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71.
72.
This paper presents the design of a new multiplier architecture for normal integer multiplication of positive and negative numbers as well as for multiplication in finite fields of order 2n. It has been developed to increase the performance of algorithms for cryptographic and signal processing applications on implementations of the Instruction Systolic Array (ISA) parallel computer model [M. Kunde, H.W. Lang, M. Schimmler, H. Schmeck, H. Schröder, Parallel Computing 7 (1988) 25-39, H.W. Lang, Integration, the VLSI Journal 4 (1986) 65-74]. The multiplier operates least significant bit (LSB)-first for integer multiplication and most significant bit ( )-first for finite field multiplication. It is a modular bit-serial design, which on the one hand can be efficiently implemented in hardware and on the other hand has the advantage that it can handle operands of arbitrary length. 相似文献
73.
74.
In many applications, especially from the business domain, the requirements specification mainly deals with use cases and
class models. Unfortunately, these models are based on different modelling techniques and aim at different levels of abstraction,
such that serious consistency and completeness problems are induced. To overcome these deficiencies, we refine activity graphs
to meet the needs for a suitable modelling element for use case behaviour. The refinement in particular supports the proper
coupling of use cases via activity graphs and the class model. The granularity and semantics of our approach allow for a seamless,
traceable transition of use cases to the class model and for the verification of the class model against the use case model.
The validation of the use case model and parts of the class model is supported as well. Experience from several applications
has shown that the investment in specification, validation and verification not only pays off during system and acceptance
testing but also significantly improves the quality of the final product. 相似文献
75.
A. P. Panayi A. R. Diaz H. J. Schock 《Structural and Multidisciplinary Optimization》2009,38(3):317-330
A method for the optimization of piston skirt profiles used in internal combustion engine piston design is proposed. The method
is based on a response surface approximation of standard performance measures used in piston design, namely, the RMS values
of the piston’s transverse and angular accelerations, used as indicators of piston slap and noise, and the friction work on
the skirt. The method is intended to be used in conjunction with computationally-intensive piston simulation tools. As such,
it can be used also as a paradigm for strategies to solve optimization problems that rely on computationally expensive simulation
models. An example illustrates the capabilities of the method and the significant enhancements in performance that result
from an optimized piston skirt profile. 相似文献
76.
77.
Carl-Philipp?FederolfEmail authorView authors OrcID profile Matthias?Westerschulte Hans-Werner?Olfs Gabriele?Broll Dieter?Trautz 《Nutrient Cycling in Agroecosystems》2017,107(1):19-31
Using pig slurry as starter fertilizer for maize (Zea mays L.), injected below the row prior to planting is a reasonable way to omit application of additional mineral fertilizer in areas with intensive animal farming. However, delayed early growth and a lack of knowledge on nutrient availability limit the interest of farmers. To extenuate farmers concerns a field trial was conducted in 2014 and 2015 to get detailed information on nitrogen (N) uptake, the subsequent influences on crop growth at different vegetative growth stages and final yield of silage maize. Besides an unfertilized control, two liquid manure injection treatments (without and with nitrification inhibitor [NI]) were compared to slurry broadcast application + mineral N and phosphorus (P) starter fertilizer at planting (MSF). In 2014, NI treatment yields increased (+16.5%) and N uptake increased (+9.6%) compared to broadcast treatment. In 2015, cold and dry conditions during early growth limited P plant availability and reduced crop growth in treatments without MSF. However, when a NI was added to the slurry prior to application, plants showed less P deficiency symptoms and better growth. At harvest no differences between the fertilized treatments were observed. In both years apparent N recovery was increased when manure was injected (48% without, and 56% with NI, respectively) compared to broadcast application of manure (43%) indicating that N losses were lower. However, further knowledge on soil N transformation and N loss pathways in systems with slurry injection is needed. 相似文献
78.
N. A. Matchanov M. Farhan J. D’Angelo E. J. Timm T. P. Hogan H. Schock E. D. Case M. G. Kanatzidis 《Applied Solar Energy》2012,48(1):5-9
This investigation reports the output parameters of thermoelectric modules on based on metal/LAST(T) hot side contacts. 相似文献
79.
N2O is emitted from agricultural soils due to microbial transformation of N from fertilizers, manures and soil N reserves. N2O also derives from N lost from agriculture to other ecosystems: as NH3 or through NO
3
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leaching. Increased efficiency in crop N uptake and reduction of N losses should in principle diminish the amount of N2O from agricultural sources. Precision in crop nutrient management is developing rapidly and should increase this efficiency. It should be possible to design guidelines on good agricultural practices for low N2O emissions in special situations, e.g. irrigated agriculture, and for special operations, e.g. deep placement of fertilizers and manures. However, current information is insufficient for such guidelines. Slow-release fertilizers and fertilizers with inhibitors of soil enzymatic processes show promise as products which give reduced N2O emissions, but they are expensive and have had little market penetration. Benefits and possible problems with their use needs further clarification. 相似文献
80.
Age-related macular degeneration (AMD) was used as a case model to longitudinally study adaptation in affective well-being under a prevalent chronic health condition. Measures of positive and negative affect, obtained at 5 subsequent measurement occasions with 3-month intervals in between, were analyzed in 90 older adults diagnosed with AMD. The authors proposed a pattern of adaptation that shows initial decline in affective well-being after disease outbreak, followed by a turnaround into a restorative phase of increase, implying nonlinear intraindividual trajectories, with changes substantially related to disease duration. Analysis was conducted by means of a nonlinear mixed models approach. Results confirmed the hypothesized adaptation pattern for positive affect but not for negative affect, which was found more stable across measurement occasions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献