解释重磁资料中最优化选择法的若干问题

本文中我们将拟牛顿法应用到磁力、重力资料的自动解释中来,通过计算对比说明,在收敛的稳定性上拟牛顿法比常用的阻尼最小二乘法大为优越。文中又讨论了最优化选择法的收敛性、多解性、模型体的选择、参量的选择和约束,以及解释三个矿区磁异常的实例。     

北京近255年雨季及其多年变化

本文利用1724—1903年北京故宫“晴雨录”中雨日记载,与现代气象资料衔接,确定了北京1724—1978年共255年雨季的起迄,并且讨论了雨季特征及其长期演变规律。 北京雨季可划分为六种类型:提前型、落后型、偏长型、偏短型、双峰型、假雨季和副雨季。北京雨季平均开始于6月25—29日,结束于8月9—13日,雨季乎均长50天。雨季起始期具有4.5年周期:雨季结束期具有4年左右和85年左右周期;雨季长度具有85年和170年左右周期。此外,北京255年雨季变化存在明显的由短变长的长期趋势。近30年来北京雨季处于近255年来异常偏长阶段。     

CONSTITUTIVE RELATIONS OF ROCK AND ROCK MASS

The constitutive relations of rock and rock mass are essential to the study of propagation of stress wave in rock medium and its interaction with structure .in this paper ,the development of the research on constitutive relations of rock and rock mass is briefly reviewed ;the equations of state of rock in fluid state at high pressures and the con equations of rock in solid state are mainly described .The cop model as the constitutive equation of rock and its generaligations especially discussed .     

A land surface model (IAP94) for climate studies Part II: Implementation and preliminary results of coupled model with IAP GCM

The Institute of Atmospheric Physics Land Surface Model (IAP94) has been incorporated into the IAP two-level atmospheric general circulation model (IAP GCM). Global and regional climatology averaged over the last 25 years of 100 year integrations from the IAP GCM with and without IAP94 (“bucket” scheme) is compared. The simulated results are also compared with the reanalysis data. Major findings are:(1) The IAP GCM simulation without IAP94 has extensive regions of warmer than observed surface air tempera?tures, while the simulation with IAP94 very much improves the surface air temperature.(2) The IAP GCM simulation with IAP94 gives improvement of the simulated precipitation pattern and intensity, especially the precipitation of East Asian summer monsoon and its intraseasonal migration of the rainbelts.(3) In five selected typical regions, for most of the surface variables such as surface air temperature, precipitation, precipitation minus evaporation, net radiation, latent heat flux and sensible heat flux, the IAP GCM with IAP94 pro?vides better simulations.     

自忆预报模式中记忆特性的探讨

运用有限振幅斜压波的截谱方程对自忆模式中的的记忆性进行了理论探讨。推导了相应的自忆性方程,在给定记忆函数呈线性和指数衰减型时求出了它的解析解,并讨论了这些解的物理意义和预报含意;证明了零解自忆性方程与记忆函数形式无关。通过计算遗忘因子,对动力可预报性和回溯阶等问题进行了讨论,并指出可将其统一纳入大气记忆理论的框架中。     

大别山地区构造地貌特征

大别山位于江淮之间,跨皖、鄂、豫三省,与其东端的张八岭和西端的鸡公山、桐柏山合称淮阳山脉。它由西北向东南延伸,在湖北省的黄梅附近转向东北,地势上为向南凸出的弧型山系,相当于李四光提出的淮阳弧构造。大别山是淮阳山脉的主体,山势较高,1500米以上山峰都集中于皖、鄂、豫三省交界处一带,形成岗峦起伏,群峰突起的壮丽景观。     

Mechanism of the reservoir impounding earthquakes at Hsinfengkiang and a preliminary endeavour to discuss their cause

After the filling up of the Hsinfengkiang Reservoir Kwangtung Province, seismicity was greatly increased. The majority of earthquakes occurred in the deep water gorge close to the dam, concentrated within a northwest belt. They are usually of shallow focal depths. A strong earthquake with magnitude 6.1 took place on March 19, 1962, about two and a half years since the impounding of the reservoir.

According to the results of analysis of data from geodetic leveling and the spectra of seismic waves, the fault parameters of the main shock were determined. The fault plane solutions of 150 small earthquakes, occurring within a period of 18 months before and after the main shock were determined from the amplitudes of the first motion of P wave. The directions of the earthquake generating stress of about 2000 small earthquakes were obtained by smoothing the first motion patterns. Displacement field and stress field in the rock bodies underneath the reservoir caused by the loading of the reservoir water were calculated. Variations of the velocity ratio of the P and S waves prior to the main shock and several strong aftershocks were analysed.

In consideration of the seismicity as well as the geological background, we endeavour to discuss the cause of reservoir impounding earthquakes at Hsinfengkiang. We have the opinion that the penetration of water along fissures becomes the most important cause of the main shock of March 19, 1962 at Hsinfengkiang.     

金华市不同区域负氧离子浓度特征与气象环境因素相关分析

利用2019—2021年金华市空气负氧离子浓度和气象环境资料，研究不同区域（平原城区、平原公园、水边景区、山林景区）负氧离子浓度时空分布特征，分析人类活动最多的城区负氧离子浓度与气象环境因素不同时间尺度的相关性，以及不同天空状况的差异。结果表明：负氧离子浓度呈现平原低、山区高的分布特征，植被茂密、动态水流可增加负氧离子浓度和提高浓度等级。山林景区日出和日落前后负氧离子浓度较高，水边景区凌晨和午后出现高值，平原地区则在下午达到高峰。不同区域四季日变化趋势整体较一致，但不同季节负氧离子浓度峰值大小、日较差和出现峰值时刻存在差异。四季不同区域负氧离子浓度有所差异，主要表现为6—9月高，其中尤以8月山林景区为最。负氧离子浓度与气象环境因素的相关性在不同时间尺度上差异较大：时尺度上与气温、风速、雨量和O3呈显著正相关，而与PM2.5呈显著负相关。四季看，负氧离子浓度春季与风速相关性最高，夏季为气温，秋季为O3，冬季为PM2.5。日尺度上则与相对湿度、风速、雨量呈显著正相关，与PM2.5和O3呈显著负相关，且雨天负氧离子浓度明显高于其他天空状况，差异在冬季达最大。     

Study on the Free Radical Scavenging Activity of Sea Cucumber (Paracaudina chinens var.) Gelatin Hydrolysate

Gelatin from the sea cucumber(Paracaudina chinens var.) was hydrolyzed by bromelain and the hydrolysate was found to have a high free radical scavenging activity. The hydrolysate was fractionated through an ultrafiltration membrane with 5 kDa molecular weight cutoff(MWCO). The portion(less than 5 kDa) was further separated by Sephadex G-25. The active peak was col-lected and assayed for free radical scavenging activity. The scavenging rates for superoxide anion radicals(O2·-) and hydroxyl radi-cals(·OH) of the fraction with the highest activity were 29.02% and 75.41%,respectively. A rabbit liver mitochondrial free radical damage model was adopted to study the free radical scavenging activity of the fraction. The results showed that the sea cucumber gelatin hydrolysate can prevent the damage of rabbit liver and mitochondria.     

Estimation of the chord length and relative height of tracking stations from single pass satellite ranging data

We describe here a technique of determining the chord length and the relative height between two laser tracking stations using single-pass satellite ranging data over very short arcs. Numerical examples show that this technique can supplement the conventional technique which requires data over much longer arcs by providing a capability for checking the accuracy of the geodetic network of laser tracking stations.