气密性对电路内部水气含量的影响

详细分析电路的检漏过程,剖析漏率测量和电路内部水气含量之间的关系。通过有针对性的预防措施,减小检漏过程对电路内部水气含量的影响,使电路内部的水气含量基本满足GJB548A要求。

产学研齐聚共话封装水气含量解决方案

由中国电子学会生产技术学分会电子封装专委会主办、环宇企业集团协办的“解决电子元器件封装水气含量问题”的技术交流会于2006年11月1日在北京应物会议中心隆重召开。大会以“展示科研成果，提倡交流合作，促进行业发展”为主旨，汇聚了电子封装行业众多专业人士。

新乡市重大地下水气异常成因分析

分析了新乡市 1996年 8月重大地下水气异常特征及异常形成的原因。结果表明 :地下水气异常的分布与活动断裂构造具有明显的不一致性。井孔排出的气体近似于空气 ,是来源于大气的土壤空气 ,未显示出来自于地壳深部的特点 ,因此不是地震前兆异常。

乌鲁木齐10号泉地下水中溶解气甲烷的映震特征

从甲烷的来源及其化学特征入手 ,结合 19年来的震例 ,分析了乌鲁木齐 10号泉水中溶解气甲烷的映震特征。结果表明 ,震前甲烷含量基本上呈正异常 ,一般在甲烷含量由高值变低时发震 ,个别地震在甲烷测值上升的过程中或恢复至背景值后数天至数十天发震。最后 ,初步认定了特殊的地震构造环境是该泉具有映震灵敏性的原因。

聊古─井水溶气体的震前异常特征

本文对聊古一井水溶气体在１９８３年菏泽５．９级地震、１９９１年大同５．８级地震和１９９２年南黄海５．３级地震前的异常特征进行了分析总结，并结合地震场、源兆进行了初步探讨。认为聊古一井水溶气体的某些组分（如汞、氦气、二氧化碳、气体总量）具有良好的映震能力；氮氦比有利于突出地震异常信息，是提取震前短临异常简单可行的方法；聊古一井水溶气体的震前异常信息具有场兆和源兆的双重特征，来自源的地震异常信息具有良好的同步性，来自场的地震异常信息具有复杂性。

云南天文台凤凰山大气含水量全年测量数据的统计分析

给出了云南天文台上空垂直大气含水量Ｗ０的全年测量数据的统计结果和精度分析。包括Ｗ０的逐日变化。

大气对频率为14.59GHz微波散射计信号衰减的计算

本文利用Seasat－A卫星辐射计实测的大气中的水气含量、云中液态水含量及降雨强度等参数计算大气对微波的衰减，从而实现对14．59GHz微波散射计衰减进行补偿之目的。

试析华清温泉水化观测中的干扰

对华清温泉在水化观测中的干扰因素及特征，进行了分析探讨。通过对观测资料、水文地质结构的分析，指出降水、排污、供水开采等因素，对泉点没有影响。得出只有本身不抽水时，井内形成的“滞留水”，对观测结果影响较大及Ｈｅ、Ｒｎ含量明显降低，Ｏ２含量增高，Ｎ２变化不大，ＣＯ２含量亦降低的结论。指出供电不足是形成滞留水的主要原因。

Sensitivity of Tropical Cyclone Precipitation to Atmospheric Moisture Content: Case Study of Bilis (2006)

In this article, the authors used the Weather Research and Forecast model to investigate the sensitivity of tropical cyclone Bilis' total precipitation to ambient water vapor content. The tropical cyclone precipitation decreased dramatically with the reduction of the ambient water vapor content in the atmosphere. The decrease of precipitation can be explained by two mechanisms. First, as the major source of precipitation, moisture conver-gence decreases accordingly with the moisture content. Second, the tropical cyclone (TC) size reduction due to the moisture decrease influences the precipitation area. Both mechanisms were observed in this study.

Global Water Vapor Content Decreases from 2003 to 2012： An Analysis Based on MODIS Data

Water vapor in the earth′s upper atmosphere plays a crucial role in the radiative balance, hydrological process, and climate change. Based on the latest moderate-resolution imaging spectroradiometer(MODIS) data, this study probes the spatio-temporal variations of global water vapor content in the past decade. It is found that overall the global water vapor content declined from 2003 to 2012(slope b = –0.0149, R = 0.893, P = 0.0005). The decreasing trend over the ocean surface(b = –0.0170, R = 0.908, P = 0.0003) is more explicit than that over terrestrial surface(b = –0.0100, R = 0.782, P = 0.0070), more significant over the Northern Hemisphere(b = –0.0175, R = 0.923, P = 0.0001) than that over the Southern Hemisphere(b = –0.0123, R = 0.826, P = 0.0030). In addition, the analytical results indicate that water vapor content are decreasing obviously between latitude of 36°N and 36°S(b = 0.0224, R = 0.892, P = 0.0005), especially between latitude of 0°N and 36°N(b = 0.0263, R = 0.931, P = 0.0001), while the water vapor concentrations are increasing slightly in the Arctic regions(b = 0.0028, R = 0.612, P = 0.0590). The decreasing and spatial variation of water vapor content regulates the effects of carbon dioxide which is the main reason of the trend in global surface temperatures becoming nearly flat since the late 1990 s. The spatio-temporal variations of water vapor content also affect the growth and spatial distribution of global vegetation which also regulates the global surface temperature change, and the climate change is mainly caused by the earth's orbit position in the solar and galaxy system. A big data model based on gravitational-magmatic change with the solar or the galactic system is proposed to be built for analyzing how the earth's orbit position in the solar and galaxy system affects spatio-temporal variations of global water vapor content, vegetation and temperature at large spatio-temporal scale. This comprehensive examination of water vapor changes promises a holistic understanding of the global climate change and potential underlying mechanisms.

Effect of Shading on Gas Exchange of Cotton Leaves Under Conditions of Different Soil Water Contents

Effect of different shading levels (no-shading, 80% shading, and 40% shading) on photosynthetic and stomatal responses in cotton leaves were investigated under conditions of different soil water contents in summer midday. All cotton leaves exhibited similar basic responses to shading, including decreased net photosynthetic rates, a tendency to decrease in transpiration rates, and increased stomatal conductance and intercellular CO2 concentration. The leaf conductance of 80% shaded and 40% shaded plants increased by 28% and 16.7% compared with no-shaded plants at high water, respectively, but the net photosynthetic rates of 80% shaded and 40% shaded plants declined by 50% and 14.73%, respectively. Results showed that combined effect of soil moisture and shading on photosynthetic and stomatal responses in cotton leaves was very remarkable.

Pulsating hydraulic fracturing technology in low permeability coal seams

Based on the difficult situation of gas drainage in a single coal bed of high gas content and low perme- ability, we investigate the technology of pulsating hydraulic pressure relief, the process of crank plunger movement and the mechanism of pulsating pressure formation using theoretical research, mathematical modeling and field testing. We analyze the effect of pulsating pressure on the formation and growth of fractures in coal by using the pulsating hydraulic theory in hydraulics. The research results show that the amplitude of fluctuating pressure tends to increase in the case where the exit is blocked, caused by pulsating pressure reflection and frictional resistance superposition, and it contributes to the growth of fractures in coal. The crack initiation pressure of pulsating hydraulic fracturing is 8 MPa, which is half than that of normal hydraulic fracturing; the pulsating hydraulic fracturing influence radius reaches 8 m. The total amount of gas extraction is increased by 3.6 times, and reaches 50 LJmin at the highest point. The extraction flow increases greatly, and is 4 times larger than that of drilling without fracturing and 1.2 times larger than that of normal hydraulic fracturing. The technology provides a technical measure for gas drainage of high gas content and low permeability in the single coal bed.

Effects of Forest Gaps on Some Microclimate Variables in Castanopsis kawakamii Natural Forest

The objective of this study was to understand the effects of forest gap and variations in different seasons, gap size, locations and diurnal variations on forest microclimate and soil water content. Spatial and temporal distribution features oi air temperature （TA）, soil temperature （Ts）, relative humidity （h） and soil water content （ψ） were measured in Castanopsis kawakamii natural forest gaps created by a severe typhoon or fallen dead trees. The results showed that： （1） the variations of TA, h, and Tsin four seasons were extremely significant. The variations of ψ in four seasons were extremely significant except for those between spring and summer. （a） The diurnal variations of TA and Tswere expressed with a single peak curve. The diurnal variations of h and ψ presented a high-low-high trend （3） The variations of TA, h, and Ts were extremely significant among the large, medium and small gaps in C. kawakamii natural forest. Medium gaps had the highest TA and the lowest h while small gaps were jusl contrary to medium gaps. The variations of T were extremely significant for large, medium and small gaps except those between the medium and large gaps （4） The TA, h, Ts and ψ were decreased from the gap center, canopy gap, expanded gap to understory. These results will help further our understanding of the abiotic and consequent biotic responses to gaps in the mid-subtropical broadleaved forests, which also provide a theoretical basis for the scientific management and population restoration of C. kawakamii natural forest.

Mechanism of gas-water flow at pore-level in aquifer gas storage

By means of the pore-level simulation, the characteristics of gas-water flow and gas-water distribution during the alternative displacement of gas and water were observed directly from etched-glass micromodel. The results show that gas-water distribution styles are divided into continuous phase type and separate phase type. The water lock exists in pore and throat during the process of gas-water displacement, and it reduces the gas flow-rate and has some effects on the recovery efficiency during the operation of gas storage. According to the experimental results of aquifer gas storage in X area, the differences in available extent among reservoirs are significant, and the availability of pore space is 33% 45%.

CO_2 Removal from Biogas by Water Washing System

CO2 removal from biogas by water washing system was investigated with various parameters, including liquid/ gas ratio, pressure, temperature, and CO2 content. The results indicate that CO2 removal ratio could reach 34.6%- 94.2% as liquid/gas ratio increased from 0.14 to 0.50. Increasing pressure （from 0.8 to 1.2 MPa） could improve gas purification with a constant inflow rate of gas. Temperature played a key role in the process and lower temper- ature in absorption tower was beneficial for reducing CO2 content. CO2 removal ratio could reach 24.4%-83.2% when CO2 content in the simulated gas was 25%-45%. The lowest CO2 content after absorption was 2.6% at 1.2 MPa with 400 L·h-1 gas flow and 200 L·h-1 water flow, which meets the requirement of CO2 content in natural Ras for vehicle fuel.

Effect of bubbles addition on teetered bed separation

To improve the separation efficiency of a conventional Teetered Bed Separator(TBS) in beneficiation of fine coal with a wide size range,an Aeration TBS(A-TBS) was proposed in this investigation.The bubbles were introduced to A-TBS by a self-priming micro-bubble generator.This study theoretically analyzed the effect of bubbles on the difference in hindered settling terminal velocity between different density particles,investigated the impact of superficial water velocity(V_(SW)) and superficial gas velocity(V_(Sg)) on bed fluidization,and compared the performance of the TBS and A-TBS in treating 1-0.25 mm size fraction particles.The results show that the expansion degree of fluidized bed which was formed by different size particles or has different initial height,is increased by the introduction of bubbles.Compared with the TBS,at the same level of clean coal ash content,the A-TBS shows an increase in the combustible recovery of clean coal,ash content of tailings,and practical separation density by 5.26%,6.56%,and 0.088 g/cm3 respectively,while it shows a decrease in the probable error(E_p) and V_(SW) by 0.031 and 3.51 mm/s,respectively.The addition of bubbles at a proper amount not only improves the separation performance of TBS,but also reduces the upward water velocity.

Comparison of steam-gasification characteristics of coal char and petroleum coke char in drop tube furnace

The steam-gasification reaction characteristics of coal and petroleum coke （PC） were studied in the drop tube furnace （DTF）. The effects of various factors such as types of carbonaceous material, gasification temperature （1100- 1400 ℃） and mass ratio of steam to char （0.4：1, 0.6：1 and 1：1 separately） on gasification gas or solid products were investigated. The results showed that for all carbonaceous materials studied, H2 content exhibited the largest part of gasification gaseous products and CH4 had the smallest part. For the two petroleum cokes, CO2 content was higher than CO, which was similar to Zun-yi char. When the steam/char ratio was constant, the carbon con- version of both Shen-fu and PC chars increased with increasing temperature. When the gasification temperature was constant, the carbon conversions of all char samples increased with increasing steam/char ratio. For all the steam/char ratios, compared to water gas shift reaction, char-H2O and char-CO2 reaction were further from the thermodynamic equilibrium due to a much lower char gasification rate than that of water gas shift reaction rate. Therefore, kinetic effects may play a more important role in a char gasification step than thermodynamic effects when the gasification reaction of char was held in DTF, The calculating method for the equilibrium shift in this study will be a worth reference for analysis of the gaseous components in industrial gasifier. The reactivity of residual cokes decreased and the crystal layer （L002/d002） numbers of residual cokes increased with increasing gasification temperature. Therefore, L002/d002, the carbon crystallite structure parameter, can be used to evaluate the reactivity of residual cokes.

Drying Characteristic of Anchovy Fish

This paper focuses on the drying characteristic of anchovy fish （Anchovia engraulidae）. It is necessary to understand the drying behavior, quality of the products and time required to optimize the energy consumption of the process. The optimum velocity and temperature of drying air for good quality dried anchovy fish was determined. In average, the fish are 7 cm in length and 3.0-3.5 g in mass. Although some research on fish drying has been done, the study of drying of anchovy fish and its characteristic has not been well reported. The fish to be dried were arranged on 15 × 15 cm2 tray in the drying chamber of 17 × 30 cm2. The hot air of 40 -70 ℃ was delivered parallel to the tray with the velocity of 0.6 and 0.9 m s-1. It is found that thermal conductivity （k） and specific heat （cp） of anchovy fish are function of the moisture content （MC）. The higher moisture content results in higher thermal conductivity and specific heat. Critical water content is also found in this experiment as well as the optimum drying condition. Drying rate period of anchovy fish will change from the constant drying rate period to the falling drying rate period when critical moisture content is about 48.8%-50.3% （wet basis）. At these experiments, there is no case-hardening, even at temperature of 70 ℃. To achieve the optimum result, the drying process should be implemented in three steps, drying process at 70 ℃ for 150 min followed by drying at 50℃ for 100 min, and finally drying at 40℃ till achieving equilibrium moisture content. This research will contribute to improvement of drying method to achieve good quality of dried fish.

Crossing point temperature of coal

A further understanding of the self-heating of coal was obtained by investigating the crossing point temperature（CPT） of different ranks of coal.The tests were carried out using a self-designed experimental system for coal self-heating.50 g（±0.01 g） of coal particles ranging from 0.18 mm to 0.38 mm in size were put into a pure copper reaction vessel attached to the center of a temperature programmed enclosure.The temperature program increased the temperature at a rate of 0.8℃/min.Dry air was permitted to flow into the coal reaction vessel at different rates.The surrounding temperature and the coal temperature were monitored by a temperature logger.The results indicate that CPT is affected by coal rank,moisture,sulfur, and the experimental conditions.Higher ranked coals show higher CPT values.A high moisture content causes a delay phenomenon during the self-heating of the coal.Drying at 40℃decreases the effects of moisture.The reactivity of sulfur components in the coal is low under dry and low-temperature conditions. These components form a film that covers the coal surface and slightly inhibits the self-heating of the coal. The flow rate of dry air,and the heating rate of the surroundings,also affect the self-heating of the coal.The most appropriate experimental conditions for coal samples of a given weight and particle size were determined through contrastive analysis.Based on this analysis we propose that CPTs be determined under the same,or nearly the same conditions,for evaluation of the spontaneous combustion of coal.

Drying of Fish Sardines in Oman Using Solar Tunnel Dryers

This paper deals with the design, construction and performance evaluation procedure of a solar tunnel dryer in drying fish. A 12 meter long and 2 meter width half-circled tunnel was designed and constructed to dry about 50-100 kg of freshly harvested fishes per batch. The half of the tunnel base was used as the flat plate air heating solar collector and the remaining half as a dryer. The drying air was forced from the collector region （north side） to the drying region （south side） of the half circled tunnel where the product is to be dried. The drying temperature could be easily raised by some 5-30 ℃ above the ambient temperature inside the tunnel at an air velocity of approximately 0.2 m/sec. The test was conducted with 51.5 kg freshly harvested sardines （hall-load） with initial moisture content of 66.5% （wet-basis） to analyze the performance of the dryer. The fishes were dried to a final average moisture content of 15.5% （wet-basis） within three days （30 hours）. It was possible to reach the moisture content level for safe storage within less than three days （30 hrs） with solar tunnel dryer and 7 days in open air natural sun drying. The improvement in the quality of fishes in terms of color, brightness, flavor, and taste and food value was distinctly recognized.