HAA体系低温固化干混消光粉末涂料用低酸值聚酯树脂的合成及性能研究

通过考察聚酯配方中的二元醇单体的作用,研究酸解剂对涂层性能的影响,并在聚酯中加入特殊搭配的光稳定剂,合成得到了适用于制备羟烷基酰胺(HAA)体系低温固化干混消光粉末涂料的低酸值聚酯树脂,同时研究了粉末涂料的固化反应。结果表明:该粉末涂料具有较低的活化能,制备涂层可以实现160℃低温固化,消光光泽约为28,涂层具有良好的耐冲击性和耐老化性能,综合性能优异。

户外用羟烷基酰胺固化干混消光粉末涂料用聚酯树脂的合成与应用

开发了适用于羟烷基酰胺(Primid)固化干混消光粉末涂料用的高、低酸值聚酯树脂。研究了高、低酸值聚酯树脂制备成粉末涂料之后烘烤形成的涂层和按质量比50∶50干混后烘烤形成的涂层的机械性能、耐水煮性和耐热性。结果表明:该Primid固化体系干混光泽可以达到25～35,表面流平性和细腻度佳,机械性能和耐水煮性能优异,可以部分替换异氰脲酸三缩水甘油酯(TGIC)固化型粉末涂料。

高酸值聚酯树脂在干混消光涂层中的应用研究

研究不同种类高酸值树脂对干混消光粉末涂层光泽、流平以及细腻度的影响规律,通过改变高酸树脂合成中单体的种类、数量以及活性,合成不同种类的高酸值聚酯树脂。采用差式扫描量热仪(DSC)测试其玻璃化转变温度(T_(g)),并将合成的聚酯树脂与固化剂、颜填料和助剂制备成90/10异氰脲酸三缩水甘油酯(TGIC)固化型快组份粉末涂料,采用DSC确定其粉末T_(g)和固化峰值温度(Peak),考察它们的储存稳定性;并将不同类型的快组份粉末与同一种慢组份粉末涂料以质量份50:50干混固化,并测试粉末涂层的消光光泽、流平、耐温、水煮和耐候等性能。

聚酯及干混消光透明粉末涂料涂层透明度的研究

制备了透明度较好的高低酸值双组分干混消光透明粉末涂料用聚酯树脂。分别讨论了合成工艺、第一步醇酸比(r1)和单体对聚酯树脂透明度的影响,以及高酸值聚酯性能对干混消光涂层透明度的影响。研究表明,采用“酯化-真空-酸解-真空”工艺,高低酸值组分r1分别为1.12和1.18左右,合成配方中加入TMP、CHDM、BEPD和CHDA单体可以提升聚酯透明度;双组分聚酯具有适度的反应活性差异、聚酯配方组成类似及粘度等指标接近时,涂膜表面流平好、消光细腻、光泽适宜,涂层透明度较高。

消渴与湿邪

中医认为消渴－症的病理多因肺燥、冒热、肾虚所致，然而通过一病例的辨证施治，作者认为除了上述因素外，湿邪内郁亦可导致本病的发生。

A Low Noise,High Linearity CMOS Receiver for 802.11b WLAN Applications

A 2.4GHz monolithic CMOS receiver with direct-conversion architecture is presented. This quadrature receiver is designed for 802.11b wireless LAN applications at the maximum data rate of 11Mbps as a low-cost solution. Five key blocks,i, e., a low noise amplifier （LNA）, a down-conversion mixer, a variable gain amplifier, a low pass filter, and a DC- offset cancellation circuit,are designed based on system design and low noise high linearity considerations. The necessary auxiliary circuits are also included. Fabricated in SMIC 0.18μm 1p6m RF CMOS process, the receiver＇s performance is measured as：4. 1 dB noise figure, - 7.5dBm input third order intercept point （IIP3） for LNA ＆ mixer at high gain setting, - 14dBm IIP3 for the whole receiver,53dBc @30MHz offset of adjacent channel power rejection,and less than 5mV out- put DC-offset. The receiver consumes 44mA under a 1.8V power supply with I,Q two paths.

Improvement of the Mirror Extending in Empirical Mode Decomposition Method and the Technology for Eliminating Frequency Mixing

The mirror extending approach proposed by Zhao and Huang in EMD method is improved in this paper. Mirror extending manner of data is kept unchanged, but the approach for determining envelopes is changed. When the end of data is obviously not extremum, the envelope is determined by the first inner extremum and the image value in the mirror, ignoring the value on the end. This improvement eliminates the frequency compression near the end and decreases the error. Meanwhile, tridiagonal equations are used and the calculation speed is much increased. The temporal process curve is more important in reflecting the real physical process and comparable with other phenomena. Frequency mixing in IMFs makes it impossible. A high frequency reconstruction (HFR) approach is proposed to eliminate common frequency mixing and reconstruct an IMF with all high frequency portions. By this approach, the IMFs without frequency mixing are obtained to express significative processes. The high frequency information restored in high frequency IMF can be extracted by general spectrum method. After obtaining IMFs by EMD method, some of the theoretical and technological issues still exist when using the IMFs. The consistency of IMFs with real physical process is discussed in detail. By virtue of the approach proposed in this paper, the EMD method can be widely used in various fields.

Possible contribution of artificial neural networks and linear discriminant analysis in recognition of patients with suspected atrophic body gastritis

AIM: To investigate whether ANNs and LDA could recognize patients with ABG in a database, containing only clinical and biochemical variables, of a pool of patients with and without ABG, by selecting the most predictive variables and by reducing input data to the minimum.METHODS: Data was collected from 350 consecutive outpatients (263 with ABG, 87 with non-atrophic gastritis and/or celiac disease [controls]). Structured questionnaires with 22 items (anagraphic, anamnestic, clinical, and biochemical data) were filled out for each patient. All patients underwent gastroscopy with biopsies. ANNs and LDA were applied to recognize patients with ABG.Experiment 1: random selection on 37 variables, experiment 2: optimization process on 30 variables, experiment 3:input data reduction on 8 variables, experiment 4: use of only clinical input data on 5 variables, and experiment 5:use of only serological variables.RESULTS: In experiment 1, overall accuracies of ANNs and LDA were 96.6% and 94.6%, respectively, for predicting patients with ABG. In experiment 2, ANNs and LDA reached an overall accuracy of 98.8% and 96.8%,respectively. In experiment 3, overall accuracy of ANNs was 98.4%. In experiment 4, overall accuracies of ANNs and LDA were, respectively, 91.3% and 88.6%. In experiment 5, overall accuracies of ANNs and LDA were,respectively, 97.7% and 94.5%.CONCLUSION: This preliminary study suggests that advanced statistical methods, not only ANNs, but also LDA,may contribute to better address bioptic sampling during gastroscopy in a subset of patients in whom ABG may be suspected on the basis of aspecific gastrointestinal symptoms or non-digestive disorders.

Biohydrogen Production from Synthetic Waste Co-digested with Liquid Dairy Cow Manure： Effect of Temperature and Mixing Ratio

Biohydrogen production from synthetic waste, SW （model organic fraction of municipal solid waste） co-digested with liquid dairy manure （M） was tested in batch reactions to assess the effect of temperature and mixing ratio of the substrates. A 5 × 2 factorial design experiment was conducted. Synthetic waste： manure mixtures of 1：1, 2：1, 3：1, 1：0, 0：1 （volatile solids, VS, basis） were tested at 37 （T37） and 55 ℃ （T55） using thirty 1 L laboratory scale digesters. Total VS of each mixture was 50 g/L except SW：M 0：I treatment, where total VS was 27.4 g/L. Gas samples were taken daily to determine hydrogen production, and slurry samples taken before and after experimentation, were analyzed for volatile fatty acid （VFA） concentration, volatile solid （VS） degradation, ammonium nitrogen （NH4＋-N） and pH. Hydrogen production （mL/g-VS fed） showed a significant two-factor interaction between incubation temperature and SW：M ratio （P 〈 0.001）. Maximum production of 15.8 mL/g-VS （fed） was achieved in SW：M ratio of 3：1 at 55 ℃. Generally, hydrogen productions at thermophilic temperature （T55） were significantly higher than at mesophilic （T37） temperature for all treatments （P 〈 0.001） except for SW：M 1：0 and SW：M 0：1 treatments （P 〉 0.05）. This study indicates that hydrogen production from co-digestion of synthetic waste and manure is dependent on incubation temperature and relative contribution of wastes in the mixture.

Evaluating performance of cutting machines during sawing dimension stones

The performance of cutting machines in terms of energy consumption and vibration directly affects the production costs. In this work, our aim was to evaluate the performance of cutting machines using hybrid intelligent models. For this purpose, a systematic experimental work was performed. A database of the carbonate and granite rocks was established, in which the physical and mechanical properties of these rocks (i.e., UCS, elastic modulus, Mohs hardness, and Schmiazek abrasivity factor) and the operational parameters (i.e., depth of cut and feed rate) were considered as the input parameters. The predictive models were developed incorporating a combination of the multi-layered perceptron artificial neural networks and genetic algorithm (GANN-BP) and the support vector regression method and Cuckoo optimization algorithm (COA-SVR). The results obtained indicated that the performance of the developed GANN-BP and COA-SVR models was close to each other and that these models had good agreements with the measured values. These results also showed that these proposed models were suitable tools in evaluating the performance of cutting machines.

Construction of a 3D meso-structure and analysis of mechanical properties for deposit body medium

For deposit body medium, the internal structural properties may be the controlling factors for the strength of the material and the mechanical response. Based on the results of soil-rock meso-statistics using digital imaging, a simulated annealing algorithm is adopted to expand the meso-structural features of deposit bodies in 3D. The construction of the 3D meso-structure of a deposit body is achieved, and then the particle flow analysis program PFC3 D is used to simulate the mechanical properties of the deposit body. It is shown that with a combination of the simulated annealing algorithm and the statistical feature functions, the randomness and heterogeneity of the rock distribution in the 3D inner structure of deposit body medium can be realized, and the reconstructed structural features of the deposit medium can match the features of the digital images well. The spatial utilizations and the compacting effects of the body-centered cubic, hexagonal close and face-centered packing models are high, so these structures can be applied in the simulations of the deposit structures. However, the shear features of the deposit medium vary depending on the different model constructive modes. Rocks, which are the backbone of the deposit, are the factors that determine the shear strength and deformation modulus of the deposit body. The modeling method proposed is useful for the construction of 3D meso-scope models from 2D meso-scope statistics and can be used for studying the mechanical properties of mixed media, such as deposit bodies.

Effects of Using Exogenous Digestive Enzymes or Natural Enhancer Mixture on Growth, Feed Utilization, and Body Composition of Rabbitfish, Siganus rivulatus

This study was conducted to study the effects of a commercial exogenous digestive enzymes （EDE） containing cellulases, xylanases, u-amylase and proteases from anaerobic bacterium and natural enhancer mixture （NEM） containing allicin, high unit hydrolytic enzyme, Bacillus subtilis spores and ginseng extracts on survival, growth, carcass composition and feed cost/benefit in rabbitfish, Siganus rivulatus. Nine net cages （100 cm × 100 cm × 40 cm; L ×W ×H） were stocked with 10 juvenile rabbitfish （1.1 g per fish） each and placed in a large rectangular tank and offered feed at 4% body weight daily. Three replicates per treatment were offered three isonitrogenous and isocaloric diets, control and two supplemented diets with EDE or NEM at 2 g/kg diet for 74 days. Fish in all cages were weighed at two-week intervals and feed regimen was adjusted accordingly. Rabbitfish offered the control diet exhibited lower growth significantly （P 〈 0.05） and feed utilization than the other two experimental treatments. Experimental diet supplemented with NEM recorded the highest growth performance, feed conversion ratio, protein efficiency ratio, net protein utilization and energy retention significantly （P 〈 0.05） than the other two tested groups. Carcass composition and somatic parameters index was not affected by dietary EDE or NEM inclusion. Ultimately, when all variables are considered, EDE and NEM inclusion to diets appears to reduce feed cost per unit growth of rabbitfish.

A Moringa Oleifera Disinfectant-Sand Filter Integration： A Review of an Alternative Sustainable Technology for Household Water Treatment

This review provides an insight and up-to-date information on the application of Moringa oleifera seeds, the short falls of existing technologies as a coagulant and disinfectant in domestic water treatment. While the coagulant properties are well reported, the disinfectant properties are not well studied. Literatures on low cost alternative technologies such as the application of hiocoagulants and slow sand filters are extensively reported. However, there is limited work addressing the limitations of these technologies that have restricted its widespread use to solve the global soaring water crises. Slow sand filters have a very slow filtration rate that depends on the biofilm layer which takes about 17 days to form. Moringa oleifera treated water cannot last more than 48 hours without bacteria regrowth. Investigation of the best method of isolating coagulant component continues with differing opinions over the nature of its coagulant ingredient not resolved in ongoing literature. An attempt was made in this paper to highlight the advantages of a Moringa disinfectant sand filter hybrid system that can purify water. Microbiological advantages of this system in providing a 100% removal of pathogens, and engineering considerations such as water treatment within an hour residence time, faster flow rates, less clogging and backwashing could be some of the advantages ofa Moringa sand filter system. The need to focus on integrating Moringa and sand filter systems for more practical applications is recommended.

Dependence of Mixed Aerosol Light Scattering Extinction on Relative Humidity in Beijing and Hong Kong

The hygroscopic properties of mixed aerosol particles are crucial for the application of remote sensing products of aerosol optical parameters in the study of air quality and climate at multiple scales. In this study, the authors investigated aerosol optical properties as a func tion of relative humidity （RH） for two representative me tropolises： Beijing and Hong Kong. In addition to the RH data, mass concentrations of PM10 （particulate matter up to 10 utm in diameter） and aerosol scattering extinction coefficient （aext） data were used. The relationship between the mass scattering extinction efficiency （MEE, defined as O＇ext/PMl0） and RH can be expressed by regression func tions asf= 1.52x ＋ 0.29 （re= 0.77）,f= 1.42x ＋ 1.53 （re= 0.58）,f= 1.19x ＋ 0.65 （re= 0.59）, andf= 1.58x ＋ 1.30 （re = 0.61） for spring, summer, autumn, and winter, respec tively, in Beijing. Here, f represents MEE, x represents I/（1-RH）, and the coefficients of determination are pre sented in parentheses. Conversely, in Hong Kong, the corresponding functions are f= 1.98x- 1.40 （r^2= 0.55）,f = 1.32x - 0.36 （r^2 = 0.26）,f= 1.87x - 0.65 （r^2 = 0.64）, and f= 2.39x - 1.47 （r^2 = 0.72）, respectively. The MEE values for Hong Kong at high RHs （RH 〉 70%） are higher than those for Beijing, except in summer; this suggests that aerosols in Hong Kong are more hygroscopic than those in Beijing for the other three seasons, but the aerosol hy groscopicity is similarly high in summer over both cities. This study describes the effects of moisture on aerosol scattering extinction coefficients and provides a potential method of studying atmospheric visibility and ground level air quality using some of the optical remote sensing products of satellites.

Synergistic and interference effects in coaxial mixers: Numerical analysis of the power consumption

This paper is concerned with the design and application of coaxial mixers with the aid of analysis of interaction between each individual impeller. Two types of coaxial mixers pitched blade turbine(PBT)-helical ribbon(HR)and inner-outer HR operated in laminar regime were studied experimentally and numerically. The interaction implies synergistic and interference effects, which was revealed through the investigation of axial circulation rate, energy dissipation rate and power consumption. The influence factors including rotational speed ratio,rotating mode and impeller configuration were explored systematically. Quantitative analysis of power consumption involves three parameters: rate of variation in power consumption, interactive mode and ratio of power consumption. Analysis indicated that some important properties were embodied in the power curve.These properties are one-way and two-way interactions, critical speed ratio and dominant impeller. Finally, a new suggestion for power estimation was given.

Carbon-emission calculation of electromechanical energy consumption of different structures during the construction phase

Due to the use of mechanical and electrical equipments in different buildings during construction phase, energy consumption produces large amounts of carbon emissions.Based on the energy use of China, we established a formula that was applicable to carbon-emission calculation, and discussed carbon-emission characteristics of concrete structures and steel construction.Owing to the difference of electrical and mechanical equipment used in construction phase, the results show that under the same conditions, the carbon emission intensity of a concrete structure building is much higher than that of a steel building.At last, we also put forward some emission reduction measures based on the calculation data of different buildings.

Performance and Ruminal Characteristics of Beef Cattle Fed Four Different Hybrids Sorghum Silages

This study was conducted to evaluate the intake, total and partial digestibility of nutrient, ruminal pH and ammonia concentration, microbial protein synthesis and performance in crossbred Holstein × Zebu cattle fed four different hybrids sorghum silages （1F305, XBF60329, BRS610, Volumax）. In Experiment 1, four rumen and abomasum fistulated steers, 400 ± 80 kg, distributed in a 4 × 4 Latin Square, were used. In Experiment 2, 28 crossbred Holstein × Zebu steers, 350 ± 50 kg, distributed in a randomized block design with four treatments and seven replicates, were used. In Experiment 1, it was observed that nutrient intake, as well as total, ruminal and intestinal digestibility of nutrient, were not affected （P 〉 0.05） by diets, except for total apparent digestibility of neutral detergent fiber （NDFap）, which was lower for the BRS610 hybrid. There was lower NDFap ingestion in animals that received a diet containing silage from the BRS610 hybrid, however, the lowest intake non-fibrous carbohydrates （NFC） was observed for the diet containing silage from the Volumax hybrid. In Experiment 2, nutrient intake were not affected by the diets （P 〉 0.05）, whereas, NDFap intake was lesser for hybrid BRS610. It was found that daily weight gain and feed conversion were not affected by different silages diets. Therefore, it may be concluded that the diets used were nutritionally equivalent, as they promoted similar animal performance without affecting ruminal parameters.

Efficiency of Structural Materials in Sustainable Design

The main aim of this paper is to investigate energy consumptions, CO2 emissions and costs during the production and life cycle of structural materials. The virgin and recycled metals as well as waste minerals such as fly ash, slag in concrete save energy consumption, CO2 emissions and costs. The importance and effectiveness of recycled materials will be statistically evaluated via energy consumption, carbon footprint, ultimate strength and their ratios. Embodied energy to ultimate strength or embodied carbon to ultimate strength ratios may emphasize the effectiveness of a sustainable material. The analyses in this study indicate the utilization of the recycled steel and C50 concrete with 50% fly ash or slag is the most efficient way of using sustainable materials.

Apparatus Prototype for Purposes of Teaching in Bio-digesters

A mathematical model is developed based on a simplified mechanism of anaerobic digestion. The main objective is to quantitatively analyze the digestion process to optimize operating conditions and maintenance of this equipment, which could be used to test different materials and be able to apply these results to the possible scaling to bio-digesters installed in the field. The experiments were carried out in a hybrid system bio-digester photovoltaic cells. The bio-digester is made of stainless steel with dimensions to treat an average of 10 kg of raw material and produce biogas from different organic materials. The reactor has been conditioned with temperature sensors, pressure and methane gas that allow monitoring the concentration of the gas and the conditions of operation during the time of digestion. The system has a photovoltaic array to provide the energy required to keep the temperature constant, The experiment was conducted using materials such as goat manure mixed with household waste, and various formulations of these materials were prepared. The experimental results were used to test the mathematical model.

A Location-Based Content Search Approach in Hybrid Delay Tolerant Networks

In Delay Tolerant Networks （DTNs）, the offiine users can, through the encountering nodes, use the specific peer-to-peer message routing approach to deliver messages to the destination. Thus, it solves the problem that users have the demands to deliver messages while they are temporarily not able to connect to the Internet. Therefore, by the characteristics of DTNs, people who are not online can still query some location based information, with the help of users using the same service in the nearby area. In this paper, we proposed a location-based content search approach. Based on the concept of three-tier area and hybrid node types, we presented four strategies to solve the query problem, namely, Data Replication, Query Replication, Data Reply, and Data Synchronization strategies. Especially we proposed a Message Queue Selection algorithm for message transferring. The priority concept is set associated with every message such that the most ＂important＂ one could be sent first. In this way, it can increase the query success ratio and reduce the query delay time. Finally, we evaluated our approach, and compared with other routing schemes. The simulation results showed that our proposed approach had better query efficiency and shorter delay.