风机盘管造型及安装中应注意问题探讨

风机盘管系统由于调控简便、易于安装和较低的造价等优点,在各种空调系统中应用范围不断扩大。尤其在更能满足人们对环境档次与居住要求的中央空调中,更是具有着不可或缺的重要地位。本文对风机盘管的造型及安装等相关问题展开深入探讨。

Hydrothermal Synthesis of Disk-Like Bi2WO6-BiPO4 Heterojunctions and Enhanced Photocatalytic Performance for Rhodamine B Degradation

Novel Bi2WO6-BiPO4 photocatalysts with heterojunction structure were fabricated through a facile hydrothermal route. The photocatalytic properties of Bi2WO6-BiPO4 composites were evaluated by photocatalytic degradation of rhodamine B （Rh B） under simulated sunlight irradiation. The results showed that Bi2WO6-BiPO4 photocatalysts displayed much higher photocatalytic performances for Rh B degradation than the single BiPO4 and Bi2WO6. The best photocatalytic activity of Bi2WO6-BiPO4 with nearly 100% Rh B degradation located at molar ratio of 1：1 after 20 min irradiation. The enhanced photo-catalytic performance could be mainly ascribed to the formation of heterojunction interface in Bi2WO6-BiPO4 which facilitated the transfer and separation of photogenerated electron-hole pairs, as well as the strong visible light absorption originating from the sensitization role of Bi2WO6 to BiPO4. It was also found that the photodegradation of Rh B molecules was mainly attributed to the oxidation action of the generated O2^· - radicals and partly to the action of hvb^＋ via direct hole oxidation process.

Facile synthesis of Ag_2O-TiO_2/sepiolite composites with enhanced visible-light photocatalytic properties

Ag2O-TiO 2/sepiolite heterostructure composites were synthesized by a simple two-step method at low temperatures（100–450 °C）. Acid red G aqueous solution and gaseous formaldehyde were chosen as model organic pollutants to evaluate the photocatalytic performance of the as-prepared composites. The results showed that the Ag2O-TiO 2/sepiolite exhibited enhanced photocatalytic activity over pure Ag2O-TiO 2,TiO 2/sepiolite,and Ag2O/sepiolite under visible-light irradiation（λ 420 nm）. The excellent photocatalytic efficiency of these composites can be ascribed to the synergistic effect between the heterojunction and the porous structure of the clay layers,which induced high adsorption and efficient charge separation. In addition,the active species involved in the degradation reaction have been investigated by photoluminescence spectroscopy and quenching experiments. A possible photocatalytic degradation mechanism of acid red G dye by the Ag2O-TiO 2/sepiolite composite is also discussed.

CPAP结合肺泡表面活性物质治疗新生儿呼吸窘迫综合征的疗效观察

目的分析CPAP结合肺泡表面活性物质治疗新生儿呼吸窘迫综合征的临床疗效。方法选取我院2016年2月—2017年4月收治的新生儿呼吸窘迫综合征患儿40例作为研究对象。通过抽签法,将其均分为观察组和对照组,每组各20例患儿。对照组患儿采用肺泡表面活性物质进行治疗,观察组患儿采用CPAP结合肺泡表面活性物质进行治疗。结果治疗前,观察组和对照组患者PaO_2、PaCO_2、PaO_2/FiO_2和pH值比较,差异无统计学意义(P>0.05)。治疗后,观察组患者PaO_2、PaCO_2、PaO_2/FiO_2和pH值与对照组比较,差异具有统计学意义(P<0.05)。结论新生儿呼吸窘迫综合征经CPAP结合肺泡表面活性物质治疗疗效确切。

In-situ polymerization for PPy/g-C_3N_4 composites with enhanced visible light photocatalytic performance

Polypyrrole‐modified graphitic carbon nitride composites(PPy/g‐C3N4)are fabricated using an in‐situ polymerization method to improve the visible light photocatalytic activity of g‐C3N4.The PPy/g‐C3N4 is applied to the photocatalytic degradation of methylene blue(MB)under visible light irradiation.Various characterization techniques are employed to investigate the relationship between the structural properties and photoactivities of the as‐prepared composites.Results show that the specific surface area of the PPy/g‐C3N4 composites increases upon assembly of the amorphous PPy nanoparticles on the g‐C3N4 surface.Owing to the strong conductivity,the PPy can be used as a transition channel for electrons to move onto the g‐C3N4 surface,thus inhibiting the recombination of photogenerated carriers of g‐C3N4 and improving the photocatalytic performance.The elevated light adsorption of PPy/g‐C3N4 composites is attributed to the strong absorption coefficient of PPy.The composite containing 0.75 wt%PPy exhibits a photocatalytic efficiency that is 3 times higher than that of g‐C3N4 in 2 h.Moreover,the degradation kinetics follow a pseudo‐first‐order model.A detailed photocatalytic mechanism is proposed with·OH and·O2-radicals as the main reactive species.The present work provides new insights into the mechanistic understanding of PPy in PPy/g‐C3N4 composites for environmental applications.

Enhanced photocatalytic performance of MoS_2 modified by AgVO_3 from improved generation of reactive oxygen species

In this work, an efficient AgVO3/MoS 2 composite photocatalyst was successfully synthesized via a hydrothermal method. The photocatalytic activity of the as-prepared photocatalyst was evaluated by using it for assessing the degradation of different organic pollutants under visible-light irradiation. The composite 3%-AgVO3/MoS 2 catalyst demonstrated a significantly enhanced photocatalytic activity compared to the pure compounds（AgVO3 and MoS2）. The reason behind the excellent photocatalytic performance was the modification of MoS 2 by AgVO3 to facilitate O2 adsorption/activation. In addition, the composite catalyst facilitates the two-electron oxygen reduction reaction whereby H2O2 is generated on the surface of MoS 2 to produce additional reactive oxygen species（ROSs）. ESR coupled with the POPHA fluorescence detection method and a free radical capture experiment were used to elucidate the mechanism of formation of the ROSs, including ·OH, ·O2- and H2O2. Furthermore, the generation of additional ROSs could accelerate electron consumption, leaving behind more holes for the oxidation of organic pollutants. A possible photocatalytic mechanism of the composite is also discussed.

Construction of Z-scheme Ag_3PO_4/Bi_2WO_6 composite with excellent visible-light photodegradation activity for removal of organic contaminants

Ag3PO4has good potential for use in photocatalytic degradation of organic contaminants.However,the activity and stability of Ag3PO4is hard to sustain because of photocorrosion and the positive potential of the conduction band of Ag3PO4.In this study,A composite consisting of Bi2WO6nanosheets and Ag3PO4was developed to curb recombination of charge carriers and enhance the activity and stability of the catalyst.Formation of a Ag3PO4/Bi2WO6composite was confirmed using X‐ray diffraction,energy‐dispersive X‐ray spectroscopy,and X‐ray photoelectron spectroscopy.Photoluminescence spectroscopy provided convincing evidence that compositing Bi2WO6with Ag3PO4effectively reduced photocorrosion of Ag3PO4.The Ag3PO4/Bi2WO6composite gave a high photocatalytic performance in photodegradation of methylene blue.A degradation rate of0.61min?1was achieved;this is1.3and6.0times higher than those achieved using Ag3PO4(0.47min?1)and Bi2WO6(0.10min?1),respectively.Reactive species trapping experiments using the Ag3PO4/Bi2WO6composite showed that holes,?OH,and?O2?all played specific roles in the photodegradation process.The photocatalytic mechanism was investigated and a Z‐scheme was proposed as a plausible mechanism.

UV-Vis Spectrophotometry and AFM Observation of Diethyl Dithiophosphate Adsorption on Chalcopyrite at Varied pHs

Adsorption of diehtyl dithiophosphate on chalcopyrite has been studied using UV-visible spectroscopy at pH values of 4, 6, and 9. It was found that the adsorption of diethyl dithiophosphate decreased with the increasing pH treatments. The inhibition of diethyl dithiophosphate adsorption was found prominent in higher pH as a result of metal hydroxide species formation onto chalcopyrite surface. First order kinetic has been proposed and represented the adsorption mechanism. Flotation test using Hallimond tube has also been conducted and the results were consistent with the proposed mechanism. Furthermore, the morphological changes of the treated chalcopyrite were observed using Atomic Force Microscopy （AFM） showing the propensity of growth of islands, the new surfaces as products of the reaction. The hydrophobicity was measured in the form of force of adhesion. The results resembled with the approached mechanism.

Comparison of Visibility Measurements over Horizontal Path by Micro-pulsed Lidar and Visibility Meter

As a powerful tool to scan the atmosphere, the I idar can derive visibility values by directly collecting the backscattering laser light from the atmosphere. Simultaneous measurements of atmospheric visibility by Micro-pulsed lidar （MPL） and a commercial visibility meter （VM） NQ-1 have been performed to evaluate the feasibility of the MPL system designed by the Ocean Remote Sensing Laboratory （ORSL） of the Ocean University of China （OUC） from October 21 2005 to November 21 2005 in the Shilaoren Sightseeing Garden on the Qingdao coast. All the 880 data samples obtained by the two instruments have high correlation coefficients （up to 0.86）, which indicates it is feasible to utilize MPL to measure atmospheric visibility.

Assessment of Coronary Stents by 64-slice Computed Tomography: In-stent Lumen Visibility and Patency

Objective To assess lumen visibility of coronary stents by 64-slice computed tomography （CT） coronary angiography, and determine the value of 64-slice CT in non-invasive detecting of in-stent restenosis after coronary artery stent implantation. Methods Totally, 60 patients （54 males, aged 57.0±12.7 years） and /05 stents were investigated by 64-slice CT at a mean interval of 20.0±16.6 months after coronary stents implantation. Axial multi-planar reconstruction images of the stents and curved-planar reconstruction images through the median of the stents were reconstructed for evaluating stent image quality on a 5-point scale （1=excellent, 5=nonassessable）, and stent lumen diameter was detected. Conventional coronary angiography was performed in 18 patients, and 32 stents were evaluated. Results Image quality was good to excellent on average （score 1.71±0.76）. Stent image quality score was correlated to heart rate （r=0. 281, P〈0.01） and stent diameter （r=-0.480, P〈0.001）. All the stents were assessable in lumen visibility with an average visible lumen diameter percentage of 60.7%±13.6%. Visible lumen diameter percentage was correlated to heart rate （r=-0.193, P〈0.05）, stent diameter （r=0.403, P〈0.001）, and stent image quality score （r=-0.500, P〈0.001）. Visible lumen diameter percentage also varied depending on the stent type. In comparison with the conventional coronary angiography, 4 of 6 in-stent stenoses were correctly detected. The sensitivity and specificity for the detection of in-stent stenosis were 66.7% and 84.6%, respectively. Conclusions Using a 64-slice CT, the stent lumen is partly visible in most of the stents. And 64-slice CT may be useful in the assessment of stent patency.

Place recognition based on saliency for topological localization

Based on salient visual regions for mobile robot navigation in unknown environments, a new place recognition system was presented. The system uses monocular camera to acquire omni-directional images of the environment where the robot locates. Salient local regions are detected from these images using center-surround difference method, which computes opponencies of color and texture among multi-scale image spaces. And then they are organized using hidden Markov model (HMM) to form the vertex of topological map. So localization, that is place recognition in our system, can be converted to evaluation of HMM. Experimental results show that the saliency detection is immune to the changes of scale, 2D rotation and viewpoint etc. The created topological map has smaller size and a higher ratio of recognition is obtained.

Immobilization of metal-organic molecular cage on g-C3N4 semiconductor for enhancement of photocatalytic H2 generation

A new compound based on immobilizing of Pd6(RuL3)8(BF4)28 (L=2-(pyridin-3-yl)-1H-imidazo [4,5-f][1,10]-phenanthroline) cage (MOC-16) on g-C3N4 was synthesized. Infrared spectrum and powder X-ray diffraction were used to characterize structure of hybrid MOC-16/g-C3N4, as well as UV-vis absorption spectrum and X-ray photoelectron spectroscopy were carried out to unveil photocatalytic mechanism. With the introduction of MOC-16, the absorption edge of MOC-16/g-C3N4 in UV-vis spectrum extended apparently to long-wavelength region compared with pristine g-C3N4. H2 evolution yielded with MOC-16/g-C3N4 in aqueous solution containing TEOA was much higher than that with RuL3/g-C3N4, Pd/RuL3/g-C3N4 and mixture of MOC-16 and g-C3N4, showing that the octahedral cage structure with high-efficient electron transfer and the interface interaction between MOC-16 and g-C3N4 were significant for improvement of H2 evolution.

Research on the Action Mechanism of Technology Foresight in Strategic Emerging Industries----Take The Delphi Method And Technology Roadmap For Example

Developing strategic emerging industries is the major strategic initiative to accelerate the transformation of economic development while Technology Foresight is a very effective tool. This essay analyses the roles and limitations of Delphi method and Technology Roadmap in development of strategic emerging industries and offers suggestions on how to strengthen the effectiveness of Technology Foresight in it.

Robust photocatalytic benzene degradation using mesoporous disk-like N-TiO2 derived from MIL-125(Ti)

N-doped anatase-rutile titanium dioxide(N-TiO2)is a classical semiconductor widely used in environmental remediation.Its photocatalytic performance is typically affected by its morphology,porous structure,and phase composition.Herein,disk-like mesoporous N-TiO2 was prepared by calcining MIL-125(Ti)and melamine matrix at different temperatures in air.The photocatalytic efficiency of the prepared mesoporous N-TiO2 for the photo-oxidation of gaseous benzene under visible-light irradiation was studied.With respect to light absorption and mass transfer,as-prepared N-TiO2 annealed at 500℃(MM-500)showed the best photocatalytic activity with corresponding photodegradation and mineralization efficiencies of 99.1%and 72.0%,respectively.In addition.MM-500 exhibited excellent reusability and stability in cyclic experiments,in which 84.8%of gaseous benzene could still be photodegraded after 10 experimental cycles.Furthermore,electron spin resonance analysis indicated that·OH and·O2-radicals were the dominating reactive oxygen species during the photo-oxidation process.Their excellent performance suggests that the as-prepared N-TiO2 photocatalysts can be used to eliminate volatile organic compounds.

Preparation of Organic Semiconductor PTCDA and Studies on Its Crystal Structure and the Absorption Spectrum

Organic semiconductoe 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) has been synthetized with 1,8-naphthalic anhydride using chemical method.X-ray diffraction spectrum shows that it is monoclinic.Visible absorption spectrum shows that its gap band is 2.2 eV with singlet exciton bandwidth of 0.9 eV.

Biological Status of Captive Crane in Southern Districts of Northern Pakistan

A study was aimed to overlook biological status including egg hatching, diet and diseases of common, Grus grus L. and demoiselle, Anthropoidedes virgo L. cranes in captive form in the southern districts of the Northern Pakistan. Field survey, questionnaire and interview with communities were the major tools for the data collection. Total 165 and 85 camps were visited, respectively, in fall, 2008 and spring, 2009. These camps were established in Baran dam, Kurram, Kashu, Kethu and Dowa in Bannu; and Gambilla, Lunder and Chall rivers in Lakki. The numbers of 1,650 hunters have 6,600 demoiselle and 3,300 common captive cranes in Bannu and Lakki, respectively. From 920 breeding pairs, 900 eggs were obtained, from which only 640 were hatched. Among natural foods of the cranes, snails, grasshoppers and earthworms, the pebbles were the most favorite foods. The young ones of cranes were fed on maize bread, eggs of insects and other small animals like wasp＇s larvae and grasshoppers by hunters. They faced the problems of development of feathers, trapping in mud and parasitic attack during their development. The cranes suffered from many diseases; head tumor, influenza and stomach blockage were the most common in the adults and young ones. The hunters used traditional things, garlic, coriander and brown sugar with antibiotics for treatments of diseases. Migratory cranes were found to be declining viewed by hunters in southern districts of Northern Pakistan. Knowledge about egg hatching, foods and diseases of common and demoiselle captive cranes, might be assisted in their conservation.

Thiazolo[5,4-d]thiazole-based covalent organic framework microspheres for blue light photocatalytic selective oxidation of amines with O2

Covalent organic frameworks(COFs)with photoactive units have attracted significant interest in visible light photocatalysis and can present a metal‐free scenario for activating O_(2).As a typical photoactive unit,thiazolo[5,4‐d]thiazole(TzTz)has rarely been added to COFs.However,circumventing the low reversibility of TzTz,it could be embedded into the building blocks beforehand,along with other bonds likeβ‐ketoenamine in forming COFs.TzTz was embedded into 1,1′‐biphenyl‐4,4′‐diamine(BD)using this approach to produce 4,4′‐(TzTz‐2,5‐diyl)dianiline(DTz).Under organobase‐modulated solvothermal conditions,combining 1,3,5‐triformylphloroglucinol(Tp)with BD and DTz resulted in the production ofβ‐ketoenamine‐linked TpBD‐COF and TpDTz‐COF.Both TpDTz‐COF and TpBD‐COF are microspheres.TpDTz‐COF possessed more adequate separation and charge migration than TpBD‐COF.This resulted in superior performance for the blue light photocatalytic selective oxidation of benzylamine with O_(2).Furthermore,with O_(2) as the main oxidant,a wealth of benzylamines could be converted into imines over TpDTz‐COF.Mechanistic investigations substantiate that oxidation of benzylamines obeys an electron transfer pathway,in which superoxide anion(O_(2)•–)is the crucial reactive oxygen species.This study highlights the superiority of TzTz‐embedded COFs in developing effective photocatalytic systems for organic transformations.

Audit Quality in Kazakhstan： Does Big 4 Provide High-Quality Audits？

This paper provides empirical evidence on audit quality in Kazakhstan as measured by audit tenure and the frequency of issuing modified opinions. In addition, an overview of audit institutions of Kazakhstan and an analysis of the current audit market for public companies are offered. This paper also sheds light upon the potential independence problems resulting in low audit quality and current barriers to audit researches in Kazakhstan. Consistent with the findings of extant researches on audit quality and the general perceptions of investors, two hypotheses were developed, i.e., the audits performed by Big 4 audit firms in Kazakhstan also have higher quality than non-Big 4 audit firms in terms of audit tenure and the frequency of issuing modified opinions. The result confirms the hypothesis that Big 4 audit firms provide higher audit quality than smaller local firms in association with audit tenure instead of in relation to the frequency of issuing modified opinions. The result indicates that Big 4 audit firms may not be as independent as they will be in a highly litigious market. Therefore, an independent inspection should be regularly implemented according to the audit law, and the inspection report should be publicized by Chamber of Auditors （COA）1. If this is not practical due to the lack of qualified inspectors, a peer review may be an altemative to implement the quality control policy immediately. To the author＇s best knowledge, this is the first audit quality research in countries of the Commonwealth of Independence States （CIS）.

Research on the Action Mechanism of Technology Foresight in Strategic Emerging Industries --Take the Delphi Method and Technology Roadmap for Example

Developing strategic emerging industries is the major strategic initiative to accelerate the transformation of economic development while Technology Foresight is a very effective tool. This essay analyses the roles and limitations of Delphi method and Technology Roadmap in development of strategic emerging industries and offers suggestions on how to strengthen the effectiveness of Technology Foresight in it.

Removal of ammonia nitrogen from inorganic wastewater by AgBr/C_(3)N_(5)heterojunction under visible light irradiation

AgBr/C_(3)N_(5)composite was prepared by in-situ precipitation of AgBr on the surface of nitrogen-rich carbon nitride(C_(3)N_(5)).The crystal phase,chemical composition,elemental composition,spectral absorption and photoelectron-hole separation of the composite were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),ultraviolet-visible diffuse reflectance spectroscopy(UV-vis DRS)and photoluminescence spectroscopy(PL).The construction of AgBr and C_(3)N_(5)heterojunction could broaden the spectral response range,realize the efficient separation of photoelectrons and holes,and thus improve the photocatalytic performance.The photocatalytic performance of the composite material was studied by simulating inorganic ammonia nitrogen wastewater with NH_(4)Cl solution.The dosage of the composite material was 0.10 g,the initial mass concentration of NH_(4)Cl solution was 100 mg/L,and the initial pH was 10.0.The removal rate of ammonia nitrogen by the composite material reached 90.27%after 60 min of simulated visible light irradiation.After 5 cycles,the removal rate of ammonia nitrogen only declined by 0.12%.The composite material showed good photocatalytic performance and stability.The Z-scheme mechanism effectively retained the reduction and oxidation activities of photoelectrons and holes,which could change O_(2)and H2O to active groups such as superoxide radicals(·O_(2)-)and hydroxyl radicals(·OH),respectively,achieving efficient removal of inorganic ammonia nitrogen.