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51.
During the past 20 years, findings have indicated that nature plays an active role in helping people recover from stress and fatigue. Two of the most cited theories in this field are Rachel and Stephen Kaplan's theory of recovery from Directed Attention Fatigue in nature and Roger Ulrich's theory of aesthetic and affective responses to natural environments and stress recovery. One aim of the present study is to test whether being outdoors in a green recreational environment causes people to be more focused, compared to being in a room indoors (in line with hypotheses suggested by the Kaplans). Another aim is to test whether people experience stress reduction, i.e. as evidenced by changes in blood pressure and heart rate, if they are placed in an environment with many green elements (in line with hypotheses suggested by Ulrich). The overall study design is that of an intervention study. Fifteen elderly persons living at a home for very elderly people participated. Their powers of concentration, blood pressure and heart rate were measured before and after an hour of rest in a garden or in an indoor setting. Seven elderly people were randomly chosen to have their first series of tests in a garden, while eight elderly people had their first series of tests indoors. The results indicate that powers of concentration increase for very elderly people after a visit to a garden outside the geriatric home in which they live, compared to that after resting indoors in their favourite room. The results did not show any effects on blood pressure or heart rate. It is suggested that having a one-hour rest outdoors in a garden setting plays a role in elderly people's powers of concentration, and could thereby affect their performance of activities of daily living. One important factor in this study was that both the outdoor environment and the indoor environment at the home were highly valued by participants.  相似文献   
52.
The present work presents methodology and development of a mathematical model for prediction of the influence of oxide scale on heat transfer during reheating of steel in an industrial furnace. In this developed model, temperatures inside the steel billet were measured and with thermocouples at selected places and were collected by a water cooled computer that was traveling inside the slab. CFD is used to calculate the flow field inside of a furnace. The mass‐transfer coefficient of the scale formation is obtained by solving the convection mass‐diffusion equation across a boundary layer to the surface of a flat plate. A model for inverse heat conduction is employed to calculate the local surface temperature and heat flux on top of the growing oxide scale layer on a slab moving through a walking beam reheating furnace. By using the inverse method, the transient temperature and heat flux was firstly determined on the surface of the steel. During subsequent computations, the growth of the scale was calculated and the surface temperature of the oxide scale was extracted by using the Cauchy data from the previous calculations. The sensibility of the model on steel physical parameters is studied, and suitable parameters were obtained for heating a low carbon steel plate in the reheating furnace. Results show that the oxide scale layer should not be neglected in reheating models.  相似文献   
53.
Highly efficient reversed-phase capillary electrochromatography (CEC) separations (plate numbers up to 700 000/m), with electrospray ionization mass spectrometry detection were achieved utilizing novel dextran-coated polymer nanoparticles as a pseudostationary phase. A continuous full filling (CFF) technique in which nanoparticles are continuously introduced into the capillary was employed for separation of neutral analytes (dialkyl phthalates), utilizing an orthogonal electrospray interface to prevent nanoparticles from entering the mass spectrometer. CFF-CEC benefits from that an entirely fresh column is employed for every analysis, avoiding carryover effects associated with stationary-phase contamination. The highly efficient separations obtained were accomplished by optimizing the organic modifier concentration in the electrolyte and by using a high nanoparticle concentration (5 mg/mL), to improve interparticle mass transfer and gain sufficient retention. Nanoparticles, with an average diameter of 600 nm, were prepared by polymerization of methacrylic acid and trimethylolpropane trimethacrylate, which in turn were coated with dextran. These nanoparticles formed stable suspensions in electrolytes having broad ranges of polarities, enabling straightforward optimization of the reversed-phase conditions.  相似文献   
54.
The development of low-cost, accurate, and equipment-free diagnostic tests is crucial to many clinical, laboratory, and field applications, including forensics and medical diagnostics. Cellulose fiber-based paper is an inexpensive, biodegradable, and renewable resource, the use of which as a biomolecule detection matrix and support confers several advantages compared to traditional materials such as glass. In this context, a new, facile method for the preparation of surface functionalized papers bearing single-stranded probe DNA (ssDNA) for rapid target hybridization via capillary transport is presented. Optimized reaction conditions were developed that allowed the direct, one-step activation of standard laboratory filters by the inexpensive and readily available bifunctional linking reagent, 1,4-phenylenediisothiocyanate. Such papers were thus amenable to subsequent coupling of amine-labeled ssDNA under standard conditions widely used for glass-based supports. The intrinsic wicking ability of the paper matrix facilitated rapid sample elution through arrays of probe DNA, leading to significant, detectable hybridization in the time required for the sample liquid to transit the vertical length of the strip (less than 2 min). The broad applicability of these paper test strips as rapid and specific diagnostics in "real-life" situations was exemplified by the discrimination of amplicons generated from canine and human mitochondrial and genomic DNA in mock forensic samples.  相似文献   
55.
The limit of detection of low-molecular weight compounds in tissue sections, analyzed by matrix assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI), was significantly improved by employing sample washing using a pH-controlled buffer solution. The pH of the washing solutions were set at values whereby the target analytes would have low solubility. Washing the tissue sections in the buffered solution resulted in removal of endogenous soluble ionization-suppressing compounds and salts, while the target compound remained in situ with minor or no delocalization during the buffered washing procedure. Two pharmaceutical compounds (cimetidine and imipramine) and one new protease inhibitor compound were successfully used to evaluate the feasibility of the pH-controlled tissue washing protocol for MALDI-MSI. Enhancement in signal-to-noise ratio was achieved by a factor of up to 10.  相似文献   
56.
57.
Photocatalytic approaches, that is the reaction of light‐produced charge carriers at a semiconductor surface with their environment, currently attract an extremely wide scientific interest. This is to a large extent due to the high expectations: i) to convert sunlight directly into an energy carrier (H2), ii) to stimulate chemical synthetic reactions, or iii) to degrade unwanted environmental pollutants. Since the early reports in 1972, TiO2 has been the most investigated photocatalytic material by far; this originates from its outstanding electronic properties that allow for a wide range of applications. Not only the material, but also its structure and morphology, can have a considerable influence on the photocatalytic performance of TiO2. In recent years, particularly 1D (or pseudo 1D) structures such as nanowires and nanotubes have received great attention. The present Review focuses on TiO2 nanotube arrays (and similar structures) that grow by self‐organizing electrochemistry (highly aligned) from a Ti metal substrate. Herein, the growth, properties, and applications of these tubes are discussed, as well as ways and means to modify critical tube properties. Common strategies are addressed to improve the performance of photocatalysts such as doping or band‐gap engineering, co‐catalyst decoration, junction formation, or applying external bias. Finally, some unique applications of the ordered tube structures in various photocatalytic approaches are outlined.  相似文献   
58.
We report for the first time on mechanical properties of anodically formed, self-organized TiO2 nanotube layers on titanium. We compare their behavior in their virgin state and after conversion to their semi-metallic form by an acetylene treatment. We show that the acetylene treatment leads to significant enhanced hardness, tensile strength and friction behavior.  相似文献   
59.
Nuclear fusion D+D processes are studied by nanosecond pulsed laser interaction with ultra-dense deuterium. This material has a density of 1029 cm?3 as shown in several previous publications. Laser power is <2 W (0.2 J pulses) and laser intensity is <1014 W cm?2 in the 5–10 μm wide beam waist. Particle detection by time-of-flight energy analysis with plastic scintillators is used. Metal foils in the particle flux to the detector remove slow ions, and make it possible to convert and count particles with energy well above 1 MeV. The variation of the signal of MeV particles from D+D fusion is measured as a function of laser power. At relatively weak laser-emitter interaction, the particle signal from the laser focus varies as the square of the laser power. This indicates collisions in the ultra-dense deuterium of two fast deuterons released by Coulomb explosions. During experiments with stronger laser-emitter interaction, the signal varies approximately as the sixth power of the laser power, indicating a plasma process. At least 2 × 106 particles are created by each laser pulse at the maximum intensity used. Our results indicate break-even in fusion at a laser pulse energy of 1 J with the same focusing, in approximate agreement with theoretical results for ignition conditions in ultra-dense deuterium. Radiation loss at high temperature will however require higher laser energy at break-even.  相似文献   
60.
The main objective of this paper is to analyze the role of policy support schemes and planning systems for inducing offshore wind power development in Sweden. Specifically, it highlights the different types of economic, political and planning-related conditions that face offshore wind power investors in Sweden, and provides brief comparisons to the corresponding investment conditions in Denmark, Norway and the UK. The analysis shows that in Sweden existing policy incentives are generally too weak to promote a significant development of offshore wind power, and the paper provides a discussion about a number of political and economic aspects on the choice between different support schemes for offshore wind in the country. Swedish permitting and planning procedures, though, appear favorable to such a development, not the least in comparison to the corresponding processes in the other major offshore wind countries in Europe (e.g., the UK). On a general level the paper illustrates that the success and failure stories of national offshore wind policies and institutions cannot be easily transferred across country borders, and the analysis shows that both the political and the legal frameworks governing the investment situation for offshore wind farms in Denmark, Norway, Sweden and the UK differ significantly.  相似文献   
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