Synthesis and characterization of a novel waterborne stilbene-based polyurethane fluorescent brightener

A novel waterborne stilbene-based polyurethane fluorescent brightener dispersion WPU-VBL was synthesized by incorporating chemically disodium 4,4＇-bis[（4-anilino-6-hydroxyethylamino-1,3,5-triazin-2-yl）amino]stilbene-2,2＇-disulphonate（VBL） into the polyurethane chain using isophorone diisocyanate,poly（propylene glycol） and 2,2-dimethylol propionic acid.The structure of WPU-VBL was confirmed by means of Fourier transform infrared spectroscopy.The UV-vis absorption analysis showed a hypsochromic shift of 16 nm when VBL was blocked into polyurethane chain.Number average molecular weight of 2.1×10~4, molecular weight distribution of 2.1 and average latex particle size of about 70 nm for WPU-VBL were determined based on the analysis of gel permeation chromatography and laser particle size analyzer.It was found that the fluorescence intensity of WPU-VBL was prominently enhanced because of the micro-circumstance of VBL and the fluorescence of WPU-VBL was very stable.

Synthesis of a Fluorophore with Improved Optical Brightness

The synthesis and characterization of a novel fluorophore(1), with potential application as an optical brightener are reported. This compound was prepared by reacting 4,4-diaminostilbene-2,2-disulfonic acid with cyanuric chloride in the presence of Na2CO3 followed by the addition of trityl aniline. Solution and solid state fluorescence demonstrated a strong blue/purple emission centered at 450 nm. 1H-NMR spectroscopy, mass spectrometry analysis, elemental analysis, and DOSY-NMR were used for the characterization of the fluorophore.

Application of Functional Polymers in Laundry Care

This paper was to describe the current situation and development prospect of the global laundry care market,and made a conjecture on the future development trend of polymers,and to list four kinds of polymers widely applied in laundry care products.

The Role of Clouds in Global Radiation Changes Measured in Israel during the Last Sixty Years

An analysis of global radiation measurements and fractional cloud cover observations made in the Israel Meteorological Service’s network of climate stations demonstrated a significant decrease in the transmittance of solar radiation through the atmosphere during the last 60 years. The major cause was the reduced transparency of clouds. Under completely overcast skies with complete cloud cover transmission in the industrialized central coastal region decreased from 0.41 in the mid-20th century to 0.21 in the first decade of the 21st century. Under cloudless skies the reduction in the transmission of global radiation was less, from 0.79 to 0.71, and not statistically significant. Similar but somewhat smaller changes were observed in the less industrialized central hill region. Multi-linear analysis showed that since 1970, 61% of the measured decline in global radiation was attributable to changes in fractional cloud cover but only 2% to the marked increase in local fuel combustion;there was no statistically significant interaction between the two parameters.

A Review of Some Experimental Spray Methods for Marine Cloud Brightening

Marine Cloud Brightening (MCB), should it ever need to be deployed, envisions the formation of 1017salt Cloud Condensation Nuclei (CCN) per second coming from each of several thousand vessels deployed worldwide. The creation of this many nuclei on such a vast scale, from micron- or submicron-sized seawater droplets, preferably mono-disperse, poses a considerable engineering challenge. Various existing or experimental spray methods were investigated for feasibility, resulting in the identification of a few with promising results. Electro-spraying from Taylor cone-jets, using either silicon micromachined long capillaries or short capillary polymer substrates attached to a porous substrate, appears to have the best potential for implementation of all the methods that have been investigated so far.

Continuing Results for Effervescent Aerosol Salt Water Spray Nozzles Intended for Marine Cloud Brightening

Marine Cloud Brightening (MCB) by effervescent spray atomization of mixed sea water brine with air is a candidate for solar radiation management to compensate for global warming. We discovered that the flow from mixing tee nozzle described earlier had occasional unstable slug flow. A new design that adding rotational swirl to the salt brine as it is mixed into the air stabilized the nozzle flow and no longer showed slug flow in spray pictures. Flow equations were developed for the relatively low speed of sound of a choked flow mixed brine and air nozzle. Experimental mixed flow measurements with 300b pressure and a 200 μm diameter nozzle and calculations using perfect gas, and isotropic processes equations compared well with the chocked flow equations. Analysis in EXCEL of particle sizers measurements from both a scanning mobility particle sizer (SMPS) and an aerodynamic particle sizer (APS) showed production of many nanometer sized particles estimated as usable for MCB. A small number of micron sized particles were also always present but with about 90% of the sprayed mass. This is a first report with good data over the complete size range. The micron sized particles measured were similar to the measurements of earlier reports which reported no nanometer sized particles. We hypothesize that many nano-particles are always produced by liquid-air effervescent sprays, but earlier, were not observed because SMPS instruments were not available. The presence of the large mass percentage of large particles in the spray may cause problems by evaporative cooling preventing the rise of the MCB particles. We suggest future systems design with an impactor filter to remove the large particles. Calculations combining increased brine concentration, lower pressure, and larger nozzle area showed that significant reductions in required power and number of nozzles could be realized. An EXCEL model is developed to calculate flow from experimental analysis equations and compare with mixed choked flow equations. Solving with the model predicted the power required and the number of nozzles required to produce 1015 particles/s. The model showed that increasing brine concentration strongly lowered total power. Lowering pressure decreased power and increased number of nozzles. Increasing nozzle area lowered the number of nozzles. This model predicted that, at 300b pressure and 200μm diameter nozzle as the experiment but using an increased brine concentration of 0.1 instead of 0.032 would require only 115 nozzles instead of 358 and power of 146 kw instead of 493 kw. Combining increased brine concentration, lower pressure, and larger nozzle area, the model predicted that with a 1 mm diameter nozzle at 30b pressure and salt concentration of 0.2, the nozzle count and power required would drop to only 24 nozzles and power of 28 kw. Whether extending the model to these conditions is valid is not known but suggests further development should be investigated. Filtering out and reusing the 90% or greater large particles mass sprayed combined with the lower power advantage of higher brine concentration is suggested for future systems.

A Late 20th Century European Climate Shift: Fingerprint of Regional Brightening?

We investigate the spatial extent of a statistically highly significant shift in atmospheric temperatures over Europe around 1987-1988 using a boot-strap change point algorithm. According to this algorithm, this change point (average warming of about one degree Celsius) is statistically highly significant (p > 99.9999%). The change point is consistently present in satellite and surface temperature measurements as well as temperature re-analyses and ocean heat content over most of Western Europe. We also find a connection with parts of the North Atlantic Ocean and eastern Asia. Although the time of change coincides with the North Atlantic Oscillation (NAO) going from negative to positive, the consistent warmer temperatures throughout the decades after 1987-1988 does not coincide with a persistent shift of the NAO, as it returns to a neutral/negative in the 1990’s. Furthermore, the shift does not coincide with any other known mode of multidecadal internal climate variability. We argue that the notion of a shift is “spurious”, i.e. the result of a fast change in Europe from dimming to brightening combined with an accidental sequence of cold (negative NAO) and warm (positive) NAO years during this period. The “shift” could therefore be considered as a fingerprint of European brightening during the last few decades.

Effect of Optical Brightening Agent(OBA)on Bleaching Process on Paper of Eucalyptus Kraft Pulp

In integrated factories of pulp and paper, the bleaching control is made by kappa number and/or brightness. However, the product paper is evaluated and valued for its whiteness. The level of final brightness of pulp certainly affects the demand for optical brighteners in paper manufacturing, nevertheless, there is not a direct correlation between consumption of optical brightener and final brightness, being the method of bleaching pulp, especially from the final stage of bleaching, also important in relation to this demand. Therefore, this study aimed to evaluate the potential of using the parameter whiteness as a tool to control bleaching pulp, instead of the traditional brightness and evaluate the impacts of different methods of bleaching and the pulp final brightness level in action of optical brighteners, to improve their performance. It was observed that the whiteness and brightness of the pulp are highly correlated and that the control of the bleaching plant can be done by any one of these two parameters. It was also concluded that, considering current prices of bleaching reagents and of optical brighteners, it is better to bleach the pulp up to lower brightness values (e.g. 88% ISO) and use larger amounts of optical brighteners to brighten the mass until the whiteness of 130 CIE. This conclusion is valid for whiteness measured before the size press. Further studies are needed to validate this conclusion considering the finished product.

Variation in Sunshine Duration and Related Aerosol Influences at Shangdianzi GAW Station, China: 1958–2021

Sunshine duration(SD) is adopted widely to study global dimming/brightening. However, long-term simultaneous measurements of SD and closely related impact factors require further analysis to elucidate how and why SD has varied during the past decades. In this study, a long-term(1958–2021) SD data series obtained from the Shangdianzi Global Atmosphere Watch(GAW) station in China was analyzed to detect linear trends, climatic jumps, and climatic periods in SD using linear fitting, the Mann–Kendall trend test, and the continuous wavelet transform method. Annual SD exhibited steady dimming(-67.3 h decade-1) before 2010, followed by a period of brightening(189.9 h decade-1)during 2011–2020. An abrupt jump in annual SD occurred in 1995, and the annual SD anomaly exhibited significant oscillation with ~3-yr periodicity during 1960–1978. Partial least squares analysis revealed that annual SD anomaly was associated with variations in relative humidity, gale days, cloud cover, and black carbon(BC). Further analysis of the clear-sky daily sunshine percentage(DSP) and simultaneous measurements of aerosol properties, including aerosol optical depth, aerosol extinction coefficient, single scattering albedo(SSA), BC, and total suspended particulates, suggested that variation in DSP was affected primarily by aerosol scattering and absorption. Furthermore, the hourly clear-sky SD at high aerosol loading was approximately 60% and 56% of that at middle and low aerosol loadings, respectively. The pattern of diurnal variation in clear-sky hourly SD, as well as the actual values, can be affected by the fine particulate concentration, aerosol extinction coefficient, and SSA.

The impact of raw material properties and process conditions on the color of a powdered formulated detergent product

The appearance of deterge nt powder plays an importa nt role in con sumer perception of powder effectiveness for cleaning applications. In this study, we investigated the influence of numerous formulation and processing conditions on product discoloration. Product color was scrutinized using the L*a*b* color space, and in particular, L* and b*. Particle size, the method for introducing the optical brightener, and the raw material grade were very important in con trolling the optical properties of detergent granules. As the particle size decreased, the light reflected to the observer appeared brighter and bluer. This was observed as increased whiteness from L*= 84.03 with a particle size of >841 μm to L*= 90.59 with a particle size of <250 μm. Reducing the level of impurities found in the raw materials by changing the material source also improved color definition. A key finding is that the optical brightener should be applied by spraying and prepared by dispersion rather than dissolution. This improves the distribution within the granules and increases the whiteness when compared with pouring the brightener into the agglomeration vessel. Additional spray applications highlighted that brightener on the granule surface influenced whiteness more than embedded brightener. In addition, we report on the effects of the drying temperature and mixer impeller speed on powder color.

Influence of Changes in Solar Radiation on Changes of Surface Temperature in China

The long-term trends of total surface solar radiation （SSR）, surface diffuse radiation, and surface air temperature were analyzed in this study based on updated 48-yr data from 55 observational stations in China, and then the correlation between SSR and the diurnal temperature range （DTR） was studied. The effect of total solar radiation on surface air temperature in China was investigated on the basis of the above analyses. A strong correlation between SSR and DTR was found for the period 1961-2008 in China. The highest correlation and steepest regression line slope occurred in winter, indicating that the solar radiation effect on DTR was the largest in this season. Clouds and water vapor have strong influences on both SSR and DTR, and hence on their relationship. The largest correlations between SSR and DTR occurred in wintertime in northern China, regardless of all-day （including clear days and cloudy days） or clear-day cases. Our results also showed that radiation arriving at the surface in China decreased significantly during 1961-1989 （dimming period）, but began to increase during 1990 2008 （brightening period）, in agreement with previous global studies. The reduction of total SSR offset partially the greenhouse warming during 1961-1989. However, with the increase of SSR after 1990, this offsetting effect vanished; on the contrary, it even made a contribution to the accelerated warming. Nonetheless, the greenhouse warming still played a controlling role because of the increasing of minimum and mean surface temperatures in the whole study period of 1961-2008. We estimated that the greenhouse gases alone may have caused surface temperatures to rise by 0.31-0.46℃ （10 yr）^-1 during 1961-2008, which is higher than previously estimated. Analysis of the corresponding changes in total solar radiation, diffuse radiation, and total cloud cover indicated that the dimming and brightening phenomena in China were likely attributable to increases in absorptive and scattering aerosols in the atmosphere, respectively.

THEMIS observations of two substorms on February 26,2008

Two substorms occurred at ～04:05 and ～04:55 UT on February 26,2008 are studied with the in-situ observations of THEMIS satellites and ground-based aurora and magnetic field measurements.Angelopoulos et al.have made a comprehensive study of the 04:55 UT event.We showed detailed features of the two substorms with much attention to the first event and to the rela-tionship between mid-tail magnetic reconnection(MR) and substorm activities.It was found that in the earlier stage of each substorm,a first auroral intensification occurred 2-3 min soon after the start of mid-tail MR,followed by a slow and very lim-ited expansion.The auroral arcs were weak,short-lived,and localized,characterizing all features of a pseudobreakup.We re-garded the first auroral brightening as the initial onset of the substorms.A few minutes later,a second stronger auroral intensification appeared,followed by quick and extensive expansions.It was interesting to note that the second brightening and related poleward expansion happened almost simultaneously(within a couple of minutes) with the onset of earthward flow and dipolarization in the near-Earth tail and other phenomenon of the substorm expansion phase.We thus regarded the second auroral brightening as the major onset of the substorms.Furthermore,it was seen that during the growth phase of the two substorms,the polar cap open flux Ψ kept increasing,while it quickly reduced during the substorm expansion and recovery phase.These variations of Ψ implied that the evolution of the two substorm expansion phases were closely related to MR of tail lobe open field lines.Analysis of substorm activities revealed that the two events studied were small substorms;while estimate of MR rate indicated that the MR processes in the two substorms were weak.The aforementioned observations suggested that mid-tail MR initiated the pseudobreakup first;the earthward flow generated by MR transported magnetic flux and energy to the near-Earth tail to cause the formation of SCW and CD,which induced near-Earth dipolarization and major auroral brightening,and eventually led to the onset of the substorm expansion phase.These results were clearly consistent with the picture of NENL and RCS models and supported the two step initiation scenario of substorms.

Study of Distinctive Regional Features of Surface Solar Radiation in North and East China

Solar radiation is an important energy source for plants on the earth and also a major component of the global energy balance. Variations in solar radiation incident at the earth’s surface profoundly affect the human and terrestrial environment, including the climate change. To provide useful information for predicting the future climate change in China, distinctive regional features in spatial and temporal variations of the surface solar radiation （SSR） and corresponding attributions （such as cloud and aerosol） are analyzed based on SSR observations and other meteorological measurements in North and East China from 1961 to 2007. Multiple models, such as the plane-parallel radiative transfer model, empirical and statistical models, and correlation and regression analysis methods are used in the study. The results are given as follows. （1） During 1961–2007, the total SSR in North China went through a process from quickly ＂dimming＂ to slowly ＂dimming＂, while in East China, a significant transition from ＂dimming＂ to ＂brightening＂ occurred. Although there are some differences between the two regional variation trends, long-term variations in SSR in the two regions are basically consistent with the observation worldwide. （2） Between the 1960s and 1980s, in both North and East China, aerosols played a critical role in the radiation dimming. However, after 1989, different variation trends of SSR occurred in North and East China, indicating that aerosols were not the dominant factor. （3） Cloud cover contributed less to the variation of SSR in North China, but was the major attribution in East China and played a promoting role in the reversal of SSR from dimming to brightening, especially in the ＂remarkable brightening＂ period, with its contribution as high as 70%.

二维钙钛矿材料CsPbBr3中暗激子的磁场调控特性研究

二维钙钛矿材料作为21世纪最热门的材料之一,其优异的光电特性使其在太阳能电池、激光器等方面具有巨大的应用潜力.二维无机钙钛矿结构CsPbX3(X=Cl,Br,I)的激子性质对其光电特性具有决定性的作用.本工作针对CsPbBr3中的暗激子进行了详细的研究,通过施加面外磁场,实现了对CsPbBr3中暗态激子的激活并发现暗态激子的荧光强度随磁场增加而呈现线性增强.本工作揭示了CsPbBr3暗激子的磁场调控行为和内在物理机制,对深入理解其光电特性具有重要的科学意义.

Economic Horizon Brightens

Ningxia Hui Autonomous Region basks in the glow of a greener economy and booming trade with Arab nations With its dynamic growth engine roaring, Ningxia came under the spotlight at the Fourth Session of the 11th National People’s Congress (NPC) held on March 5-14 in Beijing.

World Economic Survey:World Economic Climate Brightens

In January 2007 the World Economic Climateslightly improved, confirming the previous quarterforecast of an economic soft-landing. The climateindicator stands at 106.5 (1995=100) and is thusconsiderably above its long-term average (1991-