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Exploring polymeric hole-transporting materials (HTMs) with passivation functions represents a simplified and effective approach to minimize the perovskite defect density. To date, most of reported polymeric HTMs were applied to fabricate n-i-p regular perovskite solar cells (PSCs). The polymers compatible for p-i-n inverted PSCs were very limited. Moreover, the passivation polymers were devoted to passivate the uncoordinated Pb2+. However, the MA+cation defect has profound unwanted effect on device efficiency and long-term stability. In order to synchronously passivate the Pb2+and MA+defects in p-i-n inverted PSCs, a new nonfused polymer was intentionally explored via mild polymerization. The aromatic bridge instead of long alkyl chains enabled polymer BN-12 to achieve excellent thermal stability and good wettability of perovskite precursor. Furthermore, the incorporation of chemical anchor sites (“C═O” and “F”) strongly controlled the crystallization of perovskite and restrained the MA+ion migration. As a result, a significant fill factor (FF) of 82.9% and an enhanced power conversion efficiency (PCE) of 20.28% were achieved for MAPbI3-based devices with the dopant-free BN-12, exceeding those with the commercial HTM PTAA (FF = 81.7%, PCE = 19.51%). More importantly, the unencapsulated devices based on BN-12 realized outstanding long-term stability, maintaining approximately 95% of its initial efficiency after stored for 85 days. By contrast, the PTAA-based device showed rapid decrease which retained only 50% of its initial value after 45 days.

In preparing efficient and stable perovskite solar cells (PSCs), it is challenging to simultaneously overcome the inherent problems of grain boundary grooves (GBGs), residual stress, defect states in perovskite film. Herein, a small organic molecule additive, pyridinium 1,4-zwitterionic thiolates (PZT), is synthesized to prepare high-quality PZT-doped perovskite active layer through bulk molecule doping method. The PZT promotes the crystallization of perovskite, optimizes the crystal orientation, and smooths the GBGs of perovskite films. Meanwhile, PZT releases compressive stress and passivates the perovskite defects at the surface/interface as well as internal grain boundaries in the perovskite film, which inhibits the charge recombination and promotes the charge separation and transport efficiency in the bulk perovskite films through the atomic interaction at the perovskite/PZT interface. In addition, the PZT also inhibits ion migration in perovskite film and increases film hydrophobicity. Benefiting from the above benefits, the PSCs based on perovskite:PZT layer achieved a maximum power conversion efficiency of 23.45%, much higher than that (21.79%) of control device. They also show significantly improved long-term stability under different aging test conditions. Our work provides a guide for improving the performance of PSCs by designing suitable multifunctional molecules.

The two-step sequential deposition strategy has garnered widespread usage in the fabrication of high-performance perovskite solar cells based on FAPbI3. However, the rapid reaction between FAI and PbI2during preparation often leads to incomplete reactions, reducing the device efficiency and stability. Herein, we introduced a multifunctional additive, 2-thiophenyl trifluoroacetone (TTA), into the FAI precursor. The incorporation of TTA has proven to be highly effective in slowing the reaction rate between FAI and PbI2, resulting in increased perovskite formation and improved efficiency and stability of the devices. TTA’s CF3groups interact with FAI via hydrogen bonding, effectively suppressing FA+defects. The S and C═O groups share lone pair electrons with uncoordinated Pb2+, leading to a reduction in perovskite film defects and suppressing nonradiative recombination. Additionally, the CF3groups impart hydrophobicity, protecting the perovskite film from moisture-induced erosion. As a result, the TTA-modified perovskite film achieves a Champion efficiency of 23.42% compared to the control’s 21.52, with 20.58% efficiency for a 25 cm2solar module. Remarkably, the unencapsulated Champion device retains 86% of its initial PCE after 1080 h under dark conditions (60 ± 5 °C, 35 ± 5% RH), indicating enhanced long-term stability. These findings offer a promising and cost-effective tactic for high-quality perovskite film fabrication.

Two spiro-bifluorene-based dopant-free HTMs (X22 and X23) have been synthesized by facilely condensing spiro-bifluorene diamine with 3,4-ethylenedioxythiophene (EDOT)-5,7-dicarbonyl dichloride and 2,3,5,6-tetrafluoro-terephthaloyl dichloride, respectively. In the X22 molecule, lone pairs of electrons on the sulfur (S) and oxygen (O) functional groups interact with the perovskite materials. The hole mobility (μh) of X22 (3.9 × 10–4cm2V–1S1–) is more than twice that of X23 (1.4 × 10–4cm2V–1S1–). The conductivity (σ0) of X22 is 2.73 × 10–4S cm–1, which is also higher than that of X23 (2.39 × 10–4S cm–1). The EDOT moiety benefits the contact angle of CH3NH3PbI3precursor solutions on HTMs as low as 24°. The X22-based device with an indium-doped tin oxide/hole transport material (HTM)/CH3NH3PbI3/phenyl-C61-butyric acid methyl ester (PC61BM)/bathocuproine/Ag structure achieves a power conversion efficiency (PCE) of 19.18%. The PCE of the device based on X23 containing fluorine is 18.70%, and the contact angle between HTM and the perovskite precursor solution is 32°. The X22- and X23-based devices at ambient temperature (≈25 °C) in N2retain 86% and 79% of the initial PCE after 150 days. The effect of S, O, and F heteroatoms plays an important role in the side chain modification of HTMs, improving defect passivation in HTM/CH3NH3PbI3interfaces by multiple functional groups.

The selective oxidation of amines to imines under mild conditions has attracted much attention. Our study reveals that copper phenylacetylide (PhC2Cu) could serve as an efficient photocatalyst for imine synthesis under visible-light irradiation (>400 nm). Utilizing benzylamine as a model reactant, PhC2Cu achieves an imine yield of 50.4%, which is 5 times higher than that of P25 under the same conditions and comparable to the yield obtained by the 3 wt % Au/P25 photocatalyst (55.4%). Further loading 3.9 nm TiO2onto PhC2Cu through tetrabutyl titanate hydrolysis increases the imine yield to 84.7%, with a Ti:Cu atomic ratio of 3.65%. Control experiments, photoluminescence (PL) spectra, optical pump terahertz probe (OPTP) spectra, and electron spin resonance (ESR) tests confirm that the optimized TiO2modification promotes the separation of excited carriers and electron transfer in PhC2Cu and facilitates the activation of surface oxygen, thereby enhancing the formation of superoxide radicals, a key active oxygen species in the reaction system. This work presents a promising strategy for efficient imine synthesis via amine coupling and expands the application field of PhC2Cu-based photocatalysts.

In this work, a comprehensive study on the deliberate molecular design and modifications of electron donors is carried out to elucidate correlations between the methoxy effects and donor configuration of hole-transporting materials (HTMs). Our initial findings demonstrate the donor-dependent methoxy effects. Photovoltaic performance of the HTM with twisted donor highly depends on the methoxy substituent. In contrast, efficiency's reliance on methoxy is insignificant for the HTM with planar donor. The HTM (M123) featuring the methoxy‑substituted carbazole shows a decent power conversion efficiency of 19.33% due to synergistic effects from both planar structure and methoxy. This work gives a guideline to access HTMs reaching both high-performance and good stability.

The mismatch of the energy level between the electron transport layer (ETL) and the perovskite (PS) film is one of the origins of current–voltage (J–V) hysteresis in perovskite solar cells (PSCs). Drift-diffusion simulations are conducted to explain how the band alignment affects the charge extraction across the ETL/PS interface, and hence varies the responses of photocurrent. Our simulations show that the band alignment has a profound influence on the evolution of the profiles of movable ions during voltage scan. The band mismatch at the ETL/PS interface is shown to engender the accumulation of movable anions and give rise to severe J–Vhysteresis. We further demonstrate that a rational design on the energy alignment of PSCs is vital to reduce the hysteresis no matter if charge loss in PSCs is determined by bulk recombination or trap-assisted surface recombination. Moreover, the PSCs suffering from interface band mismatch are found to exhibit various hysteresis behaviors depending on the rate of voltage scan. It implies that the voltage scan at different speeds could be helpful to diagnose the problem of PSCs.

Deeply understanding of the performance discrepancy of hole-transporting materials (HTMs) in perovskite solar cells (PSCs) with different configuration (inverted or direct) is important for designing efficient HTMs. Herein, three organic HTMs TZ1, TZ2, and TZ3 have been employed to fabricate the inverted PSCs. Optoelectronic properties and photovoltaic performance of these HTMs are investigated. TZ3 featuring the 3,6-di(thiophen-2-yl)thieno[3,2-b]thiophene conjugate bridge shows a higher work function and enhanced capability of hole extraction, achieving a higher power conversion efficiency (PCE) of 16.33% in the inverted PSCs. Importantly, results reveal that the conjugate bridge has a relevant effect on the photovoltaic performance of cells with different device configuration. The PCE trend of TZ1, TZ2, and TZ3 in inverted PSCs is diametrically opposed to that of direct devices. We proposed that linear triphenylamine HTMs contain a fused bridge with high degree of conjugation are good choice for the direct PSCs. On the other hand, it is better to incorporate linear triphenylamine HTMs with deep highest occupied molecular orbital (HOMO) toward the inverted PSCs, because the photovoltage plays a crucial role in the efficiency of the inverted PSCs. This systematic study provides a new viewpoint to design HTMs toward PSCs with different device configuration.

The triple oxygen isotope signature Δ17O in atmospheric CO2, also known as its “17O excess,” has been proposed as a tracer for gross primary production (the gross uptake of CO2by vegetation through photosynthesis). We present the first global 3‐D model simulations for Δ17O in atmospheric CO2together with a detailed model description and sensitivity analyses. In our 3‐D model framework we include the stratospheric source of Δ17O in CO2and the surface sinks from vegetation, soils, ocean, biomass burning, and fossil fuel combustion. The effect of oxidation of atmospheric CO on Δ17O in CO2is also included in our model. We estimate that the global mean Δ17O (defined as Δ17O=ln(δ17O+1)−λRL·ln(δ18O+1)with λRL= 0.5229) of CO2in the lowest 500 m of the atmosphere is 39.6 per meg, which is ∼20 per meg lower than estimates from existing box models. We compare our model results with a measured stratospheric Δ17O in CO2profile from Sodankylä (Finland), which shows good agreement. In addition, we compare our model results with tropospheric measurements of Δ17O in CO2from Göttingen (Germany) and Taipei (Taiwan), which shows some agreement but we also find substantial discrepancies that are subsequently discussed. Finally, we show model results for Zotino (Russia), Mauna Loa (United States), Manaus (Brazil), and South Pole, which we propose as possible locations for future measurements of Δ17O in tropospheric CO2that can help to further increase our understanding of the global budget of Δ17O in atmospheric CO2. This work presents a first view on possible spatial and temporal gradients of Δ17O in CO2across the globeTropical, boreal, and Southern Hemisphere observations of Δ17O in CO2could be of great interestWe implemented spatially and temporally explicit sources and sinks of Δ17O in CO2in a 3‐D model framework

Diphenylamine-substituted carbazole (DPACZ) compounds are one of the most interesting hole-transporting materials (HTMs) for perovskite solar cells (PSCs). However, most studies focused on the development of symmetrical DPACZ HTMs with two DPACZ arms or multiple ones. In this work, we developed a new class of asymmetric DPACZ-based HTMs (M111–114) through a combination of one DPACZ arm and different S,N-heterocyclic compounds (phenothiazine (PTZ) and dithieno[3,2-b:2′,3′-d]pyrrole (DTP)), which endow the M111–114 with different electrochemical and photophysical properties as well as hole-transporting properties. Results conclude that the PTZ outperforms of the DTP when combined with the DPACZ arm. In addition, we have investigated the substituent and conjugation effects of heterocyclic properties on the photophysical and electrical properties, as well as performance in PSCs by using physical measurements. PSCs with M114 exhibit a power conversion efficiency of 17.17%, which is higher or comparable to that of DPACZ HTMs with more than one DPACZ arm. Importantly, the synthetic cost of the M114 is only 14.95 $ per g, which is much lower than that of spiro-OMeTAD. This work indicates that DPACZ-heterocycle compounds could be a new class of low-cost HTMs in the large-scale application of PSCs.

This work uses Sounding of the Atmosphere using Broadband Emission Radiometry CO2data from 2002 to 2015 and Specified Dynamics‐Whole Atmosphere Community Climate Model (SD‐WACCM) outputs from 1979 to 2014 to show, for the first time, the solar cycle response of CO2in the Austral winter mesosphere and lower thermosphere region. Both Sounding of the Atmosphere using Broadband Emission Radiometry and SD‐WACCM show that CO2experiences a decrease during solar maximum throughout the Austral winter mesosphere and lower thermosphere region. This work highlights the regions where CO2experiences its strongest and weakest solar cycle responses as modeled by SD‐WACCM. The region with the strongest solar cycle response experiences around 5% reduction in CO2between solar maximum and solar minimum. The region with weakest solar cycle response experiences less than 1% reduction in CO2between solar maximum and solar minimum. It is shown that the region of the strongest CO2response is driven by photodissociation, downwelling, and reduced eddy diffusion. On the other hand, the region of the weakest CO2response is driven by the opposing effects of photodissociation and enhanced eddy diffusion. This is the first work to show that the solar cycle could affect the Austral winter lower thermosphere circulation and eddy diffusion processes. These anomalies in the lower thermospheric circulation and eddy diffusion are found to be related to the solar cycle response in the Austral winter mesosphere wave‐mean flow dynamics. This work therefore concludes that the solar cycle affects lower thermospheric CO2via modulations of the lower thermospheric circulation and eddy diffusion processes. Response of CO2in the Austral winter MLT to the 11‐year solar cycle is presentedSolar cycle response of CO2in the Austral winter MLT is driven by photochemistry and transportThe residual circulation and eddy diffusion in the Austral winter lower thermosphere respond to the 11‐year solar cycle

The core plays a crucial role in achieving high performance of linear hole transport materials (HTMs) toward the perovskite solar cells (PSCs). Most studies focused on the development of fused heterocycles as cores for HTMs. Nevertheless, nonfused heterocycles deserve to be studied since they can be easily synthesized. In this work, we reported a series of low-cost triphenylamine HTMs (M101–M106) with different nonfused cores. Results concluded that the introduced core has a significant influence on conductivity, hole mobility, energy level, and solubility of linear HTMs. M103 and M104 with nonfused oligothiophene cores are superior to other HTMs in terms of conductivity, hole mobility, and surface morphology. PSCs based on M104 exhibited the highest power conversion efficiency of 16.50% under AM 1.5 sun, which is comparable to that of spiro-OMeTAD (16.67%) under the same conditions. Importantly, the employment of M104 is highly economical in terms of the cost of synthesis as compared to that of spiro-OMeTAD. This work demonstrated that nonfused heterocycles, such as oligothiophene, are promising cores for high performance of linear HTMs toward PSCs.

We have retrieved the latitudinal and vertical structures of the 11 year solar cycle modulation on ionospheric electron density using 14 years of satellite‐based radio occultation measurements utilizing the Global Positioning System. The densities at the crests of the equatorial ionization anomaly (EIA) in the subtropics near 300 km in 2003 and 2014 (high solar activity with solar 10.7 cm flux, F10.7≈ 140 solar flux unit (sfu)) were 3 times higher than that in 2009 (low solar activity F10.7≈ 70 sfu). The higher density is attributed to the elevated solar extreme ultraviolet and geomagnetic activity during high solar activity periods. The location of the EIA crests moved ~50 km upward and ~10° poleward, because of the enhanced E× Bforce. The EIA in the northern hemisphere was more pronounced than that in the southern hemisphere. This interhemispheric asymmetry is consistent with the effect of enhanced transequatorial neutral wind. The above observations were reproduced qualitatively by the two benchmark runs of the Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model. In addition, we have studied the impact of the 11 year solar cycle on the 27 day solar cycle response of the ionospheric electron density. Beside the expected modulation on the amplitude of the 27 day solar variation due to the 11 year solar cycle, we find that the altitude of the maximal 27 day solar response is unexpectedly ~50 km higher than that of the 11 year solar response. This is the first time that a vertical dependence of the solar responses on different time scales is reported. The electron densities at the crests of the equatorial ionization anomaly in 2003 and 2014 were 3 times higher than that in 2009The equatorial ionization anomaly moved poleward by ~10° and was more pronounced in the northern hemisphere during 2014The altitude of the maximal 27 day solar response is ~50 km higher than that of the 11 year solar response

Cellular senescence as a result of organismal aging or progeroid diseases leads to stem cell pool exhaustion hindering tissue regeneration and contributing to the progression of age related disorders. Here we discovered that ectopic expression of the pluripotent factor NANOG in senescent or progeroid myogenic progenitors reversed cellular aging and restored completely the ability to generate contractile force. To elicit its effects, NANOG enabled reactivation of the ROCK and Transforming Growth Factor (TGF)‐β pathways—both of which were impaired in senescent cells—leading to ACTIN polymerization, MRTF‐A translocation into the nucleus and serum response factor (SRF)‐dependent myogenic gene expression. Collectively our data reveal that cellular senescence can be reversed and provide a novel strategy to regain the lost function of aged stem cells without reprogramming to the pluripotent state. StemCells2017;35:207–221 NANOG restores the myogenic and contractile capacity of senescent stem cells and progeria derived myofibroblasts. Hair follicle derived Mesenchymal Stem Cells (MSC) were transduced with a tetracycline regulatable vector that carries the NANOG gene. This system allows NANOG expression only when cells are treated with the tetracycline analog, Doxycycline. Cells were serially passaged until they became senescent (late passage, LP MSC). Subsequently Dox was added to the culture medium to induce NANOG expression in LP MSC (LP NANOG MSC) and the myogenic capacity was evaluated and compared to early passage (EP) MSC. Similar experiments were also performed with myofibroblasts derived from patients with an accelerating aging disease (Hutchinson Gilford Progeria Syndrome (HPGS)). (A‐B): Western Blot for ACTA2 and SRF. (C‐D) SRF dependent transcriptional activity (CArG‐box). (E‐F) Immunocytochemistry for ACTA2. (G‐H): Contractile force using 3D collagen microtissue. (I): Schematic illustration describing the effects of NANOG on senescent cells. GM: Growth Medium, DM: Differentiation Medium. Scale bar: 20 μm for immunocytochemistry and 200 μm for the microtissues, data are presented as mean ± standard deviation, n= 3, *: designates statistical significance as compared to LP, LP DM or HGPS, HGPS DM (p< .05), #: designates statistical significance as compared to LP NANOG GM or HGPS NANOG GM (p< .05).

Mid‐tropospheric Carbonyl sulfide (OCS) retrievals from the Tropospheric Emission Spectrometer (TES) are utilized to study OCS distributions during the dry/wet seasons over the Amazon rainforest. TES OCS retrievals reveal positive OCS anomalies (∼16 ppt) over the central and southern parts of the Amazon during August–October (dry season) compared to January–March (wet season). There is less OCS taken up by vegetation and soil and more OCS released from biomass burning during the dry season, which causes an increase in OCS concentrations. Strong sinking air during the dry season also helps to trap OCS and this contributes to positive OCS anomalies. MOZART‐4 model captures positive OCS anomalies over the central and southern regions of the Amazon and negative OCS anomalies over the northern part of the Amazon, which are similar to those from TES mid‐tropospheric OCS retrievals. Our studies can help us better understand OCS variations and photosynthetic activities. As a photosynthetic tracer, OCS can help us better understand photosynthetic activities, the biosphere‐atmosphere interaction, and the carbon sink. There are positive OCS anomalies (∼16 ppt) over the central and southern parts of the Amazon during August–October (dry season), which is related to reduced OCS uptake from vegetation and soil, enhanced OCS emission from biomass burning, and strengthened sinking air. MOZART‐4 is used to simulate the OCS variations during dry/wet seasons. Model results are similar to those from Tropospheric Emission Spectrometer OCS retrievals. However, there are some differences between the spatial distributions of OCS in the MOZART‐4 model and the satellite retrievals. Results in this study can help us better understand the variability of OCS and photosynthetic activities over the Amazon rainforest, which is the biggest rainforest and one of the largest sinks of OCS. Tropospheric Emission Spectrometer OCS concentrations are higher over the central and southern parts of the Amazon during the dry season than the wet seasonHigh OCS concentrations are related to reduced vegetation uptake, enhanced biomass burning, and increased sinking airMOZART‐4 captures the observed positive OCS anomalies over the central and southern Amazon during August–October (dry season) Tropospheric Emission Spectrometer OCS concentrations are higher over the central and southern parts of the Amazon during the dry season than the wet season High OCS concentrations are related to reduced vegetation uptake, enhanced biomass burning, and increased sinking air MOZART‐4 captures the observed positive OCS anomalies over the central and southern Amazon during August–October (dry season)

Borondipyrromethene (BODIPY) dyes are one of the most interesting organic dyes because of their unique characteristic in capturing near-infrared (NIR) solar radiation. However, the highest reported conversion efficiency of BODIPY dyes is still far behind that of other organic dyes. Herein, we demonstrated an efficient strategy for enhancing the photovoltaic performance of BODIPY dyes, i.e., introducing a long linker between the light harvesting antenna and acceptor. Interestingly, the linker length has opposite effects on the BODIPY (M62, M63, M66, and LB1) and triphenylamine (M64 and M65) dyes. This work suggests that the incorporated long linker in BODIPY dyes shows several favorable characteristics: (i) improving the light harvesting capability of BODIPY dyes in longer wavelength without a big change of the HOMO levels; (ii) efficiently increasing the photocurrent and photovoltage, leading to dramatically improved performance; (iii) significantly reducing the charge recombination between electrons in TiO2and electrolyte acceptor species and oxidized dye molecules at the interface. As a result, M63 with a binary linker display a 4.79 times higher conversion efficiency compared to that of M62 with a single linker. This finding could contribute to molecular engineering in the design of highly efficient BODIPY dyes.

Fused-ring thiophene compounds emerged as an important type of building blocks for organic dyes toward the dye-sensitized solar cells (DSSCs) because of their good charge transfer and light-harvesting properties. Nevertheless, some fused-ring thiophenes have a lack of desired alkyl chains or side alkyl chains, which may induce a severe charge recombination in devices. In this work, the hex-1-en-1-ylbenzene (HEYB) unit was introduced in two new fused-ring thiophene organic dyes (M60 and M59), resulting in a modest dihedral angle (∼36°) between the donor and spacer in dyes. The effect of the HEYB unit on optical, electrochemical, and photovoltaic properties has been investigated by comparing with their congeners (M42 and M58) without the HEYB unit. It is found that introduction of the HEYB unit in arylamine donor enhanced the driving force for dye regeneration and beneficial for suppressing dye aggregation as well as reducing the charge recombination. Device performance characteristics demonstrate that introduction of the HEYB unit in the arylamine donor is a feasible strategy toward enhancing the performance of fused-ring thiophene organic dyes. Benefiting from this strategy, a dye-sensitized solar cell employing the M60 photosensitizer and a cobalt electrolyte exhibits a good power conversion efficiency of 9.75% measured under the 100 mW cm–2, simulated AM1.5 sunlight.

Every year, several typhoons originating from the West Pacific come close to Taiwan, modulating the regional weather through intense rainfall and enhanced humidity. The isotopic ratios (δ18O and δD) in the typhoon vapor evolve along its track due to rainout, recycling, and replenishment. In 2016, this signature was recorded in Taipei as typhoon vapors invaded the local atmosphere. After typhoon disintegration, the isotope ratios of the local atmosphere slowly return to the background value. The fall and rise in the ratios give rise to a V‐shaped variation. The processes controlling the fall (like moisture turnover, typhoon speed, wind speed, and direction) are fast (1–2 days). In contrast, the recovery is slow (several days) depending on the replacement rate of the local atmospheric moisture by incoming oceanic vapor. An isotope evolution model based on Rayleigh condensation and a box model of moisture mixing in the recovery phase are proposed and employed to explain the V‐shape. The combination of these two models for four major typhoons (Nepartak, Megi, Meranti, and Malakas) shows close agreement with observations. The evolution model suggests that the precipitation efficiency, PE (rainfall/overhead moisture), and typhoon size are two important parameters controlling the decrease in ratio. The characteristic turnover time of typhoon moisture (inverse of PE, obtained from European Centre for Medium‐Range Weather Forecasts fifth Re‐Analysis data) is estimated to be ∼2 days for a Pacific typhoon of 500 km radius. Our isotope study provides important constraints on the moisture budget of Pacific typhoons. Tropical typhoons transport heat and moisture from the ocean surface to the atmosphere at fast rates. To understand the moisture input and output during the typhoon evolution, stable oxygen and hydrogen isotope tracers in the vapor have been continuously measured at a station in Taipei, Taiwan. Four major typhoons originating in the western North Pacific in 2016 passed near the Taiwan region. The heavy‐to‐light isotope ratios of typhoon moisture that reached Taipei were analyzed. The isotope ratios of moisture changed with time due to rainout‐related fractionation processes and subsequent mixing with atmospheric vapor producing a V‐shaped pattern as the typhoon moved and disintegrated. An idealized model is presented to show how a Rayleigh fractionation operates through step‐wise rainout from existing vapor mass that is supplemented by a continuous import of moisture by low‐level inflow and ocean evaporation. The recovery of the isotope ratios to pre‐typhoon values takes place by slow mixing of the incoming oceanic vapor with the existing atmospheric vapor over the station. Vapors from tropical typhoons approaching the Taiwan region in 2016 have been tracked by continuous monitoring of stable isotope ratiosModeling of vapor isotope variation provides insight into typhoon's moisture recycling and fresh contribution from neighboring regionsRainfall/total precipitable water vapor or precipitation efficiency provides a key concept to model the vapor isotope evolution Vapors from tropical typhoons approaching the Taiwan region in 2016 have been tracked by continuous monitoring of stable isotope ratios Modeling of vapor isotope variation provides insight into typhoon's moisture recycling and fresh contribution from neighboring regions Rainfall/total precipitable water vapor or precipitation efficiency provides a key concept to model the vapor isotope evolution

Kinetics of the recombination at TiO2/dye/electrolyte interfaces is vital to establish reliable strategy for reducing energy loss in dye sensitized solar cell (DSCs). The semilogarithmic plots of open circuit voltage–light intensity indicate that the DSCs exhibit different recombination behaviors in high and low voltage regions. Even so, the average orders of recombination reaction in the two regions are both found to be expressed as the summation of the apparent charge transfer coefficient and the averaged density distribution parameter. This statement is based upon the fact that the “steady-state” electron lifetimes in cobalt complex based DSCs are well interpreted by using the Butler–Volmer model. Combining the results of electron lifetime, the order of recombination reaction, and density distribution, we addressed that the dominant pathway of recombination in cobalt complex based DSCs is via the trapping states rather than the conduction band. In addition, the variation of the Fermi level in TiO2film could affect the adsorbing configurations of 4-tert-butylpyridine molecules and Li+/H+cations at TiO2surfaces and hence engenders the nonexponential distribution of electron density at higher Fermi level.

With respect to the electron-withdrawing acceptors of D–A−π–A organic dyes, reports on the second electron-donating donors for D–D−π–A organic dyes are very limited. Both of the dyes have attracted significant attention in the field of dye-sensitized solar cells (DSCs). In this work, four new D–D−π–A organic dyes with dithieno[3,2-b:2′,3′-d]pyrrole (DTP) or bis(amine) donor have been designed and synthesized for a investigation of the influence of the terminal electron donor in D–D−π–A organic dye-sensitized solar cells. It is found that DTP is a promising building block as the terminal electron donor when introduced in the dithiophenepyrrole direction, but not just a good bridge, which exhibits several characteristics: (i) efficiently increasing the maximum molar absorption coefficient and extending the absorption bands; (ii) showing stronger charge transfer interaction as compared with the pyrrole direction; (iii) beneficial to photocurrent generation of DSCs employing cobalt electrolytes. DSCs based on M45 with the Co-phen electrolyte exhibit good light-to-electric energy conversion efficiencies as high as 9.02%, with a short circuit current density (JSC) of 15.3 mA cm–2, open circuit voltage (VOC) of 867 mV and fill factor (FF) of 0.68 under AM 1.5 illumination (100 mW cm–2). The results demonstrate that N,S-heterocycles such as DTP unit could be promising candidates for application in highly efficient DSCs employing cobalt electrolyte.

We examined the effects of senescence on the proliferation and leiomyogenic differentiation potential of mesenchymal stem cells (MSCs) isolated from bone marrow (BM-MSCs) or hair follicles (HF-MSCs). To this end, we compared ovine HF-MSCs and BM-MSCs in terms of their proliferation and differentiation potential to the smooth muscle cell lineage. We discovered that HF-MSCs are less susceptible to culture senescence compared with BM-MSCs. We hypothesized that application of mechanical forces may enhance the contractility and mechanical properties of vascular constructs prepared from senescent MSCs. Interestingly, HF-MSCs and BM-MSCs responded differently to changes in the mechanical microenvironment, suggesting that despite phenotypic similarities, MSCs from different anatomic locations may activate different pathways in response to the same microenvironmental factors. In turn, this may also suggest that cell-based tissue regeneration approaches may need to be tailored to the stem cell origin, donor age, and culture time for optimal results.

Abstract: The geogenic source of arsenic (As) in groundwater is an indisputable fact. Arsenic contamination in the shallow groundwater of West Bengal is an alarming health issue with progressive growth of regional population and demand for water. The As contamination in shallow groundwater is facilitated by microbial activities, which depend on the inflow of dissolved organic carbon (DOC), providing a temporary reducing condition conducive to the release of As from aquifer sediments. Here, we present a documentation over several years of seasonal observations on dissolved total As contents and stable isotope ratios in shallow groundwater, ‘deep pond water’ (collected from the deepest part of the pond just above the sediment–water interface), river water and rainwater from the Chakdaha region, Haringhata block, Nadia district, West Bengal. The current study shows, for the first time, a large similarity in the isotopic composition of seasonal deep pond water with the shallow aquifer-intercalated clay sediment-trapped pore water (data adopted from the literature on a Bangladesh region). We highlight the possible processes wherein seasonal eutrophication during dry time followed by monsoon time flooding and sedimentation allows the burial of organic-rich clayey sediments with trapped DOC-rich pore water, which serve as a source of clay-pocket pore water. The isotopic composition of clay-pore water formed at a historical time scale resembles the deep-bottom water composition of surface water bodies and provides an ideal composition responsible for triggering the seasonal release of As into the shallow groundwater. The processes such as excess withdrawal of groundwater during dry periods and consequent squeezing of aquifer sediment-intercalated clay-lenses can expel its organic-rich contents to trigger anaerobic microbial activities and As release into the adjoining water. Using D-excess and δ18O as conservative tracers, we have shown that ~13–14% mixing (exclusion) of clay-pore water to the adjoining As-uncontaminated (≤10 µg/L) shallow regional groundwater is sufficient to cause high As (>10 µg/L) mobilisation. Research highlights:

Shallow groundwater samples (&lt;60 m bgl) collected at seasonal time intervals (from Nadia) show increasing dissolved total arsenic (As) contents during dry pre-monsoon periods, featuring mixing of aquifer-intercalated clay-lens-trapped pore water with the adjoining groundwater.

Excessive groundwater withdrawal during dry periods generates compaction of the intercalated clay-lenses placed within the shallow aquifer and actuates the process of clay-pore water expulsion which causes land subsidence.

An estimation of ~13–14% mixing (exclusion) of aquifer-intercalated clay-pore water (high As, organic-rich) to the adjoining As-uncontaminated (≤10 µg/L) regional shallow groundwater is sufficient to trigger high As mobilisation.

Aquifer-intercalated clay-pore water is equivalent to ‘relic surface water’, making the presence of palaeo-water of quaternary time scales.

Indoline photosensitizers exhibit impressive short-circuit photocurrent but generally low molar extinction coefficient and rapid charge recombination, which limits their application in thin-film dye-sensitizerd solar cells (DSCs). Here, we incorporate a new dithieno[3,2-b:2′,3′-d]pyrrole (DTP) segment (i.e., dihexyloxy-triphenylamine (DHO-TPA) substituted DTP) as the conjugated π-linker to construct a series of high molar absorption coefficient indoline dyes (XW69, XW70, and XW71) for DSCs employing a cobalt(II/III) redox electrolyte. Interestingly, this DTP linker is demonstrated as an efficient building block, not only slowing down the kinetics of charge recombination of titania electrons with tris(1,10-phenanthroline)cobalt(III) ions but also making a great contribution to the light absorption properties in comparison with the dihexylaniline substituted DTP. With respect to the dihexyloxy-triphenylamine dye (XW68), these new indoline dyes exhibit stronger light-harvesting and thus better power conversion efficiency of DSCs made from thin titania films. Benefitting from the bulky rigidity of the donor and π-conjugation unit, the XW70 dye displays a promising conversion efficiency as high as 8.78%, with a short-circuit current density (JSC) of 13.3 mA cm–2, open-circuit voltage (VOC) of 943 mV, and fill factor (FF) of 0.70 under AM 1.5 illumination (100 mW cm–2). Furthermore, the effect of light irradiation on these dyes adsorbed on nanocrystalline TiO2films was investigated, proving the photostability of these indoline chromophores. Our work has valued the feasibility of judicious design of indoline chromophores to obtain organic photosensitizers for high-efficiency iodine-free DSCs made from thin titania films.

A simplified reaction–diffusion model is proposed to show the origins of inefficient charge transport in dye-sensitized solar cells (DSCs) based on bulky complex redox shuttles. In this model, diffusion length of the oxidized species in electrolyte solution is defined and assumed to depend on the average density of the conduction band electrons. The resulting quasi-linear equations enable the density profiles of electrons and redox shuttles to be calculated directly. When the charge transport of a DSC is under diffusion limitation, diffusion overpotential is shown to serve as an additional potential, which maintains a high level of electron density in TiO2film, even at short circuit. The photocurrent output is therefore considerably limited because of the accelerated recombination reaction. Moreover, short circuit current density is confined by the diffusion limited current density under inefficient charge transport, and close to the photocurrent density at high diffusivity of redox shuttles. For the DSC with slow redox shuttles, a critical thickness of TiO2film is observed. This is the maximum thickness allowing the charge transport to be free from diffusion limitation. The optimized film thickness yielding the maximum power conversion efficiency is shown to be slightly less than the critical thickness, which implies the potential usage of the critical thickness in designing the state-of-art DSC.

Three adsorbents, that is, 4-N,N-dimethylaminopyridine (DMAP), tetrabutylammonium isonicotinate (TBAIN), and methyl isonicotinate (MIN), were employed for blocking charge recombination in the dye-sensitized solar cells (DSCs) with poly(ethylene oxide)/poly(ethylene glycol) blend electrolyte. Photovoltage–light intensity measurements showed the adsorbents not only decrease the recombination rate but also prompt the nonideality of recombination. The energy level of the TiO2band edge (Ec) is elevated by the adsorbents, which also result in the increase in the characteristic temperature (T0), reflecting a deeper distribution of the electrons at the surface states. An electron transfer model on the basis of the Marcus theory was applied to calculate the rate of nonideal recombination as well as the ideality factor. The results indicate that the increases in Ecand T0both foster the nonideal recombination. The decreased recombination is further attributed to the upward shift of the TiO2band edge, which reduces the densities of the electrons in the conduction band and at the surface states. Another reason for that is the increase in T0, which results in the drop of the averaged possibility of electron transfer via the surface states. The enhancement of open-circuit voltage follows the sequence of DMAP > TBAIN > MIN, which is correlated to the negative charge of pyridine-N of the adsorbents in terms of the quantum calculations. By measuring IPCE and impedance spectra, the adsorbents are shown to improve the electron collection but impede the electron injection from the excited dye. As a result, the short-circuit current of the adsorbent-doped DSCs is enhanced with the sequence of TBAIN > DMAP > MIN.

Two ruthenium complexes featuring bulky ancillary ligands, XS48 and XS49, were synthesized and studied as dyes in dye-sensitized solar cells (DSCs). Both dyes exhibit higher solar-to-electrical energy conversion efficiency when compared to a commonly used N3 sensitizer under the same conditions. To examine the influence of the bulky ancillary ligands and alleviate the electron recombination in cells, we have developed a dual functioned truxene-based coadsorbent (MXD1) as an alternative candidate to chenodeoxycholic acid (CDCA). This coadsorbent not only effectively shields the back electron transfer from the TiO2to I3–ions but also enhances the light harvesting ability in the short wavelength regions. The photovoltaic performance of XS48-sensitized DSC was independent of the coadsorbents, while XS49 with large bulky ancillary ligand presented better performance when coadsorbent was employed. Interestingly, the simultaneous adsorption-to-sequential adsorption of XS48/49 and MXD1 has caused a notably improved photovoltage, which can be primarily ascribed to the enhanced dye adsorption and retardation of charge recombination. These results not only provide a new vision on how ancillary ligands affect the performance of ruthenium complexes but also open up a new way to achieve further efficiency enhancement of ruthenium complexes.

Developing photosensitizers with high extinction coefficients, proper electronic structures, and steric properties is warranted for the dye-sensitized solar cells (DSCs) employing one-electron outer-sphere redox shuttles. DSCs incorporating Co(II/III)tris(1,10-phenanthroline)-based redox electrolyte and three synthesized organic dyes as photosensitizers (M14, M18, and M19) are described. The hexapropyltruxene group on the dyes retards the rate of interfacial back electron transfer from the conduction band of the nanocrystalline titanium dioxide film to the [Co(III)(phenanthroline)3]3+ions, which enables attainment of high photovoltages approaching 0.9 V. The measurement of photocurrent transients shows that the mass transport limitation of the cobalt redox shuttle has been largely removed by using thin TiO2films. DSCs sensitized with M14 in combination with the cobalt redox shuttle yield a DSC with an overall power conversion efficiency (PCE) of 7.2% under 100 mW cm–2AM1.5 G illumination. The influences of the dye structure on the performance of DSCs were also investigated.

In this paper, we investigate the solvability of matrix equations with -involutary symmetric matrix , the general solution of which is obtained when it is solvable. Meantime, the associated optimal approximation problem for some given matrix is also considered under some particular hypothesis.

We report here on the synthesis and photophysical/electrochemical properties of three functional triarylamine organic dyes (MXD5−7)as well as their application in dye-sensitized nanocrystalline TiO2solar cells (DSSCs). For the designed dyes, the nonplanar structures of bis-hexapropyltruxeneamino take the role of electron donor. The introduction of bis-hexapropyltruxeneamino units brought about superior performance over the simple triphenylamine dye, in terms of light-capturing abilities and suppressing dye aggregation. Among three dyes, the DSSCs based on the dye MXD7showed the best photovoltaic performance: a short-circuit photocurrent density (JSC) of 11.8 mA cm−2, an open-circuit photovoltage (VOC) of 772 mV, and a fill factor (ff) of 0.68, corresponding to an overall conversion efficiency of 6.18% under 100 mW cm−2irradiation. These dyes exhibited high VOCvalues, possible origin for which was investigated regarding the TiO2surface blocking, conduction band movement, and electrolyte-dye interaction.

A series of new conjugated metal−free organic dyes (TC1, TC2, TC3, and TC4) comprising triphenylamine (TPA) moieties as the electron donor and cyanoacetic acid moieties as the electron acceptor/anchoring groups were designed at the molecular level and developed for the use in dye-sensitized solar cells (DSCs). Quantum chemical calculations have been performed to gain insight into structural, electronic, and optical properties of the as-synthesized sensitizers. The time-dependent density functional theory calculations allowed assignment of the experimental spectroscopic data. It is found that the photovoltaic performance of the DSCs with the as-synthesized dyes can be improved by enhancing the electron-donor ability and extending the -conjugated bridge of the dyes. In particular, the DSCs based on 2-cyano-5-(4-(phenyl(4-vinylphenyl)amino)phenyl) penta-2,4-dienoic acid dye (TC4) showed an open circuit voltage of 652 mV, a short circuit photocurrent density of 11.5 mA cm-2, and a fill factor of 0.64, corresponding to an overall light to electricity conversion efficiency of 4.82% under AM 1.5 irradiation (100 mW cm-2). This result reveals that efficient electron injection from the excited sensitizer to the conduction band of titania film occurs, owing to the more delocalizing electrons of the bridge and donor part of the dyes.

Two triphenylamine-based dyes (TPAR3 and TPAR6) containing two carboxylic acid groups with different conjugated lengths were synthesized and characterized with regard to their photophysical and photoelectrochemical properties. Experimental results showed that the λ maxof TPAR6 either in methanol solution or on TiO 2film was red-shifted and broadened by extending the π-conjugated bridge. However, the performance of TPAR3-based dye-sensitized solar cell (DSC) was superior to that of TPAR6. This reason was due to the serious self-quenching of the electronically excited state in TPAR6 molecule, resulting from its cis-transisomerization. The effects of addition of guanidinium thiocyanate (GT) in the electrolyte on the performance of DSCs based on TPAR3 were also investigated, revealing a maximum energy conversion efficiency of 4.02% at 0.100 mol·L −1GT.

We report here on the synthesis and photophysical/electrochemical properties of a series of novel triphenylamine (TPA)-based organic dyes (TPAR1, TPAR2, TPAR4, and TPAR5) as well as their application in dye-sensitized nanocrystalline TiO2solar cells (DSCs). In the four designed dyes, the TPA group and the rhodanine-3-acetic acid take the role of the basic electron donor unit and the electron acceptor, respectively. It was found that introduction of a CH2CH− group into the TPA unit exhibited better photovoltaic performance due to the increase of the electron-density donor moiety and that introduction of a methine (−CHCH−) unit to the bridge resulted in a red-shift and broadening of the absorption spectrum due to expansion of the -conjugation system. Density functional theory (DFT) calculation indicated that the electron distribution moved from the donor unit to the electron acceptor under light irradiation, which means efficient intramolecular charge transfer. In particular, the DSCs based on TPAR4 showed the best photovoltaic performance:  a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 81%, a short-circuit photocurrent density (Jsc) of 18.2 mA cm-2, an open-circuit photovoltage (Voc) of 563 mV, and a fill factor (ff) of 0.61, corresponding to an overall conversion efficiency of 5.84% under AM 1.5 irradiation (100 mW cm-2). This work suggests that the molecular-designed triphenylamine dyes are promising in the application of DSCs.

The first tetranuclear nickel complex with the oxamato ligand, {[Ni(en)2]4[H4L]}(ClO4)4·7H2O (1) (L = N, N′, N″, N‴‐methanetetrayltetrakismethylenetetrakis (oxamato)), has been prepared and determined by single‐crystal X‐ray analysis. 1crystallizes in the tetragonal space group I41/a, with a= 15.2744(9), c= 31.3748(2) Å and Z= 4. Each nickel (II) ion is in a distorted octahedral donor atom environment, which comprises four nitrogen atoms of two en molecules and two oxygen atoms of oxamato bridge. The shape of the entity looks like a propeller. The temperature‐dependent magnetic susceptibilities were analyzed by the Curie‐Weiss law; the following values were found C = 4.36 cm3K mol‐1, θ= ‐24.7 K, respectively.

A unique neodymium(III) complex, {[Nd(BTC)(H2O)4] · H2O}n(BTC = 1, 3, 5‐benzenetricarboxylate), was obtained from the reaction between Nd(ClO4)3· xH2O and Na3BTC. Coordination bonds, hydrogen bonds, and π‐π stacking form a supramolecular structure with a novel, two‐dimensional framework. The temperature‐dependent magnetic susceptibilities were analyzed by the Curie‐Weiss law; the following values were found C= 1.32, θ= —18.3 K, respectively.

Three novel oxamidato-bridged complexes incorporating a macrocyclic oxamide of formula [(CuL)3{CuL(C2H5OH)}Eu(H2O)](ClO4)3·1.5H2O (1), [(CuL)3{CuL(C2H5OH)}Tb(H2O)](ClO4)3·2H2O (2) and [(NiL)5Sm](ClO4)3·2H2O (3) (CuL and NiL, H2L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclopentadeca-7,13-dien), have been hydrothermally synthesized and structurally characterized. In these complexes, the central Ln^III and external copper (or nickel) ions are bridged by macrocyclic oxamide groups. The Eu^III (or Tb^III) ion of 1 (or 2) resides in a distorted tricapped trigonal prismatic environment surrounded by eight oxygen atoms from four oxamide groups and one oxygen atom from a water molecule, whereas the Sm^III ion of 3 resides in a distorted bicapped square antiprismatic environment surrounded by ten oxygen atoms from five oxamide groups. Furthermore, there are hydrogen bonding interactions in 1 and 2 between perchlorate, ethanol and water moieties. Especially for 1 and 2, O−H···O and weak coordination of ClO4⁻ groups link the pentanuclear fragments and perchlorate ions to form a 1-D supramolecular architecture. The fluorescence of Eu^III and Tb^III are almost completely quenched in 1 and 2. The magnetic properties of 1 and 2 have been characterized. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Amazon rainforest fires have significant environmental and societal impacts, but the mechanism and impact of the fires on the regional and global carbon cycles have not been fully understood. Over the rainforest, less precipitation, higher surface temperature, and enhanced mid‐tropospheric sinking air over the eastern part of the Amazon characterized the fire/dry season. These meteorological conditions will facilitate more fires in the Amazon rainforest. Using the Orbiting Carbon Observatory‐2 column CO2, we notice that there are ∼2 ppm more CO2over the Amazon compared with the surrounding area during the fire season. The higher concentrations of atmospheric CO2are related to the surface biomass burning, enhanced sinking air over the eastern part of the Amazon, and surface winds. Results from this study can help us better understand the carbon sources and sinks over the Amazon during the fire/dry season. In this study, we explore the influence of fires on atmospheric CO2over the whole Amazon region using satellite CO2data. Our analysis not only reveals an increase in the CO2concentration (∼2 ppm) over the Amazon during the fire season but also provides a possible mechanism to explain the increase. Our study further suggests that the Amazon forest changes from a CO2sink to a CO2source during the fire season. The increase in the CO2can lead to a warmer climate and produce more fires. It is still a challenge for current models to simulate the impact of fires on atmospheric CO2correctly, especially the interannual variability. Results in this study can help us better constrain models in the future. CO2concentrations are higher over the Amazon than the surrounding region during the fire/dry seasonHigh concentrations of CO2are related to the biomass burning, enhanced sinking air, and surface windsAmazon forest changes from a CO2sink to a CO2source during the fire season CO2concentrations are higher over the Amazon than the surrounding region during the fire/dry season High concentrations of CO2are related to the biomass burning, enhanced sinking air, and surface winds Amazon forest changes from a CO2sink to a CO2source during the fire season

Vehicular catalytic converters are used to regulate, reduce, and convert toxic and environmentally unfriendly compounds in exhaust gases into relatively inert and less harmful chemical species. The efficiency, however, is largely affected by the operating temperature of the converter which is set by the hot exhaust gas released from the combustion chamber. A major gas released during combustion is CO2, and its multiply substituted isotopocule, namely, 13C16O18O, provides a window of opportunity to probe directly the effective temperature of the converter in operation. Here, we report multiple isotopic measurements in exhaust CO2(δ13C, δ17O, δ18O, and Δ47) of diesel (trucks and buses) and gasoline (sedans, trucks, and two-wheel motorcycles)-powered vehicles. For investigating the efficiency of a converter in reducing toxic compounds, we studied NOxprocesses through isotopic analysis of the exhaust N2O. We found that the degree of N2O reduction to N2in gasoline-powered vehicles is high when the temperature is above 200 °C (inferred by Δ47). In contrast, diesel-powered vehicles produce N2O in abundance, probably a consequence of selective catalytic reduction of NOx, and the reduction efficiency depends on the converter temperature. In other words, the catalytic converters act as sinks and sources of N2O to the atmosphere in gasoline- and diesel-operated vehicles, respectively. We also report a new set of field data by measuring the isotopic compositions of CO2and N2O in the Hsuehshan tunnel, a ∼13 km long highway tunnel in Taiwan. Elevated N2O concentrations inside the tunnel indicate that the emission of N2O by heavy-duty diesel vehicles is much higher compared to the reduction by gasoline-operated passenger cars, making the vehicular exhausts a net source of N2O to the atmosphere. The combined study of clumped isotopes and N2O concentration in exhaust gases suggests that it is useful to probe the operational temperature of catalytic converters and monitor the pollution level in operation, thus providing an opportunity for manufacturers to optimize the catalytic efficiency to reduce the level of toxic pollutants to the environment.

This work reports the analysis of the local‐time variations of daytime CO2in the Upper Mesosphere and Lower Thermosphere region as observed by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite. Results show that daytime SABER CO2in the upper mesosphere between latitudes 30°S and 50°N is lower in the morning than in the afternoon. The same was found in the lower thermosphere but between latitudes 50°S and 50°N. The opposite was found in the upper mesosphere between 50°S and 30°S. These results are compared to simulations of CO2by the Whole Atmosphere Community Climate Model–eXtended. It was found that the local‐time variations of Whole Atmosphere Community Climate Model–eXtended CO2are weaker than SABER CO2. Model diagnostics indicated that these local‐time variations in the model are driven primarily (secondarily) by strong vertical (meridional) gradients in Upper Mesosphere and Lower Thermosphere CO2volume mixing ratios and strong local‐time variations in vertical (meridional) winds. This work concludes that SABER CO2shows significant local‐time variations that are not well simulated by Whole Atmosphere Community Climate Model–eXtended, and we suggest that this is likely because of weaker tidal forcing in the model. SABER CO2in the UMLT region has stronger local‐time variation than WACCM‐X CO2WACCM‐X suggests that tidal perturbations in meridional and vertical advection drive the local‐time variations of CO2SABER CO2indicates that WACCM‐X simulates weaker tidal perturbations in meridional and vertical advection

A three‐dimensional cyano‐bridged copper(II) complex, [Cu(dien)Ag(CN)2]2[Ag2(CN)3][Ag(CN)2] (1) (dien = diethylenetriamine), has been prepared and characterized by X‐ray crystallography. Complex 1crystallized in the monoclinic space group P21/nwith a= 6.988(2), b= 17.615(6), c= 12.564(4) Å, β= 90.790(5)°. The crystal consists of cis‐[Cu(dien)]2+units bridged by [Ag(CN)2]—to form a zig‐zag chain. The Ag atoms of the free and bridging [Ag(CN)2]—link together to form additional infinite zig‐zag chains with short Ag···Ag distances. The presence of Ag···Ag interactions effectively increases the dimensionality from a 1‐D chain to a 3‐D coordination polymer.

Two novel dicyanamide complexes [Co(dmf)2(NCNCN)2] (1) and [Cu(bipy)(NCNCN)]ClO4(2) have been synthesized and structurally characterized. 1crystallizes in the monoclinic space group C2 with a= 13.568(6)Å, b= 7.403(3)Å, c= 8.118(3)Å and Z= 2, whereas 2crystallizes in the monoclinic system, Ccgroup, a= 14.270(7)Å, b= 9.143(5)Å, c= 12.371(1) Å, β= 118.612(7)°, and Z= 4. According to X‐ray crystallographic studies, in complex 1each CoIIion is six‐coordinated with four nitrogen atoms from four μ1, 5‐dca (dca = dicyanamide) ligands and two oxygen atoms from two dmf ligands to form distorted octahedra. 1forms a 1‐D network bridged via μ1, 5‐dca. 2consists of a uniform Cu(NCNCN)Cu chain, each CuIIion is octahedrally coordinated with four nitrogen atoms from two μ1, 5‐dca ligands and one bipy ligand and two oxygen atoms from two ClO4—ions. The octahedral CuIIion shows a significant Jahn‐Teller distortion, with two axial oxygen atoms considerably farther from the copper than the four equatorial nitrogens.

This work estimates global‐mean Kzzusing Sounding of the Atmosphere using Broadband Emission Radiometry/Thermosphere‐Ionosphere‐Mesosphere Energetics and Dynamics monthly global‐mean CO2profiles and a one‐dimensional transport model. It is then specified as a lower boundary into the Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIE‐GCM). Results first show that global‐mean CO2in the mesosphere and lower thermosphere region has annual and semiannual oscillations (AO and SAO) with maxima during solstice seasons along with a primary maximum in boreal summer. Our calculated AO and SAO in global‐mean CO2are then modeled by AO and SAO in global‐mean Kzz. It is then shown that our estimated global‐mean Kzzis lower in magnitude than the suggested global‐mean Kzzfrom Qian et al. (2009) that can model the observed AO and SAO in the ionosphere/thermosphere (IT) region. However, our estimated global‐mean Kzzis similar in magnitude with recent suggestions of global‐mean Kzzin models with explicit gravity wave parameterization. Our work therefore concludes that global‐mean Kzzfrom global‐mean CO2profiles cannot model the observed AO and SAO in the IT region because our estimated global‐mean Kzzmay only be representing eddy diffusion due to gravity wave breaking. The difference between our estimated global‐mean Kzzand the global‐mean Kzzfrom Qian et al. (2009) thus represents diffusion and mixing from other nongravity wave sources not directly accounted for in the TIE‐GCM lower boundary conditions. These other sources may well be the more dominant lower atmospheric forcing behind the AO and SAO in the IT region. Global‐mean CO2has annual and semiannual oscillationsSeasonal variation of global‐mean Kzzestimated from global‐mean CO2Global‐mean Kzzfrom CO2alone cannot reproduce annual and semiannual oscillations in IT region

Methylation of arginine residues in dopamine receptors in humans and worms promotes signaling and functional responses.

Two cyano-bridged heterobimetallic coordination polymers {Mn[Au(CN)₂]₂(H₂O)₂}_n (1) and {KFe[Au(CN)₂]₃}_n (2), have been synthesized from [Au(CN)₂]− building blocks and structurally characterized. In both complexes aurophilicity play an important role in determining the 3D open microporous framework and the interpenetrating triple framework for 1 and 2, respectively. Both aqueous solutions of 1 and 2 display interesting luminescent properties.

Two cyano-bridged heterobimetallic coordination polymers MnAuCN22H2O2n1 and KFeAuCN23n2, have been synthesized from AuCN2−building blocks and structurally characterized. In both complexes aurophilicity play an important role in determining the 3D open microporous framework and the interpenetrating triple framework for 1and 2, respectively. Both aqueous solutions of 1and 2display interesting luminescent properties.

The Cassini Ion Neutral Mass Spectrometer (INMS) has measured both neutral and ion species in Titan's upper atmosphere and ionosphere and the Enceladus plumes. Ion densities derived from INMS measurements are essential data for constraining photochemical models of Titan's ionosphere. The objective of this paper is to present an optimized method for converting raw data measured by INMS to ion densities. To do this, we conduct a detailed analysis of ground and in‐flight calibration to constrain the instrument response to ion energy, the critical parameter on which the calibration is based. Data taken by the Cassini Radio Plasma Wave Science Langmuir Probe and the Cassini Plasma Spectrometer Ion Beam Spectrometer are used as independent measurement constraints in this analysis. Total ion densities derived with this method show good agreement with these data sets in the altitude region (∼1100–1400 km) where ion drift velocities are low and the mass of the ions is within the measurement range of the INMS (1–99 Daltons). Although ion densities calculated by the method presented here differ slightly from those presented in previous INMS publications, we find that the implications for the science presented in previous publications is mostly negligible. We demonstrate the role of the INMS ion densities in constraining photochemical models and find that (1) cross sections having high resolution as a function of wavelength are necessary for calculating the initial photoionization products and (2) there are disagreements between the measured ion densities representative of the initial steps in Titan photochemistry that require further investigation. Importance of environmental conditions for analysis of Cassini INMS ion dataRole of INMS ion densities in validating Titan photochemical model simulationsProduction and loss of primary photoionization products is not fully understood