Taking Malus pumila Mill, Cv. ‘Jinguan＇ as test matedal, the storage quality of the apples under the different storage conditions of plastic membrane atmosphere storage （MAP）, fruit wax coating, chitosan treatment...Taking Malus pumila Mill, Cv. ‘Jinguan＇ as test matedal, the storage quality of the apples under the different storage conditions of plastic membrane atmosphere storage （MAP）, fruit wax coating, chitosan treatment with different calcium fertilizers were studied. The results showed that different storage modes inhibited the fruit rotting and weight loss, delayed the decrease of fruit hardness and titratable acid content, reduced the soluble solid content, inhibited the degradation of vitamin C. The suitable treatment had good effect on preservation of apple fruits, in which 1% chitosan treatment had the best effect.展开更多
How animals allocate their time to various activities has significant consequences for their survival because they reflect the different constraints on time-energy balances. Many ecological variables, such as day leng...How animals allocate their time to various activities has significant consequences for their survival because they reflect the different constraints on time-energy balances. Many ecological variables, such as day length, temperature, food availabil- ity, are supposed to effect on activity budgets allocation of temperate primates. To examine the potential influence of these three variables, the activity budgets ofRhinopithecus bieti was studied at Xiaochangdu, Tibet from June 2003 to March 2005. Pearson correlations were utilized to assess potential relationships between activity budget and day length, food availability and temperature, and stepwise multiple regressions to identify the priority of resting and other activities （activities besides feeding, moving and resting）. Time spent resting and doing ＂other activities＂ is positively related to day length, temperature and food availability. No significant correlations were found between feeding/moving time and any of these variables. This suggests that foraging time （feeding ＋ moving） takes priority over rest and other activities. Day length and foraging time （as independent variables） were related to the time spent in the other two activities besides feeding/moving （as dependent variables）. Both time spent resting and in ＂other activities＂ were highly significant positive functions of day length, with the latter a highly significant negative function of feeding time and moving time. Resting time may therefore be interpreted as taking priority over ＂other activities＂ time. These results provide further evidence of the importance of day length, temperature and food availability to seasonal activity budgets [Current Zoology 56 （6）： 650q559, 2010].展开更多
In this paper we theoretically report an unconventional quantum phase transition of a simple Lipkin- Meshkow-Glick model： an interacting collective spin system without external magnetic field. It is shown that this m...In this paper we theoretically report an unconventional quantum phase transition of a simple Lipkin- Meshkow-Glick model： an interacting collective spin system without external magnetic field. It is shown that this model with integer-spin can exhibit a flrst-order quantum phase transition between different disordered phases, and more intriguingly, possesses a hidden supersymmetry at the critical point. However, for half-integer spin we predict another flrst-order quantum phase transition between two different long-range-ordered phases with a vanishing energy gap, which is induced by the destructive topological quantum interference between the intanton and anti-instanton tunneling paths and accompanies spontaneously breaking of supersymmetry at the same critical point. We also show that, when the total spin-value varies from half-integer to integer this model can exhibit an abrupt variation of Berry phase from π to zero.展开更多
A quick and sensitive method was developed for the determination of 19 metal elements in Saffron,a traditional Chinese medicinal herb,collected from Tibet Autonomous Region and Henan Province of China using inductivel...A quick and sensitive method was developed for the determination of 19 metal elements in Saffron,a traditional Chinese medicinal herb,collected from Tibet Autonomous Region and Henan Province of China using inductively coupled plasma atomic emission spectrometry（ICP-AES）or inductively coupled plasma mass spectrometry（ICP-MS）.The determined 19 metals in Saffron include Ca,Fe,Mg,P,Sr,Al,Mn,Zn,V,Cr,Se,Co,Ni,Mo,and heavy metals As,Cu,Cd,Hg and Pb.For all the analyzed elements,the correlative coefficients of the calibration curves were no less than 0.9938.This proposed method was accurate,and the relative standard deviations of the measurements were lower than 5.25%.It can be used for the quality control of metal elements in Saffron.展开更多
The recent discovery of hidden spin polarization emerging in layered materials of specific nonmagnetic crystal is a fascinating phenomenon, though hardly explored yet. Here, we have studied hidden spin tex- tures in l...The recent discovery of hidden spin polarization emerging in layered materials of specific nonmagnetic crystal is a fascinating phenomenon, though hardly explored yet. Here, we have studied hidden spin tex- tures in layered nonmagnetic 1 T-phase transition-metal dichalcogenides MX2 （M = Zr, Hf; X = S, Se, Te） by using first-principles calculations. Spin-layer locking effect, namely, energy-degenerate opposite spins spatially separated in the top and bottom layer respectively, has been identified. In particular, the hidden spin polarization of 13-band can be easily probed, which is strongly affected by the strength of spin-orbit coupling. The hidden spin polarization of k-band locating at high symmetry M point （conduction band minimum） has a strong anisotropy. In the bilayer, the hidden spin polarization is preserved at the upmost Se layer, while being suppressed if the ZrSe2 layer is taken as the symmetry partner. Our results on hidden spin polarization in 1 T-phase dichalcogenides, verifiable by spin-resolved and angle-resolved photoemis- sion spectroscopy （ARPES）, enrich our understanding of spin physics and provide important clues to search for specific spin polarization in two dimensional materials for spintronic and quantum informa- tion applications.展开更多
Using seismic data of about one year recorded by 18 broadband stations of ASCENT project, we obtained 2547 receiver func- tions in the northeastern Tibetan Plateau. The Moho depths under 14 stations were calculated by...Using seismic data of about one year recorded by 18 broadband stations of ASCENT project, we obtained 2547 receiver func- tions in the northeastern Tibetan Plateau. The Moho depths under 14 stations were calculated by applying the H-x domain search algorithm. The Moho depths under the stations with lower signal-noise ratio （SNR） were estimated by the time delay of the PS conversion. Results show that the Moho depth varies in a range of -40--60 kin. The Moho near the Haiyuan fault is vague, and its depth is larger than those on its two sides. In the Qinling-Qilian Block, the Moho becomes shallower gradually from west to east. To the east of 105~E, the average depth of the Moho is 45 km, whereas the west is 50 km or even deeper. Combining our results with surface wave research, we suggest a boundary between the Qinling and the Qilian Mountains at around 105~E. S wave velocities beneath 15 stations have been obtained through a linear inversion by using Crust2.0 as an ini- tial model, and the crustal thickness that was derived by H-x domain search algorithm was also taken into account. The results are very similar to the results of previous active source studies. The resulting figure indicates that low velocity layers devel- oped in the middle and lower crust beneath the transition zone of the Tibet Block and western Qinling, which may be related to regional faults and deep earth dynamics. The velocity of the middle and lower crust increases from the Songpan Block to the northeastern margin of Tibetan Plateau. Based on the velocity of the crust, the distribution of the low velocity zone and the composition of the curst （Poisson＇s ratio）, we infer that the crust thickening results from the crust shortening along the direc- tion of compression.展开更多
基金Supported by Youth Foundation of Ningxia Academy of Agriculture and Forestry Sciences(NKYQ-14-02)New Technology Introduction and Promotion Project of Ningxia Financial Forestry([2014]11)Special Fund of Apple System of Modern Agriculture Industry Technology System(CARS-28)~~
文摘Taking Malus pumila Mill, Cv. ‘Jinguan＇ as test matedal, the storage quality of the apples under the different storage conditions of plastic membrane atmosphere storage （MAP）, fruit wax coating, chitosan treatment with different calcium fertilizers were studied. The results showed that different storage modes inhibited the fruit rotting and weight loss, delayed the decrease of fruit hardness and titratable acid content, reduced the soluble solid content, inhibited the degradation of vitamin C. The suitable treatment had good effect on preservation of apple fruits, in which 1% chitosan treatment had the best effect.
基金supported by the Chinese Academy of Sciences (KSCX2-1-09)the National Natural Science Foundation of China (30870375,31071937)
文摘How animals allocate their time to various activities has significant consequences for their survival because they reflect the different constraints on time-energy balances. Many ecological variables, such as day length, temperature, food availabil- ity, are supposed to effect on activity budgets allocation of temperate primates. To examine the potential influence of these three variables, the activity budgets ofRhinopithecus bieti was studied at Xiaochangdu, Tibet from June 2003 to March 2005. Pearson correlations were utilized to assess potential relationships between activity budget and day length, food availability and temperature, and stepwise multiple regressions to identify the priority of resting and other activities （activities besides feeding, moving and resting）. Time spent resting and doing ＂other activities＂ is positively related to day length, temperature and food availability. No significant correlations were found between feeding/moving time and any of these variables. This suggests that foraging time （feeding ＋ moving） takes priority over rest and other activities. Day length and foraging time （as independent variables） were related to the time spent in the other two activities besides feeding/moving （as dependent variables）. Both time spent resting and in ＂other activities＂ were highly significant positive functions of day length, with the latter a highly significant negative function of feeding time and moving time. Resting time may therefore be interpreted as taking priority over ＂other activities＂ time. These results provide further evidence of the importance of day length, temperature and food availability to seasonal activity budgets [Current Zoology 56 （6）： 650q559, 2010].
基金supported by National Natural Science Foundation of China under Grant Nos.10775091 and 10704049
文摘In this paper we theoretically report an unconventional quantum phase transition of a simple Lipkin- Meshkow-Glick model： an interacting collective spin system without external magnetic field. It is shown that this model with integer-spin can exhibit a flrst-order quantum phase transition between different disordered phases, and more intriguingly, possesses a hidden supersymmetry at the critical point. However, for half-integer spin we predict another flrst-order quantum phase transition between two different long-range-ordered phases with a vanishing energy gap, which is induced by the destructive topological quantum interference between the intanton and anti-instanton tunneling paths and accompanies spontaneously breaking of supersymmetry at the same critical point. We also show that, when the total spin-value varies from half-integer to integer this model can exhibit an abrupt variation of Berry phase from π to zero.
文摘A quick and sensitive method was developed for the determination of 19 metal elements in Saffron,a traditional Chinese medicinal herb,collected from Tibet Autonomous Region and Henan Province of China using inductively coupled plasma atomic emission spectrometry（ICP-AES）or inductively coupled plasma mass spectrometry（ICP-MS）.The determined 19 metals in Saffron include Ca,Fe,Mg,P,Sr,Al,Mn,Zn,V,Cr,Se,Co,Ni,Mo,and heavy metals As,Cu,Cd,Hg and Pb.For all the analyzed elements,the correlative coefficients of the calibration curves were no less than 0.9938.This proposed method was accurate,and the relative standard deviations of the measurements were lower than 5.25%.It can be used for the quality control of metal elements in Saffron.
基金financially supported by the National Basic Research Program of China (2015CB921001, 2013CBA01600, and 2016YFA0300902)the National Natural Science Foundation of China (61306114)+2 种基金‘‘Strategic Priority Research Program (B)" of Chinese Academy of Sciences (XDB07030100)the National Natural Science Foundation of China Academy of Engineering Physics (U1430117)the Science Challenge Project (TZ2016001)
文摘The recent discovery of hidden spin polarization emerging in layered materials of specific nonmagnetic crystal is a fascinating phenomenon, though hardly explored yet. Here, we have studied hidden spin tex- tures in layered nonmagnetic 1 T-phase transition-metal dichalcogenides MX2 （M = Zr, Hf; X = S, Se, Te） by using first-principles calculations. Spin-layer locking effect, namely, energy-degenerate opposite spins spatially separated in the top and bottom layer respectively, has been identified. In particular, the hidden spin polarization of 13-band can be easily probed, which is strongly affected by the strength of spin-orbit coupling. The hidden spin polarization of k-band locating at high symmetry M point （conduction band minimum） has a strong anisotropy. In the bilayer, the hidden spin polarization is preserved at the upmost Se layer, while being suppressed if the ZrSe2 layer is taken as the symmetry partner. Our results on hidden spin polarization in 1 T-phase dichalcogenides, verifiable by spin-resolved and angle-resolved photoemis- sion spectroscopy （ARPES）, enrich our understanding of spin physics and provide important clues to search for specific spin polarization in two dimensional materials for spintronic and quantum informa- tion applications.
基金financially supported by National Natural Science Foundation of China(Grant No.40930317)CHINARE2012-02-02+1 种基金Project SinoProbe-02-03the NSFC Innovation Research Group Fund(Grant No.41021001)
文摘Using seismic data of about one year recorded by 18 broadband stations of ASCENT project, we obtained 2547 receiver func- tions in the northeastern Tibetan Plateau. The Moho depths under 14 stations were calculated by applying the H-x domain search algorithm. The Moho depths under the stations with lower signal-noise ratio （SNR） were estimated by the time delay of the PS conversion. Results show that the Moho depth varies in a range of -40--60 kin. The Moho near the Haiyuan fault is vague, and its depth is larger than those on its two sides. In the Qinling-Qilian Block, the Moho becomes shallower gradually from west to east. To the east of 105~E, the average depth of the Moho is 45 km, whereas the west is 50 km or even deeper. Combining our results with surface wave research, we suggest a boundary between the Qinling and the Qilian Mountains at around 105~E. S wave velocities beneath 15 stations have been obtained through a linear inversion by using Crust2.0 as an ini- tial model, and the crustal thickness that was derived by H-x domain search algorithm was also taken into account. The results are very similar to the results of previous active source studies. The resulting figure indicates that low velocity layers devel- oped in the middle and lower crust beneath the transition zone of the Tibet Block and western Qinling, which may be related to regional faults and deep earth dynamics. The velocity of the middle and lower crust increases from the Songpan Block to the northeastern margin of Tibetan Plateau. Based on the velocity of the crust, the distribution of the low velocity zone and the composition of the curst （Poisson＇s ratio）, we infer that the crust thickening results from the crust shortening along the direc- tion of compression.
