Effects of melatonin implantation on cashmere yield,fibre characteristics,duration of cashmere growth as well as growth and reproductive performance of Inner Mongolian cashmere goats

Background： Exogenous melatonin could induce cashmere growth. However, induced growth of cashmere fleece by melatonin implants cannot be combined with the typical growth, resulting in earlier shedding followed by another cycle of cashmere growth. To address this issue, we examine the effects on the cashmere yield, fibre characteristics, and the growth and reproductive performance of cashmere goats of planned administration of melatonin. Methods： Eighteen half-sib, female goats were assigned to two treatments （n = 9） including a control and a treatment where melatonin （2 mg/kg BW） was implanted at the end of April and end of June. Cashmere growth and shedding were observed for approximately ] year following implantation. Fibre samples were collected monthly to determine cumulative cashmere length. Initiation and cessation dates for cashmere growth as well as the rate of cashmere growth were calculated. Cashmere yield, weight gain of dam, kidding date, litter size, and birth weight were also recorded. Results： Melatonin implantation increased cashmere yield by 34.5 % （control 553.7 g vs. melatonin 745.0 g; P〈 0.01）, cashmere length by 21.3 % （control 95.2 mm vs. melatonin 115.4 mm; P 〈 0.01）, and decreased fibre diameter by 4.4 % （control 14.6 pm vs. melatonin 14.0 IJm; P 〈 0.03）. In melatonin-treated goats, the average initiation date was earlier than in control goats （May 18, 2013 vs. July 2, 20]3; P〈 0.01） but there was a similar cessation date （March 22, 2014 vs. March 27, 2014）. Consequently, the duration of cashmere growth was longer in melatonin-treated goats than in control goats （307 vs.270 days; P 〈 0.01）. The final BW, average daily gain, kidding date, litter size, and birth weight were not influenced by melatonin implantation. Conclusions： These data indicate that melatonin implantation （2 mg/kg BW） on two occasions （late April and June） increased cashmere yield by combining the induced growth of cashmere fleece with the typical growth and decreased the fibre diameter without changing dam growth rate or reproductive performance.

All-polymer solar cells

Organic solar cells(OSCs)show a promising commercialization prospect with their power conversion efficiencies(PCEs)exceeding 18%[1−6].Among various types of OSCs,all-polymer solar cells(all-PSCs)with a physical blend of p-and n-type polymer as the active layer to harvest solar irradiation attract growing attention due to their unique advantages like excellent morphological stability,and mechanical durability[7].

Polythiophene solar cells processed from non-halogenated solvent with 15.68%efficiency

Polythiophenes(PTs)are prospective polymer donors for large-scale manufacturing and industrialization owing to their simple structures and low synthetic cost.However,the fabrication of PT solar cells depends on highly toxic chlorinated solvents,and less research has been done on the use of more environmentally friendly non-halogenated solvents.Herein,highly efficient PT solar cells based on top-performance polythiophene,P5TCN-F25,processed from a non-halogenated solvent are reported by delicate aggregation control.A power conversion efficiency of up to 15.68%was achieved by depositing the active layer from a hot o-xylene solution,which is the record efficiency of non-halogenated processed PT solar cells up to date.The appropriate solution temperature is beneficial to the formation of ordered polymer stacking and desirable phase separation size,which thereby contributes to enhanced charge transfer efficiency,more balanced hole/electron mobility,and reduced trap-assisted recombination.These results provide valuable implications for improving the efficiency of PT solar cells via environmentallyfriendly processing.

Regioregular Non-Fused Polymerized Small Molecular Acceptors Enabling Efficient All-Polymer Solar Cells

Comprehensive Summary The regioregularity induced by the isomers of the end-groups has been widely recognized as a key factor that determines the photovoltaic properties of polymerized small molecular acceptors(PSMAs)in all-polymer solar cells(all-PSCs).However,the influence of regioregularity on the photovoltaic properties of non-fused PSMAs has not been explored yet.In this contribution,two regioregular non-fused PSMAs,PFBTz-T-γand PFBTz-T-δ,were synthesized for the first time by using the monomers with isomeric pure end-groups.Compared with PFBTz-T-δ,PFBTz-T-γhas more compact and more ordered packing in solid state,which results in a more red-shifted optical absorption and a higher electron mobility.More remarkably,PFBTz-T-γand PFBTz-T-δexhibited huge difference in photovoltaic performance in all-PSCs,which offered the power conversion efficiencies(PCEs)of 9.72%and 0.52%,respectively.Further studies have unveiled that the higher PCE of PFBTz-T-γis due to more efficient exciton dissociation,higher and more balanced electron/hole mobility,and less charge recombination as a result of favorable morphology of the blend film.This work demonstrates that the development of regioregular non-fused PSMAs by tuning the polymerization sites is an effective strategy for obtaining high-efficiency all-PSCs.

有机太阳电池关键材料研究进展

有机太阳电池具有质量轻、柔性、印刷制备等优点,有巨大的应用潜力,从其诞生那一刻起便引起了学术界和工业界的广泛研究兴趣.历经25年的发展,有机太阳电池效率已突破18%,其快速进步得益于不断涌现的高性能新材料和器件制备技术,以及对电池活性层形貌、分子堆积和器件机理的深入理解.基于有机共轭结构的电子给体和电子受体材料是决定有机太阳电池性能的关键材料.本文将以给、受体材料的发展历程为主线,聚焦那些明星材料和里程碑工作,阐述高性能关键材料的分子结构演变和进化过程,最后展望其面临的挑战和未来发展方向.

绵羊粒细胞集落刺激因子原核表达与提纯及用于颗粒细胞培养的效果

文中旨在研究粒细胞集落刺激因子(Granule cell stimulating factor,GCSF)对绵羊颗粒细胞体外培养过程中细胞增殖和凋亡的影响,明确GCSF对绵羊颗粒细胞生存的调节作用,为今后该蛋白用于羊繁育方面的研究奠定基础。原核克隆表达纯化羊GCSF蛋白,纯化的蛋白用M-NSF60细胞检测生物学活性,将纯化的GCSF添加到颗粒细胞培养基中作为试验组,以培养基中未添加GCSF的细胞为对照,利用Alarmarblue检测细胞增殖情况,流式细胞仪检测细胞周期和凋亡的变化。结果表明,羊GCSF可以原核表达并纯化,并且具有生物学活性。在24 h和48 h时,在0.06–600 ng/mL的范围内随着加入GCSF的终浓度增加,细胞活力升高。试验组颗粒细胞体外培养24 h后,与阴性对照相比,细胞周期的分布显著改变,S期细胞比例显著减少(P<0.05),G2/M期细胞比例显著增多(P<0.05)。试验组凋亡率和对照组相比,48 h检测时凋亡率显著降低(P<0.05)。综上表明,GCSF在体外培养的绵羊颗粒细胞中,可调控绵羊颗粒细胞周期,促进细胞增殖,抑制细胞凋亡。

Progress of the key materials for organic solar cells

Organic solar cells have attracted academic and industrial interests due to the advantages like lightweight,flexibility and roll-to-roll fabrication.Nowadays,18%power conversion efficiency has been achieved in the state-of-the-art organic solar cells.The recent rapid progress in organic solar cells relies on the continuously emerging new materials and device fabrication technologies,and the deep understanding on film morphology,molecular packing and device physics.Donor and acceptor materials are the key materials for organic solar cells since they determine the device performance.The past 25 years have witnessed an odyssey in developing high-performance donors and acceptors.In this review,we focus on those star materials and milestone work,and introduce the molecular structure evolution of key materials.These key materials include homopolymer donors,D-A copolymer donors,A-D-A small molecular donors,fullerene acceptors and nonfullerene acceptors.At last,we outlook the challenges and very important directions in key materials development.

The new era for organic solar cells: polymer donors

Organic solar cells(OSCs)based on bulk heterojunction,consisting of a polymer donor and a small molecular acceptor(SMA)represent a promising photovoltaic technology due to their prospect in producing large-area modules via low-cost roll-to-roll processing[1].This field has experienced three stages according to the type of electron acceptors.Prior to 2015,the electron acceptors were predominated by fullerene derivatives.

The new era for organic solar cells:non-fullerene small molecular acceptors

Organic solar cells(OSCs)is a promising renewable energy technology as their prospect in producing large-area photovoltaic modules via low-cost roll-to-roll processing and their widespread application including photovoltaic farms,building integration,and portable electronics,etc.[1].The key component of an OSC is its photoactive layer,which is a bulk-heterojunction blend of an electron donor and an electron acceptor[2].The electron donors are p-type semi-conducting conjugated polymers or small molecules,and the electron acceptors were predominated by fullerene derivatives in OSC history.

The new era for organic solar cells: polymer acceptors

Organic solar cells(OSCs)have made fast advance with prominent power conversion efficiencies(PCEs)achieved in non-fullerene OSCs in recent years[1].Among various types of OSCs,allpolymer solar cells(APSCs)consisting of a polymer donor and a polymer acceptor are promising power sources for portable and wearable electronics due to their intrinsic advantages in device stability and mechanical flexibility[2].

The new era for organic solar cells:small molecular donors

Solution-processed organic solar cells(OSCs)have attracted considerable attention due to their unique advantages like flexibility,semitransparency,and fabrication of large-area modules via low-cost roll-to-roll processing[1].The core of an OSC is the bulk-heterojunction photoactive layer,which consists of electron donors and electron acceptors.The leading electron donors are ptype conjugated polymers,and the electron acceptors are typically n-type conjugated small molecules[2].

15.4% Efficiency all-polymer solar cells

We report all-polymer solar cells(All-PSCs) with record-high power conversion efficiency(PCE) through tuning the molecular weights of the polymer donor(PBDB-T) to form optimal active layer morphology. By combining the polymer donors with a newly reported polymer acceptor(PJ1), an unprecedented high PCE of 15.4% and fill factor over 75% were achieved for the AllPSCs with the medium molecular weight polymer donor(PBDB-TMW), which is the highest value for All-PSCs reported so far.Detailed morphology investigation revealed that the proper phase separation in the PBDB-TMW:PJ1 blend should account for the superior device performance as PBDB-TMW exhibits appropriate miscibility with the polymer acceptor PJ1. These results demonstrated that the device performance of All-PSCs could be fully comparable to that of small molecular acceptor-based PSCs. The formation of optimized morphology via precise control of molecular weights of polymer donors and acceptors is crucial to achieve this goal.

Electrical and spin switches in single-molecule junctions

Single-molecule electrical and spin switches have been one of the main research focuses in molecular electronics and spintronics because they may form the most important elements for the future information technology,thus attracting great attention in the scientific community and witnessing significant progresses benefiting from the combination of physics,chemistry,materials,and engineering.The key issue of constructing single-molecule switches is the development of stimulus-responsive systems that provide bistable or multiple states.In this review,we summarize the recent advances of this field in terms of the external stimulus that induces the switching.A variety of external stimuli,such as light,electric field,magnetic field,mechanical force,and chemical stimulus,have been successfully employed to activate the reversible switching in single-molecule junctions by manipulating molecular structures,conformations,electronic states,and spin states.As a burgeoning field,we finally put forward the challenges in molecular electronics and spintronics that need to be solved,which will initiate intense research.

Low-bandgap conjugated polymers based on benzodipyrrolidone with reliable unipolar electron mobility exceeding 1 cm^(2) V^(-1)s^(-1)

The employment of an intrinsic quinoidal building block,benzodipyrrolidone(BDP),on constructing conjugated polymers(PBDP-2F and PBDP-2CN)with high electron mobility and unipolar transport characteristic in polyethylenimine ethoxylated(PEIE)modified organic field-effect transistors(OFETs)is reported.The intrinsic quinoidal characteristic and excellent coplanarity of BDP can lower the lowest unoccupied molecular orbital(LUMO)levels and improve ordered interchain packing of the resulting polymers in solid states,which are favorable for electron-injection and transport.By using PEIE as the interlayer to block the hole injection,unipolar n-type transport characteristics with high electron mobility of 0.58 and 1.01 cm^(2) V^(-1)s^(-1)were achieved by the OFETs based on PBDP-2F and PBDP-2CN,respectively.More importantly,the extracted mobilities are highly reliable with the reliability factor of above 80%.To the best of our knowledge,PBDP-2CN is the very first quinoid-based conjugated polymer with reliable electron mobility exceeding 1 cm^(2) V^(-1)s^(-1).This work represents a significant step in exploring intrinsic quinoidal CPs for application in n-channel OFETs and logic complementary circuits.

The effect of end-capping groups in A-D-A type non-fullerene acceptors on device performance of organic solar cells

A series of novel wide bandgap small molecules(IFT-ECA, IFT-M, IFT-TH and IFT-IC) based on the A-D-A structure with indenofluorene core, thiophene bridge, and different electron-deficient end-capping groups, were synthesized and used as non-fullerene acceptors in organic solar cells. The influences of end-capping groups on the device performance were studied.The four materials exhibited different physical and chemical properties due to the variation of end-capping groups, which further affect the exciton dissociation, charge transport, morphology of the bulk-heterojunction films and device performance. Among them, IFT-IC-based device delivered the best power conversion efficiency of 7.16% due to proper nano-scale phase separation morphology and high electron mobility, while the devices based on the other acceptors achieved lower device performance(4.14% for IFT-TH, <1% for IFT-ECA and IFT-M). Our results indicate the importance of choosing suitable electron-withdrawing groups to construct high-performance non-fullerene acceptors based on A-D-A motif.

Controllable band gap engineering of new polymer solar cell materials

The Institute of Polymer Optoelectronic Materials & Devices, South China University of Technology, Guangzhou, in close collaboration with the Department of Electrical and Electronic Engineering, The University of Hong Kong, has shown that the band gap and

High open-circuit voltage organic solar cells enabled by a difluorobenzoxadiazole-based conjugated polymer donor

A new polymer donor based on 3,3′-difluoro-2,2′-bithiophene(2F2T) and difluorobenzoxadiazole(ffBX), named 2F2T-ffBX, is designed and synthesized. The organic solar cell(OSC) based on 2F2T-ffBX donor and [6,6]-phenyl-C60-butyl acid methyl ester([60]PCBM) acceptor exhibits a high efficiency of 7.3% with a high open-circuit voltage(Voc) of 1.03 V. When blended with perylenediimide-based acceptor(PDI6), the corresponding OSC shows a higher Voc of 1.19 V with a low energy loss of 0.50 e V but a much lower efficiency of 2.0%. The detailed analyses including charge generation, transport, recombination properties, and morphology were performed to understand the performance of corresponding devices.

Synthesis of two-dimensional π-conjugated polymers pendent with benzothiadiazole and naphtho[1,2-c:5,6-c]bis[1,2,5]thiadiazole moieties for polymer solar cells

Four new 2D donor–acceptor conjugated polymers were designed and synthesized.These new polymers comprised fluorenealt-triphenylamine or carbazole-alt-triphenylamine as the backbones,and pendants with 2,1,3-benzothiadiazole(BT)or naphtho[1,2-c:5,6-c]bis[1,2,5]thiadiazole(NT)in a triphenylamine unit as the side groups.By changing the acceptor BT for a stronger electron-withdrawing unit of NT moiety in the side chain,the energy levels,absorption spectra,band gaps,and charge-transport abilities of the resultant polymers could be effectively tuned.Bulk heterojunction solar cells with these polymers as the electron donors and(6,6)-phenyl-C71-butyric acid methyl ester as the electron acceptor exhibited high open-circuit voltage(more than 0.8 e V).The power conversion efficiency can be improved from 1.37%to 3.52%by replacing the BT with an NT moiety,which indicates that introducing NT as the side-chain building block can be an effective strategy to construct efficient 2D conjugated polymers for PSCs.

Design, synthesis and photovoltaic properties of a series of new acceptor-pended conjugated polymers

A series of novel acceptor-pended conjugated polymers featuring a newly developed carbazole-derived unit are designed and synthesized. The relationships between chemical structure and optoelectronic properties of the polymers are systematically in-vestigated. The control of UV-Vis absorption spectra and energy levels in resulting polymers are achieved by introducing suitable pended acceptor units. The photovoltaic properties of the resulting polymers are evaluated by blending the polymers with （6,6）-phenyl-CTFbutyric acid methyl ester. The resulting solar cells exhibit moderate performances with high open-circuit voltage. Charge transport properties and morphology were investigated to understand the performance of corresponding solar cells.

Indoor organic photovoltaics

Indoor photovoltaics have attracted increasing attention as power sources for low power consumption wireless electronics and the rapidly-growing Internet of Things(Io T). Highly tunable optical absorption, large absorption coefficients, and low leakage currents make organic photovoltaics(OPVs) promising for indoor application [1]. Recently, a few OPVs have realized over 20% power conversion efficiencies(PCEs) under indoor light illumination.