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101.
Potassium fertiliser increases yield of sugar beet on most soils in Britain and sodium fertiliser gives a larger increase, whilst decreasing response to potassium. Sugar beet given factorial dressings of these elements was sampled periodically to determine whether they increase yield by similar effects on growth. Three experiments were made at Broom' Barn on a calcareous loam in 1971–73 and the results suggest that the two elements affect growth similarly. Both increased leaf area early in the season, improved the root: top ratio and increased sugar percentage in fresh and dried roots, all factors contributing to increased sugar yield. Analysis of the roots during September to December showed that neither element affected their processing quality; although each element increased its own concentration in the root juice, it proportionately decreased the harmful α-amino nitrogen concentration.  相似文献   
102.
Ye N  Li X  Farley T 《Ergonomics》2003,46(1-3):188-196
Hand signs are considered as one of the important ways to enter information into computers for certain tasks. Computers receive sensor data of hand signs for recognition. When using hand signs as computer inputs, we need to (1) train computer users in the sign language so that their hand signs can be easily recognized by computers, and (2) design the computer interface to avoid the use of confusing signs for improving user input performance and user satisfaction. For user training and computer interface design, it is important to have a knowledge of which signs can be easily recognized by computers and which signs are not distinguishable by computers. This paper presents a data mining technique to discover distinct patterns of hand signs from sensor data. Based on these patterns, we derive a group of indistinguishable signs by computers. Such information can in turn assist in user training and computer interface design.  相似文献   
103.
Curved frame structures are often used as part of the internal skeletal structure in aircraft. Laminated composite materials offer potential weight savings for such structures, but composite frames have different and more complex failure mechanisms than metallic frames. In particular, failure mechanisms involving interlaminar stresses are important in composite structures. Interlaminar stresses can be directly computed from three-dimensional finite element models, but the computational expense of these models is prohibitive. In this work, two- and three-dimensional (2D and 3D) finite element models are combined to reduce the computational expense associated with designing composite frames. A response surface design approach is used to approximate the failure response of curved composite C-section frames subjected to an axial tensile loading using a minimum number of finite element analyses. Results are presented for two examples with two and five design variables, respectively.  相似文献   
104.
Presents an obituary for Albert Ellis (1913–2007). Albert Ellis, originator of one of the major approaches to psychotherapy in the history of psychology, Rational-Emotive Behavior Therapy (REBT), died in New York City on July 24, 2007, at 93 years of age. Ellis began his professional life as a psychoanalyst but rejected its strong focus on early-life influences and its protracted therapeutic process. In the 1950s he developed his own cognitively oriented approach to therapy, which ultimately became REBT. It has been argued that these developments represented the first step in the cognitive revolution in psychotherapy, which culminated with cognitive approaches coming to a dominant position in contemporary therapy, not unlike the parallel dominant position of cognitive psychology in psychological science. REBT has been influential worldwide, being employed by therapists in many countries but also read about and used in self-help by a wide public. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
105.
Campaigns were conducted at the Pacific Missile Range Facility, Barking Sands, Kauai, investigating Raman lidar as a method to improve calibration of the DMSP SSM/T-2 microwave water vapor profiling instrument. Lidar mixing ratios were calibrated against AIR and Vaisala radiosondes and the calibration was tested in the vicinity of clouds. Above 6 km, radiosondes reported anomalously low relative humidity in the vicinity of clouds. Lidar measurements were confirmed by using an electro-optical shutter, which provided correct measurement of relative humidity at cloud bases above 6 km. Radiative transfer calculations applied to the lidar data closely matched signals observed in the SSM/T-2 atmospheric channels. Forward calculations for surface sensitive channels disagreed with SSM/T-2 and SSM/I observations. Fine scale surface roughness and localized orographic drying are tentatively suggested as explanations. Cloud effects were ruled out as a significant source of discrepancy  相似文献   
106.
Human mesenchymal stem cells (hMSCs) isolated from bone marrow aspirates were cultured on silk scaffolds in rotating bioreactors for three weeks with either chondrogenic or osteogenic medium supplements to engineer cartilage- or bone-like tissue constructs. Osteochondral composites formed from these cartilage and bone constructs were cultured for an additional three weeks in culture medium that was supplemented with chondrogenic factors, supplemented with osteogenic factors or unsupplemented. Progression of cartilage and bone formation and the integration between the two regions were assessed by medical imaging (magnetic resonance imaging and micro-computerized tomography imaging), and by biochemical, histological and mechanical assays. During composite culture (three to six weeks), bone-like tissue formation progressed in all three media to a markedly larger extent than cartilage-like tissue formation. The integration of the constructs was most enhanced in composites cultured in chondrogenic medium. The results suggest that tissue composites with well-mineralized regions and substantially less developed cartilage regions can be generated in vitro by culturing hMSCs on silk scaffolds in bioreactors, that hMSCs have markedly higher capacity for producing engineered bone than engineered cartilage, and that chondrogenic factors play major roles at early stages of bone formation by hMSCs and in the integration of the two tissue constructs into a tissue composite.  相似文献   
107.
108.
A long tube with elastic walls containing water is immersed in the sea aligned in the direction of wave travel. The waves generate bulges that propagate at a speed determined by the distensibility of the tube. If the bulge speed is close to the phase velocity of the waves, there is a resonant transfer of energy from the sea wave to the bulge. At the end of the tube, useful energy can be extracted. This paper sets out the theory of bulge tubes in the sea, and describes some experiments on the model scale and practical problems. The potential of a full-scale device is assessed.  相似文献   
109.
A new derivation is given of an equation, relating the capture width of a wave power converter to the polar diagram of the waves generated by the device. The pattern of waves in the lee of the device is calculated in detail.  相似文献   
110.
The Radiation Protection in Medicine conference, reviewed in this journal supplement, outlined nine strategies to promote radiation protection for patients. The Alliance for Radiation Safety in Pediatric Imaging has focused its work on three of those areas: creating awareness of the need and opportunities for radiation protection for children; developing open-source educational materials for medical professionals and parents on this critical topic for improved patient safety and communication; and lastly, advocating on behalf of children with industry, government and regulatory bodies to improve equipment design and safety features, standardisation of nomenclature and displays of dose reports across vendor platforms that reflect the special considerations of children.  相似文献   
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