Transporting Cold Atoms towards a GaN-on-Sapphire Chip via an Optical Conveyor Belt

Trapped atoms on photonic structures inspire many novel quantum devices for quantum information processing and quantum sensing.Here,we demonstrate a hybrid photonic-atom chip platform based on a Ga N-onsapphire chip and the transport of an ensemble of atoms from free space towards the chip with an optical conveyor belts.Due to our platform’s complete optical accessibility and careful control of atomic motion near the chip with a conveyor belt,successful atomic transport towards the chip is made possible.The maximum transport efficiency of atoms is about 50%with a transport distance of 500μm.Our results open up a new route toward the efficient loading of cold atoms into the evanescent-field trap formed by the photonic integrated circuits,which promises strong and controllable interactions between single atoms and single photons.

Review of current progress in hole-transporting materials for perovskite solar cells

Recent advancements in perovskites’ application as a solar energy harvester have been astonishing. The power conversion efficiency(PCE) of perovskite solar cells(PSCs) is currently reaching parity(>25 percent), an accomplishment attained over past decades. PSCs are seen as perovskites sandwiched between an electron transporting material(ETM) and a hole transporting material(HTM). As a primary component of PSCs, HTM has been shown to have a considerable effect on solar energy harvesting, carrier extraction and transport, crystallization of perovskite, stability, and price. In PSCs, it is still necessary to use a HTM.While perovskites are capable of conducting holes, they are present in trace amounts, necessitating the use of an HTM layer for efficient charge extraction. In this review, we provide an understanding of the significant forms of HTM accessible(inorganic, polymeric and small molecule-based HTMs), to motivate further research and development of such materials. The identification of additional criteria suggests a significant challenge to high stability and affordability in PSC.

High isotropic dispiro structure hole transporting materials for planar perovskite solar cells

Two novel fluorene-based hole transporting materials (HTMs) were synthesized to be used in perovskite solar cells (PSCs). C102 was designed based on C101 by simply linking the two carb on-carbon single bonds to compose a "dispiro" structure. Their typically similar structures cause them sharing almost the same energy levels. However, their photovoltaic performances are quite different due to the small variations. The PSC that contained the "dispiro" structure, C102, reached a power conversion efficiency (PCE) of 17.4%, while the device contained C101, obtained a lower PCE of 15.5%. Electrochemical properties and Photovoltaic characterization of the two materials have been investigated to explain the result. It is shown that C102 has a stronger ability to transport holes and resist the charge recombination. Thus, the dispiro structure should be more appropriate being used as HTM in PSCs.

TRUCK TRANSPORTING SYSTEM

The paper was a truck transporting system that based on system engineering theory and driver, truck-and-train, road and transporting environment were essential factors. It analyzed andstudied nine subsystems consisted of the tfour tactors, ensured running safety, high efficieney and lowconsumption of transporting truck and increased using time of truck and road.

Tetrabenzotriazacorrole and its derivatives as undopea hole transporting materials for perovskite solar cells:Synthesis,device fabrication,and device performance

Phosphorous tetrabenzotriazacorrole(TBC)and its two soluble derivatives(TBC-1 and TBC-2)were synthesized and used for the first time as undoped hole transporting materials(HTMs)in MAPbI3 perovskite solar cells(PSCs).Their performance in PSCs was measured and compared with that of SpiroOMeTAD and phthalocyanine precursor.The fundamental properties related to HTMs are also examined.These novel HTMs are easily prepared,cost-effective,and solution processable.The materials exhibited much higher hole transport mobility and broader light absorption than pristine Spiro-OMeTAD and phthalocyanine precursor.They can work efficiently in the absence of any dopant for devices composed of FTO/cp-TiO2/mp-TiO2/MAPbI3/HTM/Au.The undoped mesoscopic solar cell devices based on TBC exhibited a promising power conversion efficiency(PCE)of up to 16.2%(measured at 100 mWcm2 illumination,AM 1.5 G),together with good long-term stability under ambient conditions.This PCE of 16.2%observed using TBC is remarkably higher than the 11.2%observed using undoped Spiro-OMeTAD and also much better than the 8.70%observed using its phthalocyanine precursor.As to substitution effects,α-substituted TBC-1 was found to be a better HTM thanβ-substituted TBC-2(PCE 11.4%)and unsubstituted TBC-3(PCE 6.81%)under the same conditions.These results provide the basis for further exploiting TBC compounds as a new type of low-cost and effective HTM for PSCs.

Evaluation of Stress Corrosion Cracking Damage to an API 5L X52 Pipeline Transporting Ammonia: A Case Study

The high number of leak events that took place in recent years at a 25.4 cm (10”)Øpipeline transporting anhydrous liquid ammonia, located in the Southeast of Mexico, was the main reason to carry out a number of field studies and laboratory tests that helped establish not only the failure causes but also mitigation and control solutions. The performed activities included direct evaluation at failure sites, total repair programs, metallographic studies and pipeline flexibility analyses. The obtained results were useful to conclude that the failures obeyed a cracking mechanism by Stress Corrosion Cracking (SCC) which was caused by the combined effect of different factors: high stress resistance, high hardness of the base metal with a microstructure prone to brittleness and residual strains originated during the pipeline construction. From the operative, logistic and financial standpoints, it is not feasible to release the stress of approximately 22 km of pipeline. Therefore, the only viable solution is to install a new pipeline with suitable fabrication, construction and installation specifications aimed at preventing the SCC phenomenon.

Internal resonance of an axially transporting beam with a two-frequency parametric excitation

This paper investigates the transverse 3:1 internal resonance of an axially transporting nonlinear viscoelastic Euler-Bernoulli beam with a two-frequency parametric excitation caused by a speed perturbation.The Kelvin-Voigt model is introduced to describe the viscoelastic characteristics of the axially transporting beam.The governing equation and the associated boundary conditions are obtained by Newton’s second law.The method of multiple scales is utilized to obtain the steady-state responses.The RouthHurwitz criterion is used to determine the stabilities and bifurcations of the steady-state responses.The effects of the material viscoelastic coefficient on the dynamics of the transporting beam are studied in detail by a series of numerical demonstrations.Interesting phenomena of the steady-state responses are revealed in the 3:1 internal resonance and two-frequency parametric excitation.The approximate analytical method is validated via a differential quadrature method.

Heteroatom engineering on spiro-type hole transporting materials for perovskite solar cells

A series of spiro-type hole transporting materials, spiro-OMe TAD, spiro-SMe TAD and spiro-OSMe TAD,with methoxy, methylsulfanyl or half methoxy and half methylsulfanyl terminal groups are designed and prepared. The impact of varied terminal groups on bulk properties, such as photophysical, electrochemical, thermal, hole extraction, and photovoltaic performance in perovskite solar cells is investigated.It is noted that the terminal groups of the hole transporting material with half methoxy and half methylsulfanyl exhibit a better device performance and decreased hysteresis compared with all methoxy or methylsulfanyl counterparts due to better film-forming ability and improved hole extraction capability.Promisingly, the spiro-OSMe TAD also shows comparable performance than high-purity commercial spiro-OMe TAD. Moreover, the highest power conversion efficiency of the optimized device employing spiro-OSMe TAD exceeding 20% has been achieved.

Crucial role of charge transporting layers on ion migration in perovskite solar cells

The device preconditioning dependent hysteresis and the consequential performance degradation hinder the actual performance and stability of the perovskite solar cells. Ion migration and charge trapping in the perovskite with large contribution from grain boundaries are the most common interpretations for the hysteresis. Yet, the high performing devices often include intermediate hole and electron transporting layers, which can further complicate the dynamical process in the device. Here, by using Kelvin Probe Force Microscopy and Confocal Photoluminescence Microscopy, we elucidate the impact of chargetransporting layers and excess MAI on the spatial and temporal variations of the photovoltage on the MAPbI3-based solar cells. By studying the devices layer by layer, we found that the light-induced ion migration occurs predominantly in the presence of an imbalanced charge extraction in the solar cells, and the charge transporting layers play crucial role in suppressing it. Careful selection and processing of the electron and hole-transporting materials are thus essential for making perovskite solar cells free from the ion migration effect.

Highly stable perovskite solar cells with a novel Ni-based metal organic complex as dopant-free hole-transporting material

Hole-transporting material(HTM)plays a paramount role in enhancing the photovltaic performance of perovskite solar cells(PSCs).Currently,the vast majority of these HTMs employed in PSCs are organic small molecules and polymers,yet the use of organic metal complexes in PSCs applications remains less explored.To date,most of reported HTMs require additional chemical additives(e.g.Li-TFSI,t-TBP)towards high performance,however,the introduction of additives decrease the PSCs device stability.Herein,an organic metal complex(Ni-TPA)is first developed as a dopant-free HTM applied in PSCs for its facile synthesis and efficient hole extract/transfer ability.Consequently,the dopant-free Ni-TPAbased device achieves a champion efficiency of 17.89%,which is superior to that of pristine Spiro-OMeTAD(14.25%).Furthermore,we introduce a double HTM layer with a graded energy bandgap containing a Ni-TPA layer and a CuSCN layer into PSCs,the non-encapsulated PSCs based on the Ni-TPA/CuSCN layers affords impressive efficiency up to 20.39%and maintains 96%of the initial PCE after 1000 h at a relative humidity around 40%.The results have demonstrated that metal organic complexes represent a great promise for designing new dopant-free HTMs towards highly stable PSCs.

C≡N-based carbazole-arylamine hole transporting materials for perovskite solar cells: Substitution position matters

Hole transporting materials(HTMs)containing passivating groups for perovskite materials have attracted much attention for efficient and stable perovskite solar cells(PSCs).Among them,C≡N-based molecules have been proved as efficient HTMs.Herein,a series of novel C≡N functionalized carbazole-arylamine derivatives with variable C≡N substitution positions(para,meta,and ortho)on benzene-carbazole skeleton(on the adjacent benzene of carbazole)were synthesized(p-HTM,m-HTM and o-HTM).The experimental results exhibit that the substitution positions of the Ctriple bondN unit on HTMs have minor difference on the HOMO energy level and hydrophobicity.m-HTM has a relatively lower glass transition temperature compared with that of p-HTM and o-HTM.The functional theory calculations show that the C≡N located on meta position exposed very well,and the exposure direction is also the same with the methoxy.Upon applying these molecules as HTMs in PSCs,their device performance is found to sensitively depend on the substitution position of the C≡N unit on the molecule skeleton.The devices using m-HTM and o-HTM exhibit better performance than that of p-HTM.Moreover,m-HTM-based devices exhibit better light-soaking performance and long-term stability,which could be resulted from better interaction with the perovskite according to DFT results.Moreover,we further prepared a HTM with two C≡N units on the symmetrical meta position of molecular skeleton(2m-HTM).Interestingly,2m-HTM-based devices exhibit relatively inferior performance compared with that of the m-HTM,which could be resulted from weak negative electrical character of C≡N unit on 2m-HTM.The results give some new insights for designing ideal HTM for efficient and stable PSCs.

Research on adaptive anti-rollover control of kiloton bridge transporting and laying vehicles

The SPMT construction method is a new rapid construction technology of large urban overpass with unblocked traffic,and unstability of SPMT construction method equipment cannot be accurately described due to the concrete beam size,irregular shape and complex transport conditions,which is called kiloton bridge transporting and laying vehicle.The anti-rollover performance of SPMT suspension system is studied,and vehicle side slip angle and load transfer rate(LTR) are regarded as the evaluation indexes.An active suspension adaptive anti-rollover control model of SPMT,in which roll stability affected by the structural parameters and control parameters,is built based on fuzzy PID,and the effectiveness of the control method is verified through real vehicle test.

Effects of Cangfudaotan Tang on Expression of Organic Anion Transporting Polypeptide (oatp2b1) in Liver and Kidney Tissues of Rats with Phlegm Dampness Type Polycystic Ovary Syndrome (PCOS)

Objective: To explore the effect of Cangfudaotan Tang on phlegm dampness type of PCOS and the role of oatp2b1 in transportation and transformation of phlegm dampness. Methods: 36 SD female rats were randomly divided into three groups: blank control group, model group and Cangfudaotan Tang group, 12 cases in each one. After PCOS rat models were made, rats of Cangfudaotan Tang group were treated with Cangfudaotan Tang (1.42 g/kg/d) by intragastric administration for 14 days;blank control and model group were given with isodose saline. The expression of oatp2b1 mRNA/Protein in liver and kidney tissues was measured and the level of testosterone (T), follicle stimulating hormone(FSH), estradiol (E2), luteinizing hormone(LH), Serum total cholesterol (TG), Triacylglycerols (TC), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) were detected at the same time. Results: Compared with blank control group, the expression of oatp2b1 mRNA and the level of TC, TG, LDL, LH, FSH, T in model group were significantly increased (P < 0. 05), while the level of HDL was significantly decreased (P < 0. 05);compared with model group, the expression of oatp2b1 mRNA and the level of TC, TG, LDL in Cangfudaotan Tang group were significantly lowered (P < 0.05);the level of HDL was significantly higher;the oatp2b1 protein in kidney and liver tissues had different degrees of expression, while there was no statistical significance among the three groups. Conclusions: Oatp2b1 might be one of the material bases participating in transportation and transformation of phlegmy dampness. The mechanism of Cangfudaotan Tang treating phlegm dampness type of PCOS may be achieved by regulating the expression of oatp2b1.

TIBET’S LAST CARAVAN WITH TRANSPORTING SALT(III)——SALT LANGUAGE AND THE CARAVAN

Saltmen believed aboriginal gods were everywhere. If anyone in a caravan did something bad, offending the local gods, then these would punish the caravan and even bring down disaster upon it. If everyone respected and offered sacrifices to the gods, and followed all the caravan rules, then they the gods would protect them.

TIBET'S LAST CARAVAN CHARGED WITH TRANSPORTING SALT(Ⅸ):Kelsang Wangdul Arrives at Lhasa

The road became worse by the south part of Namtso;streams of melting snow had eroded the road until it resembled a giant comb.The vehicle alternated between speeding along and a sudden brake that made everyone lurch about as though they were all intoxicated.

Influence of organic anion transporting potypeptide(SLCO1B1 and SLCO1B3)genetic polymorphisms on mycophenolic acid in Chinese kidney transplantation patients

Objective To analyze the relationship between genetic polymorphisms of organic anion transporting polypeptide ( SLCO1B1 and SLCO1B3) and mycophenolic acid ( MPA) pharmacokinetics in Chinese kidney transplant recipients. Methods Gene mutations ( SLCO1B3 T334G,SLCO1B1 A338G) were detected in 68 recipi-

TIBET'S LAST CARAVAN CHARGED WITH TRANSPORTING SALT(Ⅶ):Barter Trade between Food Grains and Salt

By setting out for saline lakes in spring, Tibetan caravans on horseback return to farmlands in autumn to barter salt for agricultural products.

SnO2-based electron transporting layer materials for perovskite solar cells: A review of recent progress

In recent years, due to their high photo-to-electric power conversion efficiency(PCE)(up to 23%(certified)) and low cost, perovskite solar cells(PSCs) have attracted a great deal of attention in photovoltaics field. The high PCE can be attributed to the excellent physical properties of organic–inorganic hybrid perovskite materials, such as a long charge diffusion length and a high absorption coefficient in the visible range. There are different diffusion lengths of holes in electrons in a PSC device, and thus the electron transporting layer(ETL) plays a critical role in the performance of PSCs. An alternative for TiO2, to the most common ETL material is SnO2, which has similar physical properties to TiO2 but with much higher electron mobility, which is beneficial for electron extraction. In addition, there are many facile methods to fabricate SnO2 nanomaterials with low cost and low energy consumption. In this review paper, we focus on recent developments in SnO2 as the ETL of PSCs. The fabrication methods of SnO2 materials are briefly introduced. The influence of multiple Sn O2 types in the ETL on the performance of PSCs is then reviewed. Different methods for improving the PCE and long-term stability of PSCs based on SnO2 ETL are also summarized. The review provides a systematic and comprehensive understanding of the influence of different Sn O2 ETL types on PSC performance and potentially motivates further development of PSCs with an extension to SnO2-based PSCs.

Effect of hole-transporting materials on the photovoltaic performance and stability of all-ambient-processed perovskite solar cells

High-efficiency perovskite solar cells(PSCs) reported hitherto have been mostly prepared in a moisture and oxygen-free glove-box atmosphere, which hampers upscaling and real-time performance assessment of this exciting photovoltaic technology. In this work, we have systematically studied the feasibility of allambient-processing of PSCs and evaluated their photovoltaic performance. It has been shown that phasepure crystalline tetragonal MAPbI_3 perovskite films are instantly formed in ambient air at room temperature by a two-step spin coating process, undermining the need for dry atmosphere and post-annealing.All-ambient-processed PSCs with a configuration of FTO/TiO_2/MAPbI_3/Spiro-OMeTAD/Au achieve opencircuit voltage(990 mV) and short-circuit current density(20.31 mA/cm^2) comparable to those of best reported glove-box processed devices. Nevertheless, device power conversion efficiency is still constrained at 5% by the unusually low fill-factor of 0.25. Dark current–voltage characteristics reveal poor conductivity of hole-transporting layer caused by lack of oxidized spiro-OMe TAD species, resulting in high seriesresistance and decreased fill-factor. The study also establishes that the above limitations can be readily overcome by employing an inorganic p-type semiconductor, copper thiocyanate, as ambient-processable hole-transporting layer to yield a fill-factor of 0.54 and a power conversion efficiency of 7.19%. The present findings can have important implications in industrially viable fabrication of large-area PSCs.

A Study of the Factors Affecting Transporting Solid— Liquid Suspension through Pipelines

An experimental investigation was carried out on the transport of solid liquid mixture through pipelines. The principal aim of this was to study how to transport slurries through pipeline systems. The experimental tests include measurements of main parameters affecting transport of solid liquid mixture, like sand slurry and mud slurry. These parameters are deduced by applying non-dimensional approach, which includes Reynolds number, Froude number, concentration, specific gravity, and ratio of particle to pipe diameter. Preliminary results include the following general trends: 1) Increasing input concentration increases the pressure gradient, whereas decreases the efficiency of solid transport;2) As specific gravity of solid material increases, the pressure gradient increases and the efficiency of transport decreases;3) As mixture velocity increases, the efficiency of transport increases;4) Solids with fine grain size are preferred than with coarse grain size from the view points of pressure gradient and efficiency of transport. Also, the present experimental data has been compared with the correlations developed before by different authors. Such correlations relate the pressure gradient to flow velocity, specific gravity, and efficiency of transport to grain size of solid material, and input solid concentration.