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A new generalized Su-Schrieffer-Heeger model with hierarchical long-range hoppings based on the one-dimensional tetratomic chain is proposed. The properties of the topological states and phase transition, depending on the cointeraction of the intracell and intercell hoppings, are investigated by the phase diagram of the winding number. It is found that topological states with large positive/negative winding numbers can be readily generated in the system. The properties of the topological states can be verified by the ring-type structures in the trajectory diagram of the complex plane. The topological phase transition is strongly related with the opening up or closure of the energy bandgap at the center/boundaries of the Brillouin zone. Finally, the feature of the non-zeroenergy edge states at the ends of the finite system is revealed and matched with the bulk-boundary correspondence.

The design luminosity and the beam energy scale in the future Super Proton–Proton Collider (SPPC) are unprecedented. In this article, different luminosity and leveling scenarios are studied to see if the luminosity design goal is feasible. The luminosity in a collider can be optimized by a group of machine parameters including beam emittance, number of bunches, bunch population, beta functions at the interaction point (IP), colliding mode (such as head-on or crossing, round or flat optics) and their changes during the colliding process. The beam–beam effects, event pileup and machine turnaround time have direct impact on the luminosity. Different measures or scenarios by taking the above factors are studied. When crab cavities are not available, the flat optics is studied to recover the luminosity lost due to a large crossing angle. The luminosity patterns during the physics run and averaged luminosities are given for different luminosity schemes. One can compare the performance potential and the technical difficulties among the schemes. The difference between the round optics and flat optics in the case of no crab cavities is presented. SPPC has a very high performance in the averaged luminosity. Flexible luminosity optimization and leveling schemes are available to enhance the physics performance. The flat optics as a backup plan in the case of no crab cavities does help to improve the luminosity compared with the round optics.

At the end of 2017, the CSNS (China Spallation Neutron Source) started the running with the neutron beam. The white neutron source "Back-n" as the extended program of the CSNS had its first results from several experiments. The Light Charged Particle detectors array (LPDA) in this report is one of the experimental systems, including an elaborate vacuum chamber and some vary purpose detectors. During the developing and testing, this system gives excellent performance. Preliminary results from the Light Charged Particle detectors array (LPDA) show a good particle resolution with 6Li target. The more interested target will be implemented in future.

Background and Aims Stamen movements directly determine pollen fates and mating patterns by altering positions of female and male organs. However, the implications of such movements in terms of pollination are not well understood. Recently, complex patterns of stamen movements have been identified in Loasaceae, Parnassiaceae, Rutaceae and Tropaeolaceae. In this study the stamen movements in Ruta graveolens (Rutaceae) and their impact on pollination are determined. Methods Pollination effects of stamen movements were studied in Ruta graveolens , in which one-by-one uplifting and falling back is followed by simultaneous movement of all stamens in some flowers. Using 30 flowers, one stamen was manipulated either to be immobilized or to be allowed to move freely towards the centre of the flower but be prevented from falling back. Pollen loads on stigmas and ovule fertilization in flowers with or without simultaneous stamen movement were determined. Results Pollen removal decreased dramatically (P < 0·001) when the stamen was stopped from uplifting because its anther was seldom contacted by pollinators. When a stamen stayed at the flower's centre, pollen removal of the next freely moved anther decreased significantly (P < 0·005) because of fewer touches by pollinators and quick leaving of pollinators that were discouraged by the empty anther. Simultaneous stamen movement occurred only in flowers with low pollen load on the stigma and the remaining pollen in anthers dropped onto stigma surfaces after stamens moved to the flower's centre. Conclusions In R. graveolens pollen removal is promoted through one-by-one movement of the stamen, which presents pollen in doses to pollinators by successive uplifting of the stamen and avoids interference of two consecutively dehisced anthers by falling back of the former stamen before the next one moves into the flower's centre. Simultaneous stamen movement at the end of anthesis probably reflects an adaptation for late-acting self-pollination.

Intra-inflorescence variation in floral traits is important to understand the pollination function of an inflorescence and the real reproductive outputs of a plant. Ruta graveolens (Rutaceae) produce both quaternary (four petals and eight stamens) and quinary (five petals and ten stamens) flowers on the same cymes, while their pollination roles and the effects on the reproductive success remained unexplored. We experimentally examined the biomass of female versus male organs and pollen viability and stigma receptivity to explore the sex allocation patterns between the flowers. The breeding systems and reproductive outputs through either female function (seed set) or male function (pollen dispersal) were also studied for quinary and quaternary flowers to determine whether there was functional bias. The results showed that R. graveolens was protandrous, with a mixed mating system. Its stamens could slowly move one by one and only dehisce when positioning at the flower center, which could greatly enhance pollen dispersal. The first-opened quinary flower allocated significantly higher resources (dry biomass) in female organs while quaternary flowers allocated more resource in male organs. The quaternary flowers experienced higher pollen limitation in seed production but were more successful in pollen dispersal and the quinary flowers reproduced both through female and male functions. Our data suggested that quinary and quaternary flower on same inflorescence in R. graveolens functioned mainly as the sex role that most resources were allocated, which probably reflect an adaptation for floral phenology and pollination process in this plant.

In many insect‐pollinated angiosperms, stamens are grown with anthers cohered, which might affect pollination processes, but the ecological significance of this fusion of anthers remains unexplored. We studied the breeding system and pollination process of didynamous Campsis grandiflora (Bignoniaceae), with anther fusion in pairs. Pollen removal and deposition were studied in the field for naturally fused versus experimentally separated anthers. Campsis grandiflora flowers were protandrous, with a low pollen:ovule ratio, were mostly outcrossed, and were self‐compatible, with pollinators needed. The main pollinators were pollen‐collecting halictid bees and nectar‐feeding vespid wasps. Halictid bees scooped pollen on long anthers for a significantly longer time period and removed twice as much pollen from fused anthers than from separated anthers. Vespid wasps contacted fused short anthers more frequently and more precisely and removed nearly twice as much pollen than when contacting separated short anthers...

Rotaviruses cause acute diarrhea worldwide. Previous studies of rotavirus diarrhea in China found that rotavirus infection is the most common cause of severe diarrhea in young children. In the present study, surveillance of rotavirus diarrhea was conducted involving 9549 children aged

During a rotavirus surveillance conducted in Lulong County, Hebei Province, China, a total of 331 stool specimens collected in 2003 from children under 5 years old with diarrhea were screened. We identified a novel group A human rotavirus of genotype G5P[6]. Phylogenetic analysis confirmed that the VP7 protein of this newly identified strain, LL36755, was closely related to those of the G5 strains. As such, it has 95.4% homology with its counterparts in the porcine G5 strains C134 and CC117 at the amino acid sequence level. On the other hand, the VP4 protein of the LL36755 strain was 94.5% homologous to those of the porcine P[6] strains 134/04-10, 134/04-11, 221/04-7, and 221/04-13. Our findings indicate a dynamic interaction between human and porcine rotaviruses.

China has the second largest birth cohort in the world and the second highest number of deaths due to rotavirus infection. It is also the only country with a licensed rotavirus vaccine. Chinese policy makers now need credible estimates of the burden of rotavirus disease, to decide about vaccine use. From August 2001 through July 2003, prospective hospital-based surveillance for rotavirus diarrhea among children

Two Rotavirus G9P[8] strains (LL52696 and LL52727) were recognized during a sentinel-based survey in Lulong, China. Phylogenetic analysis of the VP7 gene showed that both strains isolated constituted a divergent genetic cluster distinct from the other G9 strains isolated in China. Analysis of VP4, VP6, and NSP4 genes revealed that these strains were closely related to Lulong strains. We hold that two strains were reassortant between G9 and Lulong predominant strains.

To learn the epidemiologic characteristics of rotavirus diarrhea in three hospitals under sentinel surveillance from August 2001 to July 2004 and to provide background information for developing and implementing rotavirus vaccine.Data from hospital-based rotavirus surveillance among children5 years old hospitalized with acute diarrhea was used. Patients' clinic information and feces specimens were collected. Specimens were tested and typed for rotavirus.Totally, 3121 specimens were tested and the detection rate of rotavirus was 51%. Among all the children with rotavirus diarrhea, 94% were2 years old. G3 (69.9%) was the most prevalent serotype followed by G1 (6.6%) and G2 (2.9%). P[8] was the most common genotype of rotavirus. The most common G-P combination identified in this study was P[8] G3 (64.0%). Seveal other combinations of minor frequency were also identified.Rotavirus infection was most commonly seen among children5 years old hospitalized with acute diarrhea in the three hospitals. It is important to develop and implement rotavirus vaccine to prevent and control severe rotavirus infection. Because of the diversity of rotavirus strains, it is necessary to perform rotavirus strain surveillance to understand the dynamic nature of viral transmission.

To investigate the epidemiological characteristus of human caliciviruses (HuCVs) among children under 5 years of age with acute diarrhea and to estimate the disease burden in Lulong county.HuCVs were detected by enzyme linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR). Some PCR amplicons were cloned and sequenced. Phylogenetic tree was constructed for strain characterization. The rate of HuCVs-attributed hospitalization was estimated according to the positive rate of HuCVs detection in fecal specimens collected from hospitalized diarrhea patients.Between July 1999 and June 2001, 708 fecal specimens were collected, of which 393 rotavirus-negative and 5 rotavirus-positive specimens were detected for HuCVs. Thirty-one point six percentage of fecal specimens from patients with diarrhea was HuCVs positive. Among inpatients, HuCVs positive rate was 17.5%. HuCVs detection was mainly distributed in 3 - 17 mouth-old children, in winter. All 11 strains belonged to NLV GII in which 6 strains GII-3, 2 strains GII-4 and 3 strains GII-7, and they shared 55.1% - 100% nucleotide identity. NLV GII-4 and GII-7 were identified in 2000, while NLV GII-3 and GII-7 in 2001. The preliminary estimate of HuCVs-attributed hospitalization rate was 3.6 per thousand.Human caliciviruses with different genotypes circulated among children in Lulong county with GII NLVs were the prevalent strains. The disease burden of HuCVs was second to rotavirus.

As part of a national rotavirus surveillance activity, we collected fecal specimens from 3,177 children with acute diarrhea in 10 regions of China between April 1998 and April 2000 and screened them for rotavirus. Rotavirus was detected in 41% ( n = 1,305) of specimens, and in these, G1 was the predominant serotype (72.6%), followed by G3 (14.2%), G2 (12.1%), G4 (2.5%), G9 (0.9%), and G untypeable (0.7%). Among 327 G-typed strains tested for P genotype, 14 different P-G combinations were identified, with the globally common strains P[8]G1, P[4]G2, P[8]G3, and P[8]G4 representing 75.6% of all typed rotavirus strains. Among the uncommon strains, 11 were P[6]G9, and others included P[6]G1, P[6]G3, and five novel P-G combinations (P[9]G1, P[4]G1, P[4]G3, P[4]G4, and P[8]G2). Our results indicate that while the common rotavirus strains remain predominant, the diversity of strains is much greater than was previously recognized.