalence and numbers of L. monocytogenes were estimated by Monte Carlo simulation using WinBUGS, but the model is applicable to any software featuring standard probability distributions. The estimated mean annual number of L. monocytogenes-positive broiler legs sold in Finland was 7.2x10(6) with a 95% credible interval (CI) 6.7x10(6)-7.7x10(6). That would be 34%+/-1% of the marinated broiler legs sold in Finland. The mean number of L. monocytogenes in marinated broiler legs estimated at the sell-by-date was 2 CFU/g, with a 95% CI of 0-14 CFU/g. Producer-specific L. monocytogenes strains were recovered from the products throughout the year, which emphasizes the importance of characterizing the isolates and identifying strains that may cause problems as part of risk assessment studies. As the levels of L. monocytogenes were low, the risk of acquiring listeriosis from these products proved to be insignificant. Consequently there was no need for a thorough national level risk assessment. However, an approach using worst-case and average point estimates was applied to produce an example of single producer level risk assessment based on limited data. This assessment also indicated that the risk from these products was low. The risk-based approach presented in this work can provide estimation of public health risk on which control measures at the plant level can be based. 相似文献