“度”的全家福

同学们学习角这部分知识时，在测量角的大小时要用到单位“度”，那么是不是就只有在测量角的大小时，用到单位“度”呢?在我们平时的生活中，你是否在其它地方也见到过单位“度”呢?要知道，度的含义可多了，不信看看它的全家福就知道了。

Modified algorithm of combined GPS/GLONASS precise point positioning for applications in open-pit mines

A modified algorithm of combined GPS/GLONASS precise point positioning （GG-PPP） was developed by decreasing the number of unknowns to be estimated so that accurate position solutions can be achieved in the case of less number of visible satellites. The system time difference between GPS and GLONASS （STDGG） and zenith tropospheric delay （ZTD） values were firstly estimated in an open sky condition using the traditional GG-PPP algorithm. Then, they were used as a priori known values in the modified algorithm instead of estimating them as unknowns. The proposed algorithm was tested using observations collected at BJFS station in a simulated open-pit mine environment. The results show that the position filter converges much faster to a stable value in all three coordinate components using the modified algorithm than using the traditional algorithm. The modified algorithm achieves higher positioning accuracy as well. The accuracy improvement in the horizontal direction and vertical direction reaches 69% and 95% at a satellite elevation mask angle of 50°, respectively.

Effect of dynamic light at the coronary care unit on the length of hospital stay and development of delirium： a retrospective cohort study

Background Disturbed circadian rhythm is a potential cause of delirium and is linked to disorganisation of the circadian rhythmicity. Dynamic light （DL） could reset the circadian rhythm by activation of the suprachiasmatic nucleus to prevent delirium. Evidence regarding the effects of light therapy is predominantly focused on psychiatric disorders and circadian rhythm sleep disorders. In this study, we investi- gated the effect of DL on the total hospital length of stay （LOS） and occurrence of delirium in patients admitted to the Coronary Care Unit （CCU）. Methods This was a retrospective cohort study. Patients older than 18 years, who were hospitalized longer than 12 h at the CCU and had a total hospital LOS for at least 24 h, were included. Patients were assigned to a room with DL （n = 369） or regular lighting condi- tions （n = 379）. DL was administered at the CCU by two ceiling-mounted light panels delivering light with a colour temperature between 2700 and 6500 degrees Kelvin. Reported outcome data were： total hospital LOS, delirium incidence, consultation of a geriatrician and the amount of prescripted antipsychotics. Results Between May 2015 and May 2016, data from 748 patients were collected. Baseline charac- teristics, including risk factors provoking delirium, were equal in both groups. Median total hospital LOS in the DL group was 100.5 （70.8-186.0） and 101.0 （73.0-176.4） h in the control group （P = 0.935）. The incidence of delirium in the DL and control group was 5.4% （20/369） and 5.0% （19/379）, respectively （P = 0.802）. No significant differences between the DL and control group were observed in secon- dary endpoints. Subgroup analysis based on age and CCU LOS also showed no differences. Conclusion Our study suggests exposure to DL as an early single approach does not result in a reduction of total hospital LOS or reduced incidence of delirium. When delirium was diagnosed, it was associated with poor hospital outcome.

Collapse mechanism of deep tunnels with three-centered arch cross section

The possible collapse of different circumstances is derived with the help of the limit analysis theory.Analytical equations related to collapsing mechanisms in deep tunnel with smooth three-centered arc cross sections are derived on the basis of Hoek-Brown failure criterion and upper bound limit analysis.The pore water pressure is considered in the analysis,as a work rate of external force.Numerical results about the shape of detaching curve and the weight of collapsing block per unit length corresponding to different parameters are obtained with the help of mathematical software.The shapes of collapsing block are drawn with respected to different parameters.Furthermore,the effects of different parameters on the shape of detaching curve and the weight of the collapsing block are discussed.

Differences in Soil Microbial Biomass and Activity for Six Agroecosystems with a Management Disturbance Gradient

Different management practices in six agroecosystems located near Goldsboro, NC, USA were conducted including a successional field (SU), a plantation woodlot (WO), an integrated cropping system with animals (IN), an organic farming system (OR), and two cash-grain cropping systems employing either tillage (CT) or no-tillage (NT) to examine if and how microbial biomass and activity differ in response to alterations in disturbance intensity from six land management strategies. Results showed that soil microbial biomass and activity differed, with microbial activity in intermediately disturbed ecosystems (NT, OR, IN) being significantly higher (P ＜ 0.01) than systems with either high or low disturbance intensities. There was also a significant and a highly significant ecosystem effect from the treatments on microbial biomass C (MBC) (P ＜ 0.05) and on microbial activity (respiration) (P ＜ 0.01), respectively. Multiple comparisons of mean respiration rates distinctly separated the six ecosystem types into three groups: CT ＜ NT, SU and WO ＜ OR and IN.Thus, for detecting microbial response to disturbance changes these results indicated that the active component of the soil microbial community was a better indicator than total biomass.

A new 3-D element formulation on displacement of steel-concrete composite box beam

Slip of a composite box beam may reduce its stiffness, enlarge its deformation and affect its performance. In this work, the governing differential equations and boundary conditions of composite box beams were established. Analytic solutions of combined differential equations were also established. Partial degree of freedom was adopted to establish a new FEA element of three-dimensional beam, taking into account the slip effect. Slip and its first-order derivative were introduced into the nodes of composite box beams as generalized degree of freedom. Stiffness matrix and load array of beam elements were established. A three-dimensional nonlinear calculation program was worked out. The results show that the element is reliable and easy to divide and is suitable for special nonlinear analysis of large-span composite box beams.

Raman Scattering Study on Vibrational Modes and .Structure of Lanthanum Tellurite Glasses

Raman spectra of xLa203-（1-x）TeO2 （x=0, 0.05, 0.10, 0.15, 0.20, and 0.25） lanthanum tellurite glasses were measured and analyzed over the entire glass-forming region in an effort to quantitatively follow the structural changes caused by lanthanum oxide variation. For the first time, systematic intensity measurements have been performed to elucidate the composition induced structural changes in tile high-frequency stretching vibration region and a possible mechanism was proposed. The network structure of the glasses is formed by mixing TeO4 trigonal bipyramid and Te03 trigonal pyramid units. The change of the lanthanum oxide content results in conversion of the TeO4 units to TeO3 units with a varying number of non-bridging oxygen atoms. Analysis of the Raman band contours in terms of vibrations due to different oxygen bridged trigonal bipyramid and trigonal pyramid tellurite structural units, allowed to calculate the relative amounts of the species involved in the structural changes with composition. The fraction of the terminal oxygen atoms has been estimated from the Raman intensities with the aid of a structural model concerning the structure of tellurite network systems. The simulation of the experimental density of lanthanum tellurite glasses with modifier content up to 25% revealed that the short range order building units assumed here are sufficient to account for the overall structure in these glasses.

Land deformation monitoring in mining area with PPP-AR

The mining area deformation monitoring theory and method using precise point positioning （PPP） ambi- guity resolution （AR） were studied, and an ambiguity fixing model with satellite and receiver combina- tion phase delay （CPD） was proposed for zero-differenced PPP ambiguity fixing and its corresponding formula derivation was given. The data processing results for I h at six IGS stations in China show that 93% of ambiguities can be fixed within 10 min and all ambiguities can be fixed within 15 min. After ambi- guity fixing, the positioning accuracy is improved by more than 85% in the E and N directions, with abso- lute positioning accuracy reaching millimeter level, and it was improved by 70% in the U direction, reaching centimeter level; the proposed zero-differenced ambiguity fixing model can effectively improve the convergence rate and positioning accuracy in PPP. Data monitoring continuously conducted for half a year at four COPS stations of Shanxi China Coal Pingshuo Group validated the feasibility of using PPP in mining area deformation monitoring.

Optical Fiber Instrument for Single-point Multi-parameter Measurement

A novel kind of optical fiber instrument for two channel measurement of temperature and displacement was developed. Four channel quartz fiber optics were employed to measure two channel signals of temperature and displacement simultaneously, and the operating efficiency of this instrument was greatly improved.

Dirichlet and Q_(p,0) Spaces on the Unit Ball of C^n

In this paper, we first give some new characterizations of Qp,0 spaces by means of vanishing p-Carleson measure. Using these results, we can prove that Dirichlet space is a subset of Qp,0 for(n-1)/n<p≤1.

A New Attempt of Using Crushed Plastic Solid Wastes in Water Filtration

The aim of this new study is to investigate the ability of using crushed plastic solid wastes in water filtration by using a pilot plant. Two sets of filters were used. The first set represents mono media filters. The first filter is a sand media with effective size of 0.65 mm and the others three are plastic media with different grain sizes. The second set represents dual media filters with different depths, the filters were made to operate with the same effective size （0.6-1.0 mm）. These filters were subjected to the same operating conditions of filtration rates and infiuent turbidity. The filters were operated at rates of 5, 7.5, 10, and 12.5 m/h in order to find the optimum filtration velocity with influent turbidity ranged between 7 and l0 NTU （nephelometric turbidity unit）. The results indicated that the single plastic filters and the dual filters produced water of the same high quality as the sand filter. Plastic filters were slower in the development of head losses by about of 8%-78% less and they have longer running time than the sand filter, while the dual filters were slower in the development of head losses by about of 14%-16% and they have longer running time by about of 12%-40% than the sand filter.

Collapse-type shrinkage characteristics in plantation-grown eucalypts： I . Correlations of basic density and some structural indices with shrinkage and collapse properties

Collapse-type shrinkage is one of highly refractory drying defects inlow-medium density plantation-grown eucalypt wood used as solid wood products. Basic density (BD),microfibril angle (MFA), double fibre cell wall thickness (DWT), proportion of ray parenchyma (RP),unit cell wall shrinkage, total shrinkage and residual collapse, which are associated withcollapse-type shrinkage characteristics, were investigated by using simple regression method forthree species of collapse-susceptible Eucalyptus urophyll,, E. grandis and E. urophyllaxE.grandis,planted at Dong-Men Forest Farm in Guangxi autonomous region, China. The results indicated that:unit cell wall shrinkage had a extremely strong positive correlation with BD, moderately strongpositive correlation with DWT, and a weakly or moderately negative correlation with RP and MFA;total shrinkage was positively correlated with BD, DWT and RP and negatively related to MFA, but notable to be predicted ideally by any examined factors alone owing to lower R^2 value (R^2≤0.5712);residual collapse was negatively correlated with BD and DWT, linearly positively correlated withMFA, and had strongly positive linear correlation with RP. It is concluded that BD can be used assingle factor (R^2≥ 0.9412) to predicate unit cell wall shrinkage and RP is the relatively soundindicator for predicting residual collapse

Research on the impact of pension income and expenditure patterns on the pension replacement rate of public institutions

Currently in China, to study the replacement rate of pension reform in public institutions and to find out the key problems, which is of practical significance for the reform of the pension insurance system. In this paper, the impact of pension income and expenditure patterns on the substitution rate is analyzed, and the factors that affect the level of substitution rate are analyzed, and the corresponding policy recommendations are put forward.

Improvement of Technological Solutions for Sheet Piling Walls Made of U-Shape Piles

As it is evident from the practice of construction and maintenance of thin retaining walls, the degree of developing of frictional forces in interlock connections of steel sheet U-shape piles essentially influences the realization of the values of geometric characteristics of the piles cross-section （the moment of inertia and the section modulus） reduced to the length unit of the construction. The article offers new and simple solutions for realization and economically effective technological approaches to provide joint work of the sheet piles being considered, which improve the adequacy of design and reliability of maintenance of thin retaining walls.

The Impacts of External Debt on Economic Growth in Transition Economies

The 1989 and following years were the periods in which many important economic and political tumovers took place in the world. That was the time when Berlin Wall fell down with scattering the Eastern block and many politically independent states came into being, at the same time, ongoing about 70 years socialist system also started to change into liberal system. The constituted 27 states in 1991 were tended to liberal economic system instead of socialist economy, and these states were called as transition economies. In this study, the relationship between indebtedness and growth rate of transition countries were analyzed by panel autoregressive distributed lag model （ARDL）. Before panel ARDL application, stationary properties of the variables have been checked with first and second generation unit root test. For the second generation unit root tests, CADF tests have been used. Also cross section dependency has been examined by LM tests.

Development of an Anaerobic Digestion Unit for Biogas Production from Cow Dung Substrate

An anaerobic digestion unit for producing biogas from cow dung in the rural communities was designed, fabricated and tested for performance, durability and throughput. The major components of the digester included the substrate holding tank, tank cover, agitator, debris collector, inlet and outlet pipes, gas reception tank, hose and heat source. The digester is a vertical cylindrical tank with an inlet pipe for the introduction of substrate and an outlet pipe to collect the digested substrate. An agitator is incorporated inside the digester to break scum on the substrate and create uniform temperature profile in the digester while a pressure gauge was fitted to the gas outlet valve to measure the gas pressure in the tank. The agitator shaft is extended outside to be driven by an electric motor through belt and pulley system. The criteria considered in the design of the digester included air tightness of the system, mesophilic and thermophilic temperature, nature and type of substrate used, substrate retention period, number of crank turns per minute and volumetric capacity of the digestion tank. Other considerations included the desire to make the digestion tank and gas reception tank of galvanized steel to ensure good quality of the product and the need for a strong structural support to ensure structural stability of the system. After construction and assembly, the biogas digestion unit was tested with 40 kg of cow dung diluted with 80 kg of water and subjected to a retention period to make a substrate （slurry） of 10 % total solid （TS）. Daily gas yield was determined; gas pressure in the tank was measured by the pressure gauge, while the ambient temperature was taken at five hours interval. Results showed that a cumulative gas yield of 0.415 litres after 22 d retention period at average substrate temperature and pH of 29 ℃ and 6.2, respectively. The digester has a substrate holding capacity of 330.8 litres and a production cost of $375 with all the construction materials being available locally.

Stability analysis unit and spatial distribution pattern of the terrain texture in the northern Shaanxi Loess Plateau

Terrain texture analysis is an important method of digital terrain analysis in quantitative geomorphological research and in the exploration of the spatial heterogeneity and autocorrelation of terrain features. However, a major issue often neglected in previous studies is the calculation unit of the terrain texture, that is, the stability analysis unit. As the test size increases, the derived terrain textures become increasingly similar so that their differences can be ignored. The test size of terrain texture is defined as the stability analysis unit. This study randomly selected 48 areas within the Loess Plateau in northern Shaanxi in China as the study sites and used the gray level co-occurrence matrix to calculate the terrain texture. The stability analysis unit of the terrain texture was then extracted, and its spatial distribution pattern in the Loess Plateau was studiedusing spatial interpolation method. Four terrain texture metrics, i.e., homogeneity, energy, correlation, and contrast, were extracted on the basis of the stability analysis unit, and the spatial variation patterns of these parameters were studied. Results showed that the spatial distribution pattern and the terrain texture metrics reflected a trend of high–low–high from north to south, which correlated with the spatial distribution of the landforms at the Loess Plateau. In addition, the terrain texture measures was significantly correlated with the terrain factors of gully density and slope, and this relationship showed that terrain texture measures based on the stability analysis unit could reflect the basic characteristics of terrain morphology. The stability analysis unit provided a reasonable analytical scale for terrain texture analysis and could be used as a measure of the regional topography to accurately describe basic terrain characteristics.

Residents＇ Satisfaction with the Public Housing Unit Features and Its Implications in China

This paper studied the residents＇ level of satisfaction in public housing units in Shenyang of China which aimed to identify how each housing unit feature correlates with the residents＇ overall satisfaction and implication on policy and design. The discussion is based on a questionnaire survey conducted in 2011. This research concluded that more residents were satisfied with the housing unit features than those who were dissatisfied, while some remarkable differences could be observed if comparative analysis between two different public housing types in China were studied. The affordable housing residents are generally more satisfied with housing unit features than those living in low-rent housing. The most dissatisfying feature is the living room, followed by unit size and the floor plan. Additionally, the living room and the floor plans were features which were highly and positively correlated to the residents＇ overall satisfaction of housing unit features. Consequently, improving the living room size and the design of housing unit floor plans would clearly be beneficial to alleviating residents＇ dissatisfaction to the housing units.

An Energy-Based Unit for the Thermodynamic Temperature

The article suggests to replace the conventional unit of thermodynamic temperature with one based on the energy unit joule by including the gas constant into the temperature definition. The suggestion may be seen as a contribution to the ongoing efforts to redefine base units. The gas constant includes the Boltzmann constant which both will be abrogated and molar heat capacity and entropy will become dimensionless pure numbers. The suggestion has no impact on thermodynamic theory, but will make thermodynamic relations more translucent and easier to grab for students.

Effect of Metal Contamination on the Performance of Catalyst for Deep Catalytic Cracking Process

The effect of different metal contamination levels of catalysts for Deep Catalytic Cracking(DCC) on the distribution and selectivity of DCC products was investigated in a FCC pilot unit. The pilot test results showed that the effects of the metal contamination level of catalyst on the propylene yield,the coke yield,the LPG yield,the gasoline yield,the selectivity of low carbon olefins,and coke selectivity was significant,and that the influence of metal contamination level on the conversion and dry gas yield was minor.