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About 10%-20% of all individuals who develop hepatocellular carcinoma (HCC) do not have cirrhosis. Comparisons are rarely reported regarding the effectiveness of radiofrequency ablation (RFA) and liver resection (LR) in survival of HCC without cirrhosis and stratification by tumor size ≤ 5 cm.

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Background: Posthepatitic cirrhosis is one of the leading risk factors for hepatocellular carcinoma (HCC) worldwide, among which hepatitis B cirrhosis is the dominant one. This study explored whether laparoscopic splenectomy and azygoportal disconnection (LSD) can reduce the risk of HCC among patients with hepatitis B virus (HBV)-related cirrhotic portal hypertension (CPH). Methods: A total of 383 patients with HBV-related CPH diagnosed as gastroesophageal variceal bleeding and secondary hypersplenism were identified in our hepatobiliary pancreatic center between April 2012 and April 2022, and conducted an 11-year retrospective follow-up. We used inverse probability of treatment weighting (IPTW) to correct for potential confounders, weighted Kaplan–Meier curves, and logistic regression to estimate survival and risk differences. Results: Patients were divided into two groups based on treatment method: LSD (n= 230) and endoscopic therapy (ET; n= 153) groups. Whether it was processed through IPTW or not, LSD group showed a higher survival benefit than ET group according to Kaplan–Meier analysis (P< 0.001). The incidence density of HCC was higher in the ET group compared to LSD group at the end of follow-up [32.1/1000 vs 8.0/1000 person-years; Rate ratio: 3.998, 95% confidence intervals (CI) 1.928–8.293]. Additionally, in logistic regression analyses weighted by IPTW, LSD was an independent protective predictor of HCC incidence compared to ET (odds ratio 0.516, 95% CI 0.343–0.776; P= 0.002). Conclusion: Considering the ability of LSD to improve postoperative survival and prevent HCC in HBV-related CPH patients with gastroesophageal variceal bleeding and secondary hypersplenism, it is worth promoting in the context of the shortage of liver donors. Graphical abstract:

Robotic surgery has been widely accepted in many kinds of surgical procedures. Little is known about clinical effects of robotic-assisted splenectomy and azygoportal disconnection (RSD) for gastroesophageal variceal bleeding and secondary hypersplenism owing to cirrhotic portal hypertension. The aim of this study was to evaluate whether RSD is feasible and safe for patients with cirrhotic portal hypertension and whether RSD is superior to laparoscopic splenectomy and azygoportal disconnection (LSD). We retrospectively investigated the clinical effects of 50 patients with cirrhosis who underwent vagus nerve-preserving RSD (n= 20) and LSD (n= 30) between September 2020 and October 2021. We compared patients’ demographic, intraoperative, and perioperative variables. RSD and LSD were successful in all patients. Operative time did not differ significantly between the RSD group and LSD group (151.15 ± 21.78 min vs. 144.50 ± 24.30 min, P> 0.05), but intraoperative blood loss were significantly reduced in the RSD group (61.00 ± 34.93 mL vs. 105.00 ± 68.77 mL, P< 0.05). No statistically significant differences were found regarding intraoperative allogeneic transfusion rate, visual analog scale pain score on the postoperative first day, time to first oral intake, initial passage of flatus, initial off-bed activity, postoperative hospital stay, and overall perioperative complication rate (all P> 0.05). In conclusion, RSD is not only a technically feasible and safe procedure but it was associated with less blood loss than LSD for cirrhotic portal hypertension with gastroesophageal variceal bleeding and secondary hypersplenism.

Background: In Asia, laparoscopic splenectomy and azygoportal disconnection (LSD) has been widely regarded as a preferential treatment modality for cirrhotic portal hypertension (PH). However, LSD involves high surgical risk, technical challenges, and many potential postoperative complications. Technology optimization and innovation in LSD aiming to solve to these difficulties has scarcely been reported. In this retrospective study, we aimed to evaluate the clinical therapeutic effect of our cluster technology optimization and innovation on LSD for PH. Methods: From February 2012 to January 2020, 500 patients with cirrhosis who had esophagogastric variceal bleeding and hypersplenism underwent LSD in our department. According to different operation periods, patients were divided into the early-, intermediate-, and late-period groups. We collected information regarding clinical characteristics of all patients as well as their preoperative and postoperative follow-up data. Results: Compared with the early-period group, operation time and postoperative hospital stay were all significantly different and gradually declined from the intermediate- and late-period groups, respectively (all P&lt; 0.05). Intraoperative blood loss of these three groups was gradually decreased, with significant differences (P&lt; 0.05). The incidences of delayed gastric emptying and diarrhea in the late-period group were all significantly lower than those in the early- and intermediate-period groups, respectively (all P&lt; 0.05). Compared with the early-period group, the incidence of variceal re-bleeding was significantly lower in the intermediate- and late-period groups (all P&lt; 0.05). Conclusion: Our cluster technology optimization and innovation of LSD not only contributed to faster recovery and fewer complications but also enhanced surgical safety for patients. It is worth promoting this approach among patients with EVB and hypersplenism secondary to cirrhotic PH.

Inappropriate tillage practices and nitrogen (N) management have become seriously limitations for maize (Zea maysL.) yield and N use efficiency (NUE) in the North China Plain (NCP). In the current study, we examined the effects of strip deep rotary tillage (ST) combined with controlled-release (CR) urea on maize yield and NUE, and determined the physiological factors involved in yield formation and N accumulation during a 2-year field experiment. Compared with conventional rotary tillage (RT) and no-tillage (NT), ST increased the soil water content and soil mineral N content (Nmin) in the 20–40 cm soil layer due to reduction by 10.5 and 13.7% in the soil bulk density in the 0–40 cm soil layer, respectively. Compared with the values obtained by common urea (CU) fertilization, CR increased the Nminin the 0–40 cm soil layers by 12.4 and 10.3% at the silking and maturity stages, respectively. As a result, root length and total N accumulation were enhanced under ST and CR urea, which promoted greater leaf area and dry matter (particularly at post-silking), eventually increasing the 1 000-kernel weight of maize. Thus, ST increased the maize yield by 8.3 and 11.0% compared with RT and NT, respectively, whereas CR urea increased maize yield by 8.9% above the values obtained under CU. Because of greater grain yield and N accumulation, ST combined with CR urea improved the NUE substantially. These results show that ST coupled with CR urea is an effective practice to further increase maize yield and NUE by improving soil properties and N supply, so it should be considered for sustainable maize production in the NCP (and other similar areas worldwide).

Background: Esophagogastric variceal re-bleeding (EGVR) is a common and potentially lethal complication after open or laparoscopic splenectomy and azygoportal disconnection (LSD) in patients with cirrhosis and portal hypertension. Currently, noninvasive biomarkers for predicting EGVR are lacking. This prospective study focused on developing a noninvasive and convenient clinical model for predicting postoperative EGVR. Methods: Between September 2014 and March 2017, we enrolled 164 patients with cirrhosis who successfully underwent LSD. Based on the absence or presence of EGVR, patients were divided into EGVR and non-EGVR groups. We used correlation analysis to determine significant candidate variables among the liver fibrotic markers procollagen type III (PC-III), hyaluronidase (HA), laminin (LN), and type IV collagen (C-IV). Results: Postoperative EGVR occurred in 22 (13.41%) patients. Correlation analyses showed that LN (r= 0.375; p&lt; 0.001) and C-IV (r= 0.349; p&lt; 0.001) were significantly positively associated with EGVR. The area under the receiver operating characteristic curve (AUC) of LN was 0.817 (95% confidence interval [CI] 0.722–0.913); that of C-IV was 0.795 (95% CI 0.710–0.881). In logistic multivariate regression, cutoff values LN ≥ 64 µg/L and of C-IV ≥ 65 µg/L were independent risk factors for EGVR. LN ≥ 64 µg/L combined with C-IV ≥ 65 µg/L was the best performing model, with AUC 0.867 (95% CI 0.768–0.967). Conclusion: LN and C-IV are potential markers to predict EGVR. Combining the two markers showed satisfactory ability to predict EGVR in patients with cirrhosis and portal hypertension after LSD.

Background: Digestive system complications are among the most important causes of postoperative poor quality of life after open and conventional laparoscopic splenectomy and azygoportal disconnection (CLSD). We firstly developed a modified vagus nerve-preserving laparoscopic splenectomy and azygoportal disconnection (MVLSD). In this study, we aimed to evaluate whether MVLSD is feasible and safe and to determine whether MVLSD can effectively eliminate postoperative digestive system complications, in comparison with CLSD. Method: In this randomized controlled single-center study, 60 patients with cirrhosis were randomly assigned to undergo either CLSD (n= 30) or MVLSD (n= 30) between April and December 2018. The primary outcome was delayed gastric emptying (DGE). Endoscopic physicians were blinded to group assignments. Results: One patient who received MVLSD withdrew from the study. There were no significant differences in intraoperative blood loss, incidence of blood transfusion, time to off-bed activity, time to first flatus, and postoperative hospital stay between the two groups. Compared with CLSD, operation time and incidences of DGE, diarrhea, epigastric fullness, and overall postoperative complications were all significantly reduced in the MVLSD group (all P&lt; 0.05). Compared with CLSD, MVLSD was associated with significantly increased weight and albumin levels at 1, 6, and 12 months postoperatively versus preoperative values (all P&lt; 0.05). The curative effect of resolving gastroesophageal variceal bleeding was similar between the groups. Conclusion: MVLSD is not only a technically feasible and safe procedure, it is also succinct and convenient. Furthermore, MVLSD effectively reduces postoperative digestive system complications, contributing to improved quality of life.

Background: The thrombosis of the main and intrahepatic branches of the portal vein (TMIP) is potentially lethal and deemed a common complication following laparoscopic splenectomy and azygoportal disconnection (LSD) in patients with cirrhosis and portal hypertension (PH). The predictors of TMIP after LSD remain unclear. The aim of this prospective study was to explore the predictive and risk factors for TMIP after LSD in cirrhotic patients with PH caused only by hepatitis B virus. Methods: From September 2014 to March 2017, we enrolled 115 patients with hepatitis B cirrhosis and PH who successfully underwent LSD. Patients were subdivided into a TMIP group and a non-TMIP group. Univariate and multivariate logistic regression analysis was conducted on 24 items of demographic and preoperative data, to explore the risk factors of TMIP. Results: Twenty-nine (25.22%) patients developed TMIP on postoperative day (POD) 7 and 26 (22.81%) patients developed TMIP on POD 30. From POD 7 to POD 30, 12 patients who did not have TMIP at POD 7 were newly diagnosed with TMIP, with portal vein diameter 15.05 ± 2.58 mm. Another 14 patients in whom TMIP had resolved had portal vein diameter 14.02 ± 1.76 mm. Univariate analysis and multivariate logistic regression revealed that portal vein diameter ≥ 13 mm [relative risk (RR) 5.533, 95% confidence interval (CI) 1.222–25.042; P= 0.026] and portal vein diameter ≥ 15 mm (RR 3.636, 95% CI 1.466–9.021; P= 0.005) were significant independent risk factors for TMIP on POD 7 and 30, respectively. Conclusion: Portal vein diameter ≥ 13 mm and ≥ 15 mm were significant independent predictors for TMIP after LSD in patients with hepatitis B cirrhosis and PH on POD 7 and POD 30, respectively. Trial registration: We registered our research at https://www.clinicaltrials.gov/. The name of research registered is “Warfarin Prevents Portal Vein Thrombosis in Patients After Laparoscopic Splenectomy and Azygoportal Disconnection.” The trial registration identifier at clinicaltrials.gov is NCT02247414.

Double-maize cropping system is an effective option for coping with climate change in the North China Plain. However, the effects of changes in climate on the growth and yield of maize in the two seasons are poorly understood. Forty-six cultivars of maize with different requirements for growing degree days (GDD), categorized as high (H), medium (M) or low (L), and three cultivar combinations for two seasons as LH (using JD27 and DMY1 from category L in the first season; and YD629 and XD22 from category H in the second season), MM (using JX1 and LC3 from category M in the first season; and ZD958 and JX1 from category M in the second season) and HL (using CD30 and QY9 from category H in the first season; and XK10 and DMY3 from category L in the second season) were tested to examine the eco-physiological determinants of maize yield from 2015 to 2017. The correlations between the combinations of cultivars and grain yield were examined. The combination LH produced the highest annual grain yield and total biomass, regardless of the year. It was followed, in decreasing order, by MM and HL. Higher grain yield and biomass in LH were mainly due to the greater grain yield and biomass in the second season, which were influenced mainly by the lengths of the pre- and post-silking periods and the rate of plant growth (PGR). Temperature was the primary factor that influenced dry matter accumulation. In the first season, low temperatures during pre-silking decreased both the duration and PGR in LH, whereas high temperatures during post-silking decreased the PGR in MM and HL, resulting in no significant differences in biomass being observed among the three combinations. In the second season, high temperatures decreased both the PGR and pre- and post-silking duration in MM and HL, and consequently, the biomass of those two combinations were lower than that in LH. Moreover, because of lower GDD and radiation in the first season and higher grain yield in the second season, production efficiency of temperature and radiation (Ra) was the highest in LH. More importantly, differences in temperature and radiation in the two seasons significantly affected the rate and duration of growth in maize, and thereby affecting both dry matter and grain yield. Our study indicated that the combination of LH is the best for optimizing the double-maize system under changing climatic conditions in the North China Plain.

An optoelectronic swept-frequency laser (SFL) is an optoelectronic feedback system that includes an auxiliary interferometer that can exert precise control over the optical frequency sweep. The arm-length difference (ALD) of the auxiliary interferometer directly affects the performance of the whole system. We established a theoretical model to choose the optimal ALD of an auxiliary interferometer in an optoelectronic SFL system using a frequency-modulated continuous-wave reflectometry experimental setup. The experimental results indicated that, based on our system, the optimal ALD was 7 m, which agreed with the theoretical analysis. As an example application, we implemented the proposed system for measurement of the group refractive index of a glass sample. A minimum measurement error of 0.12% was obtained with the ALD of 7 m.

Background: Laparoscopic splenectomy and azygoportal disconnection (LSD) is widely used for the treatment of esophagogastric variceal haemorrhage and hypersplenism owing to cirrhotic portal hypertension. However, whether LSD improves liver synthesis function and cirrhosis remains unclear. The aim of this study is to investigate the effect of LSD on liver synthesis function and cirrhosis based on a prospective 2-year follow-up study. Methods: A total of 118 patients with cirrhotic portal hypertension who underwent LSD were included in this study. We analysed clinical data including routine blood parameters, liver function, liver-synthesised proteins (antithrombin III, protein S, and protein C), liver fibrotic markers (type IV collagen (IV-C), procollagen type III (PC-III), laminin, and hyaluronidase), portal vein diameter, and portal blood flow velocity. Results: Postoperative portal vein diameter and portal blood flow velocity all showed gradual declines during the 2-year follow-up; compared with preoperative values, these were all significantly decreased from postoperative week (POW) 1 (all P &lt; 0.001). Postoperative Child–Pugh scores and total bilirubin, albumin, international normalised ratio, antithrombin III, protein S, protein C, IV-C, PC-III, laminin, and hyaluronidase levels also all showed gradual improvements during the 2-year follow-up; compared with preoperative levels, these were all significantly improved from postoperative month (POM) 6, POW 1, POM 3, POM 3, POM 3, POM 6, POM 18, POW 1, POM 3, POM 24, and POM 18, respectively (all P &lt; 0.05). Conclusion: LSD not only decreases portal hypertension and improves liver function, it also enhances liver synthesis function and reduces liver fibrosis.

The cast Al-Si alloy was fabricated using the Additive Pressure Casting (APC) method. The effects of holding pressure from 50 to 400 kPa on the density, cooling rate, and mechanical properties of the alloy, and the corresponding mechanism were discussed. The results indicate that the application of high holding pressure (300 kPa) enhances the feeding ability of the alloy, leading to an increase of the density. Meanwhile, the cooling rate of the alloy is increased by 100%. In addition, the tensile testing results show that the increase of holding pressure from 50 to 300 kPa improves the tensile strength and elongation of the alloy by 6.2% and 81.3%, respectively. However, excessive holding pressure (400 kPa) might lower the density and cooling rate of the alloy due to the feeding channels being blocked.

The rate of distant metastasis in patients with pancreatic neuroendocrine tumors (PNETs) is 20%-50% at the time of initial diagnosis. However, whether tumor size can predict distant metastasis for PNETs remains unknown up to date.

Oilseed rape (Brassica napusL.) is the second highest yielding oil crop worldwide. In addition to being used as an edible oil and a feed for livestock, rapeseed has high ornamental value. In this study, we identified and characterized the main floral major constituents, including phenolic acids and flavonoids components, in rapeseed accessions with different-colored petals. A total of 144 constituents were identified using ultrahigh-performance liquid chromatography–HESI-mass spectrometry (UPLC–HESI-MS/MS), 57 of which were confirmed and quantified using known standards and mainly contained phenolic acids, flavonoids, and glucosinolates compounds. Most of the epicatechin, quercetin, and isorhamnetin derivates were found in red and pink petals of B. napus, while kaempferol derivates were in yellow and pale white petals. Moreover, petal-specific compounds, including a putative hydroxycinnamic acid derivative, sinapoyl malate, 1-O-sinapoyl-β-d-glucose, feruloyl glucose, naringenin-7-O-glucoside, cyanidin-3-glucoside, cyanidin-3,5-di-O-glucoside, petunidin-3-O-β-glucopyranoside, isorhamnetin-3-O-glucoside, kaempferol-3-O-glucoside-7-O-glucoside, quercetin-3,4′-O-di-β-glucopyranoside, quercetin-3-O-glucoside, and delphinidin-3-O-glucoside, might contribute to a variety of petal colors in B. napus. In addition, bound phenolics were tentatively identified and contained three abundant compounds (p-coumaric acid, ferulic acid, and 8-O-4′-diferulic acid). These results provide insight into the molecular mechanisms underlying petal color and suggest strategies for breeding rapeseed with a specific petal color in the future.

Over-use of N fertilizer in crop production has resulted in a series of environmental problems in the North China Plain (NCP). Thus, improvement of nitrogen use efficiency (NUE) in summer maize has become an effective strategy for promoting sustainable agriculture in this region. Using twenty maize cultivars, plant dry matter production, N absorption and accumulation, yield formation, and NUE in summer maize were investigated under three N levels in two growing seasons. Based on their yield and yield components, these maize cultivars were categorized into four groups including efficient-efficient (EE) cultivars, high-nitrogen efficient (HNE) cultivars, low-nitrogen efficient (LNE) cultivars and nonefficient-nonefficient (NN) cultivars. In both two seasons, the EE cultivars improved grain yield together with increased plant biomass, and enhanced accumulative amounts as well as higher average grain yields than the other cultivar groups under deficient-N conditions. Significant correlations were observed between yield and kernel numbers (KN), dry matter (DM) amount and N accumulation at both post-silking and maturity stages. DM and N accumulation at late growth stage (i.e., from silking to maturity) contributed largely to the enhanced yield capacity and improved NUE under N-deficient conditions. Compared with the NN cultivars, the EE cultivars also showed increased N assimilation amount (NAA) and N remobilization content (NRC), and elevated N remobilization efficiency (NRE), NUE and nitrogen partial factor productivity (PFPN). Our investigation has revealed N-associated physiological processes and may provide guidance for cultivation and breeding of high yield and NUE summer maize under limited N conditions in the NCP.

Background: α-Aryl substituted nitroalkanes are important synthetic intermediates for the preparation of pharmaceutical molecules, natural products, and functional materials. Due to their scare existence in Nature, synthesis of these compounds has attracted the attention of synthetic and medicinal chemists, rendering α-arylation of nitroalkanes of an important research topic. This article summarizes the important advances of α- arylation of nitroalkanes since 1963. Results: After a brief introduction of the synthetic application and the reactions of nitroalkanes, this article reviewed the synthetic methods for the α-arylated aliphatic nitro compound. The amount of research on α-arylation of nitroalkanes using various arylation reagents and the discovery of elegant synthetic approaches towards such skeleton have been discussed. This review described these advances in two sections. One is the arylation of non-activated nitroalkanes, with an emphasis on the application of diverse arylation reagents; the other focuses on the arylation of activated nitroalkanes, including dinitroalkanes, trinitroalkanes, α-nitrosulfones, α-nitroesters, α-nitrotoluenes, and α-nitroketones. The synthetic application of these methods has also been presented in some cases. Conclusion: In this review, we described the progress of α-arylation of nitroalkanes. Although the immense amount of research on α-arylation of aliphatic nitro compounds has been achieved, many potential issues still need to be addressed, especially the asymmetric transformation and its wide application in organic synthesis.

Objective To investigate the potential antitumour effects of [2-(6-amino-purine-9-yl)-1-hydroxy-phosphine acyl ethyl] phosphonic acid (CP) against gastric adenocarcinoma.Methods Human BGC-823 xenotransplants were established in nude mice. Animals were randomly divided into control and CP groups, which were administered NaHCO3vehicle alone or CP dissolved in NaHCO3(200 µg/kg body weight) daily, respectively. Tumour volume was measured weekly for 6 weeks. Resected tumours were assayed for proliferative activity with anti-Ki-67 or anti-proliferating cell nuclear antigen (PCNA) antibodies. Cell apoptosis was examined using terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assays and with caspase-3 immunostaining. Proteins were measured by Western blotting.Results There was a significant reduction in tumour volume and a reduced percentage of Ki-67-positive or PCNA-positive cells in the CP group compared with the control group. The percentage of TUNEL-positive or caspase 3-positive cells significantly increased following CP treatment compared with the control group. Tumours from the CP group had higher levels of phosphorylated-extracellular signal-regulated kinase (p-ERK) and phosphorylated-AKT (p-AKT) compared with control tumours.Conclusion CP treatment inhibited tumour growth and induced tumour cell apoptosis in a nude mouse model of BGC-823 gastric adenocarcinoma. Activation of the AKT and ERK signalling pathways may mediate this antitumour activity.

Phenylketonuria (PKU) is a common autosomal recessive disorder of phenylalanine metabolism and mainly results a deficiency of phenylalanine hydroxylase gene (PAH). The incidence of various PAHmutations have race and ethnicity differences. We report a spectrum of PAHmutations complied from 35 PKU children who are all Chinese Han population from north Jiangsu in this study. All 13 exons and their flanking intron sequences of PAHwere determined by Ion Torrent PGM™ sequencing. The relationship of genotype and phenotype was analyzed based on the sum of the arbitrary value (AV) values of the two alleles. We identified 61 mutations, with a frequency of 87.14%, among 70 alleles of 35 patients. The most prevalent mutations were R243Q (26.23%), R241C (9.84%) and V399V (8.20%). Furthermore, the consistency between prediction of the biochemical phenotype and the observed phenotype was 81.25%, with the highest consistency observed in classic PKU (87.50%). A significant correlation was found between pretreatment levels of phenylalanine and AV sum (r = −0.87, P < 0.05). Finally, our study constructs PAH mutation spectrum by next generation sequencing (NGS), and reveals that the PAHgenotypes and biochemical phenotypes were significantly correlated. These offers facilitate the provision of appropriate genetic counseling for PKU patients.

Phenylketonuria (PKU) is a common autosomal recessive disorder of phenylalanine metabolism and mainly results a deficiency of phenylalanine hydroxylase gene (PAH). The incidence of various PAHmutations have race and ethnicity differences. We report a spectrum of PAHmutations complied from 35 PKU children who are all Chinese Han population from north Jiangsu in this study. All 13 exons and their flanking intron sequences of PAHwere determined by Ion Torrent PGM™ sequencing. The relationship of genotype and phenotype was analyzed based on the sum of the arbitrary value (AV) values of the two alleles. We identified 61 mutations, with a frequency of 87.14%, among 70 alleles of 35 patients. The most prevalent mutations were R243Q (26.23%), R241C (9.84%) and V399V (8.20%). Furthermore, the consistency between prediction of the biochemical phenotype and the observed phenotype was 81.25%, with the highest consistency observed in classic PKU (87.50%). A significant correlation was found between pretreatment levels of phenylalanine and AV sum (r = −0.87, P < 0.05). Finally, our study constructs PAH mutation spectrum by next generation sequencing (NGS), and reveals that the PAHgenotypes and biochemical phenotypes were significantly correlated. These offers facilitate the provision of appropriate genetic counseling for PKU patients.

Fracturing-drainage in low permeability reservoirs is a special method to facilitate oil production, however, conventional chemical oil displacement agents cannot adequately take advantage of this technology. Active SiDots nanofluid has special surface/interface properties and excellent stability that can contribute to improving the effect of fracturing-drainage. This paper investigates the influencing factors and mechanisms of active SiDots nanofluid assisted fracturing-drainage to enhance oil recovery (EOR) through experiments and reservoir numerical simulation. The results on the performance of the active SiDots nanofluid show that 0.10 wt% concentration was sufficient to reduce the oil-water interfacial tension from 20 mN/m to 0.32 mN/m and modify the oil-wet core to water-wet. Experimental and reservoir numerical simulation results indicate that the incremental oil recovery after the active SiDots nanofluid fracturing-drainage was more than 10%, which was more effective than surfactant alone. The optimum injection concentration and volume of active SiDots nanofluid were 0.10 wt% and 0.6 PV, respectively. To improve the utilization of active SiDots nanofluid, the well shut-in time should be at least 24 h. One-cycle active SiDots nanofluid injection was more conducive to replenishing the formation energy and expanding the swept volume. The field injection rate of the SiDots nanofluid should not be too high to prevent breakthroughs. The EOR experimental results indicate that the fracturing-drainage could increase the injection volume to replenish energy and reduce the active SiDots nanofluid adsorption loss thereby effectively peeling the oil film. This paper addresses the supply shortage of conventional chemicals used for fracturing-drainage in low-permeability reservoirs and expands the study of the influencing factors and mechanisms of fracturing-drainage.

Two types of organo-montmorillonite (OMMT) modified bismaleimide (BMI) nanocomposites based on 4,4'-bismaleimide diphenyl methane (BDM) and O,O'-diallyl bisphenol A (DBA) have been synthesized. A compression moulding process was used to fabricate carbon fibre-reinforced OMMT/BMI multiscale composites. X-ray diffractometry (XRD) and transmission electron microscopy (TEM) indicated that the silicate layers of OMMT were partially exfoliated and dispersed uniformly in the nanocomposites. The study showed that the interlaminar shear strength (ILSS) and flexural properties of the carbon fibre composites were improved by the incorporation of OMMT. The maximum increment of the ILSS, flexural strength and elastic modulus of carbon fibre composites were 19.09%, 38.26% and 26.97%, respectively. Scanning electron microscope (SEM) photographs revealed that the destruction modes of carbon fibre composites were also changed after the OMMT was introduced into the composites system.

The purpose of designing recommender systems is to help individual users find relevant information. However, many recommender systems have been facing the challenges of finding niche objects, which users may like but difficult to find due to the lack of sufficient data. In this paper, we propose a recommendation algorithm which takes a niche object as input and outputs a list of users who may be interested it. By this approach, every niche object can be recommended at least one time. Further analysis indicates that those niche objects are usually collected by active users and the owners who are very similar to each other. Therefore, this work has outlined the significant relevance with the challenge, the Long Tail problem, and provided a different perspective to solve it in the field of information filtering.

Based on typical parts CNC machining technology solutions, using the inverted spindle, high-capacity storage automatic loading and unloading of the workpiece conveyor systems, temperature tracking control system, ladder-shaped bed base and other new technologies. A milling-turning flexible machining cell was researched and developed, which means once the piece was fixed, all the procedures, including turning, milling, drilling, reaming, tapping and other processes integrated processing, can be completed. As an advanced manufacturing mode, it was suitable for the efficient processing of short-sleeve-type parts, panel parts, etc.

This paper reports a readout system for a piezoresistive accelerometer which is fabricated by LTCC thick-film process technology. The authors first introduce a LTCC compatible design of this new kind of accelerometer, which is based on piezoresistive phenomenon. As the performance of the accelerometer circuitry is affected by temperature, a readout system is introduced for compensating the temperature drift and the non-linearity of this piezoresistive accelerometer by using the MAX1452 processor. The authors give the principles of the temperature compensation and the executive processes. The readout system also includes a ZigBee wireless transmission system and a real-time curve display window. Some tests on the system are carried out and the results manifest that the readout system designed in this paper is workable.

Polysiloxane latexes were prepared by microemulsion polymerization of octamethylcyclotetrasiloxane (D4) in the absence of co-emulsifier with octadecyl trimethyl ammonium chloride as a cationic emulsifier and potassium hydrate as an initiator.

The stress, strain and stability of slope would be changed if an Electricity transmission tower built on loess slope. In this paper, the distribution of stress, strain characteristic and stability of loess slope in condition of 30 meters height and 45 °slope triggered by action of Electricity transmission tower should be studied, the result shown that stability of loess slope dominated by the initial stress states, elastic modulus, and Poisson's ratio, strength and shape, structure and load condition etc. the stability distance of transmission line tower be located on loess slope governed by the stability of initial slope and the effect range triggered by tower load, in condition of 30 meters height and 45 °loess slope, the stability distance nearly 20m to 25m.

This paper shows the result of the research on the stability of loess high slopes with 30m and 80m in Huangshui River basin. The investigations carried out the numerical simulations of the slope stability based on the drilling and sequence sampling test in a typical loess stratum of the survey region. The result shows that the mechanisms of fracture related to the gradients of slopes are different and the limit equilibrium angles of slopes are 60° and 37° respectively.

According to the structure and characteristics of HVDC system, this paper used the FTA (fault tree analysis) method to divide fault results of DC system into five transmission capacities: 0%, 25%, 50%, 75% and 100%, calculated results by incorporating DC system into AC system and used Monte Carlo simulation method to evaluate reliability of AC/DC hybrid system. Whats more, this paper established the model, algorithm and index system for risk assessment of AC/DC hybrid power system and developed corresponding software. Finally, an example was given to prove the correctness and validity of the proposed algorithm and software.

According to the high speed bearing failure problem caused by the high temperature, finite element model of high-speed hybrid ceramic angular contact ball bearing is established in this paper. Quantity of heat and heat transfer coefficient are calculated by using the heat transfer and thermodynamics theory, which are boundary condition for the temperature field simulation analysis of ball bearing. The temperature distribution of bearing is obtained when bearing speed is 12000rad/min. The results can provide a theoretical foundation for lubrication cooling system controlling temperature.

Heat generation and deformation of bearing are key factors that influence the rigidity and machining accuracy of the high-speed precision spindle system. Based on heat transfer and thermodynamics, the finite element model of angular contact ball bearing is established for thermal deformation. The contact stress and thermal deformation are analyzed and obtained at a speed of . The results show that the maximum contact stress and thermal deflection appeared at contact region, which is in accordance with actual status. The results provide the reference and the theory basis for research into thermal deformation of bearing.

Based on the introduction of the station power using system, this paper used fault tree analysis method to model the reliability of station power using system, which had been always ignored in traditional HVDC system reliability evaluation but actually had an important impact on the result of evaluation. Whats more, it assessed the reliability of the whole HVDC system (included station power using system) by means of frequency and duration method. Finally, an example was given to prove the correctness and validity of the proposed theory.

With the development of micro-nanomachining technology (MNMT), micro heat radiator is getting attention. In this paper, the heat dissipation mechanism of light emitting diode (LED) ball lamp is introduced. And the LED heat radiator is simplified. On the basis of that, a new type of micro metal-plastic heat radiator of LED is put forward. And the LED heat radiator is simplified. A series of numerical simulations are carried out to compare the heat dissipation performance of micro heat radiator respectively made by metal, plastic, metal-plastic composite by the FloEFD software. Micro metal-plastic heat radiator structures, including fin spacing, fin thickness, fin height and substrate thickness, are carry out to be simulated.

Radiometric calibration of synthetic aperture radar (SAR) is an important work related to pixel values and the backscattering coefficient of ground targets. With a consideration of the difference between near space and spaceborne, airborne platforms, this paper proposes the radiometric calibration method which is applicable to near space platform. A radiometric calibration model of near space SAR is established, and it is analyzed and validated by experimental data.

Based on the research of PCNN algorithm,details the basic idea of the genetic algorithm, introduction of genetic algorithm for optimal family.In order to verify the effectiveness of the algorithm,implements the algorithm and comparison algorithm on the PC with the VS2008, CUDA, OpenCV 2.2.The experimental results showed that:Improved PCNN algorithm to better deal with the multi-modal regional background,improve the accuracy of moving object segmentation.Effectively filter interference prospects at the same time,complete retention of the shape, the edge information of the moving object.In this paper, the improved genetic algorithm can guarantee the quality of motion detection, and provide a guarantee for the the subsequent image recognition accuracy.

Focusing on the problem of accuracy machining to the friction welder,taking the spindle box of friction welder as the research object,the finite element simulation software of ANSYS workbench is applied to the static analysis of the box ,then the stress and strain response can be available. And through the using of sensitivity analysis optimization scheme is proposed ,which prerequisite basis is obtained for the optimization design and the improvement of breed to the spindle box of large friction welder

In this paper, PEER Ground Motion Databases (PGMD) at the Pacific Earthquake Engineering Research Center (PEER) was updated by 314 sets of ground motion records of great earthquakes in recent years, which expanded the application of this database. This paper reviews alternative selection methods for strong ground motion records. The expanded database could make the different selection and scaling of strong motion records in great earthquakes, and the conditional mean spectrum (CMS) method could be applied for the strong motion records selection in structural spectrum analysis.

The defluoridation capacity of phosphate rock in the presence of oxalic acid was investigated using batch experiments. Defluoridation capacity of phosphate rock was enhanced in the presence of oxalic acid, removing fluoride from 22.46% up to 57.98% with 2.5 mmol/L oxalic acid. The contact time and pH for maximum fluoride uptake were found 2 h and 5, respectively. Maximum adsorption capacity (0.36 mg/g) of fluoride on phosphate rock was observed at 50 mg/L initial fluoride concentration using 2 g adsorbent dose.