The reusable launch vehicle (RLV) presents a new avenue for reducing cost of space transportation. The landing mechanism, which provides landing support and impact absorption, is a vital component of the RLV at final ...The reusable launch vehicle (RLV) presents a new avenue for reducing cost of space transportation. The landing mechanism, which provides landing support and impact absorption, is a vital component of the RLV at final stage of recovery. This study proposes a novel legged deployable landing mechanism (LDLM) for RLV. The Watt-II six-bar mechanism is adopted to obtain the preferred configuration via the application of the linkage variation approach. To endow the proposed LDLM with advantages of large landing support region, lightweight, and reasonable linkage internal forces, a multi-objective optimization paradigm is developed. Furthermore, the optimal scale parameters for guiding the LDLM prototype design is obtained numerically using the non-dominated sorting genetic algorithm-II (NSGA-II) evolutionary algorithm. A fully-functional scaled RLV prototype is developed by integrating the gravity-governed deploying scheme to facilitate unfolding action to avoid full-range actuation, a dual-backup locking mechanism to enhance reliability of structure stiffening as fully deployed, and a shock absorber (SA) with multistage honeycomb to offer reliable shock absorbing performance. The experimental results demonstrate that the proposed LDLM is capable of providing rapid and smooth deployment (duration less than 1.5 s) with mild posture disturbance to the cabin (yaw and pitch fluctuations less than 6°). In addition, it provides satisfactory impact attenuation (acceleration peak less than 10g (g is the gravitational acceleration)) in the 0.2 m freefall test, which makes the proposed LDLM a potential alternative for developing future RLV archetype.展开更多
The acceptability properties, total phenolic content, and antioxidant potential of four (red, green, brown, cream) desi chickpea (Cicer arietinum L.) cultivars from the World Germplasm Bank were evaluated. Protein con...The acceptability properties, total phenolic content, and antioxidant potential of four (red, green, brown, cream) desi chickpea (Cicer arietinum L.) cultivars from the World Germplasm Bank were evaluated. Protein content of the grains varied from 20.12% to 28.85% (dw), highest for Cream ICC3421. The water absorption capacity (WAC) and cooking time (CT) of the whole grains ranged from 97.7 to 117.5 g water/100 g seeds (ww) and from 109.5 to 193.5 min, respectively;the highest WAC and lowest CT corresponded to Cream ICC3421 cultivar. The total phenolic content (TPC) and total hydrophilic antioxidant activity (AoxA) [oxygen radical absorbance capacity (ORAC) value] of desi chickpea cultivars varied from 746 to 1.286 μg gallic acid equivalents (GAE)/g sample (dw) and from 43.9 to 53.9 μmol Trolox equivalents (TE)/g sample (dw);Brown ICC3512 showed the highest ORAC value. Chickpea cultivars could contribute significantly to the management and/or prevention of degenerative diseases associated with free radical damage.展开更多
We reconstruct the cosmological background evolution under the scenario of dynamical dark energy through the Gaussian process approach,using the latest Dark Energy Spectroscopic Instrument(DESI)baryon acoustic oscilla...We reconstruct the cosmological background evolution under the scenario of dynamical dark energy through the Gaussian process approach,using the latest Dark Energy Spectroscopic Instrument(DESI)baryon acoustic oscillations(BAO)combined with other observations.Our results reveal that the reconstructed dark-energy equation-of-state(EoS)parameter w(z)exhibits the so-called quintom-B behavior,crossing-1 from phantom to quintessence regime as the universe expands.We investigate under what situation this type of evolution could be achieved from the perspectives of field theories and modified gravity.In particular,we reconstruct the corresponding actions for f(R),f(T),and f(Q)gravity,respectively.We explicitly show that,certain modified gravity can exhibit the quintom dynamics and fit the recent DESI data efficiently,and for all cases the quadratic deviation from theΛCDM scenario is mildly favored.展开更多
文摘The reusable launch vehicle (RLV) presents a new avenue for reducing cost of space transportation. The landing mechanism, which provides landing support and impact absorption, is a vital component of the RLV at final stage of recovery. This study proposes a novel legged deployable landing mechanism (LDLM) for RLV. The Watt-II six-bar mechanism is adopted to obtain the preferred configuration via the application of the linkage variation approach. To endow the proposed LDLM with advantages of large landing support region, lightweight, and reasonable linkage internal forces, a multi-objective optimization paradigm is developed. Furthermore, the optimal scale parameters for guiding the LDLM prototype design is obtained numerically using the non-dominated sorting genetic algorithm-II (NSGA-II) evolutionary algorithm. A fully-functional scaled RLV prototype is developed by integrating the gravity-governed deploying scheme to facilitate unfolding action to avoid full-range actuation, a dual-backup locking mechanism to enhance reliability of structure stiffening as fully deployed, and a shock absorber (SA) with multistage honeycomb to offer reliable shock absorbing performance. The experimental results demonstrate that the proposed LDLM is capable of providing rapid and smooth deployment (duration less than 1.5 s) with mild posture disturbance to the cabin (yaw and pitch fluctuations less than 6°). In addition, it provides satisfactory impact attenuation (acceleration peak less than 10g (g is the gravitational acceleration)) in the 0.2 m freefall test, which makes the proposed LDLM a potential alternative for developing future RLV archetype.
文摘The acceptability properties, total phenolic content, and antioxidant potential of four (red, green, brown, cream) desi chickpea (Cicer arietinum L.) cultivars from the World Germplasm Bank were evaluated. Protein content of the grains varied from 20.12% to 28.85% (dw), highest for Cream ICC3421. The water absorption capacity (WAC) and cooking time (CT) of the whole grains ranged from 97.7 to 117.5 g water/100 g seeds (ww) and from 109.5 to 193.5 min, respectively;the highest WAC and lowest CT corresponded to Cream ICC3421 cultivar. The total phenolic content (TPC) and total hydrophilic antioxidant activity (AoxA) [oxygen radical absorbance capacity (ORAC) value] of desi chickpea cultivars varied from 746 to 1.286 μg gallic acid equivalents (GAE)/g sample (dw) and from 43.9 to 53.9 μmol Trolox equivalents (TE)/g sample (dw);Brown ICC3512 showed the highest ORAC value. Chickpea cultivars could contribute significantly to the management and/or prevention of degenerative diseases associated with free radical damage.
基金National Key Research and Development Program of China(2021YFC2203100)National Natural Science Foundation of China(12261131497 and 12003029)+2 种基金CAS young interdisciplinary innovation team(JCTD2022-20)111 Project(B23042)USTC Fellowship for International Cooperation,and USTC Research Funds of the Double First-Class Initiative。
文摘We reconstruct the cosmological background evolution under the scenario of dynamical dark energy through the Gaussian process approach,using the latest Dark Energy Spectroscopic Instrument(DESI)baryon acoustic oscillations(BAO)combined with other observations.Our results reveal that the reconstructed dark-energy equation-of-state(EoS)parameter w(z)exhibits the so-called quintom-B behavior,crossing-1 from phantom to quintessence regime as the universe expands.We investigate under what situation this type of evolution could be achieved from the perspectives of field theories and modified gravity.In particular,we reconstruct the corresponding actions for f(R),f(T),and f(Q)gravity,respectively.We explicitly show that,certain modified gravity can exhibit the quintom dynamics and fit the recent DESI data efficiently,and for all cases the quadratic deviation from theΛCDM scenario is mildly favored.
