3,021 research outputs found
The Research on New Town Development Strategy in Metropolitan Outskirts: A Case Study of Liangzhu New Town
New Towns in the outskirts of city has existed for a moment within the period of China urbanization, and lots of experiences are accumulated during the practices while building this system.
This essay is mainly established by the first multifunctional outskirt town, as well as the research object --- Liangzhu New Town, and it also make dicussions and summaries about the concept of design, the structure of this project, the operation process, the mode of operation and etc.
Overall, by combining the objective requirements of the outskirts new town development, which is affected by the metropolitan suburbanization, this paper explores a smart way in the construction of the new style urbanization, as well as the solution to the problems which may happen during the construction of the outskirts new town
Study on the influence of temperature on the surface asperity in micro cross wedge rolling
When the common deformation processes are scaled down to micro/meso dimensions, size effect is the particular phenomena in microforming, which is related to the dominant influence of single grains inside the micropart. The conventional cross wedge rolling (CWR) is introduced into the micro scale in order to take the advantages of CWR. The micro cross wedge rolling (MCWR) has to confront with the phenomena of size effect that occurs in the common microforming processes inevitably. One of the approaches to compensate size effect is to increase the deforming temperature. An increased formability is achieved because more slip systems of polycrystal metal are activated at the elevated temperature. This reduces the anisotropic material behavior resulting in a more homogeneous forming with improved reproducibility. In this study, a YAG laser beam is applied to heat the workpiece. Finite element model (FEM) associated with a material constitutive formulation considering dislocation mechanics is set up to simulate the MCWR of pure copper utilizing the laser heating. The surface asperity as an indication of material heterogeneity in micro scale is quantitatively analysed. The simulation results show a good agreement with experimental results in terms of the surface asperity. © 2013 AIP Publishing LLC
Networked Control Systems: The Communication Basics and Control Methodologies
As an emerging research field, networked control systems have shown the increasing importance and attracted more and more attention in the recent years. The integration of control and communication in networked control systems has made the design and analysis of such systems a great theoretical challenge for conventional control theory. Such an integration also makes the implementation of networked control systems a necessary intermediate step towards the final convergence of control, communication, and computation. We here introduce the basics of networked control systems and then describe the state-of-the-art research in this field. We hope such a brief tutorial can be useful to inspire further development of networked control systems in both theory and potential applications
Meta-analysis of scalp acupuncture for acute hypertensive intracerebral hemorrhage
Objectives: Scalp acupuncture (SA) is a commonly used therapeutic approach for primary intracerebral hemorrhage (ICH) in Traditional Chinese Medicine (TCM), but the efficacy and safety of SA therapy are still undetermined. The aim of this study is to systematically evaluate the efficacy and safety of SA therapy for the treatment of acute hypertensive ICH. Methods: Literature reports with randomized controlled clinical trials and controlled clinical trials on SA therapy for acute hypertensive ICH were searched, and the efficacy and safety of SA therapy were evaluated by using the Cochrane systematic review methods. The primary outcome measures were death or dependency at the end of long-term follow-up (at least 3 months) and adverse events. The secondary outcome measure was neurological deficit improvement at the end of the treatment course. Results: Seven (7) independent trials (230 patients) were included in this study. All trials described the methods of randomization in which four trials had adequate concealment of randomization at the level of grade A, but no trial included sham acupuncture as a control group. None of the trials included "death or dependency" as a primary outcome measure. Four (4) trials contained safety assessments and stated that no adverse event was found, whereas the other three trials did not provide the information about adverse events. By using random effects statistical model, it was found that patients with acute hypertensive ICH who received SA therapy had significantly improved neurological deficit scores (Z=4.97, p<0.01). Conclusions: Although SA therapy is widely used to treat acute hypertensive ICH in TCM, the efficacy and safety of SA therapy remain to be further determined. No evidence is available on whether SA therapy can be used to treat acute ICH according to the primary outcome measure. However, SA therapy appears to be able to improve neurological deficit in patients with acute hypertensive ICH. © 2011, Mary Ann Liebert, Inc.published_or_final_versio
Probing deep level centers in GaN epilayers with variable-frequency capacitance-voltage characteristics of AuGaN Schottky contacts
Under identical preparation conditions, AuGaN Schottky contacts were prepared on two kinds of GaN epilayers with significantly different background electron concentrations and mobility as well as yellow emission intensities. Current-voltage (I-V) and variable-frequency capacitance-voltage (C-V) characteristics show that the Schottky contacts on the GaN epilayer with a higher background carrier concentration and strong yellow emission exhibit anomalous reverse-bias I-V and C-V characteristics. This is attributed to the presence of deep level centers. Theoretical simulation of the low-frequency C-V curves leads to a determination of the density and energy level position of the deep centers. © 2006 American Institute of Physics.published_or_final_versio
Dehydration of forward osmosis membranes in treating high salinity wastewaters: Performance and implications
© 2015 Elsevier B.V. Forward osmosis (FO) is a promising technique for desalinating high salinity wastewaters, and membrane performance is critical for its successful application. In this work, the dehydration of FO membranes was demonstrated for both commercial cellulose triacetate and tailor-made thin-film composite membranes. A significant loss of FO flux was observed after membrane dehydration, but the pure water permeability and rejection properties remained about the same. Dehydrated membrane showed opaque/white spots on the initially homogeneous membrane. Once dehydrated, a membrane with a much lower water flux will be resulting in. It was demonstrated that when the active skin layer was in contact with the saline solution before the support layer was brought into contact with an aqueous solution, membrane dehydration took place. The dehydration was ascribed to osmosis gradient across the active layer that caused water flow from membrane support layer to the active layer, resulting in support dehydration. The dehydrated membrane could be rewetted again by low surface tension liquid or reverse osmosis, illustrating that membrane dehydration is reversible. Precaution should be addressed when operating large FO system to prevent the membrane dehydration for high salinity water treatment
Low temperature magneto-morphological characterisation of coronene and the resolution of previously observed unexplained phenomena
The polyaromatic hydrocarbon coronene has been the molecule of choice for understanding the physical properties of graphene for over a decade. The modelling of the latter by the former was considered to be valid, as since it was first synthesised in 1932, the physical behaviour of coronene has been determined extremely accurately. We recently discovered however, an unforeseen polymorph of coronene, which exists as an enantiotrope with the previously observed crystal structure. Using low-temperature magnetisation and crystallographic measurements, we show here for the first time that the electronic and magnetic properties of coronene depend directly on the temperature at which it is observed, with hysteretic behaviour exhibited between 300 K and 100 K. Furthermore we determine that this behaviour is a direct result of the appearance and disappearance of the newly-discovered polymorph during thermal cycling. Our results not only highlight the need for theoretical models of graphene to take into account this anomalous behaviour at low temperatures, but also explain puzzling experimental observations of coronene dating back over 40 years
Linkage and mapping analyses of the no glue egg gene Ng in the silkworm (Bombyx mori L.) using simple sequence repeats (SSR) markers
In the silkworm, Bombyx mori, no glue egg is mainly controlled by Ng (No glue) gene, which is located on the 12th chromosome. Owning to a lack of crossing over in females, reciprocal backcrossed F1 (BC1) progenies were used for linkage analysis and mapping of the Ng gene based on the simple sequence repeats (SSR) linkage map using silkworm strains H9 and P50, which are Ng mutant and normal to egg, respectively. The Ng gene was found to be linked to three SSR markers. Using a reciprocal BC1M cross, we constructed a linkage map of 36.4 cM, with Ng mapped at 15.9 cM and the nearest SSR marker at a distance of 7.4 cM. Based on fine genome map of domesticated silkworm (B. mori), the result of Kaikoblast show that the physical distance between the near markers (containing Ng gene) is 181.7 Kb. Further analysis show that BGIBMGA005833, BGIBMGA005835 and BGIBMGA005836 are closer to Ng, and the BGIBMGA005835 is nearest to Ng, which physical distance is 44 Kb.Key words: Gene location, linkage analysis, microsatellite, Ng, silkworm
Model-based assessment of chromate reduction and nitrate effect in a methane-based membrane biofilm reactor
© 2019 Zhejiang University Chromate contamination can pose a high risk to both the environment and public health. Previous studies have shown that CH4-based membrane biofilm reactor (MBfR) is a promising method for chromate removal. In this study, we developed a multispecies biofilm model to study chromate reduction and its interaction with nitrate reduction in a CH4-based MBfR. The model-simulated results were consistent with the experimental data reported in the literature. The model showed that the presence of nitrate in the influent promoted the growth of heterotrophs, while suppressing methanotrophs and chromate reducers. Moreover, it indicated that a biofilm thickness of 150 μm and an influent dissolved oxygen concentration of 0.5 mg O2/L could improve the reactor performance by increasing the chromate removal efficiency under the simulated conditions
Disparities and risks of sexually transmissible infections among men who have sex with men in China: a meta-analysis and data synthesis.
BACKGROUND: Sexually transmitted infections (STIs), including Hepatitis B and C virus, are emerging public health risks in China, especially among men who have sex with men (MSM). This study aims to assess the magnitude and risks of STIs among Chinese MSM. METHODS: Chinese and English peer-reviewed articles were searched in five electronic databases from January 2000 to February 2013. Pooled prevalence estimates for each STI infection were calculated using meta-analysis. Infection risks of STIs in MSM, HIV-positive MSM and male sex workers (MSW) were obtained. This review followed the PRISMA guidelines and was registered in PROSPERO. RESULTS: Eighty-eight articles (11 in English and 77 in Chinese) investigating 35,203 MSM in 28 provinces were included in this review. The prevalence levels of STIs among MSM were 6.3% (95% CI: 3.5-11.0%) for chlamydia, 1.5% (0.7-2.9%) for genital wart, 1.9% (1.3-2.7%) for gonorrhoea, 8.9% (7.8-10.2%) for hepatitis B (HBV), 1.2% (1.0-1.6%) for hepatitis C (HCV), 66.3% (57.4-74.1%) for human papillomavirus (HPV), 10.6% (6.2-17.6%) for herpes simplex virus (HSV-2) and 4.3% (3.2-5.8%) for Ureaplasma urealyticum. HIV-positive MSM have consistently higher odds of all these infections than the broader MSM population. As a subgroup of MSM, MSW were 2.5 (1.4-4.7), 5.7 (2.7-12.3), and 2.2 (1.4-3.7) times more likely to be infected with chlamydia, gonorrhoea and HCV than the broader MSM population, respectively. CONCLUSION: Prevalence levels of STIs among MSW were significantly higher than the broader MSM population. Co-infection of HIV and STIs were prevalent among Chinese MSM. Integration of HIV and STIs healthcare and surveillance systems is essential in providing effective HIV/STIs preventive measures and treatments. TRIAL REGISTRATION: PROSPERO NO: CRD42013003721
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