纯液体饱和蒸气压测定实验的改进

对纯液体饱和蒸气压测定实验进行了装置创新设计,该装置解决了该实验的一些关键问题:保证相平衡时的气相为纯液体蒸气;准确测定相平衡时的温度;方便有效地调节外压与液体蒸气压相等。改进后的装置设计合理,操作简单、快捷,消除了安全隐患,大大缩短了实验时间,可一人单独操作。

Antenna geometry strategy with prior information for direction-finding MIMO radars

The antenna geometry strategy for direction finding （DF） with multiple-input multiple-output （MIMO） radars is studied. One case, usually encountered is practical applications, is consi- dered. For a directional antenna geometry with a prior direction, the trace-optimal （TO） criterion （minimizing the trace） on the av- erage Cramer-Rao bound （CRB） matrix is employed. A qualitative explanation for antenna geometry is provided, which is a combi- natorial optimization problem. In the numerical example section, it is shown that the antenna geometries, designed by the proposed strategy, outperform the representative DF antenna geometries.

Detection of gas reservoirs by the joint use of P- and PS-waves: A case study on the Ordos basin, China

We present an example of using converted-waves for characterizing onshore gas reservoirs in the Ordos basin in Northwest China. The Ordos basin is the largest gas province in China. The main gas reservoirs （about 3 300 m in depth） are in upper Paleozoic sandstone that has low or reversed P-wave impedance and is immediately above a coal seam. This makes it very difficult to image the gas reservoirs using conventional P-wave data. Analysis of core, log and VSP data shows a weak PP reflection but a relatively strong PS-converted wave reflection, or both strong PP- and PS-reflections but with opposite polarity from the gas bearing sands, which indicates the potential of using PS-waves to image the gas reservoirs in the Ordos basin. Subsequently, thirteen seismic lines were acquired, processed and interpreted to verify the PP- and PS-responses, and two corresponding attributes （PP- and PS- amplitude ratio and polarity ratio） are used to map the reservoirs through joint PP and PS analysis.

Study on Behavior-oriented Performance Management of Team Member

This paper first analyses the advantages and disadvantages of performance appraisal methods on team member,then presents performance appraisal of team member must go back to behavior measure, and it must be behavior-oriented. This paper also explores the processof performance management of team member thoroughly.

Advances in magnesium-containing bioceramics for bone repair

Reconstruction of bone defects or fractures caused by ageing,trauma and tumour resection is still a great challenge in clinical treatment.Although autologous bone graft is considered as gold standard,the source of natural bone is limited.In recent years,regenerative therapy based on bioactive materials has been proposed for bone reconstruction.Specially,numerous studies have indicated that bioactive ceramics including silicate and phosphate bioceramics exhibit excellent osteoinductivity and osteoconductivity,further promote bone regeneration.In addition,magnesium(Mg)element,as an indispensable mineral element,plays a vital role in promoting bone mineralisation and formation.In this review,different types of Mg-containing bioceramics including Mg-containing calcium phosphate-based bioceramics(such as Mg-hydroxyapatite,Mg-biphasic calcium phosphate),Mg-containing calcium silicate-based bioceramics(such as Mg2SiO4,Ca2MgSi2O7 and Mg-doped bioglass),Mg-based biocements,Mg-containing metal/polymer-bioceramic composites were systematacially summarised.Additionally,the fabrication technologies and their materiobiological effects were deeply discussed.Clinical applications and perspectives of magnesium-containing bioceramics for bone repair are highlighted.Overall,Mg-containing bioceramics are regarded as regenerative therapy with their optimised performance.Furthermore,more in-depth two-way researches on their performance and structure are essential to satisfy their clinical needs.

Lithology-controlled stress variations of Longmaxi shale–Example of an appraisal wellbore in the Changning area

The Longmaxi shale is an extensive,prolific unconventional play in southwestern China.Its development in the Changning area is affected by ineffective hydraulic fracturing(HF)stimulation,fault reactivation and casing damage.It is suspected that the stress contrast within and between the shale reservoirs and the formations above and below matters to hydraulic fracture propagation and reservoir stimulation.To this end,the Longmaxi shale in the Changning area deserves a dedicated quantification of the in situ stress state and its variations.In this study,we re-visit the available data from one of the play’s first appraisal wellbores(X01)for an integrated geomechanics study,focusing on profiling the stress across the Longmaxi and its adjacent formations.Combining geophysical logs and other stress indicators,we re-interpret its stress profile in the context of lithological variations.The resulting stress variations are modeled primarily through a viscoplastic stress relaxation framework,compared with the results via the frictional equilibrium and an elastic theory(the Extended Eaton model).We offer some discussions on the differences and similarities of these stress profiling methods,and examine their applicability to Longmaxi shale in the Changning area.Our objective is to connect the lithology-controlled stress variations to the first-order complexities(HF ineffectiveness and fault reactivation)that have been observed in the area to date.

Optimal Power Allocation for Parallel Grid-Connected Inverters Based on Lagrangian Function Method

Two parallel grid-connected inverters can increase system capacitance effectively.In order to exert maximum efficiency of parallel grid-connected inverters,an optimal power allocation(OPA)method is proposed.Firstly,the power model of every inverter is established.Compared with the equal power allocation(EPA)method,theoretically,higher overall system efficiency can be achieved with the OPA method.Secondly,the overall system efficiency can be calculated with easily measurable electric parameters,and the online optimization realized by adopting an existing method,such as the hill-climbing method.Lastly,the feasibility of the OPA method is verified by simulation and experimentation.