As the core carrier of integrated circuits,packaging substrates usually respond in time to the evolution of electronic products.Among which,ceramic substrate materials are desired to have excellent dielectric and volt...As the core carrier of integrated circuits,packaging substrates usually respond in time to the evolution of electronic products.Among which,ceramic substrate materials are desired to have excellent dielectric and voltage-resistant properties,high reliability,and good thermal and chemical stability.The β-Ga_(2)O_(3)ceramic prepared in this work has excellent microwave dielectric properties with a Q×f value of ~133140 GHz(Q=1/tanδ),ε_(r) of ~9.57,and temperature coefficient of resonant frequency(TCF)value of ~−58.2 ppm℃^(−1),which meet the requirements of high-frequency packages.Another highlight is that the β-Ga_(2)O_(3)ceramic has a higher dielectric strength of ~30 kV mm^(−1)compared with conventional ceramic substrates,such as Al_(2)O_(3),AlN,etc.,allowing it to be used in higher-power circuits.Meanwhile,a flexural strength of~110 MPa,a thermal expansion of ~+8.9 ppm℃^(−1) and a thermal conductivity of ~15 Wm^(−1)K^(−1) have been achieved in the β-Ga_(2)O_(3)ceramic.In addition,a patch antenna for sub-6 GHz applications was designed and fabricated using the Ga_(2)O_(3)ceramic substrate,showing good performance with a wide bandwidth of ~140 MHz,a return loss S11 of ~−21 dB at the center frequency,a radiation efficiency of ~92% and a gain of ~5 dBi.The stated results guarantee that the Ga_(2)O_(3)ceramic shows great potential in applications towards high-frequency and high-power fields.展开更多
To overcome the disadvantages of current silkworm Bombyx mori transgenic technology,such as costly and time-consuming to maintain non-diapause transgenic silkworms,we report here on the development of treatments for t...To overcome the disadvantages of current silkworm Bombyx mori transgenic technology,such as costly and time-consuming to maintain non-diapause transgenic silkworms,we report here on the development of treatments for the germline transformation of diapause silkworm strains.Our results showed that HC1 treatment within 3 h of oviposition was able to prevent the diapause of eggs from Japanese lineage diapause silkworm strains and was also suitable for germline transformation of the same strains.By incu-bating developing mother eggs from Chinese lineage diapause silkworm strains at 15℃(15℃-IME),we were able to prevent the diapause of their daughter eggs;a similar strategy(15℃-IMES)for the germline transformation of the same strains was that the mother eggs were incubated at 15℃,and the daughter eggs were then microinjected according to the conventional microinjection methods used for non-diapause eggs.By combining tempera-ture and light controls,the improved 15℃-IMES strategy prevented diapause in daughter eggs,and also enabled the germline transformation of both Japanese and Chinese lineage diapause silkworm strains.Although each of the strategies developed here has advantages and disadvantages,we suggest that the 15℃-IMES strategy is a good reference for the establishment of germline transformation technologies of other egg diapause insects.These new strategies for the efficient germline transformation of diapause silkworm strains are likely to improve the practical use of silkworm transgenic lines in sericulture and also highlight silkworm functional genomics research and its modeling.展开更多
The existence and stability of stationary solutions for a reaction-diffusion-ODE system are investigated in this paper.We first show that there exist both continuous and discontinuous stationary solutions.Then a good ...The existence and stability of stationary solutions for a reaction-diffusion-ODE system are investigated in this paper.We first show that there exist both continuous and discontinuous stationary solutions.Then a good understanding of the stability of discontinuous stationary solutions is gained under an appropriate condition.In addition,we demonstrate the influences of the diffusion coefficient on stationary solutions.The results we obtained are based on the super-/sub-solution method and the generalized mountain pass theorem.Finally,some numerical simulations are given to illustrate the theoretical results.展开更多
基金supported by the National Natural Science Foundation of China(52072295,62175056)the International Cooperation Project of Shaanxi Province(2021KWZ-10)+2 种基金the Zhejiang Provincial Science and Technology Program under Grant LGG20F010007the Fundamental Research Funds for the Central Universitythe 111 Project of China(B14040).
文摘As the core carrier of integrated circuits,packaging substrates usually respond in time to the evolution of electronic products.Among which,ceramic substrate materials are desired to have excellent dielectric and voltage-resistant properties,high reliability,and good thermal and chemical stability.The β-Ga_(2)O_(3)ceramic prepared in this work has excellent microwave dielectric properties with a Q×f value of ~133140 GHz(Q=1/tanδ),ε_(r) of ~9.57,and temperature coefficient of resonant frequency(TCF)value of ~−58.2 ppm℃^(−1),which meet the requirements of high-frequency packages.Another highlight is that the β-Ga_(2)O_(3)ceramic has a higher dielectric strength of ~30 kV mm^(−1)compared with conventional ceramic substrates,such as Al_(2)O_(3),AlN,etc.,allowing it to be used in higher-power circuits.Meanwhile,a flexural strength of~110 MPa,a thermal expansion of ~+8.9 ppm℃^(−1) and a thermal conductivity of ~15 Wm^(−1)K^(−1) have been achieved in the β-Ga_(2)O_(3)ceramic.In addition,a patch antenna for sub-6 GHz applications was designed and fabricated using the Ga_(2)O_(3)ceramic substrate,showing good performance with a wide bandwidth of ~140 MHz,a return loss S11 of ~−21 dB at the center frequency,a radiation efficiency of ~92% and a gain of ~5 dBi.The stated results guarantee that the Ga_(2)O_(3)ceramic shows great potential in applications towards high-frequency and high-power fields.
基金supported by the Fundamen-tal Research Funds for the Central Universities(No.XDJK2010B015)China Postdoctoral Science Founda-tion Funded Project(No.20070420722 and 200801221).
文摘To overcome the disadvantages of current silkworm Bombyx mori transgenic technology,such as costly and time-consuming to maintain non-diapause transgenic silkworms,we report here on the development of treatments for the germline transformation of diapause silkworm strains.Our results showed that HC1 treatment within 3 h of oviposition was able to prevent the diapause of eggs from Japanese lineage diapause silkworm strains and was also suitable for germline transformation of the same strains.By incu-bating developing mother eggs from Chinese lineage diapause silkworm strains at 15℃(15℃-IME),we were able to prevent the diapause of their daughter eggs;a similar strategy(15℃-IMES)for the germline transformation of the same strains was that the mother eggs were incubated at 15℃,and the daughter eggs were then microinjected according to the conventional microinjection methods used for non-diapause eggs.By combining tempera-ture and light controls,the improved 15℃-IMES strategy prevented diapause in daughter eggs,and also enabled the germline transformation of both Japanese and Chinese lineage diapause silkworm strains.Although each of the strategies developed here has advantages and disadvantages,we suggest that the 15℃-IMES strategy is a good reference for the establishment of germline transformation technologies of other egg diapause insects.These new strategies for the efficient germline transformation of diapause silkworm strains are likely to improve the practical use of silkworm transgenic lines in sericulture and also highlight silkworm functional genomics research and its modeling.
基金supported by National Natural Science Foundation of China(Grant No.11790273,52276028).
文摘The existence and stability of stationary solutions for a reaction-diffusion-ODE system are investigated in this paper.We first show that there exist both continuous and discontinuous stationary solutions.Then a good understanding of the stability of discontinuous stationary solutions is gained under an appropriate condition.In addition,we demonstrate the influences of the diffusion coefficient on stationary solutions.The results we obtained are based on the super-/sub-solution method and the generalized mountain pass theorem.Finally,some numerical simulations are given to illustrate the theoretical results.
