The zebrafish has become a popular vertebrate animal model in biomedical research.However,it is still challenging to make conditional gene knockout(CKO)models in zebrafish due to the low efficiency of homologous recom...The zebrafish has become a popular vertebrate animal model in biomedical research.However,it is still challenging to make conditional gene knockout(CKO)models in zebrafish due to the low efficiency of homologous recombination(HR).Here we report an efficient non-HR-based method for generating zebrafish carrying a CKO and knockin(KI)switch(zCKOIS)coupled with dual-color fluorescent reporters.Using this strategy,we generated hey2^zCKOIS which served as a hey2 KI reporter with EGFP expression.Upon Cre induction in targeted cells,the hey2^zCKOIS was switched to a non-functional CKO allele hey2^zCKOIS-inv associated with Tag RFP expression,enabling visualization of the CKO alleles.Thus,simplification of the design,and the visibility and combination of both CKO and KI alleles make our z CKOIS strategy an applicable CKO approach for zebrafish.展开更多
The Cu2 Zn Sn S4(CZTS) powders are successfully synthesized by using Zn S and Cu2 Sn S3 as raw materials directly without any intermediate phase at 450 °C for 3 h in Ar atmosphere.The crystalline structure,morpho...The Cu2 Zn Sn S4(CZTS) powders are successfully synthesized by using Zn S and Cu2 Sn S3 as raw materials directly without any intermediate phase at 450 °C for 3 h in Ar atmosphere.The crystalline structure,morphology and optical properties of the CZTS powders are characterized by X-ray diffraction(XRD),Raman spectrum,field emission scanning electron microscopy(FESEM) and ultraviolet-visible(UV-vis) spectrophotometer,respectively.The results show that the band gap of the obtained CZTS is 1.53 e V.The CZTS film is fabricated by spin coating a mixture of CZTS powders and novolac resin with a weight percentage of 30%.The photoelectrical properties of such CZTS films are measured,and the results show an incident light density of 100 m W·cm-2 with the bias voltage of 0.40 V,and the photocurrent density can approach 9.80×10-5 A·cm2 within 50 s,giving an on/off switching ratio of 1.64.展开更多
A self-comparison method with closely interleaved switching states is analyzed and used to evaluate some type-B uncertainties of an ^87Rb atomic fountain clock. Free from additional frequency reference, the method can...A self-comparison method with closely interleaved switching states is analyzed and used to evaluate some type-B uncertainties of an ^87Rb atomic fountain clock. Free from additional frequency reference, the method can be applied to a running fountain to reach a precision beyond its uncertainty. A verification experiment proves an uncertainty of 9.2 × 10^-16 at an averaging time of 242500 s. Further, the method is applied to measure light shift, and no visible relative frequency shift is found in the fountain within the uncertainty of 2.1 × 10^-15. When applied to the evaluation of a cold collisional shift, the result gives a -2.2 × 10^-15 shift with a 9.5 × 10^-16 uncertainty.展开更多
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China(31500849)Shanghai Municipal Science and Technology Major Project(18JC1410100,2018SHZDZX05)+3 种基金the Key Research Program of Frontier Sciences(QYZDY-SSW-SMC028)the Strategic Priority Research Program(XDB32010200)of Chinese Academy of Sciencesthe International Partnership Program,Bureau of International Co-operation of Chinese Academy of Sciences(153D31KYSB20170059)China Wan-Ren Program,and Shanghai Leading Scientist Program
文摘The zebrafish has become a popular vertebrate animal model in biomedical research.However,it is still challenging to make conditional gene knockout(CKO)models in zebrafish due to the low efficiency of homologous recombination(HR).Here we report an efficient non-HR-based method for generating zebrafish carrying a CKO and knockin(KI)switch(zCKOIS)coupled with dual-color fluorescent reporters.Using this strategy,we generated hey2^zCKOIS which served as a hey2 KI reporter with EGFP expression.Upon Cre induction in targeted cells,the hey2^zCKOIS was switched to a non-functional CKO allele hey2^zCKOIS-inv associated with Tag RFP expression,enabling visualization of the CKO alleles.Thus,simplification of the design,and the visibility and combination of both CKO and KI alleles make our z CKOIS strategy an applicable CKO approach for zebrafish.
基金supported by the Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials
文摘The Cu2 Zn Sn S4(CZTS) powders are successfully synthesized by using Zn S and Cu2 Sn S3 as raw materials directly without any intermediate phase at 450 °C for 3 h in Ar atmosphere.The crystalline structure,morphology and optical properties of the CZTS powders are characterized by X-ray diffraction(XRD),Raman spectrum,field emission scanning electron microscopy(FESEM) and ultraviolet-visible(UV-vis) spectrophotometer,respectively.The results show that the band gap of the obtained CZTS is 1.53 e V.The CZTS film is fabricated by spin coating a mixture of CZTS powders and novolac resin with a weight percentage of 30%.The photoelectrical properties of such CZTS films are measured,and the results show an incident light density of 100 m W·cm-2 with the bias voltage of 0.40 V,and the photocurrent density can approach 9.80×10-5 A·cm2 within 50 s,giving an on/off switching ratio of 1.64.
基金supported by the National Natural Science Foundation of China under Grant Nos.61275204 and 91336105
文摘A self-comparison method with closely interleaved switching states is analyzed and used to evaluate some type-B uncertainties of an ^87Rb atomic fountain clock. Free from additional frequency reference, the method can be applied to a running fountain to reach a precision beyond its uncertainty. A verification experiment proves an uncertainty of 9.2 × 10^-16 at an averaging time of 242500 s. Further, the method is applied to measure light shift, and no visible relative frequency shift is found in the fountain within the uncertainty of 2.1 × 10^-15. When applied to the evaluation of a cold collisional shift, the result gives a -2.2 × 10^-15 shift with a 9.5 × 10^-16 uncertainty.
