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121.
Three populations of Pistacia lentiscus fruits were analyzed for their contents, classes and different molecular species of glycerophospholipids (PL) in order to promote their production and marketability. The LC–ESI–TOF–MS and MS/MS were used to accomplish this analysis. Only four classes of PL were detected at different retention times—phosphatidic acid (PA), phosphatidylethanolamine (PE), phosphatidylglycerol (PG) and phosphatidylinositol (PI). There was a significant difference in the relative observed abundance of various glycerophospholipid classes. PI was found to be the dominant class in the all provenances of lentisc fruit, followed by the PG class in the KO and RM populations. Within the TB population, the PA class is more abundant than PG and PE. The major molecular specie in the PA class is PA-C16:0/18:2 followed by PA-C18:1/18:2; and the minor species were determined to be PA-C16:0/18:3, and PA-C18:3/18:2. In the PE class of phospholipids PE-C18:1/18:1 and PE-C18:2/18:2 are the major species identified. The phospholipids PG-C18:2/18:2, PG-18:2/18:1, PI-C16:0/18:2 and PI-C16:0/18:1 are the most abundant species within the PG and PI classes. PG-C18:1/18:1, PI-C18:0/18:1 and PI-C16:0/18:3 are found to be only relatively minor chemical species. In conclusion, it is clear that the predominant molecular species of PL are those containing C16:0, C18;1, C18:2 fatty acids and the minor species are those containing C18:0 and C18:3.  相似文献   
122.
This review attempts to answer the following questions: what are the interest and benefits of polymerizing in supercritical media and what type of polymer and polymerization process can be used? Supercritical fluids (SCFs) in theory offer many advantages since they have intermediate properties between liquids and gases. Also, at a time when the environment is undergoing such great impacts as the depletion of the ozone layer by chlorofluorocarbons (CFCs), the use of CO2 seems an attractive alternative for sustainability and conservation. This is why heterogeneous polymerization methods, particularly suspension and dispersion processes, offer great potential with an SCF as a suspending medium. Unfortunately, polyolefins and other commodities, such as poly(vinyl chloride) (PVC), may not benefit from SCF technology today for profitability reasons, but acrylics, styrenics and other fluorinated plastics are open to this new technology. Furthermore, SCFs may have an impact on polyamides, polycarbonates and other speciality polymers.  相似文献   
123.
The reliability and latency requirements of wireless sensor network-based smart grid communications are met in large part by MAC protocols. Developed by IEEE, time slotted channel hopping (TSCH), a method that is effective, dependable, and predictable. However, the TSCH standard does not enable mobility and does not offer any solution for scheduling, especially in IEEE 802.15.4 TSCH, the most recent generation of extremely dependable and low-power MAC protocols. Recently, MSU-TSCH a time-frequency communication schedule was proposed to provide mobility to TSCH. Despite its distinctive qualities, MSU-TSCH has the drawback of computing the TSCH schedule at each node independently of its traffic load, which can significantly increase the communication delay. Due to this limitation, MSU-TSCH is not suitable for some delay-sensitive smart grid applications. In this article, we provide an improved MSU-TSCH-based TSCH protocol, called Mobility-TSCH, that dynamically adjusts time slot assignments based on traffic volume and latency requirement. Moreover, the protocol Mobility-TSCH adapts to topology changes and supports mobility. Additionally, it optimizes time slot allocation by prioritizing nodes closest to the sink. The performance and evaluation analysis of Mobility-TSCH compared to the original MSU-TSCH, reveal that the communication delay is greatly reduced, decreases the average end-to-end latency, the high packet delivery ratio (PDR), Increase the performance of both metrics, parent connectivity ratio (PCR) and convergence time (CT), while maintaining a minimal overhead signaling.  相似文献   
124.
A brief history of cereal grain moisture measurement by sensing the electrical properties of grain is presented. The basic principles are also described for using radio-frequency (RF) and microwave dielectric properties, or permittivity, of grain for sensing moisture through their correlation with moisture content. The development of density-independent functions of the permittivity is explained. The findings of recent research are summarized, which indicate that reliable density-independent moisture content determinations can be realized by measurements on grain at RF and microwave frequencies. Development of these techniques will provide useful instruments for on-line monitoring of moisture content in flowing grain to manage moisture in grain, prevent spoilage in storage and transport, improve processing, and provide information important for yield determinations in precision agriculture applications  相似文献   
125.
Simulation results of a 863-870 MHz frequency-hopped spread-spectrum (FHSS) transceiver with binary frequency shift keying (BFSK) modulation at 20 kb/s for wireless sensor applications is presented.The transmit/receive RF front end contains a BFSK modulator, an upconversion mixer, a power amplifier (PA), and an 863-870 MHz band pass filter (BPF) at the transmitter side and a low-noise amplifier with down conversion mixer to zero-IF, a low-pass channel-select filter, a limiter and a BFSK demodulator at the receiver side. The various block parameters of the transmit/receive RF front end like noise figure (NF), gain, 1 dB compression point (P-1 dB), and IIP3 are simulated and optimized to meet low power and low cost transceiver specifications.The transmitter simulations show an output ACPR (adjacent channel power ratio) of −22 dBc, 3.3 dBm P-1 dB of PA, and transmitted power of 0 dBm. The receiver simulations show 51.1 dB conversion gain, −7 dBm IIP3, −15 dB return loss (S11), and 10 dB NF. Low power arctangent-differentiated BFSK demodulator has been chosen and the BER performance has been co simulated with the analog receiver. The complete receiver achieves a BER of 10−3 at 10.5 dB of EbtoNo. The transceiver simulations show an RMS frequency error of 1.45 kHz.  相似文献   
126.
127.
Storage effects on dielectric properties of eggs from 10 to 1800 MHz   总被引:4,自引:0,他引:4  
ABSTRACT:  The dielectric constant and loss factor of egg albumen and egg yolk over the frequency range from 10 to 1800 MHz were measured at 24 °C at weekly intervals during 5-wk storage at 15 °C. Moisture and ash contents of albumen and yolk, as well as Haugh unit and yolk index, were also measured. The dielectric constant and loss factor of albumen were higher than those of yolk. Linear relationships were evident between the log of frequency, below about 1000 MHz, and the log of loss factor of albumen as well as that of yolk. The dielectric constants of albumen and yolk at 10 MHz were lower than those of fresh albumen and yolk when eggs were stored at 15 °C for 1 wk. However, after 2 wk in storage these dielectric constants rose and remained at higher levels for the rest of the 5-wk period. At frequencies of 100 MHz and higher, the dielectric constant was essentially constant during the entire storage period. Storage had much less influence on the loss factor of either albumen or yolk. In general, the moisture content and ash content of albumen and yolk decreased slightly as eggs aged. The moisture content of yolk increased somewhat with storage, and there was a corresponding decrease in albumen moisture content. The freshness qualities, Haugh unit and yolk index, also decreased as eggs aged. No obvious correlation between dielectric properties and moisture content, ash content, Haugh unit, or yolk index was observed.  相似文献   
128.
129.
Objectives: This study was aimed to develop dual-purpose natamycin (NAT)-loaded niosomes in ketorolac tromethamine (KT) gels topical ocular drug delivery system to improve the clinical efficacy of natamycin through enhancing its penetration through corneal tissue and reducing inflammation associated with Fungal keratitis (FK).

Significance: Nanosized carrier systems, as niosomes would provide great potential for improving NAT ocular bioavailability.NAT niosomal dispersion formulae were prepared and then incorporated in 0.5%KT gels using different mucoadhesive viscosifying polymers.

Methods: Niosomes were prepared using the reverse-phase evaporation technique. In vitro experimental, and in vivo clinical evaluations for these formulations were done for assessment of their safety and efficacy for treatment of Candida Keratitis in Rabbits. In vitro release study was carried out by the dialysis method. In vivo and histopathological studies were performed on albino rabbits.

Results: NAT niosomes exhibited high entrapment efficiency percentage (E.E%) up to96.43% and particle size diameter ranging from 181.75?±?0.64 to 498.95?±?0.64?nm, with negatively charged zeta potential (ZP). NAT niosomal dispersion exhibited prolonged in vitro drug release (40.96–77.49% over 24h). NAT-loaded niosomes/0.5%KT gel formulae revealed retardation in vitro release, compared to marketed-product (NATACYN®) and NAT-loaded niosomes up to57.32% (F8). In vivo experimental studies showed the superiority for F8 in treatment of candida keratitis and better results on corneal infiltration and hypopyon level. These results were consistent with histopathological examination in comparison with F5 and combined marketed products (NATACYN® and Ketoroline®).

Conclusions: This study showed that F8 has the best results from all pharmaceutical in vitro evaluations and a better cure percent in experimental application and enhancing the prolonged delivery of NAT and penetrating the cornea tissues.  相似文献   

130.
This article is concerned with synchronisation of complex stochastic dynamical networks in the presence of noise and functional uncertainty. A probabilistic control method for adaptive synchronisation is presented. All required probabilistic models of the network are assumed to be unknown, therefore estimated to be dependent on the connectivity strength, the state and control values. Robustness of the probabilistic controller is proved via the Lyapunov method. Furthermore, based on the residual error of the network states we introduce the definition of stochastic pinning controllability. A coupled map lattice with spatiotemporal chaos is taken as an example to illustrate all theoretical developments. The theoretical derivation is complemented by its validation on two representative examples.  相似文献   
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