Nanocrystalline diamond matrix deposited on copper substrate by radical species restricted diffusion.

Nanocrystalline diamond matrix (or patterned nanocrystalline diamond) have been grown by hot filament chemical vapor deposition (HFCVD) on copper substrates, which were masked by a copper template filled with through-holes. The influence of the mixing ratio for CH4/H2 source gases, total gas pressure and the aspect ratio (the ratio of hole depth to its diameter) on the morphology, grain size and quality of diamond films were investigated. Continuous diamond films were obtained under 2.0 kpa. When increasing the aspect ratio from 0.67 to 2.0, a gradual reduction of diamond grain size from micrometer to nanometers scale was observed. The formation of nanocrystalline diamond (NCD) matrix can be attributed to the restricted diffusion of radical species and the diamond nucleation kinetics on copper substrates. By through-holes of templates on copper substrates to restrict the diffusion and transport of radical species, NCD matrix was successfully deposited on copper substrates.

[Short-term effectiveness of lateral raft plate combined with Jail screw fixation in treatment of tibial plateau collapse fractures involved posterior-lateral column].

Objective: To investigate the short-term effectiveness of proximal tibial lateral raft plate combined combined with or without Jail screw fixation in the treatment of tibial plateau collapse fractures involved posterior-lateral column. Methods: A retrospective analysis was performed on 106 patients (106 knees) with tibial plateau collapse fracture involved posterior-lateral column admitted between January 2016 and January 2021. According to the combination with Jail screw fixation or not, patients were divided into control group (treated by lateral raft plate without Jail screw fixation, 52 cases) and study group (treated by lateral raft plate with Jail screw fixation, 54 cases). There was no significant difference between the two groups in terms of gender, age, affected knee side, cause of injury, Schatzker classification, Tscherne-Gotzen classification, time from injury to operation, and preoperative lateral tibial plateau posterior slope angle (PSA), tibial plateau varus angle (TPVA), Rasmussen anatomical score (P>0.05). The operation time, cumulative fluoroscopy time, intraoperative blood loss, hospitalization stay, fracture healing time, complications, and lateral tibial plateau PSA, TPVA, Rasmussen anatomical score detected by X-ray films and CT before operation and at 1 year after operation of the two groups were recorded and compared. The number of cases of articular surface collapse in the two groups was recorded at 1 year after operation, and the effectiveness was evaluated by American Special Surgery Hospital (HSS) score. Results: All patients were followed up 12-32 months (mean, 19.5 months). There was no significant difference between the two groups in operation time, cumulative fluoroscopy time, intraoperative blood loss, hospitalization stay, and fracture healing time (P>0.05). There were 2 patients (3.7%) in the study group and 3 patients (5.8%) in the control group with superficial wound infection, which were cured after debridement and dressing change. There was no significant difference in the incidence between the two groups (χ2=0.252, P=0.616). There was no complication such as vascular and nerve injury, internal fixation failure, nonunion or malunion of fracture, and deep vein thrombosis of lower limbs in both groups. At 1 year after operation, 9 cases (17.3%) in the control group had joint collapse of 2-3 mm, while only 2 cases (3.7%) in the study group had joint collapse, showing significant difference (χ2=5.271, P=0.022). At 1 year after operation, the PSA, TPVA, and Rasmussen anatomical scores of the two groups were significantly improved when compared with preoperative ones (P<0.05); the differences of pre- and post-operative PSA, TPVA, Rasmussen anatomical score, and postoperative HSS score in the study group were significantly better than those in the control group (P<0.05). Conclusion: The lateral raft plate combined with or without Jail screw fixation can achieve satisfactory short-term effectiveness in the treatment of tibial plateau collapse fractures involved posterior-lateral column. Combined with Jail screw, it can enhance the fixation and avoid the occurrence of secondary articular surface collapse, which can be used as a better choice.

Productivity and sustainability of rainfed wheat-soybean system in the North China Plain: results from a long-term experiment and crop modelling.

A quantitative understanding of yield response to water and nutrients is key to improving the productivity and sustainability of rainfed cropping systems. Here, we quantified the effects of rainfall, fertilization (NPK) and soil organic amendments (with straw and manure) on yields of a rainfed wheat-soybean system in the North China Plain (NCP), using 30-years' field experimental data (1982-2012) and the simulation model-AquaCrop. On average, wheat and soybean yields were 5 and 2.5 times higher in the fertilized treatments than in the unfertilized control (CK), respectively. Yields of fertilized treatments increased and yields of CK decreased over time. NPK + manure increased yields more than NPK alone or NPK + straw. The additional effect of manure is likely due to increased availability of K and micronutrients. Wheat yields were limited by rainfall and can be increased through soil mulching (15%) or irrigation (35%). In conclusion, combined applications of fertilizer NPK and manure were more effective in sustaining high crop yields than recommended fertilizer NPK applications. Manure applications led to strong accumulation of NPK and relatively low NPK use efficiencies. Water deficiency in wheat increased over time due to the steady increase in yields, suggesting that the need for soil mulching increases.

Spatial and seasonal characterization of net primary productivity and climate variables in southeastern China using MODIS data.

We developed a sophisticated method to depict the spatial and seasonal characterization of net primary productivity (NPP) and climate variables. The role of climate variability in the seasonal variation of NPP exerts delayed and continuous effects. This study expands on this by mapping the seasonal characterization of NPP and climate variables from space using geographic information system (GIS) technology at the pixel level. Our approach was developed in southeastern China using moderate-resolution imaging spectroradiometer (MODIS) data. The results showed that air temperature, precipitation and sunshine percentage contributed significantly to seasonal variation of NPP. In the northern portion of the study area, a significant positive 32-d lagged correlation was observed between seasonal variation of NPP and climate (P<0.01), and the influences of changing climate on NPP lasted for 48 d or 64 d. In central southeastern China, NPP showed 16-d, 48-d, and 96-d lagged correlation with air temperature, precipitation, and sunshine percentage, respectively (P<0.01); the influences of air temperature and precipitation on NPP lasted for 48 d or 64 d, while sunshine influence on NPP only persisted for 16 d. Due to complex topography and vegetation distribution in the southern part of the study region, the spatial patterns of vegetation-climate relationship became complicated and diversiform, especially for precipitation influences on NPP. In the northern part of the study area, all vegetation NPP had an almost similar response to seasonal variation of air temperature except for broad crops. The impacts of seasonal variation of precipitation and sunshine on broad and cereal crop NPP were slightly different from other vegetation NPP.