Highly efficient solution-processed CZTSSe solar cells based on a convenient sodium-incorporated post-treatment method

In CZTSSe solar cells,a simple sodium-incorporation post-treatment method toward solution-processed Cu2Zn Sn S4precursor films is presented in this work.An ultrathin NaCl film is deposited on Cu2Zn Sn S4precursor films by spin-coating NaCl solution.In subsequent selenization process,the introduction of Na Cl is found to be benefacial for the formation of Cu2-xSe,which can further facilitate the element transportation,leading to dense and smooth CZTSSe films with large grains and less impurity Cu2Sn(S,Se)3phase.SIMS depth profiles confirm the gradient distribution of the sodium element in Na-doped absorbers.Photoluminescence spectra show that the introduction of appropriate sodium into the absorber can inhibit the band tail states.As high as 11.18% of power conversion efficiency(PCE)is achieved for the device treated with 5 mg mL^-1 NaCl solution,and an average efficiency of Na-doped devices is 10.71%,13%higher than that of the control groups(9.45%).Besides,the depletion width and the charge recombination lifetime can also have regular variation with sodium treatment.This work offers an easy modification method for high-quality Na-doped CZTSSe films and high-performance devices,in the meantime,it can also help to further understand the effects of sodium in CZTSSe solar cells.

Comparison of pre-treatment and post-treatment use of selenium in retinal ischemia reperfusion injury

AIM: To investigate the effects of selenium in rat retinal ischemia reperfusion(IR) model and compare pretreatment and post-treatment use.METHODS: Selenium pre-treatment group(n =8) was treated with intraperitoneal(i.p.) selenium 0.5 mg/kg for7 d and terminated 24 h after the IR injury. Selenium posttreatment group( n = 8) was treated with i. p. selenium0.5 mg/kg for 7d after the IR injury with termination at the end of the 7d period. Sham group(n =8) received i.p.saline injections identical to the selenium volume for 7d with termination 24 h after the IR injury. Control group(n =8) received no intervention. Main outcome measures were retina superoxide dismutase(SOD), glutathione(GSH),total antioxidant status(TAS), malondialdehyde(MDA),DNA fragmentation levels, and immunohistological apoptosis evaluation.RESULTS: Compared to the Sham group, selenium pre-treatment had a statistical difference in all parameters except SOD. Post-treatment selenium also resulted in statistical differences in all parameters except the MDA levels. When comparing selenium groups, the pre-treatment selenium group had a statistically higher success in reduction of markers of cell damage such as MDA and DNA fragmentation. In contrast, the post-selenium treatment group had resulted in statisticallyhigher levels of GSH. Histologically both selenium groups succeeded to limit retinal thickening and apoptosis. Pre-treatment use was statistically more successful in decreasing apoptosis in ganglion cell layer compared to post-treatment use.CONCLUSION: Selenium was successful in retinal protection in IR injuries. Pre-treatment efficacy was superior in terms of prevention of tissue damage and apoptosis.

Influence of the post-treatment of HZSM-5 zeolite on catalytic performance for alkylation of benzene with methanol

The porous material HZSM-5 zeolite with micro-mesopore hierarchical porosity was prepared by post-treatment （combined alkali treatment and acid leaching） of parent zeolite and its catalytic performance for benzene alkylation with methanol was investigated. The effect of post-treatment on the textural properties was characterized by various techniques （including ICP-AES, XRD, nitrogen sorption isotherms, SEM, NH3-TPD, Py-IR and TG）. The results indicated that the post-treatment could modify the structural and acidic properties of HZSM-5 zeolite. In this procedure, not only additional mesopores were created by selective extraction of silicon but also the acidity was tuned. Consequently, the modified HZSM-5 zeolite showed larger external surface area with less acid sites as compared to the parent zeolite. It was found out that the modified zeolite exhibited a higher benzene conversion and xylene selectivity for alkylation of benzene with methanol as well as excellent life span of the catalyst than conventional ones. This can be explained by the facts that the presence of additional mesopores improved the diffusion property in the reactions. Furthermore, the modified zeolite showed an appropriate Bronsted acidity for effective suppression of the side reaction of methanol to olefins, thus reduced the accumulation of coke on the HZSM-5 zeolite, which was favorable for the catalyst stability. In comparison with the parent HZSM-5 zeolite, the modified zeolite by alkali treatment and acid leaching showed better performance for the benzene alkylation with methanol.

Curcumin pretreatment and post-treatment both improve the antioxidative ability of neurons with oxygen-glucose deprivation

Recent studies have shown that induced expression of endogenous antioxidative enzymes thr- ough activation of the antioxidant response element/nuclear factor erythroid 2-related factor 2 （Nrf2） pathway may be a neuroprotective strategy. In this study, rat cerebral cortical neurons cultured in vitro were pretreated with 10 ktM curcumin or post-treated with 5 pM curcumin, respectively before or after being subjected to oxygen-glucose deprivation and reoxygenation for 24 hours. Both pretreatment and post-treatment resulted in a significant decrease of cell injury as indicated by propidium iodide/Hoechst 33258 staining, a prominent increase of Nrf2 protein expression as indicated by western blot analysis, and a remarkable increase of protein expression and enzyme activity in whole cell lysates of thioredoxin before ischemia, after ischemia, and after reoxygenation. In addition, post-treatment with curcumin inhibited early DNA/RNA oxidation as indicated by immunocytochemistry and increased nuclear Nrf2 protein by inducing nuclear accumulation of Nrf2. These findings suggest that curcumin activates the expression of thi- oredoxin, an antioxidant protein in the Nrf2 pathway, and protects neurons from death caused by oxygen-glucose deprivation in an in vitro model of ischemia/reperfusion. We speculate that pharmacologic stimulation of antioxidant gene expression may be a promising approach to neu- roprotection after cerebral ischemia.

Post-treatment of TS-1 with Mixtures of TPAOH and Ammonium Salts and the Catalytic Properties in Propylene Epoxidation

TS-1/SiO_2 extrudate was post-treated with mixed solution of tetrapropyl ammonium hydroxide(TPAOH)and various ammonium salts solution(NH_4F,(NH_4)_3PO_4,(NH_4)_2CO_3,(NH_4)_2SO_4,NH_4CH_3CO_2,NH_4NO_3,NH_4Cl and(NH_4)_2TiF_6).The obtained hierarchical TS-1 catalysts were characterized by many techniques and tested for propylene epoxidation using hydrogen peroxide as an oxidant in a fixed-bed reactor.It was shown that the physicochemical and catalytic properties of the treated TS-1/SiO_2 extrudate depended on the types of ammonium salts added.Compared to the treatment with TPAOH alone,the treatment with a mixed solution of TPAOH and some ammonium salts can greatly improve the catalytic properties of the treated TS-1/SiO_2 extrudate.Some of these ammonium salts were favorable for the incorporation of titanium in the framework,and the beneficial effect depended on the types of ammonium salt.TS-1/SiO_2 extrudate treated with a mixed solution of TPAOH and(NH_4)_3PO_4 exhibited the highest catalyst stability in propylene epoxidation.Such catalytic property can be correlated to high crystallinity,more framework titanium,large specific surface area and large external surface area.

Effect of Post-Treatment Conditions on the Inactivation of MS2 Bacteriophage as Indicator for Pathogenic Viruses after the Composting Process

A rural model composting toilet system still had some pathogens in the compost after months of operation and hence requires a post-treatment. The aim of the study was to sanitize compost withdrawn from the composting toilet by setting post-treatment conditions. The kinetics inactivation of MS2 bacteriophage, selected as indicator for pathogenic viruses were determined during post-treatment at different temperatures (30°C, 40°C and 50°C) with varying moisture contents (50%, 60% and 70%). As a result, the inactivation rates during the post-treatment were 0.093 - 0.020 h-1, 0.025 - 0.088 h1, 0.447 - 0.100 h-1 at 30°C, 40°C and 50°C respectively. The inactivation rate coefficient (k) values of MS2 bacteriophage depended on higher temperature but not on moisture content.

Heat Post-Treatment to Reduce Thickness Swelling of Particleboard from Fast-Growing Poplars

According to the high thickness swelling and low dimensional stability of Poplars particleboard, this paper studied the effect of heat post-treatment on the board properties. The results indicated that the post-treatment could be a very effective way to produce dimensinaly stable fast-growing poplars particleboard. The thickness swelling of the board decreased with increasing the time and temperatures of post-heat treatment. So under190℃, being treated for 15 min., the total thickness swelling (TS1) of the board was 8.96%, reduced by 22.88%. The irreversible thickness swelling (TS2) was also reduced with the post-treatment of 190 ℃ or 220℃; The reversible thickness swelling (TS3) was not signifcantly changed when the time of treatment increased up to 25 min. under 190℃.

Post-treatments of Super Absorbent Polymer

Properties of high absorbency and modulus (gel strength) were both needed in applications of superabsorbent polymer (SAP). Generally, the absorption characteristic and gel strength reach a crossover point for a given system. Beyond this point, a given property will show improvement at the expense of another property. To synthesize SAP with properties superior to this optimum value, further modification in the process becomes essential. In our post-treatment modification of superabsorbent polymer, neither the variety of the crosslinkers, nor their amount was found the effective factors to the polymer performance, but the liquor ratio of the treating liquid to polymer. The combination of the chemical treating and heat-treating method was also explored. But this didn’t put any positive effect on SAP’s properties.

Method for determining the sliding-friction coefficient of the aluminum-zincplated post-treatment plate

With reference to the testing standard ASTM D1894,the sliding-friction coefficient of the aluminumzinc-plated post-treatment plate was measured.To reduce the detection error in practical applications,a correction factor is proposed.Although the test results showed that the relative standard deviation of the friction coefficient of the aluminum-zinc-plated post-treatment plate was 12.1%indicating that the test results experienced a certain fluctuation,it can nevertheless be used as an internal factory-controlled test method.At the same time,problems were encountered with respect to sample contact,sample edge burr,and sample surface contamination.However,measures can be taken to reduce the impact of these factors.

Effects of microwave post-treatments on leaching resistance of ACQ-D treated Chinese fir

In order to improve the leaching resistance of active ingredient-copper in ammoniacal copper quat-type D （ACQ-D） treated Chinese fir （Cunninghamia lanceolata Hook.）, microwave post-treatments were carried out. The percentages of leached copper from ACQ-D treated Chinese fir with different microwave post-treatments were obtained after leaching tests by analyzing the copper retention in treated wood. The fixation mechanism of copper in the treated wood was determined with the help of SEM and FTIR spectra, while the valence conversion of copper after microwave post-treatments was studied by UV spectroscopy. Our experimental results show that the percentage of leached copper was reduced significantly after microwave post-treatment over time. This development was reinforced by allowing even more time for the treatment as well as with an increase in the power of microwave post-treatment. The leaching resistance of copper in wrapped samples was better than that in unwrapped samples, which is attributed to the combined effects of temperature and moisture content. Compared with air-dried samples, the valence conversion in the samples with microwave post-treatments changed slightly, which demonstrates that microwave post-treatments cannot impair the natural decay resistance of ACQ-D treated wood. SEM and FTIR spectra showed the presence of crystal particles formed by chemical reactions between copper and wood ingredients in wood cell walls and wood pits. Only a small amount of copper reacted with cellulose, while lignin and hemicellulose were the major bonding sites for copper in wood. Given the experimental results of mechanical properties, microwave post-treatments had a slight effect on the compression strength parallel to the grain and on the erystallinity of ACQ-D treated Chinese fir.

Revolutionizing tumor immunotherapy:unleashing the power of progenitor exhausted T cells

In exploring persistent infections and malignancies, a distinctive subgroup of CD8^(+) T cells, progenitor exhausted CD8^(+) T(Tpex) cells, has been identified. These Tpex cells are notable for their remarkable self-renewal and rapid proliferation abilities. Recent strides in immunotherapy have demonstrated that Tpex cells expand and differentiate into responsive exhausted CD8^(+) T cells, thus underscoring their critical role in the immunotherapeutic retort. Clinical examinations have further clarified a robust positive correlation between the proportional abundance of Tpex cells and enhanced clinical prognosis. Tpex cells have found noteworthy applications in the formulation of inventive immunotherapeutic approaches against tumors. This review describes the functions of Tpex cells in the tumor milieu, particularly their potential utility in tumor immunotherapy. Precisely directing Tpex cells may be essential to achieving successful outcomes in immunotherapy against tumors.

Heat Recovery from Automotive Exhaust Using Heat Pipes with Limited Fluid Charge

Experiments were conducted in this study to examine the thermal performance of a thermosyphon,made from Inconel alloy 625,could recover waste heat from automobile exhaust using a limited amount of fluid.The thermosyphon has an outer diameter of 27 mm,a thickness of 2.6 mm,and an overall length of 483 mm.The study involved directing exhaust gas onto the evaporator.This length includes a 180-mm evaporator,a 70-mm adiabatic section,a 223-mm condenser,and a 97-mm finned exchanger.The study examined the thermal performance of the thermosyphon under exhaust flow rates ranging from 0–10 g/sec and temperatures varying from 300℃–900℃.The influence of three parameters—inclination angle(5°–45°),water mass(2–5.3 g),and the quantity of non-condensable gas Argon(0–0.6 g)—was investigated to assess their impacts on the thermosyphon’s thermal efficiency.The experimental findings revealed that with 3 g of water and 0.0564 g of argon in the thermosyphon,the condenser reached its highest temperature at around 200℃.The ideal fuel loading rate for the thermosyphon falls between 0.2 and 0.7 g/s.Moreover,as inclination angles rise,outer wall temperatures of the thermosyphon increase.This is attributed to the explicit expansion of the effective heating area within the evaporation section,coupled with an amplified gravitational component of the water flux.Additionally,an upsurge in the quantity of non-condensable gas(NCG)can mitigate temperature gradients on the outer wall,resulting in a decline in the thermosyphon’s performance.The insulation applied to the adiabatic section demonstrated efficacy in augmenting temperature gradients on the outer wall,thereby improving the overall performance of the thermosyphon.As the water charge within the thermosyphon increases,there is a corresponding rise in heat transfer rates both from the exhaust to the thermosyphon and from the thermosyphon to the fuel.

基于CFD−DPM的空气幕协同排风罩增效除尘研究

以某机械厂打磨车间为研究对象,利用Solidworks软件建立带有空气幕协同排风罩除尘的打磨车间模型,基于气固两相流理论,采用计算流体力学离散颗粒模型(CFD−DPM)模拟分析空气幕送风速度、射流角度和射流宽度对除尘效率的影响,选取空气幕的最优参数;在此基础上,对比分析未开启排风罩、开启排风罩、同时开启排风罩与空气幕3种工况的风速分布、粉尘运移轨迹及粉尘质量浓度分布,探讨空气幕协同排风罩除尘的效果。结果表明:粉尘最大浓度、呼吸带粉尘浓度随空气幕送风速度、射流宽度的增大而减小,但不随空气幕射流角度的变化而变化;粉尘浓度随地面高度的增大先增后减,不同高度处粉尘浓度变化趋势基本一致;当空气幕射流宽度30 mm、射流角度30°、送风速度3 m/s时,通风除尘效果最佳,除尘效率高达94.2%。相比于仅开启排风罩,排风罩与空气幕协同作用下的除尘效率提高了38.8%,空气幕协同排风罩对车间除尘具有较好的增效作用。

INVESTIGATION IN REDUCING EXHAUST EMISSIONS FROM TWO STROKE MOTORCYCLES

Test results of reducing two stroke motorcycle emissions with new type carburettors and electronic fuel injection systems are presented. Analyses and comparison between different systems are discussed. The adoption of electronically controlled injection and corresponding electronic control technique is an effective measure of prolonged vitality to improve emissions from two stroke motorcycles. Suggestions about the strategic steps of China′s motorcycle emission control are proposed.

A Novel Technology for Post-Treating of Porous Silicon Thick Films in H_2O_2

The solution of H 2O 2 is proposed to post-treat thick porous silicon (PS) films.The prepared PS film as the cathode is applied about 10mA/cm 2 current in mixture of ethanol,HF,and H 2O 2 solutions,which is expected to improve the stability and the smoothness of the surface and the mechanical property of the thick porous silicon films.The microstructure of the PS thick films with thicknesse of 20μm and 70μm has been studied.The SEM images show significant improved smoothness on surface of PS films,and XRD spectra suggest the formation of oxide layer after post-treating in H 2O 2.

Computation of Electromagnetic Properties of Mildly Overexpanded and Underexpanded Rocket Exhaust Plume

An improved near far field divided coupled method was established to investigate the electromagnetic properties of mildly overexpanded and underexpanded rocket exhaust plumes. Firstly, axisymmetric Navier Stokes equations incorporated with k ε two equation turbulence models were solved using time dependent approach to calculate the pressure of the near filed. Secondly, parabolized axisymmetric Navier Stokes equations incorporated with finite rate chemical kinetics models were marching on the detailed pressure map of the near field. The termination of the near field would yield the initial line for the far field. In addition, in the far field, the spatial marching method was directly used under the constant pressure condition, but considering more complicated chemically reacting process. Finally, the electromagnetic parameters of the whole plume were calculated with the electron conductive model. The calculated results of the overexpanded and underexpanded rocket exhaust plume were discussed. The predicted microwave attenuation accorded with the experimental results. This improved method is feasible for calculating the microwave attenuation characteristics of mildly non fully expanded rocket exhaust plumes.

汽油HCCI发动机串联复合涡轮废气能量分配研究

为了更好地进行复合涡轮匹配,对各工况下发动机排气能量利用进行研究,建立汽油均质充量压燃(HCCI)发动机热力学模型和串联复合涡轮系统数学模型,构建汽油均质压燃发动机一维仿真模型.基于数学模型计算所得复合涡轮参数,选择合适的复合涡轮系统,并进行一维仿真验证.基于匹配结果对复合涡轮系统中的能量分配进行研究.结果表明:通过所提出匹配方法选配的串联复合涡轮系统能够有效回收废气能量,实现整机性能提升,在转速为2200 r/min、平均指示压力(IMEP)为1.26 MPa时整机功率提高3.17 kW,整机效率改善2.49%;总结所得废气能量分配规律是:动力涡轮适用于转速高于1600 r/min及IMEP大于1.07 MPa工况,此时存在最优进气压力,使得动力涡轮所得废气能量有最佳废气能量占比,并使发动机整机效率达到最优.

纵向风下大间距排烟阀集中排烟模式温度及烟气蔓延研究

为研究盾构隧道组合排烟模式下火灾时烟气流动特性,采用数值模拟方法研究了盾构隧道在纵向通风与集中排烟协同作用下的隧道温度分布和烟气蔓延长度。选取火源功率50 MW,分析不同纵向风速、排烟口间距及排烟量作用下隧道内温度分布和烟气蔓延长度。结果表明:大间距排烟阀组合排烟隧道火源下游的顶板下方纵向温度分布符合双指数衰减模型,隧道内温度分布情况主要受纵向风速和火源热释放速率主导,集中排烟量对隧道纵向温度分布影响不大;大间距排烟阀组合排烟模式下,火源下游的烟气蔓延长度随热释放速率的增大而增大,随排烟量的增大而减小,随纵向风速的增大而增大。对于大间距排烟阀集中排烟模式,具体设计应考虑三项原则:(1)纵向风速达到临界风速来抑制烟气向火源上游回流;(2)兼顾人员安全和漏风量的设计标准,在满足漏风量的设计前提下尽量缩短排烟阀间距;(3)排烟量达到一定量来控制烟气在两个排烟阀范围内。通过量纲分析,得到大间距排烟阀组合排烟模式下火源下游烟气蔓延长度预测模型。

ExperimentonPerformanceofLow-TemperatureExhaustSteamReclamation

针对不同的喉嘴距、面积比，实验研究了不同的进水压力、进水温度和出水压力对低温乏汽回收利用装置性能的影响规律．发现在进水压力为0．14～O．50MPa、进水温度为23～60℃、出水压力为0．096-0．110MPa，以及4种喉嘴距、3种面积比的实验条件范围内，随着喉嘴距和面积比的增加，加热温升和流量比先增大后减小，得到最佳归一化喉嘴距L=4．50，以及最佳面积比m=6．25，使得加热温升和流量比最大．同时，加热温升和流量比均随着进水压力和进水温度的增加而减小，当出水压力升高时，装置性能变差，加热温升和流量比均减小．

Transitional Road of Resources-exhausted Cities to Low-carbon Economy:Tourism Resources Development——A Case Study of Gejiu City

Tourism is of vital practical significance to low-carbon economic transition of resources-exhausted cities.By taking Gejiu City of Yunnan Province for example,the paper discussed that Gejiu City as the resources-exhausted city should positively develop tourism,particularly industrial heritage tourism,treating tourism development as the breakthrough and motive power of low-carbon economic transition of resources-exhausted cities,so as to walk out a unique road of tourism promoting low-carbon economic development.