Optical lattice clocks demonstrate advantages in metrology and frontier physics because of their high stability.Here,we present approaches to enhancing the stability by decoupling the noise related to the short-term a...Optical lattice clocks demonstrate advantages in metrology and frontier physics because of their high stability.Here,we present approaches to enhancing the stability by decoupling the noise related to the short-term and long-term stability.For the short-term stability,we optimize the clock laser by decoupling the frequency noise,and optimize each noise contribution individually until it is below the thermal noise limit.For the long-term stability,we introduce a method to decouple the instability caused by systematic effects.Having identified that the collision frequency shift was the main limiting factor in our systems,we thus optimized the atom number fluctuations in optical lattices.Through targeted optimization,we achieve a synchronous comparison of two clocks with an average stability of 3.2×10^(-16)/√τ and a long-term stability of 2.4×10^(-18)at 8000 s.This work provides an analytical framework for enhancing optical clock stability.展开更多
In China, it is widely believed that teacher feedback plays a crucial role in EFL writing course, exerting a great impact on the improvement of Chinese EFL students＇ writing abilities so that teachers have been requi...In China, it is widely believed that teacher feedback plays a crucial role in EFL writing course, exerting a great impact on the improvement of Chinese EFL students＇ writing abilities so that teachers have been required to deliver feedback on students＇ writings. Teachers, consequently, spare no pains to give feedback, expecting their students would make progress in their writing, but it seems that things go contrary to their wishes. Although there are various complicated factors contributing to the situation, one of the important factors lies in the teachers, a number of whom do not grasp a systematic and effective mechanism of delivering feedback on EFL student writing. Much importance has been attached to Chinese EFL student writing, however, rare attention has been paid to conducting research on concrete ways of delivering feedback on Chinese EFL student writing in China. Therefore, this paper serves to fill the gap, mainly devoting itself to exploring concrete methods of delivering teacher feedback on EFL student writing.展开更多
Objective:To systematically evaluate the clinical efficacy of traditional Chinese medicine(TCM)in auxiliary treatment of grade 1 hypertension.Methods:The China National Knowledge Infrastructure,Wan Fang Data,VIP,PubMe...Objective:To systematically evaluate the clinical efficacy of traditional Chinese medicine(TCM)in auxiliary treatment of grade 1 hypertension.Methods:The China National Knowledge Infrastructure,Wan Fang Data,VIP,PubMed were searched to screen the literature of randomized controlled trials of TCM or non-drug therapies assisting conventional medicine to treat grade 1 hypertension.The search time was from the establishment of the database to October 1,2020.Revman5.3 was used for meta-analysis.Results:8 Chinese literatures were included.The results of the study showed that 24h diastolic blood pressure(DBP),24h systolic blood pressure(SBP),DBP lowering effect and TCM syndrome curative efficacy of the experimental group using TCM was better than that of the control group.However,TCM combined conventional medicine did not show an advantage on SBP lowering effect,antihypertensive efficacy rate and total clinical efficacy rate.Conclusion:TCM has a significant effect on lowering blood pressure for adjuvant treatment of grade 1 hypertension and can significantly improve clinical symptoms.展开更多
The aim of this article was to assess the clinical evidence for or against the blinding effect of non-penetrating sham needle as placebo needle. This systematic review included randomized controlled trials(RCTs) of ac...The aim of this article was to assess the clinical evidence for or against the blinding effect of non-penetrating sham needle as placebo needle. This systematic review included randomized controlled trials(RCTs) of acupuncture taking non-penetrating sham acupuncture as placebo needle. Systematic searches were conducted in 13 electronic databases up to July 2012: Medline, PubMed, the Cochrane Library, CINAHL, EMBASE, a Chinese medical database. All parallel or cross-over RCTs of acupuncture for the blinding effect of non-penetrating needle were chosen without language restrictions. Finally, totally 7 RCTs met the inclusion criteria. In conclusion, our systematic review and meta-analysis demonstrate that the non-penetrating needle is an effective instrument for placebo control in the acupuncture RCTs.展开更多
基金supported by the Shanghai Municipal Science and Technology Major Project(No.2019SHZDZX01)the National Natural Science Foundation of China(No.11134003)+1 种基金the National Key Research and Development Program of China(Nos.2016YFA0302103,2017YFF0212003,and 2016YFB0501601)the Shanghai Excellent Academic Leaders Program(No.12XD1402400)。
文摘Optical lattice clocks demonstrate advantages in metrology and frontier physics because of their high stability.Here,we present approaches to enhancing the stability by decoupling the noise related to the short-term and long-term stability.For the short-term stability,we optimize the clock laser by decoupling the frequency noise,and optimize each noise contribution individually until it is below the thermal noise limit.For the long-term stability,we introduce a method to decouple the instability caused by systematic effects.Having identified that the collision frequency shift was the main limiting factor in our systems,we thus optimized the atom number fluctuations in optical lattices.Through targeted optimization,we achieve a synchronous comparison of two clocks with an average stability of 3.2×10^(-16)/√τ and a long-term stability of 2.4×10^(-18)at 8000 s.This work provides an analytical framework for enhancing optical clock stability.
文摘In China, it is widely believed that teacher feedback plays a crucial role in EFL writing course, exerting a great impact on the improvement of Chinese EFL students＇ writing abilities so that teachers have been required to deliver feedback on students＇ writings. Teachers, consequently, spare no pains to give feedback, expecting their students would make progress in their writing, but it seems that things go contrary to their wishes. Although there are various complicated factors contributing to the situation, one of the important factors lies in the teachers, a number of whom do not grasp a systematic and effective mechanism of delivering feedback on EFL student writing. Much importance has been attached to Chinese EFL student writing, however, rare attention has been paid to conducting research on concrete ways of delivering feedback on Chinese EFL student writing in China. Therefore, this paper serves to fill the gap, mainly devoting itself to exploring concrete methods of delivering teacher feedback on EFL student writing.
文摘Objective:To systematically evaluate the clinical efficacy of traditional Chinese medicine(TCM)in auxiliary treatment of grade 1 hypertension.Methods:The China National Knowledge Infrastructure,Wan Fang Data,VIP,PubMed were searched to screen the literature of randomized controlled trials of TCM or non-drug therapies assisting conventional medicine to treat grade 1 hypertension.The search time was from the establishment of the database to October 1,2020.Revman5.3 was used for meta-analysis.Results:8 Chinese literatures were included.The results of the study showed that 24h diastolic blood pressure(DBP),24h systolic blood pressure(SBP),DBP lowering effect and TCM syndrome curative efficacy of the experimental group using TCM was better than that of the control group.However,TCM combined conventional medicine did not show an advantage on SBP lowering effect,antihypertensive efficacy rate and total clinical efficacy rate.Conclusion:TCM has a significant effect on lowering blood pressure for adjuvant treatment of grade 1 hypertension and can significantly improve clinical symptoms.
基金supported by Traditional Chinese Medicine and Integrated Traditional and Western Medicine Scientific Research Project of Tianjin Municipal Administration of Traditional Chinese Medicine(No.11047)Development Plan of Changjiang Scholars and Innovative Research Team
文摘The aim of this article was to assess the clinical evidence for or against the blinding effect of non-penetrating sham needle as placebo needle. This systematic review included randomized controlled trials(RCTs) of acupuncture taking non-penetrating sham acupuncture as placebo needle. Systematic searches were conducted in 13 electronic databases up to July 2012: Medline, PubMed, the Cochrane Library, CINAHL, EMBASE, a Chinese medical database. All parallel or cross-over RCTs of acupuncture for the blinding effect of non-penetrating needle were chosen without language restrictions. Finally, totally 7 RCTs met the inclusion criteria. In conclusion, our systematic review and meta-analysis demonstrate that the non-penetrating needle is an effective instrument for placebo control in the acupuncture RCTs.
